wip

Signed-off-by: William Woodall <william@osrfoundation.org>

README.md

@@ -0,0 +1,17 @@
+# rclcpp
+
+This repository contains the source code for the ROS Client Library for C++ package, included with a standard install of any ROS 2 distro.
+
+rclcpp provides the standard C++ API for interacting with ROS 2.
+
+## Usage
+
+`#include "rclcpp/rclcpp.hpp"` allows use of the most common elements of the ROS 2 system.
+
+Visit the [rclcpp API documentation](http://docs.ros2.org/eloquent/api/rclcpp/) for a complete list of its main components.
+
+### Examples
+
+The ROS 2 tutorials [Writing a simple publisher and subscriber](https://index.ros.org/doc/ros2/Tutorials/Writing-A-Simple-Cpp-Publisher-And-Subscriber/)
+and [Writing a simple service and client](https://index.ros.org/doc/ros2/Tutorials/Writing-A-Simple-Cpp-Service-And-Client/)
+contain some examples of rclcpp APIs in use.

rclcpp/CHANGELOG.rst

@@ -2,6 +2,138 @@
 Changelog for package rclcpp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+0.8.3 (2019-11-19)
+------------------
+
+0.8.2 (2019-11-18)
+------------------
+* Updated tracing logic to match changes in rclcpp's intra-process system (`#918 <https://github.com/ros2/rclcpp/issues/918>`_)
+* Fixed a bug that prevented the ``shutdown_on_sigint`` option to not work correctly (`#850 <https://github.com/ros2/rclcpp/issues/850>`_)
+* Added support for STREAM logging macros (`#926 <https://github.com/ros2/rclcpp/issues/926>`_)
+* Relaxed multithreaded test constraint (`#907 <https://github.com/ros2/rclcpp/issues/907>`_)
+* Contributors: Anas Abou Allaban, Christophe Bedard, Dirk Thomas, alexfneves
+
+0.8.1 (2019-10-23)
+------------------
+* De-flake tests for rmw_connext (`#899 <https://github.com/ros2/rclcpp/issues/899>`_)
+* rename return functions for loaned messages (`#896 <https://github.com/ros2/rclcpp/issues/896>`_)
+* Enable throttling logs (`#879 <https://github.com/ros2/rclcpp/issues/879>`_)
+* New Intra-Process Communication (`#778 <https://github.com/ros2/rclcpp/issues/778>`_)
+* Instrumentation update (`#789 <https://github.com/ros2/rclcpp/issues/789>`_)
+* Zero copy api (`#864 <https://github.com/ros2/rclcpp/issues/864>`_)
+* Drop rclcpp remove_ros_arguments_null test case. (`#894 <https://github.com/ros2/rclcpp/issues/894>`_)
+* add mechanism to pass rmw impl specific payloads during pub/sub creation (`#882 <https://github.com/ros2/rclcpp/issues/882>`_)
+* make get_actual_qos return a rclcpp::QoS (`#883 <https://github.com/ros2/rclcpp/issues/883>`_)
+* Fix Compiler Warning (`#881 <https://github.com/ros2/rclcpp/issues/881>`_)
+* Add callback handler for use_sim_time parameter `#802 <https://github.com/ros2/rclcpp/issues/802>`_ (`#875 <https://github.com/ros2/rclcpp/issues/875>`_)
+* Contributors: Alberto Soragna, Brian Marchi, Hunter L. Allen, Ingo Lütkebohle, Karsten Knese, Michael Carroll, Michel Hidalgo, William Woodall
+
+0.8.0 (2019-09-26)
+------------------
+* clean up publisher and subscription creation logic (`#867 <https://github.com/ros2/rclcpp/issues/867>`_)
+* Take parameter overrides provided through the CLI. (`#865 <https://github.com/ros2/rclcpp/issues/865>`_)
+* add more context to exception message (`#858 <https://github.com/ros2/rclcpp/issues/858>`_)
+* remove features and related code which were deprecated in dashing (`#852 <https://github.com/ros2/rclcpp/issues/852>`_)
+* check valid timer handler 1st to reduce the time window for scan. (`#841 <https://github.com/ros2/rclcpp/issues/841>`_)
+* Add throwing parameter name if parameter is not set (`#833 <https://github.com/ros2/rclcpp/issues/833>`_)
+* Fix typo in deprecated warning. (`#848 <https://github.com/ros2/rclcpp/issues/848>`_)
+* Fail on invalid and unknown ROS specific arguments (`#842 <https://github.com/ros2/rclcpp/issues/842>`_)
+* Force explicit --ros-args in NodeOptions::arguments(). (`#845 <https://github.com/ros2/rclcpp/issues/845>`_)
+* Use of -r/--remap flags where appropriate. (`#834 <https://github.com/ros2/rclcpp/issues/834>`_)
+* Fix hang with timers in MultiThreadedExecutor (`#835 <https://github.com/ros2/rclcpp/issues/835>`_) (`#836 <https://github.com/ros2/rclcpp/issues/836>`_)
+* add mutex in add/remove_node and wait_for_work to protect concurrent use/change of memory_strategy\_ (`#837 <https://github.com/ros2/rclcpp/issues/837>`_)
+* Crash in callback group pointer vector iterator (`#814 <https://github.com/ros2/rclcpp/issues/814>`_)
+* Wrap documentation examples in code blocks (`#830 <https://github.com/ros2/rclcpp/issues/830>`_)
+* add callback group as member variable and constructor arg (`#811 <https://github.com/ros2/rclcpp/issues/811>`_)
+* Fix get_node_interfaces functions taking a pointer (`#821 <https://github.com/ros2/rclcpp/issues/821>`_)
+* Delete unnecessary call for get_node_by_group (`#823 <https://github.com/ros2/rclcpp/issues/823>`_)
+* Allow passing logger by const ref (`#820 <https://github.com/ros2/rclcpp/issues/820>`_)
+* Explain return value of spin_until_future_complete (`#792 <https://github.com/ros2/rclcpp/issues/792>`_)
+* Adapt to '--ros-args ... [--]'-based ROS args extraction (`#816 <https://github.com/ros2/rclcpp/issues/816>`_)
+* Add line break after first open paren in multiline function call (`#785 <https://github.com/ros2/rclcpp/issues/785>`_)
+* remove mock msgs from rclcpp (`#800 <https://github.com/ros2/rclcpp/issues/800>`_)
+* Make TimeSource ignore use_sim_time events coming from other nodes. (`#799 <https://github.com/ros2/rclcpp/issues/799>`_)
+* Allow registering multiple on_parameters_set_callback (`#772 <https://github.com/ros2/rclcpp/issues/772>`_)
+* Add free function for creating service clients (`#788 <https://github.com/ros2/rclcpp/issues/788>`_)
+* Include missing rcl headers in use. (`#782 <https://github.com/ros2/rclcpp/issues/782>`_)
+* Switch the NodeParameters lock to recursive. (`#781 <https://github.com/ros2/rclcpp/issues/781>`_)
+* changed on_parameter_event qos profile to rmw_qos_profile_parameter_events (`#774 <https://github.com/ros2/rclcpp/issues/774>`_)
+* Adding a factory method to create a Duration from seconds (`#567 <https://github.com/ros2/rclcpp/issues/567>`_)
+* Fix a comparison with a sign mismatch (`#771 <https://github.com/ros2/rclcpp/issues/771>`_)
+* delete superfluous spaces (`#770 <https://github.com/ros2/rclcpp/issues/770>`_)
+* Use params from node '/\*\*' from parameter YAML file (`#762 <https://github.com/ros2/rclcpp/issues/762>`_)
+* Add ignore override argument to declare parameter (`#767 <https://github.com/ros2/rclcpp/issues/767>`_)
+* use default parameter descriptor in parameters interface (`#765 <https://github.com/ros2/rclcpp/issues/765>`_)
+* Added support for const member functions (`#763 <https://github.com/ros2/rclcpp/issues/763>`_)
+* add get_actual_qos() feature to subscriptions (`#754 <https://github.com/ros2/rclcpp/issues/754>`_)
+* Ignore parameters overrides in set parameter methods when allowing undeclared parameters (`#756 <https://github.com/ros2/rclcpp/issues/756>`_)
+* Add rclcpp::create_timer() (`#757 <https://github.com/ros2/rclcpp/issues/757>`_)
+* checking origin of intra-process msg before taking them (`#753 <https://github.com/ros2/rclcpp/issues/753>`_)
+* Contributors: Alberto Soragna, Carl Delsey, Chris Lalancette, Dan Rose, Dirk Thomas, Esteve Fernandez, Guillaume Autran, Jacob Perron, Karsten Knese, Luca Della Vedova, M. M, Michel Hidalgo, Scott K Logan, Shane Loretz, Todd Malsbary, William Woodall, bpwilcox, fujitatomoya, ivanpauno
+
+0.7.5 (2019-05-30)
+------------------
+* Avoid 'Intra process message no longer being stored when trying to handle it' warning (`#749 <https://github.com/ros2/rclcpp/issues/749>`_)
+* Contributors: ivanpauno
+
+0.7.4 (2019-05-29)
+------------------
+* Rename parameter options (`#745 <https://github.com/ros2/rclcpp/issues/745>`_)
+* Bionic use of strerror_r (`#742 <https://github.com/ros2/rclcpp/issues/742>`_)
+* Enforce parameter ranges (`#735 <https://github.com/ros2/rclcpp/issues/735>`_)
+* removed not used parameter client (`#740 <https://github.com/ros2/rclcpp/issues/740>`_)
+* ensure removal of guard conditions of expired nodes from memory strategy (`#741 <https://github.com/ros2/rclcpp/issues/741>`_)
+* Fix typo in log warning message (`#737 <https://github.com/ros2/rclcpp/issues/737>`_)
+* Throw nice errors when creating a publisher with intraprocess communication and incompatible qos policy (`#729 <https://github.com/ros2/rclcpp/issues/729>`_)
+* Contributors: Alberto Soragna, Dirk Thomas, Jacob Perron, William Woodall, ivanpauno, roderick-koehle
+
+0.7.3 (2019-05-20)
+------------------
+* Fixed misspelling, volitile -> volatile (`#724 <https://github.com/ros2/rclcpp/issues/724>`_), and then fixed that since it is a C++ keyword to be ``durability_volatile`` (`#725 <https://github.com/ros2/rclcpp/issues/725>`_)
+* Fixed a clang warning (`#723 <https://github.com/ros2/rclcpp/issues/723>`_)
+* Added ``on_parameter_event`` static method to the ``AsyncParametersClient`` (`#688 <https://github.com/ros2/rclcpp/issues/688>`_)
+* Added a guard against ``ParameterNotDeclaredException`` throwing from within the parameter service callbacks. (`#718 <https://github.com/ros2/rclcpp/issues/718>`_)
+* Added missing template functionality to lifecycle_node. (`#707 <https://github.com/ros2/rclcpp/issues/707>`_)
+* Fixed heap-use-after-free and memory leaks reported from ``test_node.cpp`` (`#719 <https://github.com/ros2/rclcpp/issues/719>`_)
+* Contributors: Alberto Soragna, Dirk Thomas, Emerson Knapp, Jacob Perron, Michael Jeronimo, Prajakta Gokhale
+
+0.7.2 (2019-05-08)
+------------------
+* Added new way to specify QoS settings for publishers and subscriptions. (`#713 <https://github.com/ros2/rclcpp/issues/713>`_)
+  * The new way requires that you specify a history depth when creating a publisher or subscription.
+  * In the past it was possible to create one without specifying any history depth, but these signatures have been deprecated.
+* Deprecated ``shared_ptr`` and raw pointer versions of ``Publisher<T>::publish()``. (`#709 <https://github.com/ros2/rclcpp/issues/709>`_)
+* Implemented API to set callbacks for liveliness and deadline QoS events for publishers and subscriptions. (`#695 <https://github.com/ros2/rclcpp/issues/695>`_)
+* Fixed a segmentation fault when publishing a parameter event when they ought to be disabled. (`#714 <https://github.com/ros2/rclcpp/issues/714>`_)
+* Changes required for upcoming pre-allocation API. (`#711 <https://github.com/ros2/rclcpp/issues/711>`_)
+* Changed ``Node::get_node_names()`` to return the full node names rather than just the base name. (`#698 <https://github.com/ros2/rclcpp/issues/698>`_)
+* Remove logic made redundant by the `ros2/rcl#255 <https://github.com/ros2/rcl/issues/255>`_ pull request. (`#712 <https://github.com/ros2/rclcpp/issues/712>`_)
+* Various improvements for ``rclcpp::Clock``. (`#696 <https://github.com/ros2/rclcpp/issues/696>`_)
+  * Fixed uninitialized bool in ``clock.cpp``.
+  * Fixed up includes of ``clock.hpp/cpp``.
+  * Added documentation for exceptions to ``clock.hpp``.
+  * Adjusted function signature of getters of ``clock.hpp/cpp``.
+  * Removed raw pointers to ``Clock::create_jump_callback``.
+  * Removed unnecessary ``rclcpp`` namespace reference from ``clock.cpp``.
+  * Changed exception to ``bad_alloc`` on ``JumpHandler`` allocation failure.
+  * Fixed missing ``nullptr`` check in ``Clock::on_time_jump``.
+  * Added ``JumpHandler::callback`` types.
+  * Added warning for lifetime of Clock and JumpHandler
+* Fixed bug left over from the `pull request #495 <https://github.com/ros2/rclcpp/pull/495>`_. (`#708 <https://github.com/ros2/rclcpp/issues/708>`_)
+* Changed the ``IntraProcessManager`` to be capable of storing ``shared_ptr<const T>`` in addition to ``unique_ptr<T>``. (`#690 <https://github.com/ros2/rclcpp/issues/690>`_)
+* Contributors: Alberto Soragna, Dima Dorezyuk, M. M, Michael Carroll, Michael Jeronimo, Tully Foote, William Woodall, ivanpauno, jhdcs
+
+0.7.1 (2019-04-26)
+------------------
+* Added read only parameters. (`#495 <https://github.com/ros2/rclcpp/issues/495>`_)
+* Fixed a concurrency problem in the multithreaded executor. (`#703 <https://github.com/ros2/rclcpp/issues/703>`_)
+* Fixup utilities. (`#692 <https://github.com/ros2/rclcpp/issues/692>`_)
+* Added method to read timer cancellation. (`#697 <https://github.com/ros2/rclcpp/issues/697>`_)
+* Added Exception Generator function for implementing "from_rcl_error". (`#678 <https://github.com/ros2/rclcpp/issues/678>`_)
+* Updated initialization of rmw_qos_profile_t struct instances. (`#691 <https://github.com/ros2/rclcpp/issues/691>`_)
+* Removed the const value from the logger before comparison. (`#680 <https://github.com/ros2/rclcpp/issues/680>`_)
+* Contributors: Devin Bonnie, Dima Dorezyuk, Guillaume Autran, M. M, Shane Loretz, Víctor Mayoral Vilches, William Woodall, jhdcs
+
 0.7.0 (2019-04-14)
 ------------------
 * Added Options-struct interfaces for creating publishers/subscribers (pre-QoS, standalone). (`#673 <https://github.com/ros2/rclcpp/issues/673>`_)

rclcpp/CMakeLists.txt

@@ -4,15 +4,19 @@ project(rclcpp)
 
 find_package(ament_cmake_ros REQUIRED)
 find_package(builtin_interfaces REQUIRED)
+find_package(libstatistics_collector REQUIRED)
 find_package(rcl REQUIRED)
 find_package(rcl_interfaces REQUIRED)
 find_package(rcl_yaml_param_parser REQUIRED)
+find_package(rcpputils REQUIRED)
+find_package(rcutils REQUIRED)
 find_package(rmw REQUIRED)
-find_package(rmw_implementation REQUIRED)
 find_package(rosgraph_msgs REQUIRED)
-find_package(rosidl_generator_cpp REQUIRED)
+find_package(rosidl_runtime_cpp REQUIRED)
 find_package(rosidl_typesupport_c REQUIRED)
 find_package(rosidl_typesupport_cpp REQUIRED)
+find_package(statistics_msgs REQUIRED)
+find_package(tracetools REQUIRED)
 
 # Default to C++14
 if(NOT CMAKE_CXX_STANDARD)
@@ -31,21 +35,30 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/clock.cpp
   src/rclcpp/context.cpp
   src/rclcpp/contexts/default_context.cpp
+  src/rclcpp/detail/rmw_implementation_specific_payload.cpp
+  src/rclcpp/detail/rmw_implementation_specific_publisher_payload.cpp
+  src/rclcpp/detail/rmw_implementation_specific_subscription_payload.cpp
+  src/rclcpp/detail/utilities.cpp
   src/rclcpp/duration.cpp
   src/rclcpp/event.cpp
-  src/rclcpp/exceptions.cpp
+  src/rclcpp/exceptions/exceptions.cpp
+  src/rclcpp/executable_list.cpp
   src/rclcpp/executor.cpp
   src/rclcpp/executors.cpp
   src/rclcpp/expand_topic_or_service_name.cpp
   src/rclcpp/executors/multi_threaded_executor.cpp
   src/rclcpp/executors/single_threaded_executor.cpp
+  src/rclcpp/executors/static_executor_entities_collector.cpp
+  src/rclcpp/executors/static_single_threaded_executor.cpp
+  src/rclcpp/future_return_code.cpp
   src/rclcpp/graph_listener.cpp
+  src/rclcpp/guard_condition.cpp
   src/rclcpp/init_options.cpp
   src/rclcpp/intra_process_manager.cpp
-  src/rclcpp/intra_process_manager_impl.cpp
   src/rclcpp/logger.cpp
   src/rclcpp/memory_strategies.cpp
   src/rclcpp/memory_strategy.cpp
+  src/rclcpp/message_info.cpp
   src/rclcpp/node.cpp
   src/rclcpp/node_options.cpp
   src/rclcpp/node_interfaces/node_base.cpp
@@ -64,15 +77,21 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/parameter_events_filter.cpp
   src/rclcpp/parameter_map.cpp
   src/rclcpp/parameter_service.cpp
-  src/rclcpp/publisher.cpp
+  src/rclcpp/publisher_base.cpp
+  src/rclcpp/qos.cpp
+  src/rclcpp/qos_event.cpp
+  src/rclcpp/serialization.cpp
+  src/rclcpp/serialized_message.cpp
   src/rclcpp/service.cpp
   src/rclcpp/signal_handler.cpp
-  src/rclcpp/subscription.cpp
+  src/rclcpp/subscription_base.cpp
+  src/rclcpp/subscription_intra_process_base.cpp
   src/rclcpp/time.cpp
   src/rclcpp/time_source.cpp
   src/rclcpp/timer.cpp
   src/rclcpp/type_support.cpp
   src/rclcpp/utilities.cpp
+  src/rclcpp/wait_set_policies/detail/write_preferring_read_write_lock.cpp
   src/rclcpp/waitable.cpp
 )
 
@@ -102,12 +121,18 @@ add_library(${PROJECT_NAME}
   ${${PROJECT_NAME}_SRCS})
 # specific order: dependents before dependencies
 ament_target_dependencies(${PROJECT_NAME}
+  "libstatistics_collector"
   "rcl"
   "rcl_yaml_param_parser"
+  "rcpputils"
+  "rcutils"
   "builtin_interfaces"
   "rosgraph_msgs"
   "rosidl_typesupport_cpp"
-  "rosidl_generator_cpp")
+  "rosidl_runtime_cpp"
+  "statistics_msgs"
+  "tracetools"
+)
 
 # Causes the visibility macros to use dllexport rather than dllimport,
 # which is appropriate when building the dll but not consuming it.
@@ -125,14 +150,18 @@ install(
 ament_export_include_directories(include)
 ament_export_libraries(${PROJECT_NAME})
 
-ament_export_dependencies(ament_cmake)
+ament_export_dependencies(libstatistics_collector)
 ament_export_dependencies(rcl)
+ament_export_dependencies(rcpputils)
+ament_export_dependencies(rcutils)
 ament_export_dependencies(builtin_interfaces)
 ament_export_dependencies(rosgraph_msgs)
 ament_export_dependencies(rosidl_typesupport_cpp)
 ament_export_dependencies(rosidl_typesupport_c)
-ament_export_dependencies(rosidl_generator_cpp)
+ament_export_dependencies(rosidl_runtime_cpp)
 ament_export_dependencies(rcl_yaml_param_parser)
+ament_export_dependencies(statistics_msgs)
+ament_export_dependencies(tracetools)
 
 if(BUILD_TESTING)
   find_package(ament_cmake_gtest REQUIRED)
@@ -141,22 +170,40 @@ if(BUILD_TESTING)
 
   find_package(rmw_implementation_cmake REQUIRED)
 
+  find_package(test_msgs REQUIRED)
+
+  include(cmake/rclcpp_add_build_failure_test.cmake)
+
+  add_definitions(-DTEST_RESOURCES_DIRECTORY="${CMAKE_CURRENT_BINARY_DIR}/test/resources")
+
   ament_add_gtest(test_client test/test_client.cpp)
   if(TARGET test_client)
     ament_target_dependencies(test_client
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_client ${PROJECT_NAME})
   endif()
+  ament_add_gtest(test_create_timer test/test_create_timer.cpp)
+  if(TARGET test_create_timer)
+    ament_target_dependencies(test_create_timer
+      "rcl_interfaces"
+      "rmw"
+      "rcl"
+      "rosidl_runtime_cpp"
+      "rosidl_typesupport_cpp"
+    )
+    target_link_libraries(test_create_timer ${PROJECT_NAME})
+    target_include_directories(test_create_timer PRIVATE test/)
+  endif()
   ament_add_gtest(test_expand_topic_or_service_name test/test_expand_topic_or_service_name.cpp)
   if(TARGET test_expand_topic_or_service_name)
     ament_target_dependencies(test_expand_topic_or_service_name
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_expand_topic_or_service_name ${PROJECT_NAME})
@@ -166,60 +213,116 @@ if(BUILD_TESTING)
     ament_target_dependencies(test_function_traits
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
   endif()
-  ament_add_gtest(test_mapped_ring_buffer test/test_mapped_ring_buffer.cpp)
-  if(TARGET test_mapped_ring_buffer)
-    ament_target_dependencies(test_mapped_ring_buffer
-      "rcl"
-      "rcl_interfaces"
-      "rmw"
-      "rosidl_generator_cpp"
-      "rosidl_typesupport_cpp"
-    )
-  endif()
-  ament_add_gtest(test_intra_process_manager test/test_intra_process_manager.cpp)
+  ament_add_gmock(test_intra_process_manager test/test_intra_process_manager.cpp)
   if(TARGET test_intra_process_manager)
     ament_target_dependencies(test_intra_process_manager
       "rcl"
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
+    target_link_libraries(test_intra_process_manager ${PROJECT_NAME})
   endif()
-  ament_add_gtest(test_node test/test_node.cpp)
+  ament_add_gtest(test_ring_buffer_implementation test/test_ring_buffer_implementation.cpp)
+  if(TARGET test_ring_buffer_implementation)
+    ament_target_dependencies(test_ring_buffer_implementation
+      "rcl_interfaces"
+      "rmw"
+      "rosidl_runtime_cpp"
+      "rosidl_typesupport_cpp"
+    )
+    target_link_libraries(test_ring_buffer_implementation ${PROJECT_NAME})
+  endif()
+  ament_add_gtest(test_intra_process_buffer test/test_intra_process_buffer.cpp)
+  if(TARGET test_intra_process_buffer)
+    ament_target_dependencies(test_intra_process_buffer
+      "rcl_interfaces"
+      "rmw"
+      "rosidl_runtime_cpp"
+      "rosidl_typesupport_cpp"
+    )
+    target_link_libraries(test_intra_process_buffer ${PROJECT_NAME})
+  endif()
+
+  ament_add_gtest(test_loaned_message test/test_loaned_message.cpp)
+  ament_target_dependencies(test_loaned_message
+    "test_msgs"
+  )
+  target_link_libraries(test_loaned_message ${PROJECT_NAME})
+
+  ament_add_gtest(test_node test/test_node.cpp TIMEOUT 240)
   if(TARGET test_node)
     ament_target_dependencies(test_node
       "rcl_interfaces"
+      "rcpputils"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
+      "test_msgs"
     )
     target_link_libraries(test_node ${PROJECT_NAME})
   endif()
+
+  ament_add_gtest(test_node_interfaces__get_node_interfaces
+    test/node_interfaces/test_get_node_interfaces.cpp)
+  if(TARGET test_node_interfaces__get_node_interfaces)
+    target_link_libraries(test_node_interfaces__get_node_interfaces ${PROJECT_NAME})
+  endif()
+
+  # TODO(wjwwood): reenable these build failure tests when I can get Jenkins to ignore their output
+  # rclcpp_add_build_failure_test(build_failure__get_node_topics_interface_const_ref_rclcpp_node
+  #   test/node_interfaces/test_does_not_compile/get_node_topics_interface_const_ref_rclcpp_node.cpp)
+  # target_link_libraries(build_failure__get_node_topics_interface_const_ref_rclcpp_node
+  #   ${PROJECT_NAME})
+
+  # rclcpp_add_build_failure_test(build_failure__get_node_topics_interface_const_ptr_rclcpp_node
+  #   test/node_interfaces/test_does_not_compile/get_node_topics_interface_const_ptr_rclcpp_node.cpp)
+  # target_link_libraries(build_failure__get_node_topics_interface_const_ptr_rclcpp_node
+  #   ${PROJECT_NAME})
+
+  # rclcpp_add_build_failure_test(build_failure__get_node_topics_interface_const_ref_wrapped_node
+  #   test/node_interfaces/test_does_not_compile/get_node_topics_interface_const_ref_wrapped_node.cpp)
+  # target_link_libraries(build_failure__get_node_topics_interface_const_ref_rclcpp_node
+  #   ${PROJECT_NAME})
+
+  # rclcpp_add_build_failure_test(build_failure__get_node_topics_interface_const_ptr_wrapped_node
+  #   test/node_interfaces/test_does_not_compile/get_node_topics_interface_const_ptr_wrapped_node.cpp)
+  # target_link_libraries(build_failure__get_node_topics_interface_const_ptr_rclcpp_node
+  #   ${PROJECT_NAME})
+
   ament_add_gtest(test_node_global_args test/test_node_global_args.cpp)
   if(TARGET test_node_global_args)
     ament_target_dependencies(test_node_global_args
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_node_global_args ${PROJECT_NAME})
   endif()
-  ament_add_gtest(test_node_initial_parameters test/test_node_initial_parameters.cpp)
-  if(TARGET test_node_initial_parameters)
-    target_link_libraries(test_node_initial_parameters ${PROJECT_NAME})
+  ament_add_gtest(test_node_options test/test_node_options.cpp)
+  if(TARGET test_node_options)
+    ament_target_dependencies(test_node_options "rcl")
+    target_link_libraries(test_node_options ${PROJECT_NAME})
+  endif()
+  ament_add_gtest(test_parameter_client test/test_parameter_client.cpp)
+  if(TARGET test_parameter_client)
+    ament_target_dependencies(test_parameter_client
+      "rcl_interfaces"
+    )
+    target_link_libraries(test_parameter_client ${PROJECT_NAME})
   endif()
   ament_add_gtest(test_parameter_events_filter test/test_parameter_events_filter.cpp)
   if(TARGET test_parameter_events_filter)
     ament_target_dependencies(test_parameter_events_filter
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_parameter_events_filter ${PROJECT_NAME})
@@ -229,7 +332,7 @@ if(BUILD_TESTING)
     ament_target_dependencies(test_parameter
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_parameter ${PROJECT_NAME})
@@ -241,38 +344,49 @@ if(BUILD_TESTING)
   ament_add_gtest(test_publisher test/test_publisher.cpp)
   if(TARGET test_publisher)
     ament_target_dependencies(test_publisher
-      "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
+      "test_msgs"
     )
     target_link_libraries(test_publisher ${PROJECT_NAME})
   endif()
-  ament_add_gtest(test_pub_sub_option_interface test/test_pub_sub_option_interface.cpp)
-  if(TARGET test_pub_sub_option_interface)
-    ament_target_dependencies(test_pub_sub_option_interface
-      test_msgs
-    )
-    target_link_libraries(test_pub_sub_option_interface
-      ${PROJECT_NAME}
-    )
-  endif()
   ament_add_gtest(test_publisher_subscription_count_api test/test_publisher_subscription_count_api.cpp)
   if(TARGET test_publisher_subscription_count_api)
     ament_target_dependencies(test_publisher_subscription_count_api
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
+      "test_msgs"
     )
     target_link_libraries(test_publisher_subscription_count_api ${PROJECT_NAME})
   endif()
+  ament_add_gtest(test_qos test/test_qos.cpp)
+  if(TARGET test_qos)
+    ament_target_dependencies(test_qos
+      "rmw"
+    )
+    target_link_libraries(test_qos
+      ${PROJECT_NAME}
+    )
+  endif()
+  ament_add_gtest(test_qos_event test/test_qos_event.cpp)
+  if(TARGET test_qos_event)
+    ament_target_dependencies(test_qos_event
+      "rmw"
+      "test_msgs"
+    )
+    target_link_libraries(test_qos_event
+      ${PROJECT_NAME}
+    )
+  endif()
   ament_add_gtest(test_rate test/test_rate.cpp)
   if(TARGET test_rate)
     ament_target_dependencies(test_rate
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_rate
@@ -288,12 +402,21 @@ if(BUILD_TESTING)
       ${PROJECT_NAME}
     )
   endif()
+  ament_add_gtest(test_serialized_message test/test_serialized_message.cpp)
+  if(TARGET test_serialized_message)
+    ament_target_dependencies(test_serialized_message
+      test_msgs
+    )
+    target_link_libraries(test_serialized_message
+      ${PROJECT_NAME}
+    )
+  endif()
   ament_add_gtest(test_service test/test_service.cpp)
   if(TARGET test_service)
     ament_target_dependencies(test_service
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
     )
     target_link_libraries(test_service ${PROJECT_NAME})
@@ -303,8 +426,9 @@ if(BUILD_TESTING)
     ament_target_dependencies(test_subscription
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
+      "test_msgs"
     )
     target_link_libraries(test_subscription ${PROJECT_NAME})
   endif()
@@ -313,18 +437,19 @@ if(BUILD_TESTING)
     ament_target_dependencies(test_subscription_publisher_count_api
       "rcl_interfaces"
       "rmw"
-      "rosidl_generator_cpp"
+      "rosidl_runtime_cpp"
       "rosidl_typesupport_cpp"
+      "test_msgs"
     )
     target_link_libraries(test_subscription_publisher_count_api ${PROJECT_NAME})
   endif()
-  find_package(test_msgs REQUIRED)
   ament_add_gtest(test_subscription_traits test/test_subscription_traits.cpp)
   if(TARGET test_subscription_traits)
     ament_target_dependencies(test_subscription_traits
       "rcl"
       "test_msgs"
     )
+    target_link_libraries(test_subscription_traits ${PROJECT_NAME})
   endif()
   ament_add_gtest(test_find_weak_nodes test/test_find_weak_nodes.cpp)
   if(TARGET test_find_weak_nodes)
@@ -334,38 +459,17 @@ if(BUILD_TESTING)
     target_link_libraries(test_find_weak_nodes ${PROJECT_NAME})
   endif()
 
-  get_default_rmw_implementation(default_rmw)
-  find_package(${default_rmw} REQUIRED)
-  get_rmw_typesupport(typesupport_impls_cpp "${default_rmw}" LANGUAGE "cpp")
-  get_rmw_typesupport(typesupport_impls_c "${default_rmw}" LANGUAGE "c")
-  set(mock_msg_files
-    "test/mock_msgs/srv/Mock.srv")
-  rosidl_generate_interfaces(mock_msgs
-    ${mock_msg_files}
-    LIBRARY_NAME "rclcpp"
-    SKIP_INSTALL)
-
   set(append_library_dirs "${CMAKE_CURRENT_BINARY_DIR}")
   if(WIN32)
     set(append_library_dirs "${append_library_dirs}/$<CONFIG>")
   endif()
 
-  ament_add_gtest(test_externally_defined_services test/test_externally_defined_services.cpp
-    APPEND_LIBRARY_DIRS "${append_library_dirs}")
-  if(TARGET test_externally_defined_services)
-    ament_target_dependencies(test_externally_defined_services
-      "rcl"
-    )
-    target_link_libraries(test_externally_defined_services ${PROJECT_NAME})
-    foreach(typesupport_impl_cpp ${typesupport_impls_cpp})
-      rosidl_target_interfaces(test_externally_defined_services
-        mock_msgs ${typesupport_impl_cpp})
-    endforeach()
-    foreach(typesupport_impl_c ${typesupport_impls_c})
-      rosidl_target_interfaces(test_externally_defined_services
-        mock_msgs ${typesupport_impl_c})
-    endforeach()
-  endif()
+  ament_add_gtest(test_externally_defined_services test/test_externally_defined_services.cpp)
+  ament_target_dependencies(test_externally_defined_services
+    "rcl"
+    "test_msgs"
+  )
+  target_link_libraries(test_externally_defined_services ${PROJECT_NAME})
 
   ament_add_gtest(test_duration test/test_duration.cpp
     APPEND_LIBRARY_DIRS "${append_library_dirs}")
@@ -397,6 +501,14 @@ if(BUILD_TESTING)
     target_link_libraries(test_time ${PROJECT_NAME})
   endif()
 
+  ament_add_gtest(test_timer test/test_timer.cpp
+    APPEND_LIBRARY_DIRS "${append_library_dirs}")
+  if(TARGET test_timer)
+    ament_target_dependencies(test_timer
+      "rcl")
+    target_link_libraries(test_timer ${PROJECT_NAME})
+  endif()
+
   ament_add_gtest(test_time_source test/test_time_source.cpp
     APPEND_LIBRARY_DIRS "${append_library_dirs}")
   if(TARGET test_time_source)
@@ -429,16 +541,43 @@ if(BUILD_TESTING)
     target_link_libraries(test_multi_threaded_executor ${PROJECT_NAME})
   endif()
 
-  ament_add_gtest(test_local_parameters test/test_local_parameters.cpp)
-  if(TARGET test_local_parameters)
-    ament_target_dependencies(test_local_parameters
-      "rcl_interfaces"
-      "rmw"
-      "rosidl_generator_cpp"
-      "rosidl_typesupport_cpp"
-    )
-    target_link_libraries(test_local_parameters ${PROJECT_NAME})
+  ament_add_gtest(test_guard_condition test/test_guard_condition.cpp
+    APPEND_LIBRARY_DIRS "${append_library_dirs}")
+  if(TARGET test_guard_condition)
+    target_link_libraries(test_guard_condition ${PROJECT_NAME})
   endif()
+
+  ament_add_gtest(test_wait_set test/test_wait_set.cpp
+    APPEND_LIBRARY_DIRS "${append_library_dirs}")
+  if(TARGET test_wait_set)
+    ament_target_dependencies(test_wait_set "test_msgs")
+    target_link_libraries(test_wait_set ${PROJECT_NAME})
+  endif()
+
+  ament_add_gtest(test_subscription_topic_statistics test/topic_statistics/test_subscription_topic_statistics.cpp)
+  if(TARGET test_subscription_topic_statistics)
+    ament_target_dependencies(test_subscription_topic_statistics
+      "libstatistics_collector"
+      "rcl_interfaces"
+      "rcutils"
+      "rmw"
+      "rosidl_runtime_cpp"
+      "rosidl_typesupport_cpp"
+      "statistics_msgs"
+      "test_msgs")
+    target_link_libraries(test_subscription_topic_statistics ${PROJECT_NAME})
+  endif()
+
+  ament_add_gtest(test_subscription_options test/test_subscription_options.cpp)
+  if(TARGET test_subscription_options)
+    ament_target_dependencies(test_subscription_options "rcl")
+    target_link_libraries(test_subscription_options ${PROJECT_NAME})
+  endif()
+
+  # Install test resources
+  install(
+    DIRECTORY test/resources
+    DESTINATION ${CMAKE_CURRENT_BINARY_DIR}/test)
 endif()
 
 ament_package()

rclcpp/cmake/rclcpp_add_build_failure_test.cmake

@@ -0,0 +1,56 @@
+# Copyright 2019 Open Source Robotics Foundation, Inc.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+#
+# Register a test which tries to compile a file and expects it to fail to build.
+#
+# This will create two targets, one by the given target name and a test target
+# which has the same name prefixed with `test_`.
+# For example, if target is `should_not_compile__use_const_argument` then there
+# will be an executable target called `should_not_compile__use_const_argument`
+# and a test target called `test_should_not_compile__use_const_argument`.
+#
+# :param target: the name of the target to be created
+# :type target: string
+# :param ARGN: the list of source files to be used to create the test executable
+# :type ARGN: list of strings
+#
+macro(rclcpp_add_build_failure_test target)
+  if(${ARGC} EQUAL 0)
+    message(
+      FATAL_ERROR
+      "rclcpp_add_build_failure_test() requires a target name and "
+      "at least one source file")
+  endif()
+
+  add_executable(${target} ${ARGN})
+  set_target_properties(${target}
+    PROPERTIES
+      EXCLUDE_FROM_ALL TRUE
+      EXCLUDE_FROM_DEFAULT_BUILD TRUE)
+
+  add_test(
+    NAME test_${target}
+    COMMAND
+      ${CMAKE_COMMAND}
+      --build .
+      --target ${target}
+      --config $<CONFIGURATION>
+    WORKING_DIRECTORY ${CMAKE_BINARY_DIR})
+  set_tests_properties(test_${target}
+    PROPERTIES
+      WILL_FAIL TRUE
+      LABELS "build_failure"
+  )
+endmacro()

rclcpp/include/rclcpp/allocator/allocator_common.hpp

@@ -65,7 +65,8 @@ void * retyped_reallocate(void * untyped_pointer, size_t size, void * untyped_al
 
 // Convert a std::allocator_traits-formatted Allocator into an rcl allocator
 template<
-  typename T, typename Alloc,
+  typename T,
+  typename Alloc,
   typename std::enable_if<!std::is_same<Alloc, std::allocator<void>>::value>::type * = nullptr>
 rcl_allocator_t get_rcl_allocator(Alloc & allocator)
 {
@@ -83,7 +84,8 @@ rcl_allocator_t get_rcl_allocator(Alloc & allocator)
 
 // TODO(jacquelinekay) Workaround for an incomplete implementation of std::allocator<void>
 template<
-  typename T, typename Alloc,
+  typename T,
+  typename Alloc,
   typename std::enable_if<std::is_same<Alloc, std::allocator<void>>::value>::type * = nullptr>
 rcl_allocator_t get_rcl_allocator(Alloc & allocator)
 {

rclcpp/include/rclcpp/any_executable.hpp

@@ -29,8 +29,6 @@
 
 namespace rclcpp
 {
-namespace executor
-{
 
 struct AnyExecutable
 {
@@ -42,16 +40,20 @@ struct AnyExecutable
 
   // Only one of the following pointers will be set.
   rclcpp::SubscriptionBase::SharedPtr subscription;
-  rclcpp::SubscriptionBase::SharedPtr subscription_intra_process;
   rclcpp::TimerBase::SharedPtr timer;
   rclcpp::ServiceBase::SharedPtr service;
   rclcpp::ClientBase::SharedPtr client;
   rclcpp::Waitable::SharedPtr waitable;
   // These are used to keep the scope on the containing items
-  rclcpp::callback_group::CallbackGroup::SharedPtr callback_group;
+  rclcpp::CallbackGroup::SharedPtr callback_group;
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base;
 };
 
+namespace executor
+{
+
+using AnyExecutable [[deprecated("use rclcpp::AnyExecutable instead")]] = AnyExecutable;
+
 }  // namespace executor
 }  // namespace rclcpp
 

rclcpp/include/rclcpp/any_service_callback.hpp

@@ -23,6 +23,8 @@
 #include "rclcpp/function_traits.hpp"
 #include "rclcpp/visibility_control.hpp"
 #include "rmw/types.h"
+#include "tracetools/tracetools.h"
+#include "tracetools/utils.hpp"
 
 namespace rclcpp
 {
@@ -86,6 +88,7 @@ public:
     std::shared_ptr<typename ServiceT::Request> request,
     std::shared_ptr<typename ServiceT::Response> response)
   {
+    TRACEPOINT(callback_start, (const void *)this, false);
     if (shared_ptr_callback_ != nullptr) {
       (void)request_header;
       shared_ptr_callback_(request, response);
@@ -94,6 +97,24 @@ public:
     } else {
       throw std::runtime_error("unexpected request without any callback set");
     }
+    TRACEPOINT(callback_end, (const void *)this);
+  }
+
+  void register_callback_for_tracing()
+  {
+#ifndef TRACETOOLS_DISABLED
+    if (shared_ptr_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(shared_ptr_callback_));
+    } else if (shared_ptr_with_request_header_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(shared_ptr_with_request_header_callback_));
+    }
+#endif  // TRACETOOLS_DISABLED
   }
 };
 

rclcpp/include/rclcpp/any_subscription_callback.hpp

@@ -25,7 +25,10 @@
 
 #include "rclcpp/allocator/allocator_common.hpp"
 #include "rclcpp/function_traits.hpp"
+#include "rclcpp/message_info.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "tracetools/tracetools.h"
+#include "tracetools/utils.hpp"
 
 namespace rclcpp
 {
@@ -36,17 +39,18 @@ class AnySubscriptionCallback
   using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
   using MessageAlloc = typename MessageAllocTraits::allocator_type;
   using MessageDeleter = allocator::Deleter<MessageAlloc, MessageT>;
+  using ConstMessageSharedPtr = std::shared_ptr<const MessageT>;
   using MessageUniquePtr = std::unique_ptr<MessageT, MessageDeleter>;
 
   using SharedPtrCallback = std::function<void (const std::shared_ptr<MessageT>)>;
   using SharedPtrWithInfoCallback =
-    std::function<void (const std::shared_ptr<MessageT>, const rmw_message_info_t &)>;
+    std::function<void (const std::shared_ptr<MessageT>, const rclcpp::MessageInfo &)>;
   using ConstSharedPtrCallback = std::function<void (const std::shared_ptr<const MessageT>)>;
   using ConstSharedPtrWithInfoCallback =
-    std::function<void (const std::shared_ptr<const MessageT>, const rmw_message_info_t &)>;
+    std::function<void (const std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)>;
   using UniquePtrCallback = std::function<void (MessageUniquePtr)>;
   using UniquePtrWithInfoCallback =
-    std::function<void (MessageUniquePtr, const rmw_message_info_t &)>;
+    std::function<void (MessageUniquePtr, const rclcpp::MessageInfo &)>;
 
   SharedPtrCallback shared_ptr_callback_;
   SharedPtrWithInfoCallback shared_ptr_with_info_callback_;
@@ -152,9 +156,9 @@ public:
   }
 
   void dispatch(
-    std::shared_ptr<MessageT> message, const rmw_message_info_t & message_info)
+    std::shared_ptr<MessageT> message, const rclcpp::MessageInfo & message_info)
   {
-    (void)message_info;
+    TRACEPOINT(callback_start, (const void *)this, false);
     if (shared_ptr_callback_) {
       shared_ptr_callback_(message);
     } else if (shared_ptr_with_info_callback_) {
@@ -174,31 +178,86 @@ public:
     } else {
       throw std::runtime_error("unexpected message without any callback set");
     }
+    TRACEPOINT(callback_end, (const void *)this);
   }
 
   void dispatch_intra_process(
-    MessageUniquePtr & message, const rmw_message_info_t & message_info)
+    ConstMessageSharedPtr message, const rclcpp::MessageInfo & message_info)
   {
-    (void)message_info;
+    TRACEPOINT(callback_start, (const void *)this, true);
+    if (const_shared_ptr_callback_) {
+      const_shared_ptr_callback_(message);
+    } else if (const_shared_ptr_with_info_callback_) {
+      const_shared_ptr_with_info_callback_(message, message_info);
+    } else {
+      if (
+        unique_ptr_callback_ || unique_ptr_with_info_callback_ ||
+        shared_ptr_callback_ || shared_ptr_with_info_callback_)
+      {
+        throw std::runtime_error(
+                "unexpected dispatch_intra_process const shared "
+                "message call with no const shared_ptr callback");
+      } else {
+        throw std::runtime_error("unexpected message without any callback set");
+      }
+    }
+    TRACEPOINT(callback_end, (const void *)this);
+  }
+
+  void dispatch_intra_process(
+    MessageUniquePtr message, const rclcpp::MessageInfo & message_info)
+  {
+    TRACEPOINT(callback_start, (const void *)this, true);
     if (shared_ptr_callback_) {
       typename std::shared_ptr<MessageT> shared_message = std::move(message);
       shared_ptr_callback_(shared_message);
     } else if (shared_ptr_with_info_callback_) {
       typename std::shared_ptr<MessageT> shared_message = std::move(message);
       shared_ptr_with_info_callback_(shared_message, message_info);
-    } else if (const_shared_ptr_callback_) {
-      typename std::shared_ptr<MessageT const> const_shared_message = std::move(message);
-      const_shared_ptr_callback_(const_shared_message);
-    } else if (const_shared_ptr_with_info_callback_) {
-      typename std::shared_ptr<MessageT const> const_shared_message = std::move(message);
-      const_shared_ptr_with_info_callback_(const_shared_message, message_info);
     } else if (unique_ptr_callback_) {
       unique_ptr_callback_(std::move(message));
     } else if (unique_ptr_with_info_callback_) {
       unique_ptr_with_info_callback_(std::move(message), message_info);
+    } else if (const_shared_ptr_callback_ || const_shared_ptr_with_info_callback_) {
+      throw std::runtime_error(
+              "unexpected dispatch_intra_process unique message call"
+              " with const shared_ptr callback");
     } else {
       throw std::runtime_error("unexpected message without any callback set");
     }
+    TRACEPOINT(callback_end, (const void *)this);
+  }
+
+  bool use_take_shared_method() const
+  {
+    return const_shared_ptr_callback_ || const_shared_ptr_with_info_callback_;
+  }
+
+  void register_callback_for_tracing()
+  {
+#ifndef TRACETOOLS_DISABLED
+    if (shared_ptr_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(shared_ptr_callback_));
+    } else if (shared_ptr_with_info_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(shared_ptr_with_info_callback_));
+    } else if (unique_ptr_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(unique_ptr_callback_));
+    } else if (unique_ptr_with_info_callback_) {
+      TRACEPOINT(
+        rclcpp_callback_register,
+        (const void *)this,
+        get_symbol(unique_ptr_with_info_callback_));
+    }
+#endif  // TRACETOOLS_DISABLED
   }
 
 private:

rclcpp/include/rclcpp/callback_group.hpp

@@ -21,8 +21,9 @@
 #include <vector>
 
 #include "rclcpp/client.hpp"
+#include "rclcpp/publisher_base.hpp"
 #include "rclcpp/service.hpp"
-#include "rclcpp/subscription.hpp"
+#include "rclcpp/subscription_base.hpp"
 #include "rclcpp/timer.hpp"
 #include "rclcpp/visibility_control.hpp"
 #include "rclcpp/waitable.hpp"
@@ -39,9 +40,6 @@ class NodeTopics;
 class NodeWaitables;
 }  // namespace node_interfaces
 
-namespace callback_group
-{
-
 enum class CallbackGroupType
 {
   MutuallyExclusive,
@@ -61,25 +59,40 @@ public:
   RCLCPP_PUBLIC
   explicit CallbackGroup(CallbackGroupType group_type);
 
-  RCLCPP_PUBLIC
-  const std::vector<rclcpp::SubscriptionBase::WeakPtr> &
-  get_subscription_ptrs() const;
+  template<typename Function>
+  rclcpp::SubscriptionBase::SharedPtr
+  find_subscription_ptrs_if(Function func) const
+  {
+    return _find_ptrs_if_impl<rclcpp::SubscriptionBase, Function>(func, subscription_ptrs_);
+  }
 
-  RCLCPP_PUBLIC
-  const std::vector<rclcpp::TimerBase::WeakPtr> &
-  get_timer_ptrs() const;
+  template<typename Function>
+  rclcpp::TimerBase::SharedPtr
+  find_timer_ptrs_if(Function func) const
+  {
+    return _find_ptrs_if_impl<rclcpp::TimerBase, Function>(func, timer_ptrs_);
+  }
 
-  RCLCPP_PUBLIC
-  const std::vector<rclcpp::ServiceBase::WeakPtr> &
-  get_service_ptrs() const;
+  template<typename Function>
+  rclcpp::ServiceBase::SharedPtr
+  find_service_ptrs_if(Function func) const
+  {
+    return _find_ptrs_if_impl<rclcpp::ServiceBase, Function>(func, service_ptrs_);
+  }
 
-  RCLCPP_PUBLIC
-  const std::vector<rclcpp::ClientBase::WeakPtr> &
-  get_client_ptrs() const;
+  template<typename Function>
+  rclcpp::ClientBase::SharedPtr
+  find_client_ptrs_if(Function func) const
+  {
+    return _find_ptrs_if_impl<rclcpp::ClientBase, Function>(func, client_ptrs_);
+  }
 
-  RCLCPP_PUBLIC
-  const std::vector<rclcpp::Waitable::WeakPtr> &
-  get_waitable_ptrs() const;
+  template<typename Function>
+  rclcpp::Waitable::SharedPtr
+  find_waitable_ptrs_if(Function func) const
+  {
+    return _find_ptrs_if_impl<rclcpp::Waitable, Function>(func, waitable_ptrs_);
+  }
 
   RCLCPP_PUBLIC
   std::atomic_bool &
@@ -92,6 +105,10 @@ public:
 protected:
   RCLCPP_DISABLE_COPY(CallbackGroup)
 
+  RCLCPP_PUBLIC
+  void
+  add_publisher(const rclcpp::PublisherBase::SharedPtr publisher_ptr);
+
   RCLCPP_PUBLIC
   void
   add_subscription(const rclcpp::SubscriptionBase::SharedPtr subscription_ptr);
@@ -125,8 +142,29 @@ protected:
   std::vector<rclcpp::ClientBase::WeakPtr> client_ptrs_;
   std::vector<rclcpp::Waitable::WeakPtr> waitable_ptrs_;
   std::atomic_bool can_be_taken_from_;
+
+private:
+  template<typename TypeT, typename Function>
+  typename TypeT::SharedPtr _find_ptrs_if_impl(
+    Function func, const std::vector<typename TypeT::WeakPtr> & vect_ptrs) const
+  {
+    std::lock_guard<std::mutex> lock(mutex_);
+    for (auto & weak_ptr : vect_ptrs) {
+      auto ref_ptr = weak_ptr.lock();
+      if (ref_ptr && func(ref_ptr)) {
+        return ref_ptr;
+      }
+    }
+    return typename TypeT::SharedPtr();
+  }
 };
 
+namespace callback_group
+{
+
+using CallbackGroupType [[deprecated("use rclcpp::CallbackGroupType instead")]] = CallbackGroupType;
+using CallbackGroup [[deprecated("use rclcpp::CallbackGroup instead")]] = CallbackGroup;
+
 }  // namespace callback_group
 }  // namespace rclcpp
 

rclcpp/include/rclcpp/client.hpp

@@ -15,6 +15,7 @@
 #ifndef RCLCPP__CLIENT_HPP_
 #define RCLCPP__CLIENT_HPP_
 
+#include <atomic>
 #include <future>
 #include <map>
 #include <memory>
@@ -62,6 +63,27 @@ public:
   RCLCPP_PUBLIC
   virtual ~ClientBase();
 
+  /// Take the next response for this client as a type erased pointer.
+  /**
+   * The type erased pointer allows for this method to be used in a type
+   * agnostic way along with ClientBase::create_response(),
+   * ClientBase::create_request_header(), and ClientBase::handle_response().
+   * The typed version of this can be used if the Service type is known,
+   * \sa Client::take_response().
+   *
+   * \param[out] response_out The type erased pointer to a Service Response into
+   *   which the middleware will copy the response being taken.
+   * \param[out] request_header_out The request header to be filled by the
+   *   middleware when taking, and which can be used to associte the response
+   *   to a specific request.
+   * \returns true if the response was taken, otherwise false.
+   * \throws rclcpp::exceptions::RCLError based exceptions if the underlying
+   *   rcl function fail.
+   */
+  RCLCPP_PUBLIC
+  bool
+  take_type_erased_response(void * response_out, rmw_request_id_t & request_header_out);
+
   RCLCPP_PUBLIC
   const char *
   get_service_name() const;
@@ -93,6 +115,20 @@ public:
   virtual void handle_response(
     std::shared_ptr<rmw_request_id_t> request_header, std::shared_ptr<void> response) = 0;
 
+  /// Exchange the "in use by wait set" state for this client.
+  /**
+   * This is used to ensure this client is not used by multiple
+   * wait sets at the same time.
+   *
+   * \param[in] in_use_state the new state to exchange into the state, true
+   *   indicates it is now in use by a wait set, and false is that it is no
+   *   longer in use by a wait set.
+   * \returns the previous state.
+   */
+  RCLCPP_PUBLIC
+  bool
+  exchange_in_use_by_wait_set_state(bool in_use_state);
+
 protected:
   RCLCPP_DISABLE_COPY(ClientBase)
 
@@ -113,6 +149,8 @@ protected:
   std::shared_ptr<rclcpp::Context> context_;
 
   std::shared_ptr<rcl_client_t> client_handle_;
+
+  std::atomic<bool> in_use_by_wait_set_{false};
 };
 
 template<typename ServiceT>
@@ -171,6 +209,25 @@ public:
   {
   }
 
+  /// Take the next response for this client.
+  /**
+   * \sa ClientBase::take_type_erased_response().
+   *
+   * \param[out] response_out The reference to a Service Response into
+   *   which the middleware will copy the response being taken.
+   * \param[out] request_header_out The request header to be filled by the
+   *   middleware when taking, and which can be used to associte the response
+   *   to a specific request.
+   * \returns true if the response was taken, otherwise false.
+   * \throws rclcpp::exceptions::RCLError based exceptions if the underlying
+   *   rcl function fail.
+   */
+  bool
+  take_response(typename ServiceT::Response & response_out, rmw_request_id_t & request_header_out)
+  {
+    return this->take_type_erased_response(&response_out, request_header_out);
+  }
+
   std::shared_ptr<void>
   create_response() override
   {

rclcpp/include/rclcpp/clock.hpp

@@ -18,13 +18,14 @@
 #include <functional>
 #include <memory>
 #include <mutex>
-#include <vector>
 
 #include "rclcpp/macros.hpp"
 #include "rclcpp/time.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 #include "rcl/time.h"
+#include "rcutils/time.h"
+#include "rcutils/types/rcutils_ret.h"
 
 namespace rclcpp
 {
@@ -35,13 +36,17 @@ class JumpHandler
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(JumpHandler)
+
+  using pre_callback_t = std::function<void ()>;
+  using post_callback_t = std::function<void (const rcl_time_jump_t &)>;
+
   JumpHandler(
-    std::function<void()> pre_callback,
-    std::function<void(const rcl_time_jump_t &)> post_callback,
+    pre_callback_t pre_callback,
+    post_callback_t post_callback,
     const rcl_jump_threshold_t & threshold);
 
-  std::function<void()> pre_callback;
-  std::function<void(const rcl_time_jump_t &)> post_callback;
+  pre_callback_t pre_callback;
+  post_callback_t post_callback;
   rcl_jump_threshold_t notice_threshold;
 };
 
@@ -50,38 +55,78 @@ class Clock
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(Clock)
 
+  /// Default c'tor
+  /**
+   * Initializes the clock instance with the given clock_type.
+   *
+   * \param clock_type type of the clock.
+   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
+   */
   RCLCPP_PUBLIC
   explicit Clock(rcl_clock_type_t clock_type = RCL_SYSTEM_TIME);
 
   RCLCPP_PUBLIC
   ~Clock();
 
+  /**
+   * Returns current time from the time source specified by clock_type.
+   *
+   * \return current time.
+   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
+   */
   RCLCPP_PUBLIC
   Time
   now();
 
+  /**
+   * Returns the clock of the type `RCL_ROS_TIME` is active.
+   *
+   * \return true if the clock is active
+   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw if
+   * the current clock does not have the clock_type `RCL_ROS_TIME`.
+   */
   RCLCPP_PUBLIC
   bool
   ros_time_is_active();
 
   RCLCPP_PUBLIC
   rcl_clock_t *
-  get_clock_handle();
+  get_clock_handle() noexcept;
 
   RCLCPP_PUBLIC
   rcl_clock_type_t
-  get_clock_type();
+  get_clock_type() const noexcept;
+
+  RCLCPP_PUBLIC
+  std::mutex &
+  get_clock_mutex() noexcept;
 
   // Add a callback to invoke if the jump threshold is exceeded.
   /**
    * These callback functions must remain valid as long as the
    * returned shared pointer is valid.
+   *
+   * Function will register callbacks to the callback queue. On time jump all
+   * callbacks will be executed whose threshold is greater then the time jump;
+   * The logic will first call selected pre_callbacks and then all selected
+   * post_callbacks.
+   *
+   * Function is only applicable if the clock_type is `RCL_ROS_TIME`
+   *
+   * \param pre_callback. Must be non-throwing
+   * \param post_callback. Must be non-throwing.
+   * \param threshold. Callbacks will be triggered if the time jump is greater
+   * then the threshold.
+   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
+   * \throws std::bad_alloc if the allocation of the JumpHandler fails.
+   * \warning the instance of the clock must remain valid as long as any created
+   * JumpHandler.
    */
   RCLCPP_PUBLIC
   JumpHandler::SharedPtr
   create_jump_callback(
-    std::function<void()> pre_callback,
-    std::function<void(const rcl_time_jump_t &)> post_callback,
+    JumpHandler::pre_callback_t pre_callback,
+    JumpHandler::post_callback_t post_callback,
     const rcl_jump_threshold_t & threshold);
 
 private:
@@ -93,10 +138,10 @@ private:
     bool before_jump,
     void * user_data);
 
-  /// Internal storage backed by rcl
-  rcl_clock_t rcl_clock_;
-  friend TimeSource;  /// Allow TimeSource to access the rcl_clock_ datatype.
-  rcl_allocator_t allocator_;
+  /// Private internal storage
+  class Impl;
+
+  std::shared_ptr<Impl> impl_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/context.hpp

@@ -159,7 +159,7 @@ public:
    *
    * \param[in] reason the description of why shutdown happened
    * \return true if shutdown was successful, false if context was already shutdown
-   * \throw various exceptions derived from RCLErrorBase, if rcl_shutdown fails
+   * \throw various exceptions derived from rclcpp::exceptions::RCLError, if rcl_shutdown fails
    */
   RCLCPP_PUBLIC
   virtual

rclcpp/include/rclcpp/contexts/default_context.hpp

@@ -22,8 +22,6 @@ namespace rclcpp
 {
 namespace contexts
 {
-namespace default_context
-{
 
 class DefaultContext : public rclcpp::Context
 {
@@ -38,6 +36,21 @@ RCLCPP_PUBLIC
 DefaultContext::SharedPtr
 get_global_default_context();
 
+namespace default_context
+{
+
+using DefaultContext
+[[deprecated("use rclcpp::contexts::DefaultContext instead")]] = DefaultContext;
+
+[[deprecated("use rclcpp::contexts::get_global_default_context() instead")]]
+RCLCPP_PUBLIC
+inline
+DefaultContext::SharedPtr
+get_global_default_context()
+{
+  return rclcpp::contexts::get_global_default_context();
+}
+
 }  // namespace default_context
 }  // namespace contexts
 }  // namespace rclcpp

rclcpp/include/rclcpp/create_client.hpp

@@ -0,0 +1,56 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__CREATE_CLIENT_HPP_
+#define RCLCPP__CREATE_CLIENT_HPP_
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/node_interfaces/node_services_interface.hpp"
+#include "rmw/rmw.h"
+
+namespace rclcpp
+{
+
+/// Create a service client with a given type.
+/// \internal
+template<typename ServiceT>
+typename rclcpp::Client<ServiceT>::SharedPtr
+create_client(
+  std::shared_ptr<node_interfaces::NodeBaseInterface> node_base,
+  std::shared_ptr<node_interfaces::NodeGraphInterface> node_graph,
+  std::shared_ptr<node_interfaces::NodeServicesInterface> node_services,
+  const std::string & service_name,
+  const rmw_qos_profile_t & qos_profile,
+  rclcpp::CallbackGroup::SharedPtr group)
+{
+  rcl_client_options_t options = rcl_client_get_default_options();
+  options.qos = qos_profile;
+
+  auto cli = rclcpp::Client<ServiceT>::make_shared(
+    node_base.get(),
+    node_graph,
+    service_name,
+    options);
+
+  auto cli_base_ptr = std::dynamic_pointer_cast<rclcpp::ClientBase>(cli);
+  node_services->add_client(cli_base_ptr, group);
+  return cli;
+}
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__CREATE_CLIENT_HPP_

rclcpp/include/rclcpp/create_publisher.hpp

@@ -18,31 +18,51 @@
 #include <memory>
 #include <string>
 
+#include "rclcpp/node_interfaces/get_node_topics_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
+#include "rclcpp/node_options.hpp"
 #include "rclcpp/publisher_factory.hpp"
+#include "rclcpp/publisher_options.hpp"
+#include "rclcpp/qos.hpp"
 #include "rmw/qos_profiles.h"
 
 namespace rclcpp
 {
 
-template<typename MessageT, typename AllocatorT, typename PublisherT>
+/// Create and return a publisher of the given MessageT type.
+/**
+ * The NodeT type only needs to have a method called get_node_topics_interface()
+ * which returns a shared_ptr to a NodeTopicsInterface.
+ */
+template<
+  typename MessageT,
+  typename AllocatorT = std::allocator<void>,
+  typename PublisherT = rclcpp::Publisher<MessageT, AllocatorT>,
+  typename NodeT>
 std::shared_ptr<PublisherT>
 create_publisher(
-  rclcpp::node_interfaces::NodeTopicsInterface * node_topics,
+  NodeT & node,
   const std::string & topic_name,
-  const rmw_qos_profile_t & qos_profile,
-  bool use_intra_process_comms,
-  std::shared_ptr<AllocatorT> allocator)
+  const rclcpp::QoS & qos,
+  const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::PublisherOptionsWithAllocator<AllocatorT>()
+  )
+)
 {
-  auto publisher_options = rcl_publisher_get_default_options();
-  publisher_options.qos = qos_profile;
+  // Extract the NodeTopicsInterface from the NodeT.
+  using rclcpp::node_interfaces::get_node_topics_interface;
+  auto node_topics = get_node_topics_interface(node);
 
+  // Create the publisher.
   auto pub = node_topics->create_publisher(
     topic_name,
-    rclcpp::create_publisher_factory<MessageT, AllocatorT, PublisherT>(allocator),
-    publisher_options,
-    use_intra_process_comms);
-  node_topics->add_publisher(pub);
+    rclcpp::create_publisher_factory<MessageT, AllocatorT, PublisherT>(options),
+    qos
+  );
+
+  // Add the publisher to the node topics interface.
+  node_topics->add_publisher(pub, options.callback_group);
+
   return std::dynamic_pointer_cast<PublisherT>(pub);
 }
 

rclcpp/include/rclcpp/create_service.hpp

@@ -37,7 +37,7 @@ create_service(
   const std::string & service_name,
   CallbackT && callback,
   const rmw_qos_profile_t & qos_profile,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group)
+  rclcpp::CallbackGroup::SharedPtr group)
 {
   rclcpp::AnyServiceCallback<ServiceT> any_service_callback;
   any_service_callback.set(std::forward<CallbackT>(callback));

rclcpp/include/rclcpp/create_subscription.hpp

@@ -19,47 +19,60 @@
 #include <string>
 #include <utility>
 
+#include "rclcpp/node_interfaces/get_node_topics_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
 #include "rclcpp/subscription_factory.hpp"
+#include "rclcpp/subscription_options.hpp"
+#include "rclcpp/qos.hpp"
 #include "rmw/qos_profiles.h"
 
 namespace rclcpp
 {
 
+/// Create and return a subscription of the given MessageT type.
+/**
+ * The NodeT type only needs to have a method called get_node_topics_interface()
+ * which returns a shared_ptr to a NodeTopicsInterface, or be a
+ * NodeTopicsInterface pointer itself.
+ */
 template<
   typename MessageT,
   typename CallbackT,
-  typename AllocatorT,
-  typename CallbackMessageT,
-  typename SubscriptionT = rclcpp::Subscription<CallbackMessageT, AllocatorT>>
+  typename AllocatorT = std::allocator<void>,
+  typename CallbackMessageT =
+  typename rclcpp::subscription_traits::has_message_type<CallbackT>::type,
+  typename SubscriptionT = rclcpp::Subscription<CallbackMessageT, AllocatorT>,
+  typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<
+    CallbackMessageT,
+    AllocatorT
+  >,
+  typename NodeT>
 typename std::shared_ptr<SubscriptionT>
 create_subscription(
-  rclcpp::node_interfaces::NodeTopicsInterface * node_topics,
+  NodeT && node,
   const std::string & topic_name,
+  const rclcpp::QoS & qos,
   CallbackT && callback,
-  const rmw_qos_profile_t & qos_profile,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group,
-  bool ignore_local_publications,
-  bool use_intra_process_comms,
-  typename rclcpp::message_memory_strategy::MessageMemoryStrategy<
-    CallbackMessageT, AllocatorT>::SharedPtr
-  msg_mem_strat,
-  typename std::shared_ptr<AllocatorT> allocator)
+  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>()
+  ),
+  typename MessageMemoryStrategyT::SharedPtr msg_mem_strat = (
+    MessageMemoryStrategyT::create_default()
+  )
+)
 {
-  auto subscription_options = rcl_subscription_get_default_options();
-  subscription_options.qos = qos_profile;
-  subscription_options.ignore_local_publications = ignore_local_publications;
+  using rclcpp::node_interfaces::get_node_topics_interface;
+  auto node_topics = get_node_topics_interface(std::forward<NodeT>(node));
 
-  auto factory = rclcpp::create_subscription_factory
-    <MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT>(
-    std::forward<CallbackT>(callback), msg_mem_strat, allocator);
+  auto factory = rclcpp::create_subscription_factory<MessageT>(
+    std::forward<CallbackT>(callback),
+    options,
+    msg_mem_strat
+  );
+
+  auto sub = node_topics->create_subscription(topic_name, factory, qos);
+  node_topics->add_subscription(sub, options.callback_group);
 
-  auto sub = node_topics->create_subscription(
-    topic_name,
-    factory,
-    subscription_options,
-    use_intra_process_comms);
-  node_topics->add_subscription(sub, group);
   return std::dynamic_pointer_cast<SubscriptionT>(sub);
 }
 

rclcpp/include/rclcpp/create_timer.hpp

@@ -0,0 +1,73 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__CREATE_TIMER_HPP_
+#define RCLCPP__CREATE_TIMER_HPP_
+
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "rclcpp/duration.hpp"
+#include "rclcpp/node_interfaces/get_node_base_interface.hpp"
+#include "rclcpp/node_interfaces/get_node_timers_interface.hpp"
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/node_interfaces/node_timers_interface.hpp"
+
+namespace rclcpp
+{
+/// Create a timer with a given clock
+/// \internal
+template<typename CallbackT>
+typename rclcpp::TimerBase::SharedPtr
+create_timer(
+  node_interfaces::NodeBaseInterface * node_base,
+  node_interfaces::NodeTimersInterface * node_timers,
+  rclcpp::Clock::SharedPtr clock,
+  rclcpp::Duration period,
+  CallbackT && callback,
+  rclcpp::CallbackGroup::SharedPtr group = nullptr)
+{
+  auto timer = rclcpp::GenericTimer<CallbackT>::make_shared(
+    clock,
+    period.to_chrono<std::chrono::nanoseconds>(),
+    std::forward<CallbackT>(callback),
+    node_base->get_context());
+
+  node_timers->add_timer(timer, group);
+  return timer;
+}
+
+/// Create a timer with a given clock
+template<typename NodeT, typename CallbackT>
+typename rclcpp::TimerBase::SharedPtr
+create_timer(
+  NodeT node,
+  rclcpp::Clock::SharedPtr clock,
+  rclcpp::Duration period,
+  CallbackT && callback,
+  rclcpp::CallbackGroup::SharedPtr group = nullptr)
+{
+  return create_timer(
+    rclcpp::node_interfaces::get_node_base_interface(node),
+    rclcpp::node_interfaces::get_node_timers_interface(node),
+    clock,
+    period,
+    std::forward<CallbackT>(callback),
+    group);
+}
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__CREATE_TIMER_HPP_

rclcpp/include/rclcpp/detail/README.md

@@ -0,0 +1,3 @@
+Notice that headers in this folder should only provide symbols in the rclcpp::detail namespace.
+
+Also that these headers are not considered part of the public API and are subject to change without notice.

rclcpp/include/rclcpp/detail/resolve_enable_topic_statistics.hpp

@@ -0,0 +1,54 @@
+// Copyright 2020 Amazon.com, Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RESOLVE_ENABLE_TOPIC_STATISTICS_HPP_
+#define RCLCPP__DETAIL__RESOLVE_ENABLE_TOPIC_STATISTICS_HPP_
+
+#include <stdexcept>
+
+#include "rclcpp/topic_statistics_state.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+/// Return whether or not topic statistics is enabled, resolving "NodeDefault" if needed.
+template<typename OptionsT, typename NodeBaseT>
+bool
+resolve_enable_topic_statistics(const OptionsT & options, const NodeBaseT & node_base)
+{
+  bool topic_stats_enabled;
+  switch (options.topic_stats_options.state) {
+    case TopicStatisticsState::Enable:
+      topic_stats_enabled = true;
+      break;
+    case TopicStatisticsState::Disable:
+      topic_stats_enabled = false;
+      break;
+    case TopicStatisticsState::NodeDefault:
+      topic_stats_enabled = node_base.get_enable_topic_statistics_default();
+      break;
+    default:
+      throw std::runtime_error("Unrecognized EnableTopicStatistics value");
+      break;
+  }
+
+  return topic_stats_enabled;
+}
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RESOLVE_ENABLE_TOPIC_STATISTICS_HPP_

rclcpp/include/rclcpp/detail/resolve_intra_process_buffer_type.hpp

@@ -0,0 +1,54 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RESOLVE_INTRA_PROCESS_BUFFER_TYPE_HPP_
+#define RCLCPP__DETAIL__RESOLVE_INTRA_PROCESS_BUFFER_TYPE_HPP_
+
+#include <stdexcept>
+
+#include "rclcpp/any_subscription_callback.hpp"
+#include "rclcpp/intra_process_buffer_type.hpp"
+
+namespace rclcpp
+{
+
+namespace detail
+{
+
+/// Return the buffer type, resolving the "CallbackDefault" type to an actual type if needed.
+template<typename CallbackMessageT, typename AllocatorT>
+rclcpp::IntraProcessBufferType
+resolve_intra_process_buffer_type(
+  const rclcpp::IntraProcessBufferType buffer_type,
+  const rclcpp::AnySubscriptionCallback<CallbackMessageT, AllocatorT> & any_subscription_callback)
+{
+  rclcpp::IntraProcessBufferType resolved_buffer_type = buffer_type;
+
+  // If the user has not specified a type for the intra-process buffer, use the callback's type.
+  if (resolved_buffer_type == IntraProcessBufferType::CallbackDefault) {
+    if (any_subscription_callback.use_take_shared_method()) {
+      resolved_buffer_type = IntraProcessBufferType::SharedPtr;
+    } else {
+      resolved_buffer_type = IntraProcessBufferType::UniquePtr;
+    }
+  }
+
+  return resolved_buffer_type;
+}
+
+}  // namespace detail
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RESOLVE_INTRA_PROCESS_BUFFER_TYPE_HPP_

rclcpp/include/rclcpp/detail/resolve_use_intra_process.hpp

@@ -0,0 +1,56 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RESOLVE_USE_INTRA_PROCESS_HPP_
+#define RCLCPP__DETAIL__RESOLVE_USE_INTRA_PROCESS_HPP_
+
+#include <stdexcept>
+
+#include "rclcpp/intra_process_setting.hpp"
+
+namespace rclcpp
+{
+
+namespace detail
+{
+
+/// Return whether or not intra process is enabled, resolving "NodeDefault" if needed.
+template<typename OptionsT, typename NodeBaseT>
+bool
+resolve_use_intra_process(const OptionsT & options, const NodeBaseT & node_base)
+{
+  bool use_intra_process;
+  switch (options.use_intra_process_comm) {
+    case IntraProcessSetting::Enable:
+      use_intra_process = true;
+      break;
+    case IntraProcessSetting::Disable:
+      use_intra_process = false;
+      break;
+    case IntraProcessSetting::NodeDefault:
+      use_intra_process = node_base.get_use_intra_process_default();
+      break;
+    default:
+      throw std::runtime_error("Unrecognized IntraProcessSetting value");
+      break;
+  }
+
+  return use_intra_process;
+}
+
+}  // namespace detail
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RESOLVE_USE_INTRA_PROCESS_HPP_

rclcpp/include/rclcpp/detail/rmw_implementation_specific_payload.hpp

@@ -0,0 +1,51 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PAYLOAD_HPP_
+#define RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PAYLOAD_HPP_
+
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+/// Mechanism for passing rmw implementation specific settings through the ROS interfaces.
+class RCLCPP_PUBLIC RMWImplementationSpecificPayload
+{
+public:
+  virtual
+  ~RMWImplementationSpecificPayload() = default;
+
+  /// Return false if this class has not been customized, otherwise true.
+  /**
+   * It does this based on the value of the rmw implementation identifier that
+   * this class reports, and so it is important for a specialization of this
+   * class to override the get_rmw_implementation_identifier() method to return
+   * something other than nullptr.
+   */
+  bool
+  has_been_customized() const;
+
+  /// Derrived classes should override this and return the identifier of its rmw implementation.
+  virtual
+  const char *
+  get_implementation_identifier() const;
+};
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PAYLOAD_HPP_

rclcpp/include/rclcpp/detail/rmw_implementation_specific_publisher_payload.hpp

@@ -0,0 +1,52 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PUBLISHER_PAYLOAD_HPP_
+#define RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PUBLISHER_PAYLOAD_HPP_
+
+#include "rcl/publisher.h"
+
+#include "rclcpp/detail/rmw_implementation_specific_payload.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+class RCLCPP_PUBLIC RMWImplementationSpecificPublisherPayload
+  : public RMWImplementationSpecificPayload
+{
+public:
+  ~RMWImplementationSpecificPublisherPayload() override = default;
+
+  /// Opportunity for a derived class to inject information into the rcl options.
+  /**
+   * This is called after the rcl_publisher_options_t has been prepared by
+   * rclcpp, but before rcl_publisher_init() is called.
+   *
+   * The passed option is the rmw_publisher_options field of the
+   * rcl_publisher_options_t that will be passed to rcl_publisher_init().
+   *
+   * By default the options are unmodified.
+   */
+  virtual
+  void
+  modify_rmw_publisher_options(rmw_publisher_options_t & rmw_publisher_options) const;
+};
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_PUBLISHER_PAYLOAD_HPP_

rclcpp/include/rclcpp/detail/rmw_implementation_specific_subscription_payload.hpp

@@ -0,0 +1,53 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_SUBSCRIPTION_PAYLOAD_HPP_
+#define RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_SUBSCRIPTION_PAYLOAD_HPP_
+
+#include "rcl/subscription.h"
+
+#include "rclcpp/detail/rmw_implementation_specific_payload.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+/// Subscription payload that may be rmw implementation specific.
+class RCLCPP_PUBLIC RMWImplementationSpecificSubscriptionPayload
+  : public RMWImplementationSpecificPayload
+{
+public:
+  ~RMWImplementationSpecificSubscriptionPayload() override = default;
+
+  /// Opportunity for a derived class to inject information into the rcl options.
+  /**
+   * This is called after the rcl_subscription_options_t has been prepared by
+   * rclcpp, but before rcl_subscription_init() is called.
+   *
+   * The passed option is the rmw_subscription_options field of the
+   * rcl_subscription_options_t that will be passed to rcl_subscription_init().
+   *
+   * By default the options are unmodified.
+   */
+  virtual
+  void
+  modify_rmw_subscription_options(rmw_subscription_options_t & rmw_subscription_options) const;
+};
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RMW_IMPLEMENTATION_SPECIFIC_SUBSCRIPTION_PAYLOAD_HPP_

rclcpp/include/rclcpp/detail/utilities.hpp

@@ -0,0 +1,40 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__UTILITIES_HPP_
+#define RCLCPP__DETAIL__UTILITIES_HPP_
+
+#include "rclcpp/detail/utilities.hpp"
+
+#include <string>
+#include <vector>
+
+#include "rcl/allocator.h"
+#include "rcl/arguments.h"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+std::vector<std::string>
+get_unparsed_ros_arguments(
+  int argc, char const * const argv[],
+  rcl_arguments_t * arguments,
+  rcl_allocator_t allocator);
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__UTILITIES_HPP_

rclcpp/include/rclcpp/duration.hpp

@@ -23,91 +23,93 @@
 
 namespace rclcpp
 {
-class Duration
+class RCLCPP_PUBLIC Duration
 {
 public:
-  RCLCPP_PUBLIC
   Duration(int32_t seconds, uint32_t nanoseconds);
 
-  RCLCPP_PUBLIC
-  explicit Duration(
-    rcl_duration_value_t nanoseconds);
+  // This constructor matches any numeric value - ints or floats
+  explicit Duration(rcl_duration_value_t nanoseconds);
 
-  RCLCPP_PUBLIC
-  explicit Duration(
-    std::chrono::nanoseconds nanoseconds);
+  explicit Duration(std::chrono::nanoseconds nanoseconds);
 
-  RCLCPP_PUBLIC
-  Duration(
-    const builtin_interfaces::msg::Duration & duration_msg);
+  // This constructor matches any std::chrono value other than nanoseconds
+  // intentionally not using explicit to create a conversion constructor
+  template<class Rep, class Period>
+  // cppcheck-suppress noExplicitConstructor
+  Duration(const std::chrono::duration<Rep, Period> & duration)  // NOLINT(runtime/explicit)
+  : Duration(std::chrono::duration_cast<std::chrono::nanoseconds>(duration))
+  {}
+
+  // cppcheck-suppress noExplicitConstructor
+  Duration(const builtin_interfaces::msg::Duration & duration_msg);  // NOLINT(runtime/explicit)
 
-  RCLCPP_PUBLIC
   explicit Duration(const rcl_duration_t & duration);
 
-  RCLCPP_PUBLIC
   Duration(const Duration & rhs);
 
-  RCLCPP_PUBLIC
-  virtual ~Duration();
+  virtual ~Duration() = default;
 
-  RCLCPP_PUBLIC
   operator builtin_interfaces::msg::Duration() const;
 
-  RCLCPP_PUBLIC
+  // cppcheck-suppress operatorEq // this is a false positive from cppcheck
   Duration &
   operator=(const Duration & rhs);
 
-  RCLCPP_PUBLIC
   Duration &
   operator=(const builtin_interfaces::msg::Duration & Duration_msg);
 
-  RCLCPP_PUBLIC
   bool
   operator==(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   bool
   operator<(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   bool
   operator<=(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   bool
   operator>=(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   bool
   operator>(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   Duration
   operator+(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
   Duration
   operator-(const rclcpp::Duration & rhs) const;
 
-  RCLCPP_PUBLIC
-  static Duration
+  static
+  Duration
   max();
 
-  RCLCPP_PUBLIC
   Duration
   operator*(double scale) const;
 
-  RCLCPP_PUBLIC
   rcl_duration_value_t
   nanoseconds() const;
 
   /// \return the duration in seconds as a floating point number.
   /// \warning Depending on sizeof(double) there could be significant precision loss.
   /// When an exact time is required use nanoseconds() instead.
-  RCLCPP_PUBLIC
   double
   seconds() const;
 
+  // Create a duration object from a floating point number representing seconds
+  static Duration
+  from_seconds(double seconds);
+
+  template<class DurationT>
+  DurationT
+  to_chrono() const
+  {
+    return std::chrono::duration_cast<DurationT>(std::chrono::nanoseconds(this->nanoseconds()));
+  }
+
+  rmw_time_t
+  to_rmw_time() const;
+
 private:
   rcl_duration_t rcl_duration_;
 };

rclcpp/include/rclcpp/exceptions.hpp

@@ -15,188 +15,6 @@
 #ifndef RCLCPP__EXCEPTIONS_HPP_
 #define RCLCPP__EXCEPTIONS_HPP_
 
-#include <stdexcept>
-#include <string>
-
-#include "rcl/error_handling.h"
-#include "rcl/types.h"
-#include "rclcpp/visibility_control.hpp"
-
-namespace rclcpp
-{
-namespace exceptions
-{
-
-/// Thrown when a method is trying to use a node, but it is invalid.
-class InvalidNodeError : public std::runtime_error
-{
-public:
-  InvalidNodeError()
-  : std::runtime_error("node is invalid") {}
-};
-
-/// Thrown when a any kind of name (node, namespace, topic, etc.) is invalid.
-class NameValidationError : public std::invalid_argument
-{
-public:
-  NameValidationError(
-    const char * name_type_,
-    const char * name_,
-    const char * error_msg_,
-    size_t invalid_index_)
-  : std::invalid_argument(format_error(name_type_, name_, error_msg_, invalid_index_)),
-    name_type(name_type_), name(name_), error_msg(error_msg_), invalid_index(invalid_index_)
-  {}
-
-  static std::string
-  format_error(
-    const char * name_type,
-    const char * name,
-    const char * error_msg,
-    size_t invalid_index);
-
-  const std::string name_type;
-  const std::string name;
-  const std::string error_msg;
-  const size_t invalid_index;
-};
-
-/// Thrown when a node name is invalid.
-class InvalidNodeNameError : public NameValidationError
-{
-public:
-  InvalidNodeNameError(const char * node_name, const char * error_msg, size_t invalid_index)
-  : NameValidationError("node name", node_name, error_msg, invalid_index)
-  {}
-};
-
-/// Thrown when a node namespace is invalid.
-class InvalidNamespaceError : public NameValidationError
-{
-public:
-  InvalidNamespaceError(const char * namespace_, const char * error_msg, size_t invalid_index)
-  : NameValidationError("namespace", namespace_, error_msg, invalid_index)
-  {}
-};
-
-/// Thrown when a topic name is invalid.
-class InvalidTopicNameError : public NameValidationError
-{
-public:
-  InvalidTopicNameError(const char * namespace_, const char * error_msg, size_t invalid_index)
-  : NameValidationError("topic name", namespace_, error_msg, invalid_index)
-  {}
-};
-
-/// Thrown when a service name is invalid.
-class InvalidServiceNameError : public NameValidationError
-{
-public:
-  InvalidServiceNameError(const char * namespace_, const char * error_msg, size_t invalid_index)
-  : NameValidationError("service name", namespace_, error_msg, invalid_index)
-  {}
-};
-
-/// Throw a C++ std::exception which was created based on an rcl error.
-/**
- * Passing nullptr for reset_error is safe and will avoid calling any function
- * to reset the error.
- *
- * \param ret the return code for the current error state
- * \param prefix string to prefix to the error if applicable (not all errors have custom messages)
- * \param error_state error state to create exception from, if nullptr rcl_get_error_state is used
- * \param reset_error function to be called before throwing which whill clear the error state
- * \throws std::invalid_argument if ret is RCL_RET_OK
- * \throws std::runtime_error if the rcl_get_error_state returns 0
- * \throws RCLErrorBase some child class exception based on ret
- */
-RCLCPP_PUBLIC
-void
-throw_from_rcl_error(
-  rcl_ret_t ret,
-  const std::string & prefix = "",
-  const rcl_error_state_t * error_state = nullptr,
-  void (* reset_error)() = rcl_reset_error);
-
-class RCLErrorBase
-{
-public:
-  RCLCPP_PUBLIC
-  RCLErrorBase(rcl_ret_t ret, const rcl_error_state_t * error_state);
-  virtual ~RCLErrorBase() {}
-
-  rcl_ret_t ret;
-  std::string message;
-  std::string file;
-  size_t line;
-  std::string formatted_message;
-};
-
-/// Created when the return code does not match one of the other specialized exceptions.
-class RCLError : public RCLErrorBase, public std::runtime_error
-{
-public:
-  RCLCPP_PUBLIC
-  RCLError(rcl_ret_t ret, const rcl_error_state_t * error_state, const std::string & prefix);
-  RCLCPP_PUBLIC
-  RCLError(const RCLErrorBase & base_exc, const std::string & prefix);
-};
-
-/// Created when the ret is RCL_RET_BAD_ALLOC.
-class RCLBadAlloc : public RCLErrorBase, public std::bad_alloc
-{
-public:
-  RCLCPP_PUBLIC
-  RCLBadAlloc(rcl_ret_t ret, const rcl_error_state_t * error_state);
-  RCLCPP_PUBLIC
-  explicit RCLBadAlloc(const RCLErrorBase & base_exc);
-};
-
-/// Created when the ret is RCL_RET_INVALID_ARGUMENT.
-class RCLInvalidArgument : public RCLErrorBase, public std::invalid_argument
-{
-public:
-  RCLCPP_PUBLIC
-  RCLInvalidArgument(
-    rcl_ret_t ret,
-    const rcl_error_state_t * error_state,
-    const std::string & prefix);
-  RCLCPP_PUBLIC
-  RCLInvalidArgument(const RCLErrorBase & base_exc, const std::string & prefix);
-};
-
-/// Thrown when an invalid rclcpp::Event object or SharedPtr is encountered.
-class InvalidEventError : public std::runtime_error
-{
-public:
-  InvalidEventError()
-  : std::runtime_error("event is invalid") {}
-};
-
-/// Thrown when an unregistered rclcpp::Event is encountered where a registered one was expected.
-class EventNotRegisteredError : public std::runtime_error
-{
-public:
-  EventNotRegisteredError()
-  : std::runtime_error("event already registered") {}
-};
-
-/// Thrown if passed parameters are inconsistent or invalid
-class InvalidParametersException : public std::runtime_error
-{
-public:
-  // Inherit constructors from runtime_error;
-  using std::runtime_error::runtime_error;
-};
-
-/// Throwing if passed parameter value is invalid.
-class InvalidParameterValueException : public std::runtime_error
-{
-  // Inherit constructors from runtime_error;
-  using std::runtime_error::runtime_error;
-};
-
-}  // namespace exceptions
-}  // namespace rclcpp
+#include "rclcpp/exceptions/exceptions.hpp"
 
 #endif  // RCLCPP__EXCEPTIONS_HPP_

rclcpp/include/rclcpp/exceptions/exceptions.hpp

@@ -0,0 +1,279 @@
+// Copyright 2016 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXCEPTIONS__EXCEPTIONS_HPP_
+#define RCLCPP__EXCEPTIONS__EXCEPTIONS_HPP_
+
+#include <stdexcept>
+#include <string>
+#include <vector>
+
+#include "rcl/error_handling.h"
+#include "rcl/types.h"
+#include "rclcpp/visibility_control.hpp"
+
+#include "rcpputils/join.hpp"
+
+namespace rclcpp
+{
+namespace exceptions
+{
+
+/// Thrown when a method is trying to use a node, but it is invalid.
+class InvalidNodeError : public std::runtime_error
+{
+public:
+  InvalidNodeError()
+  : std::runtime_error("node is invalid") {}
+};
+
+/// Thrown when a any kind of name (node, namespace, topic, etc.) is invalid.
+class NameValidationError : public std::invalid_argument
+{
+public:
+  NameValidationError(
+    const char * name_type_,
+    const char * name_,
+    const char * error_msg_,
+    size_t invalid_index_)
+  : std::invalid_argument(format_error(name_type_, name_, error_msg_, invalid_index_)),
+    name_type(name_type_), name(name_), error_msg(error_msg_), invalid_index(invalid_index_)
+  {}
+
+  static std::string
+  format_error(
+    const char * name_type,
+    const char * name,
+    const char * error_msg,
+    size_t invalid_index);
+
+  const std::string name_type;
+  const std::string name;
+  const std::string error_msg;
+  const size_t invalid_index;
+};
+
+/// Thrown when a node name is invalid.
+class InvalidNodeNameError : public NameValidationError
+{
+public:
+  InvalidNodeNameError(const char * node_name, const char * error_msg, size_t invalid_index)
+  : NameValidationError("node name", node_name, error_msg, invalid_index)
+  {}
+};
+
+/// Thrown when a node namespace is invalid.
+class InvalidNamespaceError : public NameValidationError
+{
+public:
+  InvalidNamespaceError(const char * namespace_, const char * error_msg, size_t invalid_index)
+  : NameValidationError("namespace", namespace_, error_msg, invalid_index)
+  {}
+};
+
+/// Thrown when a topic name is invalid.
+class InvalidTopicNameError : public NameValidationError
+{
+public:
+  InvalidTopicNameError(const char * namespace_, const char * error_msg, size_t invalid_index)
+  : NameValidationError("topic name", namespace_, error_msg, invalid_index)
+  {}
+};
+
+/// Thrown when a service name is invalid.
+class InvalidServiceNameError : public NameValidationError
+{
+public:
+  InvalidServiceNameError(const char * namespace_, const char * error_msg, size_t invalid_index)
+  : NameValidationError("service name", namespace_, error_msg, invalid_index)
+  {}
+};
+
+/// Throw a C++ std::exception which was created based on an rcl error.
+/**
+ * Passing nullptr for reset_error is safe and will avoid calling any function
+ * to reset the error.
+ *
+ * \param ret the return code for the current error state
+ * \param prefix string to prefix to the error if applicable (not all errors have custom messages)
+ * \param error_state error state to create exception from, if nullptr rcl_get_error_state is used
+ * \param reset_error function to be called before throwing which whill clear the error state
+ * \throws std::invalid_argument if ret is RCL_RET_OK
+ * \throws std::runtime_error if the rcl_get_error_state returns 0
+ * \throws RCLErrorBase some child class exception based on ret
+ */
+/* *INDENT-OFF* */  // Uncrustify cannot yet understand [[noreturn]] properly
+RCLCPP_PUBLIC
+void
+throw_from_rcl_error [[noreturn]] (
+  rcl_ret_t ret,
+  const std::string & prefix = "",
+  const rcl_error_state_t * error_state = nullptr,
+  void (* reset_error)() = rcl_reset_error);
+/* *INDENT-ON* */
+
+class RCLErrorBase
+{
+public:
+  RCLCPP_PUBLIC
+  RCLErrorBase(rcl_ret_t ret, const rcl_error_state_t * error_state);
+  virtual ~RCLErrorBase() {}
+
+  rcl_ret_t ret;
+  std::string message;
+  std::string file;
+  size_t line;
+  std::string formatted_message;
+};
+
+/// Created when the return code does not match one of the other specialized exceptions.
+class RCLError : public RCLErrorBase, public std::runtime_error
+{
+public:
+  RCLCPP_PUBLIC
+  RCLError(rcl_ret_t ret, const rcl_error_state_t * error_state, const std::string & prefix);
+  RCLCPP_PUBLIC
+  RCLError(const RCLErrorBase & base_exc, const std::string & prefix);
+};
+
+/// Created when the ret is RCL_RET_BAD_ALLOC.
+class RCLBadAlloc : public RCLErrorBase, public std::bad_alloc
+{
+public:
+  RCLCPP_PUBLIC
+  RCLBadAlloc(rcl_ret_t ret, const rcl_error_state_t * error_state);
+  RCLCPP_PUBLIC
+  explicit RCLBadAlloc(const RCLErrorBase & base_exc);
+};
+
+/// Created when the ret is RCL_RET_INVALID_ARGUMENT.
+class RCLInvalidArgument : public RCLErrorBase, public std::invalid_argument
+{
+public:
+  RCLCPP_PUBLIC
+  RCLInvalidArgument(
+    rcl_ret_t ret,
+    const rcl_error_state_t * error_state,
+    const std::string & prefix);
+  RCLCPP_PUBLIC
+  RCLInvalidArgument(const RCLErrorBase & base_exc, const std::string & prefix);
+};
+
+/// Created when the ret is RCL_RET_INVALID_ROS_ARGS.
+class RCLInvalidROSArgsError : public RCLErrorBase, public std::runtime_error
+{
+public:
+  RCLCPP_PUBLIC
+  RCLInvalidROSArgsError(
+    rcl_ret_t ret, const rcl_error_state_t * error_state, const std::string & prefix);
+  RCLCPP_PUBLIC
+  RCLInvalidROSArgsError(const RCLErrorBase & base_exc, const std::string & prefix);
+};
+
+/// Thrown when unparsed ROS specific arguments are found.
+class UnknownROSArgsError : public std::runtime_error
+{
+public:
+  explicit UnknownROSArgsError(std::vector<std::string> && unknown_ros_args_in)
+  : std::runtime_error(
+      "found unknown ROS arguments: '" + rcpputils::join(unknown_ros_args_in, "', '") + "'"),
+    unknown_ros_args(unknown_ros_args_in)
+  {
+  }
+
+  const std::vector<std::string> unknown_ros_args;
+};
+
+/// Thrown when an invalid rclcpp::Event object or SharedPtr is encountered.
+class InvalidEventError : public std::runtime_error
+{
+public:
+  InvalidEventError()
+  : std::runtime_error("event is invalid") {}
+};
+
+/// Thrown when an unregistered rclcpp::Event is encountered where a registered one was expected.
+class EventNotRegisteredError : public std::runtime_error
+{
+public:
+  EventNotRegisteredError()
+  : std::runtime_error("event already registered") {}
+};
+
+/// Thrown if passed parameters are inconsistent or invalid
+class InvalidParametersException : public std::runtime_error
+{
+public:
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+/// Thrown if passed parameter value is invalid.
+class InvalidParameterValueException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+/// Thrown if requested parameter type is invalid.
+/**
+ * Essentially the same as rclcpp::ParameterTypeException, but with parameter
+ * name in the error message.
+ */
+class InvalidParameterTypeException : public std::runtime_error
+{
+public:
+  /// Construct an instance.
+  /**
+   * \param[in] name the name of the parameter.
+   * \param[in] message custom exception message.
+   */
+  RCLCPP_PUBLIC
+  InvalidParameterTypeException(const std::string & name, const std::string message)
+  : std::runtime_error("parameter '" + name + "' has invalid type: " + message)
+  {}
+};
+
+/// Thrown if parameter is already declared.
+class ParameterAlreadyDeclaredException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+/// Thrown if parameter is not declared, e.g. either set or get was called without first declaring.
+class ParameterNotDeclaredException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+/// Thrown if parameter is immutable and therefore cannot be undeclared.
+class ParameterImmutableException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+/// Thrown if parameter is modified while in a set callback.
+class ParameterModifiedInCallbackException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
+}  // namespace exceptions
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXCEPTIONS__EXCEPTIONS_HPP_

rclcpp/include/rclcpp/executor.hpp

@@ -22,134 +22,248 @@
 #include <iostream>
 #include <list>
 #include <memory>
+#include <mutex>
 #include <string>
 #include <vector>
 
 #include "rcl/guard_condition.h"
 #include "rcl/wait.h"
 
-#include "rclcpp/contexts/default_context.hpp"
+#include "rclcpp/callback_group.hpp"
+#include "rclcpp/executor_options.hpp"
+#include "rclcpp/executor_policies/timer_favoring_priority_queue.hpp"
+#include "rclcpp/future_return_code.hpp"
+#include "rclcpp/guard_condition.hpp"
 #include "rclcpp/memory_strategies.hpp"
 #include "rclcpp/memory_strategy.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "rclcpp/wait_set.hpp"
 
 namespace rclcpp
 {
 
-// Forward declaration is used in convenience method signature.
-class Node;
-
-namespace executor
-{
-
-/// Return codes to be used with spin_until_future_complete.
-/**
- * SUCCESS: The future is complete and can be accessed with "get" without blocking.
- * INTERRUPTED: The future is not complete, spinning was interrupted by Ctrl-C or another error.
- * TIMEOUT: Spinning timed out.
- */
-enum class FutureReturnCode {SUCCESS, INTERRUPTED, TIMEOUT};
-
-RCLCPP_PUBLIC
-std::ostream &
-operator<<(std::ostream & os, const FutureReturnCode & future_return_code);
-
-RCLCPP_PUBLIC
-std::string
-to_string(const FutureReturnCode & future_return_code);
-
-///
-/**
- * Options to be passed to the executor constructor.
- */
-struct ExecutorArgs
-{
-  ExecutorArgs()
-  : memory_strategy(memory_strategies::create_default_strategy()),
-    context(rclcpp::contexts::default_context::get_global_default_context()),
-    max_conditions(0)
-  {}
-
-  memory_strategy::MemoryStrategy::SharedPtr memory_strategy;
-  std::shared_ptr<rclcpp::Context> context;
-  size_t max_conditions;
-};
-
-static inline ExecutorArgs create_default_executor_arguments()
-{
-  return ExecutorArgs();
-}
-
-/// Coordinate the order and timing of available communication tasks.
-/**
- * Executor provides spin functions (including spin_node_once and spin_some).
- * It coordinates the nodes and callback groups by looking for available work and completing it,
- * based on the threading or concurrency scheme provided by the subclass implementation.
- * An example of available work is executing a subscription callback, or a timer callback.
- * The executor structure allows for a decoupling of the communication graph and the execution
- * model.
- * See SingleThreadedExecutor and MultiThreadedExecutor for examples of execution paradigms.
- */
-class Executor
+/// Base class for Executor providing the common interface for adding items, spinning, etc.
+class ExecutorBase
 {
 public:
-  RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(Executor)
+  RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(ExecutorBase)
 
   /// Default constructor.
-  // \param[in] ms The memory strategy to be used with this executor.
+  /**
+   * \param[in] options Options for the executor.
+   */
   RCLCPP_PUBLIC
-  explicit Executor(const ExecutorArgs & args = ExecutorArgs());
+  explicit ExecutorBase(const ExecutorOptions & options = ExecutorOptions());
 
   /// Default destructor.
   RCLCPP_PUBLIC
-  virtual ~Executor();
+  virtual ~ExecutorBase();
 
-  /// Do work periodically as it becomes available to us. Blocking call, may block indefinitely.
-  // It is up to the implementation of Executor to implement spin.
-  virtual void
+  /// Execution loop which waits for work, executes work, and repeats until canceled.
+  /**
+   * This will block, continuing to wait for work and then execute it, until
+   * canceled, either by the cancel() method or by the associated context being
+   * shutdown, either explicitly or due to a SIGINT (perhaps due to ctrl-c).
+   */
+  virtual
+  void
   spin() = 0;
 
-  /// Add a node to the executor.
+  /// Add all of a node's callback groups to the executor.
   /**
-   * An executor can have zero or more nodes which provide work during `spin` functions.
-   * \param[in] node_ptr Shared pointer to the node to be added.
-   * \param[in] notify True to trigger the interrupt guard condition during this function. If
-   * the executor is blocked at the rmw layer while waiting for work and it is notified that a new
-   * node was added, it will wake up.
+   * Add all of the callback groups of a node to this executor.
+   *
+   * If any callback groups are associated with another executor, this method
+   * will throw a std::runtime_error.
+   *
+   * It will also trigger the interrupt guard condition which will cause the
+   * executor to wake up and consider the changes, then go back to waiting.
+   * Unless the notify parameter is passed false, in which case it will not
+   * interrupt the executor, and the changes may not be considered immediately.
+   *
+   * \param[in] node_ptr Shared pointer to the node which will have callback groups added.
+   * \param[in] notify If true, notfiy the executor of changes, otherwise do not.
+   * \throws std::runtime_error if any callback groups are associated with another executor.
+   */
+  template<class NodeT>
+  void
+  add_node(const std::shared_ptr<NodeT> & node_ptr, bool notify = true)
+  {
+    this->add_node(
+      node_ptr->get_node_base_interface(),
+      notify,
+      false  // raise on encountering already associated callback groups
+    );
+  }
+
+  /// Overload that takes the NodeBaseInterface directly.
+  template<class NodeT>
+  void
+  add_node(
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+    bool notify = true)
+  {
+    this->add_node(
+      node_ptr,
+      notify,
+      false  // raise on encountering already associated callback groups
+    );
+  }
+
+  /// Add all unassociated callback groups of the given node to this executor.
+  /**
+   * Same as add_node(), but instead of throwing if a callback group is already
+   * associated with another exector (already added to it) it will just ignore
+   * it rather than throwing.
+   *
+   * \param[in] node_ptr Shared pointer to the node which will have callback groups added.
+   * \param[in] notify If true, notfiy the executor of changes, otherwise do not.
+   */
+  template<class NodeT>
+  void
+  add_unassociated_callback_groups_from_node(
+    const std::shared_ptr<NodeT> & node_ptr,
+    bool notify = true)
+  {
+    this->add_node(
+      node_ptr->get_node_base_interface(),
+      notify,
+      true  // ignore already associated callback groups
+    );
+  }
+
+  /// Overload that takes the NodeBaseInterface directly.
+  template<class NodeT>
+  void
+  add_unassociated_callback_groups_from_node(
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+    bool notify = true)
+  {
+    this->add_node(
+      node_ptr,
+      notify,
+      true  // ignore already associated callback groups
+    );
+  }
+
+  /// Remove all of a node's callback groups from the executor.
+  /**
+   * Remove all of the callback groups of a node from this executor.
+   *
+   * It will also trigger the interrupt guard condition which will cause the
+   * executor to wake up and consider the changes, then go back to waiting.
+   * Unless the notify parameter is passed false, in which case it will not
+   * interrupt the executor, and the changes may not be considered immediately.
+   *
+   * \param[in] node Node which will have callback groups removed.
+   * \param[in] notify If true, notfiy the executor of changes, otherwise do not.
+   */
+  template<class NodeT>
+  void
+  remove_node(const NodeT & node, bool notify = true)
+  {
+    this->remove_node(*node.get_node_base_interface(), notify);
+  }
+
+  /// Overload that takes a shared pointer to the node.
+  /**
+   * This is kept for backwards compatibility from when executors shared
+   * ownership of Nodes.
+   */
+  template<class NodeT>
+  void
+  remove_node(const std::shared_ptr<NodeT> & node_ptr, bool notify = true)
+  {
+    this->remove_node(*node_ptr->get_node_base_interface(), notify);
+  }
+
+  /// Placeholder used to indicate that a method overload should not notify the executor.
+  struct DoNotNotify {};
+
+  /// Add a callback group to this executor.
+  /**
+   * If the given callback group is already associated with another executor,
+   * this method will throw a std::runtime_error.
+   *
+   * This overload of add_callback_group() will notify the executor so it will
+   * wake up if waiting and consider the changes.
+   *
+   * Weak ownership of the callback group is kept by the executor all of the
+   * time, but while waiting the weak ownership is periodically elevated to
+   * shared ownership.
+   * Therefore, if you let the callback group shared pointer go out of scope
+   * then it will stay in scope until this executor is done using it, at which
+   * point the callback group will be destructed and automatically removed from
+   * this executor in the next pass.
+   *
+   * \param[in] callback_group_ptr The callback group to be added.
+   * \throws std::runtime_error if the callback group is associated with another
+   *   executor already.
+   * \throws std::invalid_argument if the callback group pointer is nullptr.
    */
   RCLCPP_PUBLIC
-  virtual void
-  add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify = true);
+  virtual
+  void
+  add_callback_group(rclcpp::CallbackGroup::SharedPtr callback_group_ptr) = 0;
 
-  /// Convenience function which takes Node and forwards NodeBaseInterface.
-  RCLCPP_PUBLIC
-  virtual void
-  add_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true);
-
-  /// Remove a node from the executor.
+  /// Add a callback group to this executor without notifying the executor.
   /**
-   * \param[in] node_ptr Shared pointer to the node to remove.
-   * \param[in] notify True to trigger the interrupt guard condition and wake up the executor.
-   * This is useful if the last node was removed from the executor while the executor was blocked
-   * waiting for work in another thread, because otherwise the executor would never be notified.
+   * The same as the other overload of add_callback_group(), except it does not
+   * notify the executor, so it will not wake up and these changes may not be
+   * considered immediately.
+   *
+   * Note, a bool with a default value would be preferable for controlling the
+   * notify behavior, and we're using it in the add/remove node above, but
+   * in order to keep this function virtual, and to avoid using default values
+   * in conjunction with virtual methods, we use an overload instead, in the
+   * spirit of std::nothrow_t, e.g.:
+   *   https://en.cppreference.com/w/cpp/memory/new/nothrow
    */
   RCLCPP_PUBLIC
-  virtual void
-  remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify = true);
+  virtual
+  void
+  add_callback_group(rclcpp::CallbackGroup::SharedPtr callback_group_ptr, DoNotNotify) = 0;
 
-  /// Convenience function which takes Node and forwards NodeBaseInterface.
+  /// Remove a callback group from this executor.
+  /**
+   * If the given callback group is not associated with this executor, this
+   * method will throw a std::runtime_error.
+   *
+   * This overload of add_callback_group() will notify the executor so it will
+   * wake up if waiting and consider the changes.
+   *
+   * \param[in] callback_group The callback group to be removed.
+   * \throws std::runtime_error if the callback group is not associated with
+   *   this executor.
+   * \throws std::invalid_argument if the callback group pointer is nullptr.
+   */
   RCLCPP_PUBLIC
-  virtual void
-  remove_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true);
+  virtual
+  void
+  remove_callback_group(const rclcpp::CallbackGroup & callback_group) = 0;
+
+  /// Remove a callback group from this executor without notifying the executor.
+  /**
+   * The same as the other overload of remove_callback_group(), except it does not
+   * notify the executor, so it will not wake up and these changes may not be
+   * considered immediately.
+   *
+   * See add_callback_group() for a note about the use of DoNotNotify.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  void
+  remove_callback_group(const rclcpp::CallbackGroup & callback_group, DoNotNotify) = 0;
 
   /// Add a node to executor, execute the next available unit of work, and remove the node.
   /**
    * \param[in] node Shared pointer to the node to add.
-   * \param[in] timeout How long to wait for work to become available. Negative values cause
-   * spin_node_once to block indefinitely (the default behavior). A timeout of 0 causes this
-   * function to be non-blocking.
+   * \param[in] timeout How long to wait for work to become available.
+   *   Negative values cause spin_node_once to block indefinitely (the default
+   *   behavior).
+   *   A timeout of 0 causes this function to be non-blocking.
    */
   template<typename RepT = int64_t, typename T = std::milli>
   void
@@ -164,7 +278,7 @@ public:
   }
 
   /// Convenience function which takes Node and forwards NodeBaseInterface.
-  template<typename NodeT = rclcpp::Node, typename RepT = int64_t, typename T = std::milli>
+  template<typename NodeT, typename RepT = int64_t, typename T = std::milli>
   void
   spin_node_once(
     std::shared_ptr<NodeT> node,
@@ -178,16 +292,14 @@ public:
 
   /// Add a node, complete all immediately available work, and remove the node.
   /**
-   * \param[in] node Shared pointer to the node to add.
+   * \param[in] node Shared pointer to the node to spin some.
    */
-  RCLCPP_PUBLIC
+  template<class NodeT>
   void
-  spin_node_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node);
-
-  /// Convenience function which takes Node and forwards NodeBaseInterface.
-  RCLCPP_PUBLIC
-  void
-  spin_node_some(std::shared_ptr<rclcpp::Node> node);
+  spin_node_some(const std::shared_ptr<NodeT> & node)
+  {
+    this->spin_node_some(node->get_node_base_interface());
+  }
 
   /// Complete all available queued work without blocking.
   /**
@@ -201,17 +313,19 @@ public:
    * been exceeded.
    */
   RCLCPP_PUBLIC
-  virtual void
-  spin_some(std::chrono::nanoseconds max_duration = std::chrono::nanoseconds(0));
+  virtual
+  void
+  spin_some(std::chrono::nanoseconds max_duration = std::chrono::nanoseconds(0)) = 0;
 
   RCLCPP_PUBLIC
-  virtual void
-  spin_once(std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1));
+  virtual
+  void
+  spin_once(std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1)) = 0;
 
   /// Spin (blocking) until the future is complete, it times out waiting, or rclcpp is interrupted.
   /**
-   * \param[in] future The future to wait on. If SUCCESS, the future is safe to access after this
-   *   function.
+   * \param[in] future The future to wait on. If this function returns SUCCESS, the future can be
+   *   accessed without blocking (though it may still throw an exception).
    * \param[in] timeout Optional timeout parameter, which gets passed to Executor::spin_node_once.
    *   `-1` is block forever, `0` is non-blocking.
    *   If the time spent inside the blocking loop exceeds this timeout, return a TIMEOUT return
@@ -221,7 +335,7 @@ public:
   template<typename ResponseT, typename TimeRepT = int64_t, typename TimeT = std::milli>
   FutureReturnCode
   spin_until_future_complete(
-    std::shared_future<ResponseT> & future,
+    const std::shared_future<ResponseT> & future,
     std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
   {
     // TODO(wjwwood): does not work recursively; can't call spin_node_until_future_complete
@@ -268,56 +382,79 @@ public:
   }
 
   /// Cancel any running spin* function, causing it to return.
-  /* This function can be called asynchonously from any thread. */
-  RCLCPP_PUBLIC
-  void
-  cancel();
-
-  /// Support dynamic switching of the memory strategy.
   /**
-   * Switching the memory strategy while the executor is spinning in another threading could have
-   * unintended consequences.
-   * \param[in] memory_strategy Shared pointer to the memory strategy to set.
+   * This function can be called asynchronously from any thread.
    */
   RCLCPP_PUBLIC
+  virtual
   void
-  set_memory_strategy(memory_strategy::MemoryStrategy::SharedPtr memory_strategy);
+  cancel() = 0;
 
 protected:
+  /// Implementation of add_node().
+  /**
+   * \param[in] node_ptr The node which will have its callback groups added.
+   * \param[in] notify If true, the executor is interrupted to consider the
+   *   changes, otherwise it is not interrupted.
+   * \param[in] ignore_associated_callback_groups If true, then when a callback
+   *   group which is already been added to another executor is encountered
+   *   it will be ignored, if false then std::runtime_error is thrown instead.
+   * \throws std::runtime_error if ignore_associated_callback_groups is false
+   *   and a callback group which is already associated with another executor
+   *   is encountered.
+   * \throws std::invalid_argument if node_ptr is nullptr.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  void
+  add_node(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+    bool notify,
+    bool ignore_associated_callback_groups) = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  void
+  remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify) = 0;
+
   RCLCPP_PUBLIC
   void
   spin_node_once_nanoseconds(
     rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
     std::chrono::nanoseconds timeout);
 
+  RCLCPP_PUBLIC
+  virtual
+  void
+  spin_node_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node);
+
   /// Find the next available executable and do the work associated with it.
   /** \param[in] any_exec Union structure that can hold any executable type (timer, subscription,
    * service, client).
    */
   RCLCPP_PUBLIC
   void
-  execute_any_executable(AnyExecutable & any_exec);
+  execute_any_executable(rclcpp::AnyExecutable & any_exec);
 
   RCLCPP_PUBLIC
-  static void
+  static
+  void
   execute_subscription(
     rclcpp::SubscriptionBase::SharedPtr subscription);
 
   RCLCPP_PUBLIC
-  static void
-  execute_intra_process_subscription(
-    rclcpp::SubscriptionBase::SharedPtr subscription);
-
-  RCLCPP_PUBLIC
-  static void
+  static
+  void
   execute_timer(rclcpp::TimerBase::SharedPtr timer);
 
   RCLCPP_PUBLIC
-  static void
+  static
+  void
   execute_service(rclcpp::ServiceBase::SharedPtr service);
 
   RCLCPP_PUBLIC
-  static void
+  static
+  void
   execute_client(rclcpp::ClientBase::SharedPtr client);
 
   RCLCPP_PUBLIC
@@ -325,48 +462,103 @@ protected:
   wait_for_work(std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1));
 
   RCLCPP_PUBLIC
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr
-  get_node_by_group(rclcpp::callback_group::CallbackGroup::SharedPtr group);
-
-  RCLCPP_PUBLIC
-  rclcpp::callback_group::CallbackGroup::SharedPtr
+  rclcpp::CallbackGroup::SharedPtr
   get_group_by_timer(rclcpp::TimerBase::SharedPtr timer);
 
-  RCLCPP_PUBLIC
-  void
-  get_next_timer(AnyExecutable & any_exec);
-
   RCLCPP_PUBLIC
   bool
-  get_next_ready_executable(AnyExecutable & any_executable);
+  get_next_ready_executable(rclcpp::AnyExecutable & any_executable);
 
   RCLCPP_PUBLIC
   bool
   get_next_executable(
-    AnyExecutable & any_executable,
+    rclcpp::AnyExecutable & any_executable,
     std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1));
 
+  RCLCPP_DISABLE_COPY(ExecutorBase)
+
   /// Spinning state, used to prevent multi threaded calls to spin and to cancel blocking spins.
   std::atomic_bool spinning;
 
   /// Guard condition for signaling the rmw layer to wake up for special events.
-  rcl_guard_condition_t interrupt_guard_condition_ = rcl_get_zero_initialized_guard_condition();
+  rclcpp::GuardCondition interrupt_guard_condition_;
+  // rcl_guard_condition_t interrupt_guard_condition_ = rcl_get_zero_initialized_guard_condition();
 
-  /// Wait set for managing entities that the rmw layer waits on.
-  rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
+  // /// Wait set for managing entities that the rmw layer waits on.
+  // rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
 
-  /// The memory strategy: an interface for handling user-defined memory allocation strategies.
-  memory_strategy::MemoryStrategy::SharedPtr memory_strategy_;
+  // // Mutex to protect the subsequent memory_strategy_.
+  // std::mutex memory_strategy_mutex_;
+
+  // /// The memory strategy: an interface for handling user-defined memory allocation strategies.
+  // memory_strategy::MemoryStrategy::SharedPtr memory_strategy_;
 
   /// The context associated with this executor.
-  std::shared_ptr<rclcpp::Context> context_;
+  rclcpp::Context::SharedPtr context_;
 
-private:
-  RCLCPP_DISABLE_COPY(Executor)
+  // std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
+  // std::list<const rcl_guard_condition_t *> guard_conditions_;
+  std::vector<rclcpp::CallbackGroup::WeakPtr> weak_guard_conditions_;
 
-  std::vector<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
 };
 
+/// Template class which serves as the foundation of actual executors.
+/**
+ * This class combines the wait set, scheduling policy, and the ExecutorBase
+ * class, and implements all of the pure virtual functions of ExecutorBase
+ * making it a concrete class.
+ */
+template<class WaitSetT, class SchedulingPolicy>
+class ExecutorTemplate : public ExecutorBase, public SchedulingPolicy
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(ExecutorTemplate)
+
+  /// Default constructor.
+  /**
+   * \param[in] options Options for the executor.
+   */
+  explicit ExecutorTemplate(const ExecutorOptions & options = ExecutorOptions())
+  : ExecutorBase(options), SchedulingPolicy(options), WaitSetT(options.context)
+  {}
+
+  /// Default virtual destructor.
+  RCLCPP_PUBLIC
+  virtual
+  ~ExecutorTemplate() = default;
+
+protected:
+  WaitSetT wait_set_;
+};
+
+/// Executor concept which waits for work and coordinates execution of user callbacks.
+/**
+ * Executor provides spin functions (including spin_node_once and spin_some).
+ * It coordinates the nodes and callback groups by looking for available work
+ * and completing it, based on the threading or concurrency scheme provided by
+ * the subclass implementation.
+ * An example of available work is executing a subscription callback, or a
+ * timer callback.
+ * The executor structure allows for a decoupling of the communication graph
+ * and the execution model.
+ * See SingleThreadedExecutor and MultiThreadedExecutor for examples of
+ * different execution paradigms.
+ *
+ * By default this alias provides a foundation based on specific wait set type
+ * and a scheduling policy.
+ * The wait set is expected to be dynamic, i.e. items can be added or removed
+ * after creation, and thread-safe, i.e. items can be added or removed while
+ * also waiting concurrently.
+ */
+using Executor = ExecutorTemplate<
+  rclcpp::ThreadSafeWaitSet,
+  rclcpp::executor_policies::TimerFavoringPriorityQueue>;
+
+namespace executor
+{
+
+using Executor [[deprecated("use rclcpp::Executor instead")]] = Executor;
+
 }  // namespace executor
 }  // namespace rclcpp
 

rclcpp/include/rclcpp/executor_options.hpp

@@ -0,0 +1,49 @@
+// Copyright 2014 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXECUTOR_OPTIONS_HPP_
+#define RCLCPP__EXECUTOR_OPTIONS_HPP_
+
+#include "rclcpp/context.hpp"
+#include "rclcpp/contexts/default_context.hpp"
+#include "rclcpp/memory_strategies.hpp"
+#include "rclcpp/memory_strategy.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// Options to be passed to the executor constructor.
+struct ExecutorOptions
+{
+  ExecutorOptions()
+  : memory_strategy(rclcpp::memory_strategies::create_default_strategy()),
+    context(rclcpp::contexts::get_global_default_context()),
+    max_conditions(0)
+  {}
+
+  rclcpp::memory_strategy::MemoryStrategy::SharedPtr memory_strategy;
+  rclcpp::Context::SharedPtr context;
+  size_t max_conditions;
+};
+
+namespace executor
+{
+
+using ExecutorArgs [[deprecated("use rclcpp::ExecutorOptions instead")]] = ExecutorOptions;
+
+}  // namespace executor
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXECUTOR_OPTIONS_HPP_

rclcpp/include/rclcpp/executor_policies/scheduling_result.hpp

@@ -0,0 +1,35 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXECUTOR_POLICIES__SCHEDULING_RESULT_HPP_
+#define RCLCPP__EXECUTOR_POLICIES__SCHEDULING_RESULT_HPP_
+
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace executor_policies
+{
+
+/// Represents the directions a SchedulingPolicy can give to an Executor.
+enum RCLCPP_PUBLIC SchedulingResult
+{
+  ContinueExecuting,  //<! Indicates more work should be done before waiting.
+  WaitForWork,  //<! Indicates that the executor should wait on the wait set again.
+};
+
+}  // namespace executor_policies
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXECUTOR_POLICIES__SCHEDULING_RESULT_HPP_

rclcpp/include/rclcpp/executor_policies/timer_favoring_priority_queue.hpp

@@ -0,0 +1,77 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXECUTOR_POLICIES__TIMER_FAVORING_PRIORITY_QUEUE_HPP_
+#define RCLCPP__EXECUTOR_POLICIES__TIMER_FAVORING_PRIORITY_QUEUE_HPP_
+
+#include "rclcpp/any_executable.hpp"
+#include "rclcpp/executor_options.hpp"
+#include "rclcpp/executor_policies/scheduling_result.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rclcpp/wait_result.hpp"
+
+namespace rclcpp
+{
+namespace executor_policies
+{
+
+/// A naive scheduling policy which selects Timers first, then Subscriptions and other items.
+/**
+ * Items are executed in the order they were added, favoring Timers, then
+ * Subscriptions, Service Servers, Service Clients, and finally Waitables.
+ * All Timers are executed before any Subscriptions, and all Subscriptions
+ * before any Service Servers, and so on.
+ *
+ * User guard conditions are not yet supported by the Executor and so all guard
+ * condition are used by the executor itself and are handled before this policy
+ * is consulted.
+ * Therefore, guard conditions are ignored for the purposes of scheduling.
+ *
+ * This is a naive policy, but is the default until a better one is implemented.
+ */
+class TimerFavoringPriorityQueue
+{
+public:
+  explicit TimerFavoringPriorityQueue(const rclcpp::ExecutorOptions &) {}
+
+  /// Select which item should next be executed, and indicate if waiting should resume.
+  /**
+   * Selects which item to be executed next, assign it to the any_executable, or
+   * assigning nullptr if no work should be done right now.
+   *
+   * This method is called by the executor after waiting on a wait set, in
+   * order to determine what to execute next based on the result.
+   *
+   * Additionally, if returning SchedulingResult::ContinueExecuting then the
+   * executor will call this function again without waiting on the wait set, or
+   * if returning SchedulingResult::WaitForWork then the executor will wait on
+   * the wait set again after executing the selected any_executable, or
+   * immediately if any_executable was assigned nullptr.
+   */
+  template<class WaitSetT>
+  rclcpp::executor_policies::SchedulingResult
+  schedule_next_any_executable(
+    const WaitResult<WaitSetT> & wait_result,
+    rclcpp::AnyExecutable & any_executable)
+  {
+    // Explicitly ignore guard conditions.
+    // Check Timers for being ready.
+
+  }
+};
+
+}  // namespace executor_policies
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXECUTOR_POLICIES__TIMER_FAVORING_PRIORITY_QUEUE_HPP_

rclcpp/include/rclcpp/executors.hpp

@@ -20,6 +20,7 @@
 
 #include "rclcpp/executors/multi_threaded_executor.hpp"
 #include "rclcpp/executors/single_threaded_executor.hpp"
+#include "rclcpp/executors/static_single_threaded_executor.hpp"
 #include "rclcpp/node.hpp"
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -66,11 +67,11 @@ using rclcpp::executors::SingleThreadedExecutor;
  * \return The return code, one of `SUCCESS`, `INTERRUPTED`, or `TIMEOUT`.
  */
 template<typename ResponseT, typename TimeRepT = int64_t, typename TimeT = std::milli>
-rclcpp::executor::FutureReturnCode
+rclcpp::FutureReturnCode
 spin_node_until_future_complete(
-  rclcpp::executor::Executor & executor,
+  rclcpp::Executor & executor,
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
-  std::shared_future<ResponseT> & future,
+  const std::shared_future<ResponseT> & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
   // TODO(wjwwood): does not work recursively; can't call spin_node_until_future_complete
@@ -83,11 +84,11 @@ spin_node_until_future_complete(
 
 template<typename NodeT = rclcpp::Node, typename ResponseT, typename TimeRepT = int64_t,
   typename TimeT = std::milli>
-rclcpp::executor::FutureReturnCode
+rclcpp::FutureReturnCode
 spin_node_until_future_complete(
-  rclcpp::executor::Executor & executor,
+  rclcpp::Executor & executor,
   std::shared_ptr<NodeT> node_ptr,
-  std::shared_future<ResponseT> & future,
+  const std::shared_future<ResponseT> & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
   return rclcpp::executors::spin_node_until_future_complete(
@@ -100,10 +101,10 @@ spin_node_until_future_complete(
 }  // namespace executors
 
 template<typename FutureT, typename TimeRepT = int64_t, typename TimeT = std::milli>
-rclcpp::executor::FutureReturnCode
+rclcpp::FutureReturnCode
 spin_until_future_complete(
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
-  std::shared_future<FutureT> & future,
+  const std::shared_future<FutureT> & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
   rclcpp::executors::SingleThreadedExecutor executor;
@@ -112,10 +113,10 @@ spin_until_future_complete(
 
 template<typename NodeT = rclcpp::Node, typename FutureT, typename TimeRepT = int64_t,
   typename TimeT = std::milli>
-rclcpp::executor::FutureReturnCode
+rclcpp::FutureReturnCode
 spin_until_future_complete(
   std::shared_ptr<NodeT> node_ptr,
-  std::shared_future<FutureT> & future,
+  const std::shared_future<FutureT> & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
   return rclcpp::spin_until_future_complete(node_ptr->get_node_base_interface(), future, timeout);

rclcpp/include/rclcpp/executors/multi_threaded_executor.hpp

@@ -15,6 +15,7 @@
 #ifndef RCLCPP__EXECUTORS__MULTI_THREADED_EXECUTOR_HPP_
 #define RCLCPP__EXECUTORS__MULTI_THREADED_EXECUTOR_HPP_
 
+#include <chrono>
 #include <memory>
 #include <mutex>
 #include <set>
@@ -31,7 +32,7 @@ namespace rclcpp
 namespace executors
 {
 
-class MultiThreadedExecutor : public executor::Executor
+class MultiThreadedExecutor : public rclcpp::Executor
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(MultiThreadedExecutor)
@@ -44,23 +45,24 @@ public:
    * This is useful for reproducing some bugs related to taking work more than
    * once.
    *
-   * \param args common arguments for all executors
+   * \param options common options for all executors
    * \param number_of_threads number of threads to have in the thread pool,
    *   the default 0 will use the number of cpu cores found instead
    * \param yield_before_execute if true std::this_thread::yield() is called
    */
   RCLCPP_PUBLIC
   MultiThreadedExecutor(
-    const executor::ExecutorArgs & args = executor::ExecutorArgs(),
+    const rclcpp::ExecutorOptions & options = rclcpp::ExecutorOptions(),
     size_t number_of_threads = 0,
-    bool yield_before_execute = false);
+    bool yield_before_execute = false,
+    std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1));
 
   RCLCPP_PUBLIC
   virtual ~MultiThreadedExecutor();
 
   RCLCPP_PUBLIC
   void
-  spin();
+  spin() override;
 
   RCLCPP_PUBLIC
   size_t
@@ -77,6 +79,7 @@ private:
   std::mutex wait_mutex_;
   size_t number_of_threads_;
   bool yield_before_execute_;
+  std::chrono::nanoseconds next_exec_timeout_;
 
   std::set<TimerBase::SharedPtr> scheduled_timers_;
 };

rclcpp/include/rclcpp/executors/single_threaded_executor.hpp

@@ -35,28 +35,34 @@ namespace rclcpp
 namespace executors
 {
 
-/// Single-threaded executor implementation
-// This is the default executor created by rclcpp::spin.
-class SingleThreadedExecutor : public executor::Executor
+/// Single-threaded executor implementation.
+/**
+ * This is the default executor created by rclcpp::spin.
+ */
+class SingleThreadedExecutor : public rclcpp::Executor
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(SingleThreadedExecutor)
 
   /// Default constructor. See the default constructor for Executor.
   RCLCPP_PUBLIC
-  SingleThreadedExecutor(
-    const executor::ExecutorArgs & args = executor::ExecutorArgs());
+  explicit SingleThreadedExecutor(
+    const rclcpp::ExecutorOptions & options = rclcpp::ExecutorOptions());
 
-  /// Default destrcutor.
+  /// Default destructor.
   RCLCPP_PUBLIC
   virtual ~SingleThreadedExecutor();
 
   /// Single-threaded implementation of spin.
-  // This function will block until work comes in, execute it, and keep blocking.
-  // It will only be interrupt by a CTRL-C (managed by the global signal handler).
+  /**
+   * This function will block until work comes in, execute it, and then repeat
+   * the process until canceled.
+   * It may be interrupt by a call to rclcpp::Executor::cancel() or by ctrl-c
+   * if the associated context is configured to shutdown on SIGINT.
+   */
   RCLCPP_PUBLIC
   void
-  spin();
+  spin() override;
 
 private:
   RCLCPP_DISABLE_COPY(SingleThreadedExecutor)

rclcpp/include/rclcpp/executors/static_executor_entities_collector.hpp

@@ -0,0 +1,168 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXECUTORS__STATIC_EXECUTOR_ENTITIES_COLLECTOR_HPP_
+#define RCLCPP__EXECUTORS__STATIC_EXECUTOR_ENTITIES_COLLECTOR_HPP_
+
+#include <chrono>
+#include <list>
+#include <memory>
+
+#include "rcl/guard_condition.h"
+#include "rcl/wait.h"
+
+#include "rclcpp/experimental/executable_list.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/memory_strategy.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rclcpp/waitable.hpp"
+
+namespace rclcpp
+{
+namespace executors
+{
+
+class StaticExecutorEntitiesCollector final
+  : public rclcpp::Waitable,
+  public std::enable_shared_from_this<StaticExecutorEntitiesCollector>
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(StaticExecutorEntitiesCollector)
+
+  // Constructor
+  RCLCPP_PUBLIC
+  StaticExecutorEntitiesCollector() = default;
+
+  // Destructor
+  ~StaticExecutorEntitiesCollector();
+
+  RCLCPP_PUBLIC
+  void
+  init(
+    rcl_wait_set_t * p_wait_set,
+    rclcpp::memory_strategy::MemoryStrategy::SharedPtr & memory_strategy,
+    rcl_guard_condition_t * executor_guard_condition);
+
+  RCLCPP_PUBLIC
+  void
+  execute() override;
+
+  RCLCPP_PUBLIC
+  void
+  fill_memory_strategy();
+
+  RCLCPP_PUBLIC
+  void
+  fill_executable_list();
+
+  /// Function to reallocate space for entities in the wait set.
+  RCLCPP_PUBLIC
+  void
+  prepare_wait_set();
+
+  /// Function to add_handles_to_wait_set and wait for work and
+  // block until the wait set is ready or until the timeout has been exceeded.
+  RCLCPP_PUBLIC
+  void
+  refresh_wait_set(std::chrono::nanoseconds timeout = std::chrono::nanoseconds(-1));
+
+  RCLCPP_PUBLIC
+  bool
+  add_to_wait_set(rcl_wait_set_t * wait_set) override;
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_ready_guard_conditions() override;
+
+  RCLCPP_PUBLIC
+  void
+  add_node(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+
+  RCLCPP_PUBLIC
+  bool
+  remove_node(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+
+  /// Complete all available queued work without blocking.
+  /**
+   * This function checks if after the guard condition was triggered
+   * (or a spurious wakeup happened) we are really ready to execute
+   * i.e. re-collect entities
+   */
+  RCLCPP_PUBLIC
+  bool
+  is_ready(rcl_wait_set_t * wait_set) override;
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_timers() {return exec_list_.number_of_timers;}
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_subscriptions() {return exec_list_.number_of_subscriptions;}
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_services() {return exec_list_.number_of_services;}
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_clients() {return exec_list_.number_of_clients;}
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_waitables() {return exec_list_.number_of_waitables;}
+
+  RCLCPP_PUBLIC
+  rclcpp::SubscriptionBase::SharedPtr
+  get_subscription(size_t i) {return exec_list_.subscription[i];}
+
+  RCLCPP_PUBLIC
+  rclcpp::TimerBase::SharedPtr
+  get_timer(size_t i) {return exec_list_.timer[i];}
+
+  RCLCPP_PUBLIC
+  rclcpp::ServiceBase::SharedPtr
+  get_service(size_t i) {return exec_list_.service[i];}
+
+  RCLCPP_PUBLIC
+  rclcpp::ClientBase::SharedPtr
+  get_client(size_t i) {return exec_list_.client[i];}
+
+  RCLCPP_PUBLIC
+  rclcpp::Waitable::SharedPtr
+  get_waitable(size_t i) {return exec_list_.waitable[i];}
+
+private:
+  /// Nodes guard conditions which trigger this waitable
+  std::list<const rcl_guard_condition_t *> guard_conditions_;
+
+  /// Memory strategy: an interface for handling user-defined memory allocation strategies.
+  rclcpp::memory_strategy::MemoryStrategy::SharedPtr memory_strategy_;
+
+  /// List of weak nodes registered in the static executor
+  std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
+
+  /// Wait set for managing entities that the rmw layer waits on.
+  rcl_wait_set_t * p_wait_set_ = nullptr;
+
+  /// Executable list: timers, subscribers, clients, services and waitables
+  rclcpp::experimental::ExecutableList exec_list_;
+};
+
+}  // namespace executors
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXECUTORS__STATIC_EXECUTOR_ENTITIES_COLLECTOR_HPP_

rclcpp/include/rclcpp/executors/static_single_threaded_executor.hpp

@@ -0,0 +1,200 @@
+// Copyright 2019 Nobleo Technology
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXECUTORS__STATIC_SINGLE_THREADED_EXECUTOR_HPP_
+#define RCLCPP__EXECUTORS__STATIC_SINGLE_THREADED_EXECUTOR_HPP_
+
+#include <cassert>
+#include <cstdlib>
+#include <memory>
+#include <vector>
+#include <string>
+
+#include "rmw/rmw.h"
+
+#include "rclcpp/executor.hpp"
+#include "rclcpp/executors/static_executor_entities_collector.hpp"
+#include "rclcpp/experimental/executable_list.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/memory_strategies.hpp"
+#include "rclcpp/node.hpp"
+#include "rclcpp/rate.hpp"
+#include "rclcpp/utilities.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace executors
+{
+
+/// Static executor implementation
+/**
+ * This executor is a static version of the original single threaded executor.
+ * It's static because it doesn't reconstruct the executable list for every iteration.
+ * All nodes, callbackgroups, timers, subscriptions etc. are created before
+ * spin() is called, and modified only when an entity is added/removed to/from a node.
+ *
+ * To run this executor instead of SingleThreadedExecutor replace:
+ * rclcpp::executors::SingleThreadedExecutor exec;
+ * by
+ * rclcpp::executors::StaticSingleThreadedExecutor exec;
+ * in your source code and spin node(s) in the following way:
+ * exec.add_node(node);
+ * exec.spin();
+ * exec.remove_node(node);
+ */
+class StaticSingleThreadedExecutor : public rclcpp::Executor
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(StaticSingleThreadedExecutor)
+
+  /// Default constructor. See the default constructor for Executor.
+  RCLCPP_PUBLIC
+  explicit StaticSingleThreadedExecutor(
+    const rclcpp::ExecutorOptions & options = rclcpp::ExecutorOptions());
+
+  /// Default destrcutor.
+  RCLCPP_PUBLIC
+  virtual ~StaticSingleThreadedExecutor();
+
+  /// Static executor implementation of spin.
+  // This function will block until work comes in, execute it, and keep blocking.
+  // It will only be interrupt by a CTRL-C (managed by the global signal handler).
+  RCLCPP_PUBLIC
+  void
+  spin() override;
+
+  /// Add a node to the executor.
+  /**
+   * An executor can have zero or more nodes which provide work during `spin` functions.
+   * \param[in] node_ptr Shared pointer to the node to be added.
+   * \param[in] notify True to trigger the interrupt guard condition during this function. If
+   * the executor is blocked at the rmw layer while waiting for work and it is notified that a new
+   * node was added, it will wake up.
+   */
+  RCLCPP_PUBLIC
+  void
+  add_node(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+    bool notify = true) override;
+
+  /// Convenience function which takes Node and forwards NodeBaseInterface.
+  RCLCPP_PUBLIC
+  void
+  add_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true) override;
+
+  /// Remove a node from the executor.
+  /**
+   * \param[in] node_ptr Shared pointer to the node to remove.
+   * \param[in] notify True to trigger the interrupt guard condition and wake up the executor.
+   * This is useful if the last node was removed from the executor while the executor was blocked
+   * waiting for work in another thread, because otherwise the executor would never be notified.
+   */
+  RCLCPP_PUBLIC
+  void
+  remove_node(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+    bool notify = true) override;
+
+  /// Convenience function which takes Node and forwards NodeBaseInterface.
+  RCLCPP_PUBLIC
+  void
+  remove_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true) override;
+
+  /// Spin (blocking) until the future is complete, it times out waiting, or rclcpp is interrupted.
+  /**
+   * \param[in] future The future to wait on. If this function returns SUCCESS, the future can be
+   *   accessed without blocking (though it may still throw an exception).
+   * \param[in] timeout Optional timeout parameter, which gets passed to
+   *    Executor::execute_ready_executables.
+   *   `-1` is block forever, `0` is non-blocking.
+   *   If the time spent inside the blocking loop exceeds this timeout, return a TIMEOUT return
+   *   code.
+   * \return The return code, one of `SUCCESS`, `INTERRUPTED`, or `TIMEOUT`.
+   *
+   *  Example usage:
+   *  rclcpp::executors::StaticSingleThreadedExecutor exec;
+   *  // ... other part of code like creating node
+   *  // define future
+   *  exec.add_node(node);
+   *  exec.spin_until_future_complete(future);
+   */
+  template<typename ResponseT, typename TimeRepT = int64_t, typename TimeT = std::milli>
+  rclcpp::FutureReturnCode
+  spin_until_future_complete(
+    std::shared_future<ResponseT> & future,
+    std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
+  {
+    std::future_status status = future.wait_for(std::chrono::seconds(0));
+    if (status == std::future_status::ready) {
+      return rclcpp::FutureReturnCode::SUCCESS;
+    }
+
+    auto end_time = std::chrono::steady_clock::now();
+    std::chrono::nanoseconds timeout_ns = std::chrono::duration_cast<std::chrono::nanoseconds>(
+      timeout);
+    if (timeout_ns > std::chrono::nanoseconds::zero()) {
+      end_time += timeout_ns;
+    }
+    std::chrono::nanoseconds timeout_left = timeout_ns;
+
+    entities_collector_ = std::make_shared<StaticExecutorEntitiesCollector>();
+    entities_collector_->init(&wait_set_, memory_strategy_, &interrupt_guard_condition_);
+
+    while (rclcpp::ok(this->context_)) {
+      // Do one set of work.
+      entities_collector_->refresh_wait_set(timeout_left);
+      execute_ready_executables();
+      // Check if the future is set, return SUCCESS if it is.
+      status = future.wait_for(std::chrono::seconds(0));
+      if (status == std::future_status::ready) {
+        return rclcpp::FutureReturnCode::SUCCESS;
+      }
+      // If the original timeout is < 0, then this is blocking, never TIMEOUT.
+      if (timeout_ns < std::chrono::nanoseconds::zero()) {
+        continue;
+      }
+      // Otherwise check if we still have time to wait, return TIMEOUT if not.
+      auto now = std::chrono::steady_clock::now();
+      if (now >= end_time) {
+        return rclcpp::FutureReturnCode::TIMEOUT;
+      }
+      // Subtract the elapsed time from the original timeout.
+      timeout_left = std::chrono::duration_cast<std::chrono::nanoseconds>(end_time - now);
+    }
+
+    // The future did not complete before ok() returned false, return INTERRUPTED.
+    return rclcpp::FutureReturnCode::INTERRUPTED;
+  }
+
+protected:
+  /// Check which executables in ExecutableList struct are ready from wait_set and execute them.
+  /**
+   * \param[in] exec_list Structure that can hold subscriptionbases, timerbases, etc
+   * \param[in] timeout Optional timeout parameter.
+   */
+  RCLCPP_PUBLIC
+  void
+  execute_ready_executables();
+
+private:
+  RCLCPP_DISABLE_COPY(StaticSingleThreadedExecutor)
+
+  StaticExecutorEntitiesCollector::SharedPtr entities_collector_;
+};
+
+}  // namespace executors
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXECUTORS__STATIC_SINGLE_THREADED_EXECUTOR_HPP_

rclcpp/include/rclcpp/experimental/README.md

@@ -0,0 +1,4 @@
+Notice that headers in this folder should only provide symbols in the rclcpp::experimental namespace.
+
+Also notice that these headers are not considered part of the public API as they have not yet been stabilized.
+And therefore they are subject to change without notice.

rclcpp/include/rclcpp/experimental/buffers/buffer_implementation_base.hpp

@@ -0,0 +1,42 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__BUFFERS__BUFFER_IMPLEMENTATION_BASE_HPP_
+#define RCLCPP__EXPERIMENTAL__BUFFERS__BUFFER_IMPLEMENTATION_BASE_HPP_
+
+namespace rclcpp
+{
+namespace experimental
+{
+namespace buffers
+{
+
+template<typename BufferT>
+class BufferImplementationBase
+{
+public:
+  virtual ~BufferImplementationBase() {}
+
+  virtual BufferT dequeue() = 0;
+  virtual void enqueue(BufferT request) = 0;
+
+  virtual void clear() = 0;
+  virtual bool has_data() const = 0;
+};
+
+}  // namespace buffers
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__BUFFERS__BUFFER_IMPLEMENTATION_BASE_HPP_

rclcpp/include/rclcpp/experimental/buffers/intra_process_buffer.hpp

@@ -0,0 +1,241 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__BUFFERS__INTRA_PROCESS_BUFFER_HPP_
+#define RCLCPP__EXPERIMENTAL__BUFFERS__INTRA_PROCESS_BUFFER_HPP_
+
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#include "rclcpp/allocator/allocator_common.hpp"
+#include "rclcpp/allocator/allocator_deleter.hpp"
+#include "rclcpp/experimental/buffers/buffer_implementation_base.hpp"
+#include "rclcpp/macros.hpp"
+
+namespace rclcpp
+{
+namespace experimental
+{
+namespace buffers
+{
+
+class IntraProcessBufferBase
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(IntraProcessBufferBase)
+
+  virtual ~IntraProcessBufferBase() {}
+
+  virtual void clear() = 0;
+
+  virtual bool has_data() const = 0;
+  virtual bool use_take_shared_method() const = 0;
+};
+
+template<
+  typename MessageT,
+  typename Alloc = std::allocator<void>,
+  typename MessageDeleter = std::default_delete<MessageT>>
+class IntraProcessBuffer : public IntraProcessBufferBase
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(IntraProcessBuffer)
+
+  virtual ~IntraProcessBuffer() {}
+
+  using MessageUniquePtr = std::unique_ptr<MessageT, MessageDeleter>;
+  using MessageSharedPtr = std::shared_ptr<const MessageT>;
+
+  virtual void add_shared(MessageSharedPtr msg) = 0;
+  virtual void add_unique(MessageUniquePtr msg) = 0;
+
+  virtual MessageSharedPtr consume_shared() = 0;
+  virtual MessageUniquePtr consume_unique() = 0;
+};
+
+template<
+  typename MessageT,
+  typename Alloc = std::allocator<void>,
+  typename MessageDeleter = std::default_delete<MessageT>,
+  typename BufferT = std::unique_ptr<MessageT>>
+class TypedIntraProcessBuffer : public IntraProcessBuffer<MessageT, Alloc, MessageDeleter>
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(TypedIntraProcessBuffer)
+
+  using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
+  using MessageAlloc = typename MessageAllocTraits::allocator_type;
+  using MessageUniquePtr = std::unique_ptr<MessageT, MessageDeleter>;
+  using MessageSharedPtr = std::shared_ptr<const MessageT>;
+
+  explicit
+  TypedIntraProcessBuffer(
+    std::unique_ptr<BufferImplementationBase<BufferT>> buffer_impl,
+    std::shared_ptr<Alloc> allocator = nullptr)
+  {
+    bool valid_type = (std::is_same<BufferT, MessageSharedPtr>::value ||
+      std::is_same<BufferT, MessageUniquePtr>::value);
+    if (!valid_type) {
+      throw std::runtime_error("Creating TypedIntraProcessBuffer with not valid BufferT");
+    }
+
+    buffer_ = std::move(buffer_impl);
+
+    if (!allocator) {
+      message_allocator_ = std::make_shared<MessageAlloc>();
+    } else {
+      message_allocator_ = std::make_shared<MessageAlloc>(*allocator.get());
+    }
+  }
+
+  virtual ~TypedIntraProcessBuffer() {}
+
+  void add_shared(MessageSharedPtr msg) override
+  {
+    add_shared_impl<BufferT>(std::move(msg));
+  }
+
+  void add_unique(MessageUniquePtr msg) override
+  {
+    buffer_->enqueue(std::move(msg));
+  }
+
+  MessageSharedPtr consume_shared() override
+  {
+    return consume_shared_impl<BufferT>();
+  }
+
+  MessageUniquePtr consume_unique() override
+  {
+    return consume_unique_impl<BufferT>();
+  }
+
+  bool has_data() const override
+  {
+    return buffer_->has_data();
+  }
+
+  void clear() override
+  {
+    buffer_->clear();
+  }
+
+  bool use_take_shared_method() const override
+  {
+    return std::is_same<BufferT, MessageSharedPtr>::value;
+  }
+
+private:
+  std::unique_ptr<BufferImplementationBase<BufferT>> buffer_;
+
+  std::shared_ptr<MessageAlloc> message_allocator_;
+
+  // MessageSharedPtr to MessageSharedPtr
+  template<typename DestinationT>
+  typename std::enable_if<
+    std::is_same<DestinationT, MessageSharedPtr>::value
+  >::type
+  add_shared_impl(MessageSharedPtr shared_msg)
+  {
+    buffer_->enqueue(std::move(shared_msg));
+  }
+
+  // MessageSharedPtr to MessageUniquePtr
+  template<typename DestinationT>
+  typename std::enable_if<
+    std::is_same<DestinationT, MessageUniquePtr>::value
+  >::type
+  add_shared_impl(MessageSharedPtr shared_msg)
+  {
+    // This should not happen: here a copy is unconditionally made, while the intra-process manager
+    // can decide whether a copy is needed depending on the number and the type of buffers
+
+    MessageUniquePtr unique_msg;
+    MessageDeleter * deleter = std::get_deleter<MessageDeleter, const MessageT>(shared_msg);
+    auto ptr = MessageAllocTraits::allocate(*message_allocator_.get(), 1);
+    MessageAllocTraits::construct(*message_allocator_.get(), ptr, *shared_msg);
+    if (deleter) {
+      unique_msg = MessageUniquePtr(ptr, *deleter);
+    } else {
+      unique_msg = MessageUniquePtr(ptr);
+    }
+
+    buffer_->enqueue(std::move(unique_msg));
+  }
+
+  // MessageSharedPtr to MessageSharedPtr
+  template<typename OriginT>
+  typename std::enable_if<
+    std::is_same<OriginT, MessageSharedPtr>::value,
+    MessageSharedPtr
+  >::type
+  consume_shared_impl()
+  {
+    return buffer_->dequeue();
+  }
+
+  // MessageUniquePtr to MessageSharedPtr
+  template<typename OriginT>
+  typename std::enable_if<
+    (std::is_same<OriginT, MessageUniquePtr>::value),
+    MessageSharedPtr
+  >::type
+  consume_shared_impl()
+  {
+    // automatic cast from unique ptr to shared ptr
+    return buffer_->dequeue();
+  }
+
+  // MessageSharedPtr to MessageUniquePtr
+  template<typename OriginT>
+  typename std::enable_if<
+    (std::is_same<OriginT, MessageSharedPtr>::value),
+    MessageUniquePtr
+  >::type
+  consume_unique_impl()
+  {
+    MessageSharedPtr buffer_msg = buffer_->dequeue();
+
+    MessageUniquePtr unique_msg;
+    MessageDeleter * deleter = std::get_deleter<MessageDeleter, const MessageT>(buffer_msg);
+    auto ptr = MessageAllocTraits::allocate(*message_allocator_.get(), 1);
+    MessageAllocTraits::construct(*message_allocator_.get(), ptr, *buffer_msg);
+    if (deleter) {
+      unique_msg = MessageUniquePtr(ptr, *deleter);
+    } else {
+      unique_msg = MessageUniquePtr(ptr);
+    }
+
+    return unique_msg;
+  }
+
+  // MessageUniquePtr to MessageUniquePtr
+  template<typename OriginT>
+  typename std::enable_if<
+    (std::is_same<OriginT, MessageUniquePtr>::value),
+    MessageUniquePtr
+  >::type
+  consume_unique_impl()
+  {
+    return buffer_->dequeue();
+  }
+};
+
+}  // namespace buffers
+}  // namespace experimental
+}  // namespace rclcpp
+
+
+#endif  // RCLCPP__EXPERIMENTAL__BUFFERS__INTRA_PROCESS_BUFFER_HPP_

rclcpp/include/rclcpp/experimental/buffers/ring_buffer_implementation.hpp

@@ -0,0 +1,122 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_
+#define RCLCPP__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_
+
+#include <algorithm>
+#include <cstddef>
+#include <cstdint>
+#include <memory>
+#include <mutex>
+#include <stdexcept>
+#include <utility>
+#include <vector>
+
+#include "rclcpp/experimental/buffers/buffer_implementation_base.hpp"
+#include "rclcpp/logger.hpp"
+#include "rclcpp/logging.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace experimental
+{
+namespace buffers
+{
+
+template<typename BufferT>
+class RingBufferImplementation : public BufferImplementationBase<BufferT>
+{
+public:
+  explicit RingBufferImplementation(size_t capacity)
+  : capacity_(capacity),
+    ring_buffer_(capacity),
+    write_index_(capacity_ - 1),
+    read_index_(0),
+    size_(0)
+  {
+    if (capacity == 0) {
+      throw std::invalid_argument("capacity must be a positive, non-zero value");
+    }
+  }
+
+  virtual ~RingBufferImplementation() {}
+
+  void enqueue(BufferT request)
+  {
+    std::lock_guard<std::mutex> lock(mutex_);
+
+    write_index_ = next(write_index_);
+    ring_buffer_[write_index_] = std::move(request);
+
+    if (is_full()) {
+      read_index_ = next(read_index_);
+    } else {
+      size_++;
+    }
+  }
+
+  BufferT dequeue()
+  {
+    std::lock_guard<std::mutex> lock(mutex_);
+
+    if (!has_data()) {
+      RCLCPP_ERROR(rclcpp::get_logger("rclcpp"), "Calling dequeue on empty intra-process buffer");
+      throw std::runtime_error("Calling dequeue on empty intra-process buffer");
+    }
+
+    auto request = std::move(ring_buffer_[read_index_]);
+    read_index_ = next(read_index_);
+
+    size_--;
+
+    return request;
+  }
+
+  inline size_t next(size_t val)
+  {
+    return (val + 1) % capacity_;
+  }
+
+  inline bool has_data() const
+  {
+    return size_ != 0;
+  }
+
+  inline bool is_full()
+  {
+    return size_ == capacity_;
+  }
+
+  void clear() {}
+
+private:
+  size_t capacity_;
+
+  std::vector<BufferT> ring_buffer_;
+
+  size_t write_index_;
+  size_t read_index_;
+  size_t size_;
+
+  std::mutex mutex_;
+};
+
+}  // namespace buffers
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__BUFFERS__RING_BUFFER_IMPLEMENTATION_HPP_

rclcpp/include/rclcpp/experimental/create_intra_process_buffer.hpp

@@ -0,0 +1,99 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__CREATE_INTRA_PROCESS_BUFFER_HPP_
+#define RCLCPP__EXPERIMENTAL__CREATE_INTRA_PROCESS_BUFFER_HPP_
+
+#include <memory>
+#include <type_traits>
+#include <utility>
+
+#include "rcl/subscription.h"
+
+#include "rclcpp/experimental/buffers/intra_process_buffer.hpp"
+#include "rclcpp/experimental/buffers/ring_buffer_implementation.hpp"
+#include "rclcpp/intra_process_buffer_type.hpp"
+
+namespace rclcpp
+{
+namespace experimental
+{
+
+template<
+  typename MessageT,
+  typename Alloc = std::allocator<void>,
+  typename Deleter = std::default_delete<MessageT>>
+typename rclcpp::experimental::buffers::IntraProcessBuffer<MessageT, Alloc, Deleter>::UniquePtr
+create_intra_process_buffer(
+  IntraProcessBufferType buffer_type,
+  rmw_qos_profile_t qos,
+  std::shared_ptr<Alloc> allocator)
+{
+  using MessageSharedPtr = std::shared_ptr<const MessageT>;
+  using MessageUniquePtr = std::unique_ptr<MessageT, Deleter>;
+
+  size_t buffer_size = qos.depth;
+
+  using rclcpp::experimental::buffers::IntraProcessBuffer;
+  typename IntraProcessBuffer<MessageT, Alloc, Deleter>::UniquePtr buffer;
+
+  switch (buffer_type) {
+    case IntraProcessBufferType::SharedPtr:
+      {
+        using BufferT = MessageSharedPtr;
+
+        auto buffer_implementation =
+          std::make_unique<rclcpp::experimental::buffers::RingBufferImplementation<BufferT>>(
+          buffer_size);
+
+        // Construct the intra_process_buffer
+        buffer =
+          std::make_unique<rclcpp::experimental::buffers::TypedIntraProcessBuffer<MessageT, Alloc,
+            Deleter, BufferT>>(
+          std::move(buffer_implementation),
+          allocator);
+
+        break;
+      }
+    case IntraProcessBufferType::UniquePtr:
+      {
+        using BufferT = MessageUniquePtr;
+
+        auto buffer_implementation =
+          std::make_unique<rclcpp::experimental::buffers::RingBufferImplementation<BufferT>>(
+          buffer_size);
+
+        // Construct the intra_process_buffer
+        buffer =
+          std::make_unique<rclcpp::experimental::buffers::TypedIntraProcessBuffer<MessageT, Alloc,
+            Deleter, BufferT>>(
+          std::move(buffer_implementation),
+          allocator);
+
+        break;
+      }
+    default:
+      {
+        throw std::runtime_error("Unrecognized IntraProcessBufferType value");
+        break;
+      }
+  }
+
+  return buffer;
+}
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__CREATE_INTRA_PROCESS_BUFFER_HPP_

rclcpp/include/rclcpp/experimental/executable_list.hpp

@@ -0,0 +1,92 @@
+// Copyright 2019 Nobleo Technology
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__EXECUTABLE_LIST_HPP_
+#define RCLCPP__EXPERIMENTAL__EXECUTABLE_LIST_HPP_
+
+#include <memory>
+#include <vector>
+
+#include "rclcpp/client.hpp"
+#include "rclcpp/service.hpp"
+#include "rclcpp/subscription_base.hpp"
+#include "rclcpp/timer.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rclcpp/waitable.hpp"
+
+namespace rclcpp
+{
+namespace experimental
+{
+
+/// This class contains subscriptionbase, timerbase, etc. which can be used to run callbacks.
+class ExecutableList final
+{
+public:
+  RCLCPP_PUBLIC
+  ExecutableList();
+
+  RCLCPP_PUBLIC
+  ~ExecutableList();
+
+  RCLCPP_PUBLIC
+  void
+  clear();
+
+  RCLCPP_PUBLIC
+  void
+  add_subscription(rclcpp::SubscriptionBase::SharedPtr subscription);
+
+  RCLCPP_PUBLIC
+  void
+  add_timer(rclcpp::TimerBase::SharedPtr timer);
+
+  RCLCPP_PUBLIC
+  void
+  add_service(rclcpp::ServiceBase::SharedPtr service);
+
+  RCLCPP_PUBLIC
+  void
+  add_client(rclcpp::ClientBase::SharedPtr client);
+
+  RCLCPP_PUBLIC
+  void
+  add_waitable(rclcpp::Waitable::SharedPtr waitable);
+
+  // Vector containing the SubscriptionBase of all the subscriptions added to the executor.
+  std::vector<rclcpp::SubscriptionBase::SharedPtr> subscription;
+  // Contains the count of added subscriptions
+  size_t number_of_subscriptions;
+  // Vector containing the TimerBase of all the timers added to the executor.
+  std::vector<rclcpp::TimerBase::SharedPtr> timer;
+  // Contains the count of added timers
+  size_t number_of_timers;
+  // Vector containing the ServiceBase of all the services added to the executor.
+  std::vector<rclcpp::ServiceBase::SharedPtr> service;
+  // Contains the count of added services
+  size_t number_of_services;
+  // Vector containing the ClientBase of all the clients added to the executor.
+  std::vector<rclcpp::ClientBase::SharedPtr> client;
+  // Contains the count of added clients
+  size_t number_of_clients;
+  // Vector containing all the waitables added to the executor.
+  std::vector<rclcpp::Waitable::SharedPtr> waitable;
+  // Contains the count of added waitables
+  size_t number_of_waitables;
+};
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__EXECUTABLE_LIST_HPP_

rclcpp/include/rclcpp/experimental/intra_process_manager.hpp

@@ -0,0 +1,424 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__INTRA_PROCESS_MANAGER_HPP_
+#define RCLCPP__EXPERIMENTAL__INTRA_PROCESS_MANAGER_HPP_
+
+#include <rmw/types.h>
+
+#include <shared_mutex>
+
+#include <algorithm>
+#include <atomic>
+#include <cstdint>
+#include <exception>
+#include <map>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "rclcpp/allocator/allocator_deleter.hpp"
+#include "rclcpp/experimental/subscription_intra_process.hpp"
+#include "rclcpp/experimental/subscription_intra_process_base.hpp"
+#include "rclcpp/logger.hpp"
+#include "rclcpp/logging.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/publisher_base.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+namespace experimental
+{
+
+/// This class performs intra process communication between nodes.
+/**
+ * This class is used in the creation of publishers and subscriptions.
+ * A singleton instance of this class is owned by a rclcpp::Context and a
+ * rclcpp::Node can use an associated Context to get an instance of this class.
+ * Nodes which do not have a common Context will not exchange intra process
+ * messages because they do not share access to the same instance of this class.
+ *
+ * When a Node creates a subscription, it can also create a helper class,
+ * called SubscriptionIntraProcess, meant to receive intra process messages.
+ * It can be registered with this class.
+ * It is also allocated an id which is unique among all publishers
+ * and subscriptions in this process and that is associated to the subscription.
+ *
+ * When a Node creates a publisher, as with subscriptions, a helper class can
+ * be registered with this class.
+ * This is required in order to publish intra-process messages.
+ * It is also allocated an id which is unique among all publishers
+ * and subscriptions in this process and that is associated to the publisher.
+ *
+ * When a publisher or a subscription are registered, this class checks to see
+ * which other subscriptions or publishers it will communicate with,
+ * i.e. they have the same topic and compatible QoS.
+ *
+ * When the user publishes a message, if intra-process communication is enabled
+ * on the publisher, the message is given to this class.
+ * Using the publisher id, a list of recipients for the message is selected.
+ * For each subscription in the list, this class stores the message, whether
+ * sharing ownership or making a copy, in a buffer associated with the
+ * subscription helper class.
+ *
+ * The subscription helper class contains a buffer where published
+ * intra-process messages are stored until they are taken from the subscription.
+ * Depending on the data type stored in the buffer, the subscription helper
+ * class can request either shared or exclusive ownership on the message.
+ *
+ * Thus, when an intra-process message is published, this class knows how many
+ * intra-process subscriptions needs it and how many require ownership.
+ * This information allows this class to operate efficiently by performing the
+ * fewest number of copies of the message required.
+ *
+ * This class is neither CopyConstructable nor CopyAssignable.
+ */
+class IntraProcessManager
+{
+private:
+  RCLCPP_DISABLE_COPY(IntraProcessManager)
+
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(IntraProcessManager)
+
+  RCLCPP_PUBLIC
+  IntraProcessManager();
+
+  RCLCPP_PUBLIC
+  virtual ~IntraProcessManager();
+
+  /// Register a subscription with the manager, returns subscriptions unique id.
+  /**
+   * This method stores the subscription intra process object, together with
+   * the information of its wrapped subscription (i.e. topic name and QoS).
+   *
+   * In addition this generates a unique intra process id for the subscription.
+   *
+   * \param subscription the SubscriptionIntraProcess to register.
+   * \return an unsigned 64-bit integer which is the subscription's unique id.
+   */
+  RCLCPP_PUBLIC
+  uint64_t
+  add_subscription(rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr subscription);
+
+  /// Unregister a subscription using the subscription's unique id.
+  /**
+   * This method does not allocate memory.
+   *
+   * \param intra_process_subscription_id id of the subscription to remove.
+   */
+  RCLCPP_PUBLIC
+  void
+  remove_subscription(uint64_t intra_process_subscription_id);
+
+  /// Register a publisher with the manager, returns the publisher unique id.
+  /**
+   * This method stores the publisher intra process object, together with
+   * the information of its wrapped publisher (i.e. topic name and QoS).
+   *
+   * In addition this generates a unique intra process id for the publisher.
+   *
+   * \param publisher publisher to be registered with the manager.
+   * \return an unsigned 64-bit integer which is the publisher's unique id.
+   */
+  RCLCPP_PUBLIC
+  uint64_t
+  add_publisher(rclcpp::PublisherBase::SharedPtr publisher);
+
+  /// Unregister a publisher using the publisher's unique id.
+  /**
+   * This method does not allocate memory.
+   *
+   * \param intra_process_publisher_id id of the publisher to remove.
+   */
+  RCLCPP_PUBLIC
+  void
+  remove_publisher(uint64_t intra_process_publisher_id);
+
+  /// Publishes an intra-process message, passed as a unique pointer.
+  /**
+   * This is one of the two methods for publishing intra-process.
+   *
+   * Using the intra-process publisher id, a list of recipients is obtained.
+   * This list is split in half, depending whether they require ownership or not.
+   *
+   * This particular method takes a unique pointer as input.
+   * The pointer can be promoted to a shared pointer and passed to all the subscriptions
+   * that do not require ownership.
+   * In case of subscriptions requiring ownership, the message will be copied for all of
+   * them except the last one, when ownership can be transferred.
+   *
+   * This method can save an additional copy compared to the shared pointer one.
+   *
+   * This method can throw an exception if the publisher id is not found or
+   * if the publisher shared_ptr given to add_publisher has gone out of scope.
+   *
+   * This method does allocate memory.
+   *
+   * \param intra_process_publisher_id the id of the publisher of this message.
+   * \param message the message that is being stored.
+   */
+  template<
+    typename MessageT,
+    typename Alloc = std::allocator<void>,
+    typename Deleter = std::default_delete<MessageT>>
+  void
+  do_intra_process_publish(
+    uint64_t intra_process_publisher_id,
+    std::unique_ptr<MessageT, Deleter> message,
+    std::shared_ptr<typename allocator::AllocRebind<MessageT, Alloc>::allocator_type> allocator)
+  {
+    using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
+    using MessageAllocatorT = typename MessageAllocTraits::allocator_type;
+
+    std::shared_lock<std::shared_timed_mutex> lock(mutex_);
+
+    auto publisher_it = pub_to_subs_.find(intra_process_publisher_id);
+    if (publisher_it == pub_to_subs_.end()) {
+      // Publisher is either invalid or no longer exists.
+      RCLCPP_WARN(
+        rclcpp::get_logger("rclcpp"),
+        "Calling do_intra_process_publish for invalid or no longer existing publisher id");
+      return;
+    }
+    const auto & sub_ids = publisher_it->second;
+
+    if (sub_ids.take_ownership_subscriptions.empty()) {
+      // None of the buffers require ownership, so we promote the pointer
+      std::shared_ptr<MessageT> msg = std::move(message);
+
+      this->template add_shared_msg_to_buffers<MessageT>(msg, sub_ids.take_shared_subscriptions);
+    } else if (!sub_ids.take_ownership_subscriptions.empty() && // NOLINT
+      sub_ids.take_shared_subscriptions.size() <= 1)
+    {
+      // There is at maximum 1 buffer that does not require ownership.
+      // So we this case is equivalent to all the buffers requiring ownership
+
+      // Merge the two vector of ids into a unique one
+      std::vector<uint64_t> concatenated_vector(sub_ids.take_shared_subscriptions);
+      concatenated_vector.insert(
+        concatenated_vector.end(),
+        sub_ids.take_ownership_subscriptions.begin(),
+        sub_ids.take_ownership_subscriptions.end());
+
+      this->template add_owned_msg_to_buffers<MessageT, Alloc, Deleter>(
+        std::move(message),
+        concatenated_vector,
+        allocator);
+    } else if (!sub_ids.take_ownership_subscriptions.empty() && // NOLINT
+      sub_ids.take_shared_subscriptions.size() > 1)
+    {
+      // Construct a new shared pointer from the message
+      // for the buffers that do not require ownership
+      auto shared_msg = std::allocate_shared<MessageT, MessageAllocatorT>(*allocator, *message);
+
+      this->template add_shared_msg_to_buffers<MessageT>(
+        shared_msg, sub_ids.take_shared_subscriptions);
+      this->template add_owned_msg_to_buffers<MessageT, Alloc, Deleter>(
+        std::move(message), sub_ids.take_ownership_subscriptions, allocator);
+    }
+  }
+
+  template<
+    typename MessageT,
+    typename Alloc = std::allocator<void>,
+    typename Deleter = std::default_delete<MessageT>>
+  std::shared_ptr<const MessageT>
+  do_intra_process_publish_and_return_shared(
+    uint64_t intra_process_publisher_id,
+    std::unique_ptr<MessageT, Deleter> message,
+    std::shared_ptr<typename allocator::AllocRebind<MessageT, Alloc>::allocator_type> allocator)
+  {
+    using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
+    using MessageAllocatorT = typename MessageAllocTraits::allocator_type;
+
+    std::shared_lock<std::shared_timed_mutex> lock(mutex_);
+
+    auto publisher_it = pub_to_subs_.find(intra_process_publisher_id);
+    if (publisher_it == pub_to_subs_.end()) {
+      // Publisher is either invalid or no longer exists.
+      RCLCPP_WARN(
+        rclcpp::get_logger("rclcpp"),
+        "Calling do_intra_process_publish for invalid or no longer existing publisher id");
+      return nullptr;
+    }
+    const auto & sub_ids = publisher_it->second;
+
+    if (sub_ids.take_ownership_subscriptions.empty()) {
+      // If there are no owning, just convert to shared.
+      std::shared_ptr<MessageT> shared_msg = std::move(message);
+      if (!sub_ids.take_shared_subscriptions.empty()) {
+        this->template add_shared_msg_to_buffers<MessageT>(
+          shared_msg, sub_ids.take_shared_subscriptions);
+      }
+      return shared_msg;
+    } else {
+      // Construct a new shared pointer from the message for the buffers that
+      // do not require ownership and to return.
+      auto shared_msg = std::allocate_shared<MessageT, MessageAllocatorT>(*allocator, *message);
+
+      if (!sub_ids.take_shared_subscriptions.empty()) {
+        this->template add_shared_msg_to_buffers<MessageT>(
+          shared_msg,
+          sub_ids.take_shared_subscriptions);
+      }
+      if (!sub_ids.take_ownership_subscriptions.empty()) {
+        this->template add_owned_msg_to_buffers<MessageT, Alloc, Deleter>(
+          std::move(message),
+          sub_ids.take_ownership_subscriptions,
+          allocator);
+      }
+
+      return shared_msg;
+    }
+  }
+
+  /// Return true if the given rmw_gid_t matches any stored Publishers.
+  RCLCPP_PUBLIC
+  bool
+  matches_any_publishers(const rmw_gid_t * id) const;
+
+  /// Return the number of intraprocess subscriptions that are matched with a given publisher id.
+  RCLCPP_PUBLIC
+  size_t
+  get_subscription_count(uint64_t intra_process_publisher_id) const;
+
+  RCLCPP_PUBLIC
+  rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr
+  get_subscription_intra_process(uint64_t intra_process_subscription_id);
+
+private:
+  struct SubscriptionInfo
+  {
+    SubscriptionInfo() = default;
+
+    rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr subscription;
+    rmw_qos_profile_t qos;
+    const char * topic_name;
+    bool use_take_shared_method;
+  };
+
+  struct PublisherInfo
+  {
+    PublisherInfo() = default;
+
+    rclcpp::PublisherBase::WeakPtr publisher;
+    rmw_qos_profile_t qos;
+    const char * topic_name;
+  };
+
+  struct SplittedSubscriptions
+  {
+    std::vector<uint64_t> take_shared_subscriptions;
+    std::vector<uint64_t> take_ownership_subscriptions;
+  };
+
+  using SubscriptionMap =
+    std::unordered_map<uint64_t, SubscriptionInfo>;
+
+  using PublisherMap =
+    std::unordered_map<uint64_t, PublisherInfo>;
+
+  using PublisherToSubscriptionIdsMap =
+    std::unordered_map<uint64_t, SplittedSubscriptions>;
+
+  RCLCPP_PUBLIC
+  static
+  uint64_t
+  get_next_unique_id();
+
+  RCLCPP_PUBLIC
+  void
+  insert_sub_id_for_pub(uint64_t sub_id, uint64_t pub_id, bool use_take_shared_method);
+
+  RCLCPP_PUBLIC
+  bool
+  can_communicate(PublisherInfo pub_info, SubscriptionInfo sub_info) const;
+
+  template<typename MessageT>
+  void
+  add_shared_msg_to_buffers(
+    std::shared_ptr<const MessageT> message,
+    std::vector<uint64_t> subscription_ids)
+  {
+    for (auto id : subscription_ids) {
+      auto subscription_it = subscriptions_.find(id);
+      if (subscription_it == subscriptions_.end()) {
+        throw std::runtime_error("subscription has unexpectedly gone out of scope");
+      }
+      auto subscription_base = subscription_it->second.subscription;
+
+      auto subscription = std::static_pointer_cast<
+        rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+        >(subscription_base);
+
+      subscription->provide_intra_process_message(message);
+    }
+  }
+
+  template<
+    typename MessageT,
+    typename Alloc = std::allocator<void>,
+    typename Deleter = std::default_delete<MessageT>>
+  void
+  add_owned_msg_to_buffers(
+    std::unique_ptr<MessageT, Deleter> message,
+    std::vector<uint64_t> subscription_ids,
+    std::shared_ptr<typename allocator::AllocRebind<MessageT, Alloc>::allocator_type> allocator)
+  {
+    using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
+    using MessageUniquePtr = std::unique_ptr<MessageT, Deleter>;
+
+    for (auto it = subscription_ids.begin(); it != subscription_ids.end(); it++) {
+      auto subscription_it = subscriptions_.find(*it);
+      if (subscription_it == subscriptions_.end()) {
+        throw std::runtime_error("subscription has unexpectedly gone out of scope");
+      }
+      auto subscription_base = subscription_it->second.subscription;
+
+      auto subscription = std::static_pointer_cast<
+        rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+        >(subscription_base);
+
+      if (std::next(it) == subscription_ids.end()) {
+        // If this is the last subscription, give up ownership
+        subscription->provide_intra_process_message(std::move(message));
+      } else {
+        // Copy the message since we have additional subscriptions to serve
+        MessageUniquePtr copy_message;
+        Deleter deleter = message.get_deleter();
+        auto ptr = MessageAllocTraits::allocate(*allocator.get(), 1);
+        MessageAllocTraits::construct(*allocator.get(), ptr, *message);
+        copy_message = MessageUniquePtr(ptr, deleter);
+
+        subscription->provide_intra_process_message(std::move(copy_message));
+      }
+    }
+  }
+
+  PublisherToSubscriptionIdsMap pub_to_subs_;
+  SubscriptionMap subscriptions_;
+  PublisherMap publishers_;
+
+  mutable std::shared_timed_mutex mutex_;
+};
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__INTRA_PROCESS_MANAGER_HPP_

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -0,0 +1,176 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_HPP_
+#define RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_HPP_
+
+#include <rmw/rmw.h>
+
+#include <functional>
+#include <memory>
+#include <string>
+#include <utility>
+
+#include "rcl/error_handling.h"
+
+#include "rclcpp/any_subscription_callback.hpp"
+#include "rclcpp/experimental/buffers/intra_process_buffer.hpp"
+#include "rclcpp/experimental/create_intra_process_buffer.hpp"
+#include "rclcpp/experimental/subscription_intra_process_base.hpp"
+#include "rclcpp/type_support_decl.hpp"
+#include "rclcpp/waitable.hpp"
+#include "tracetools/tracetools.h"
+
+namespace rclcpp
+{
+namespace experimental
+{
+
+template<
+  typename MessageT,
+  typename Alloc = std::allocator<void>,
+  typename Deleter = std::default_delete<MessageT>,
+  typename CallbackMessageT = MessageT>
+class SubscriptionIntraProcess : public SubscriptionIntraProcessBase
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(SubscriptionIntraProcess)
+
+  using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
+  using MessageAlloc = typename MessageAllocTraits::allocator_type;
+  using ConstMessageSharedPtr = std::shared_ptr<const MessageT>;
+  using MessageUniquePtr = std::unique_ptr<MessageT, Deleter>;
+
+  using BufferUniquePtr = typename rclcpp::experimental::buffers::IntraProcessBuffer<
+    MessageT,
+    Alloc,
+    Deleter
+    >::UniquePtr;
+
+  SubscriptionIntraProcess(
+    AnySubscriptionCallback<CallbackMessageT, Alloc> callback,
+    std::shared_ptr<Alloc> allocator,
+    rclcpp::Context::SharedPtr context,
+    const std::string & topic_name,
+    rmw_qos_profile_t qos_profile,
+    rclcpp::IntraProcessBufferType buffer_type)
+  : SubscriptionIntraProcessBase(topic_name, qos_profile),
+    any_callback_(callback)
+  {
+    if (!std::is_same<MessageT, CallbackMessageT>::value) {
+      throw std::runtime_error("SubscriptionIntraProcess wrong callback type");
+    }
+
+    // Create the intra-process buffer.
+    buffer_ = rclcpp::experimental::create_intra_process_buffer<MessageT, Alloc, Deleter>(
+      buffer_type,
+      qos_profile,
+      allocator);
+
+    // Create the guard condition.
+    rcl_guard_condition_options_t guard_condition_options =
+      rcl_guard_condition_get_default_options();
+
+    gc_ = rcl_get_zero_initialized_guard_condition();
+    rcl_ret_t ret = rcl_guard_condition_init(
+      &gc_, context->get_rcl_context().get(), guard_condition_options);
+
+    if (RCL_RET_OK != ret) {
+      throw std::runtime_error("SubscriptionIntraProcess init error initializing guard condition");
+    }
+
+    TRACEPOINT(
+      rclcpp_subscription_callback_added,
+      (const void *)this,
+      (const void *)&any_callback_);
+    // The callback object gets copied, so if registration is done too early/before this point
+    // (e.g. in `AnySubscriptionCallback::set()`), its address won't match any address used later
+    // in subsequent tracepoints.
+#ifndef TRACETOOLS_DISABLED
+    any_callback_.register_callback_for_tracing();
+#endif
+  }
+
+  bool
+  is_ready(rcl_wait_set_t * wait_set)
+  {
+    (void)wait_set;
+    return buffer_->has_data();
+  }
+
+  void execute()
+  {
+    execute_impl<CallbackMessageT>();
+  }
+
+  void
+  provide_intra_process_message(ConstMessageSharedPtr message)
+  {
+    buffer_->add_shared(std::move(message));
+    trigger_guard_condition();
+  }
+
+  void
+  provide_intra_process_message(MessageUniquePtr message)
+  {
+    buffer_->add_unique(std::move(message));
+    trigger_guard_condition();
+  }
+
+  bool
+  use_take_shared_method() const
+  {
+    return buffer_->use_take_shared_method();
+  }
+
+private:
+  void
+  trigger_guard_condition()
+  {
+    rcl_ret_t ret = rcl_trigger_guard_condition(&gc_);
+    (void)ret;
+  }
+
+  template<typename T>
+  typename std::enable_if<std::is_same<T, rcl_serialized_message_t>::value, void>::type
+  execute_impl()
+  {
+    throw std::runtime_error("Subscription intra-process can't handle serialized messages");
+  }
+
+  template<class T>
+  typename std::enable_if<!std::is_same<T, rcl_serialized_message_t>::value, void>::type
+  execute_impl()
+  {
+    rmw_message_info_t msg_info;
+    msg_info.publisher_gid = {0, {0}};
+    msg_info.from_intra_process = true;
+
+    if (any_callback_.use_take_shared_method()) {
+      ConstMessageSharedPtr msg = buffer_->consume_shared();
+      any_callback_.dispatch_intra_process(msg, msg_info);
+    } else {
+      MessageUniquePtr msg = buffer_->consume_unique();
+      any_callback_.dispatch_intra_process(std::move(msg), msg_info);
+    }
+  }
+
+  AnySubscriptionCallback<CallbackMessageT, Alloc> any_callback_;
+  BufferUniquePtr buffer_;
+};
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_HPP_

rclcpp/include/rclcpp/experimental/subscription_intra_process_base.hpp

@@ -0,0 +1,88 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_BASE_HPP_
+#define RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_BASE_HPP_
+
+#include <rmw/rmw.h>
+
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <string>
+#include <utility>
+
+#include "rcl/error_handling.h"
+
+#include "rclcpp/type_support_decl.hpp"
+#include "rclcpp/waitable.hpp"
+
+namespace rclcpp
+{
+namespace experimental
+{
+
+class SubscriptionIntraProcessBase : public rclcpp::Waitable
+{
+public:
+  RCLCPP_SMART_PTR_ALIASES_ONLY(SubscriptionIntraProcessBase)
+
+  RCLCPP_PUBLIC
+  SubscriptionIntraProcessBase(const std::string & topic_name, rmw_qos_profile_t qos_profile)
+  : topic_name_(topic_name), qos_profile_(qos_profile)
+  {}
+
+  virtual ~SubscriptionIntraProcessBase() = default;
+
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_ready_guard_conditions() {return 1;}
+
+  RCLCPP_PUBLIC
+  bool
+  add_to_wait_set(rcl_wait_set_t * wait_set);
+
+  virtual bool
+  is_ready(rcl_wait_set_t * wait_set) = 0;
+
+  virtual void
+  execute() = 0;
+
+  virtual bool
+  use_take_shared_method() const = 0;
+
+  RCLCPP_PUBLIC
+  const char *
+  get_topic_name() const;
+
+  RCLCPP_PUBLIC
+  rmw_qos_profile_t
+  get_actual_qos() const;
+
+protected:
+  std::recursive_mutex reentrant_mutex_;
+  rcl_guard_condition_t gc_;
+
+private:
+  virtual void
+  trigger_guard_condition() = 0;
+
+  std::string topic_name_;
+  rmw_qos_profile_t qos_profile_;
+};
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_BASE_HPP_

rclcpp/include/rclcpp/function_traits.hpp

@@ -88,8 +88,24 @@ struct function_traits<std::_Bind<ReturnTypeT(ClassT::*(FArgs ...))(Args ...)>>
 struct function_traits<std::_Bind<std::_Mem_fn<ReturnTypeT (ClassT::*)(Args ...)>(FArgs ...)>>
 #elif defined _MSC_VER  // MS Visual Studio
 struct function_traits<
-  std::_Binder<std::_Unforced, ReturnTypeT(__cdecl ClassT::*)(Args ...), FArgs ...>
->
+  std::_Binder<std::_Unforced, ReturnTypeT (ClassT::*)(Args ...), FArgs ...>>
+#else
+#error "Unsupported C++ compiler / standard library"
+#endif
+  : function_traits<ReturnTypeT(Args ...)>
+{};
+
+// std::bind for object const methods
+template<typename ClassT, typename ReturnTypeT, typename ... Args, typename ... FArgs>
+#if defined _LIBCPP_VERSION  // libc++ (Clang)
+struct function_traits<std::__bind<ReturnTypeT (ClassT::*)(Args ...) const, FArgs ...>>
+#elif defined _GLIBCXX_RELEASE  // glibc++ (GNU C++ >= 7.1)
+struct function_traits<std::_Bind<ReturnTypeT(ClassT::*(FArgs ...))(Args ...) const>>
+#elif defined __GLIBCXX__  // glibc++ (GNU C++)
+struct function_traits<std::_Bind<std::_Mem_fn<ReturnTypeT (ClassT::*)(Args ...) const>(FArgs ...)>>
+#elif defined _MSC_VER  // MS Visual Studio
+struct function_traits<
+  std::_Binder<std::_Unforced, ReturnTypeT (ClassT::*)(Args ...) const, FArgs ...>>
 #else
 #error "Unsupported C++ compiler / standard library"
 #endif
@@ -103,7 +119,7 @@ struct function_traits<std::__bind<ReturnTypeT( &)(Args ...), FArgs ...>>
 #elif defined __GLIBCXX__  // glibc++ (GNU C++)
 struct function_traits<std::_Bind<ReturnTypeT(*(FArgs ...))(Args ...)>>
 #elif defined _MSC_VER  // MS Visual Studio
-struct function_traits<std::_Binder<std::_Unforced, ReturnTypeT(__cdecl &)(Args ...), FArgs ...>>
+struct function_traits<std::_Binder<std::_Unforced, ReturnTypeT( &)(Args ...), FArgs ...>>
 #else
 #error "Unsupported C++ compiler / standard library"
 #endif

rclcpp/include/rclcpp/future_return_code.hpp

@@ -0,0 +1,53 @@
+// Copyright 2014 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__FUTURE_RETURN_CODE_HPP_
+#define RCLCPP__FUTURE_RETURN_CODE_HPP_
+
+#include <iostream>
+#include <string>
+
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// Return codes to be used with spin_until_future_complete.
+/**
+ * SUCCESS: The future is complete and can be accessed with "get" without blocking.
+ *          This does not indicate that the operation succeeded; "get" may still throw an exception.
+ * INTERRUPTED: The future is not complete, spinning was interrupted by Ctrl-C or another error.
+ * TIMEOUT: Spinning timed out.
+ */
+enum class FutureReturnCode {SUCCESS, INTERRUPTED, TIMEOUT};
+
+/// Stream operator for FutureReturnCode.
+RCLCPP_PUBLIC
+std::ostream &
+operator<<(std::ostream & os, const FutureReturnCode & future_return_code);
+
+/// String conversion function for FutureReturnCode.
+RCLCPP_PUBLIC
+std::string
+to_string(const FutureReturnCode & future_return_code);
+
+namespace executor
+{
+
+using FutureReturnCode [[deprecated("use rclcpp::FutureReturnCode instead")]] = FutureReturnCode;
+
+}  // namespace executor
+}  // namespace rclcpp
+
+#endif  // RCLCPP__FUTURE_RETURN_CODE_HPP_

rclcpp/include/rclcpp/graph_listener.hpp

@@ -165,7 +165,7 @@ private:
   void
   __shutdown(bool);
 
-  rclcpp::Context::SharedPtr parent_context_;
+  rclcpp::Context::WeakPtr parent_context_;
 
   std::thread listener_thread_;
   bool is_started_;
@@ -177,7 +177,6 @@ private:
   std::vector<rclcpp::node_interfaces::NodeGraphInterface *> node_graph_interfaces_;
 
   rcl_guard_condition_t interrupt_guard_condition_ = rcl_get_zero_initialized_guard_condition();
-  std::shared_ptr<rcl_context_t> interrupt_guard_condition_context_;
   rcl_guard_condition_t * shutdown_guard_condition_;
   rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
 };

rclcpp/include/rclcpp/guard_condition.hpp

@@ -0,0 +1,100 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__GUARD_CONDITION_HPP_
+#define RCLCPP__GUARD_CONDITION_HPP_
+
+#include <atomic>
+
+#include "rcl/guard_condition.h"
+
+#include "rclcpp/context.hpp"
+#include "rclcpp/contexts/default_context.hpp"
+#include "rclcpp/macros.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// A condition that can be waited on in a single wait set and asynchronously triggered.
+class GuardCondition
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(GuardCondition)
+
+  // TODO(wjwwood): support custom allocator, maybe restrict to polymorphic allocator
+  /// Construct the guard condition, optionally specifying which Context to use.
+  /**
+   * \param[in] context Optional custom context to be used.
+   *   Defaults to using the global default context singleton.
+   *   Shared ownership of the context is held with the guard condition until
+   *   destruction.
+   * \throws std::invalid_argument if the context is nullptr.
+   * \throws rclcpp::exceptions::RCLError based exceptions when underlying
+   *   rcl functions fail.
+   */
+  RCLCPP_PUBLIC
+  explicit GuardCondition(
+    rclcpp::Context::SharedPtr context =
+    rclcpp::contexts::get_global_default_context());
+
+  RCLCPP_PUBLIC
+  virtual
+  ~GuardCondition();
+
+  /// Return the context used when creating this guard condition.
+  RCLCPP_PUBLIC
+  rclcpp::Context::SharedPtr
+  get_context() const;
+
+  /// Return the underlying rcl guard condition structure.
+  RCLCPP_PUBLIC
+  const rcl_guard_condition_t &
+  get_rcl_guard_condition() const;
+
+  /// Notify the wait set waiting on this condition, if any, that the condition had been met.
+  /**
+   * This function is thread-safe, and may be called concurrently with waiting
+   * on this guard condition in a wait set.
+   *
+   * \throws rclcpp::exceptions::RCLError based exceptions when underlying
+   *   rcl functions fail.
+   */
+  RCLCPP_PUBLIC
+  void
+  trigger();
+
+  /// Exchange the "in use by wait set" state for this guard condition.
+  /**
+   * This is used to ensure this guard condition is not used by multiple
+   * wait sets at the same time.
+   *
+   * \param[in] in_use_state the new state to exchange into the state, true
+   *   indicates it is now in use by a wait set, and false is that it is no
+   *   longer in use by a wait set.
+   * \returns the previous state.
+   */
+  RCLCPP_PUBLIC
+  bool
+  exchange_in_use_by_wait_set_state(bool in_use_state);
+
+protected:
+  rclcpp::Context::SharedPtr context_;
+  rcl_guard_condition_t rcl_guard_condition_;
+  std::atomic<bool> in_use_by_wait_set_{false};
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__GUARD_CONDITION_HPP_

rclcpp/include/rclcpp/intra_process_buffer_type.hpp

@@ -0,0 +1,35 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__INTRA_PROCESS_BUFFER_TYPE_HPP_
+#define RCLCPP__INTRA_PROCESS_BUFFER_TYPE_HPP_
+
+namespace rclcpp
+{
+
+/// Used as argument in create_publisher and create_subscriber
+/// when intra-process communication is enabled
+enum class IntraProcessBufferType
+{
+  /// Set the data type used in the intra-process buffer as std::shared_ptr<MessageT>
+  SharedPtr,
+  /// Set the data type used in the intra-process buffer as std::unique_ptr<MessageT>
+  UniquePtr,
+  /// Set the data type used in the intra-process buffer as the same used in the callback
+  CallbackDefault
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__INTRA_PROCESS_BUFFER_TYPE_HPP_

rclcpp/include/rclcpp/intra_process_manager.hpp

@@ -1,366 +0,0 @@
-// Copyright 2015 Open Source Robotics Foundation, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef RCLCPP__INTRA_PROCESS_MANAGER_HPP_
-#define RCLCPP__INTRA_PROCESS_MANAGER_HPP_
-
-#include <rmw/types.h>
-
-#include <algorithm>
-#include <atomic>
-#include <cstdint>
-#include <exception>
-#include <map>
-#include <memory>
-#include <mutex>
-#include <unordered_map>
-#include <set>
-
-#include "rclcpp/allocator/allocator_deleter.hpp"
-#include "rclcpp/intra_process_manager_impl.hpp"
-#include "rclcpp/mapped_ring_buffer.hpp"
-#include "rclcpp/macros.hpp"
-#include "rclcpp/publisher.hpp"
-#include "rclcpp/subscription.hpp"
-#include "rclcpp/visibility_control.hpp"
-
-namespace rclcpp
-{
-namespace intra_process_manager
-{
-
-/// This class facilitates intra process communication between nodes.
-/**
- * This class is used in the creation of publishers and subscriptions.
- * A singleton instance of this class is owned by a rclcpp::Context and a
- * rclcpp::Node can use an associated Context to get an instance of this class.
- * Nodes which do not have a common Context will not exchange intra process
- * messages because they will not share access to an instance of this class.
- *
- * When a Node creates a publisher or subscription, it will register them
- * with this class.
- * The node will also hook into the publisher's publish call
- * in order to do intra process related work.
- *
- * When a publisher is created, it advertises on the topic the user provided,
- * as well as a "shadowing" topic of type rcl_interfaces/IntraProcessMessage.
- * For instance, if the user specified the topic '/namespace/chatter', then the
- * corresponding intra process topic might be '/namespace/chatter/_intra'.
- * The publisher is also allocated an id which is unique among all publishers
- * and subscriptions in this process.
- * Additionally, when registered with this class a ring buffer is created and
- * owned by this class as a temporary place to hold messages destined for intra
- * process subscriptions.
- *
- * When a subscription is created, it subscribes to the topic provided by the
- * user as well as to the corresponding intra process topic.
- * It is also gets a unique id from the singleton instance of this class which
- * is unique among publishers and subscriptions.
- *
- * When the user publishes a message, the message is stored by calling
- * store_intra_process_message on this class.
- * The instance of that message is uniquely identified by a publisher id and a
- * message sequence number.
- * The publisher id, message sequence pair is unique with in the process.
- * At that point a list of the id's of intra process subscriptions which have
- * been registered with the singleton instance of this class are stored with
- * the message instance so that delivery is only made to those subscriptions.
- * Then an instance of rcl_interfaces/IntraProcessMessage is published to the
- * intra process topic which is specific to the topic specified by the user.
- *
- * When an instance of rcl_interfaces/IntraProcessMessage is received by a
- * subscription, then it is handled by calling take_intra_process_message
- * on a singleton of this class.
- * The subscription passes a publisher id, message sequence pair which
- * uniquely identifies the message instance it was suppose to receive as well
- * as the subscriptions unique id.
- * If the message is still being held by this class and the subscription's id
- * is in the list of intended subscriptions then the message is returned.
- * If either of those predicates are not satisfied then the message is not
- * returned and the subscription does not call the users callback.
- *
- * Since the publisher builds a list of destined subscriptions on publish, and
- * other requests are ignored, this class knows how many times a message
- * instance should be requested.
- * The final time a message is requested, the ownership is passed out of this
- * class and passed to the final subscription, effectively freeing space in
- * this class's internal storage.
- *
- * Since a topic is being used to ferry notifications about new intra process
- * messages between publishers and subscriptions, it is possible for that
- * notification to be lost.
- * It is also possible that a subscription which was available when publish was
- * called will no longer exist once the notification gets posted.
- * In both cases this might result in a message instance getting requested
- * fewer times than expected.
- * This is why the internal storage of this class is a ring buffer.
- * That way if a message is orphaned it will eventually be dropped from storage
- * when a new message instance is stored and will not result in a memory leak.
- *
- * However, since the storage system is finite, this also means that a message
- * instance might get displaced by an incoming message instance before all
- * interested parties have called take_intra_process_message.
- * Because of this the size of the internal storage should be carefully
- * considered.
- *
- * /TODO(wjwwood): update to include information about handling latching.
- * /TODO(wjwwood): consider thread safety of the class.
- *
- * This class is neither CopyConstructable nor CopyAssignable.
- */
-class IntraProcessManager
-{
-private:
-  RCLCPP_DISABLE_COPY(IntraProcessManager)
-
-public:
-  RCLCPP_SMART_PTR_DEFINITIONS(IntraProcessManager)
-
-  RCLCPP_PUBLIC
-  explicit IntraProcessManager(
-    IntraProcessManagerImplBase::SharedPtr state = create_default_impl());
-
-  RCLCPP_PUBLIC
-  virtual ~IntraProcessManager();
-
-  /// Register a subscription with the manager, returns subscriptions unique id.
-  /**
-   * In addition to generating a unique intra process id for the subscription,
-   * this method also stores the topic name of the subscription.
-   *
-   * This method is normally called during the creation of a subscription,
-   * but after it creates the internal intra process rmw_subscription_t.
-   *
-   * This method will allocate memory.
-   *
-   * \param subscription the Subscription to register.
-   * \return an unsigned 64-bit integer which is the subscription's unique id.
-   */
-  RCLCPP_PUBLIC
-  uint64_t
-  add_subscription(SubscriptionBase::SharedPtr subscription);
-
-  /// Unregister a subscription using the subscription's unique id.
-  /**
-   * This method does not allocate memory.
-   *
-   * \param intra_process_subscription_id id of the subscription to remove.
-   */
-  RCLCPP_PUBLIC
-  void
-  remove_subscription(uint64_t intra_process_subscription_id);
-
-  /// Register a publisher with the manager, returns the publisher unique id.
-  /**
-   * In addition to generating and returning a unique id for the publisher,
-   * this method creates internal ring buffer storage for "in-flight" intra
-   * process messages which are stored when store_intra_process_message is
-   * called with this publisher's unique id.
-   *
-   * The buffer_size must be less than or equal to the max uint64_t value.
-   * If the buffer_size is 0 then a buffer size is calculated using the
-   * publisher's QoS settings.
-   * The default is to use the depth field of the publisher's QoS.
-   * TODO(wjwwood): Consider doing depth *= 1.2, round up, or similar.
-   * TODO(wjwwood): Consider what to do for keep all.
-   *
-   * This method is templated on the publisher's message type so that internal
-   * storage of the same type can be allocated.
-   *
-   * This method will allocate memory.
-   *
-   * \param publisher publisher to be registered with the manager.
-   * \param buffer_size if 0 (default) a size is calculated based on the QoS.
-   * \return an unsigned 64-bit integer which is the publisher's unique id.
-   */
-  template<typename MessageT, typename Alloc>
-  uint64_t
-  add_publisher(
-    typename Publisher<MessageT, Alloc>::SharedPtr publisher,
-    size_t buffer_size = 0)
-  {
-    auto id = IntraProcessManager::get_next_unique_id();
-    size_t size = buffer_size > 0 ? buffer_size : publisher->get_queue_size();
-    auto mrb = mapped_ring_buffer::MappedRingBuffer<
-      MessageT,
-      typename Publisher<MessageT, Alloc>::MessageAlloc
-      >::make_shared(size, publisher->get_allocator());
-    impl_->add_publisher(id, publisher, mrb, size);
-    return id;
-  }
-
-  /// Unregister a publisher using the publisher's unique id.
-  /**
-   * This method does not allocate memory.
-   *
-   * \param intra_process_publisher_id id of the publisher to remove.
-   */
-  RCLCPP_PUBLIC
-  void
-  remove_publisher(uint64_t intra_process_publisher_id);
-
-  /// Store a message in the manager, and return the message sequence number.
-  /**
-   * The given message is stored in internal storage using the given publisher
-   * id and the newly generated message sequence, which is also returned.
-   * The combination of publisher id and message sequence number can later
-   * be used with a subscription id to retrieve the message by calling
-   * take_intra_process_message.
-   * The number of times take_intra_process_message can be called with this
-   * unique pair of id's is determined by the number of subscriptions currently
-   * subscribed to the same topic and which share the same Context, i.e. once
-   * for each subscription which should receive the intra process message.
-   *
-   * The ownership of the incoming message is transfered to the internal
-   * storage in order to avoid copying the message data.
-   * Therefore, the message parameter will no longer contain the original
-   * message after calling this method.
-   * Instead it will either be a nullptr or it will contain the ownership of
-   * the message instance which was displaced.
-   * If the message parameter is not equal to nullptr after calling this method
-   * then a message was prematurely displaced, i.e. take_intra_process_message
-   * had not been called on it as many times as was expected.
-   *
-   * This method can throw an exception if the publisher id is not found or
-   * if the publisher shared_ptr given to add_publisher has gone out of scope.
-   *
-   * This method does allocate memory.
-   *
-   * \param intra_process_publisher_id the id of the publisher of this message.
-   * \param message the message that is being stored.
-   * \return the message sequence number.
-   */
-  template<
-    typename MessageT, typename Alloc = std::allocator<void>,
-    typename Deleter = std::default_delete<MessageT>>
-  uint64_t
-  store_intra_process_message(
-    uint64_t intra_process_publisher_id,
-    std::unique_ptr<MessageT, Deleter> & message)
-  {
-    using MRBMessageAlloc = typename std::allocator_traits<Alloc>::template rebind_alloc<MessageT>;
-    using TypedMRB = typename mapped_ring_buffer::MappedRingBuffer<MessageT, MRBMessageAlloc>;
-    uint64_t message_seq = 0;
-    mapped_ring_buffer::MappedRingBufferBase::SharedPtr buffer = impl_->get_publisher_info_for_id(
-      intra_process_publisher_id, message_seq);
-    typename TypedMRB::SharedPtr typed_buffer = std::static_pointer_cast<TypedMRB>(buffer);
-    if (!typed_buffer) {
-      throw std::runtime_error("Typecast failed due to incorrect message type");
-    }
-
-    // Insert the message into the ring buffer using the message_seq to identify it.
-    bool did_replace = typed_buffer->push_and_replace(message_seq, message);
-    // TODO(wjwwood): do something when a message was displaced. log debug?
-    (void)did_replace;  // Avoid unused variable warning.
-
-    impl_->store_intra_process_message(intra_process_publisher_id, message_seq);
-
-    // Return the message sequence which is sent to the subscription.
-    return message_seq;
-  }
-
-  /// Take an intra process message.
-  /**
-   * The intra_process_publisher_id and message_sequence_number parameters
-   * uniquely identify a message instance, which should be taken.
-   *
-   * The requesting_subscriptions_intra_process_id parameter is used to make
-   * sure the requesting subscription was intended to receive this message
-   * instance.
-   * This check is made because it could happen that the requester
-   * comes up after the publish event, so it still receives the notification of
-   * a new intra process message, but it wasn't registered with the manager at
-   * the time of publishing, causing it to take when it wasn't intended.
-   * This should be avioded unless latching-like behavior is involved.
-   *
-   * The message parameter is used to store the taken message.
-   * On the last expected call to this method, the ownership is transfered out
-   * of internal storage and into the message parameter.
-   * On all previous calls a copy of the internally stored message is made and
-   * the ownership of the copy is transfered to the message parameter.
-   * TODO(wjwwood): update this documentation when latching is supported.
-   *
-   * The message parameter can be set to nullptr if:
-   *
-   * - The publisher id is not found.
-   * - The message sequence is not found for the given publisher id.
-   * - The requesting subscription's id is not in the list of intended takers.
-   * - The requesting subscription's id has been used before with this message.
-   *
-   * This method may allocate memory to copy the stored message.
-   *
-   * \param intra_process_publisher_id the id of the message's publisher.
-   * \param message_sequence_number the sequence number of the message.
-   * \param requesting_subscriptions_intra_process_id the subscription's id.
-   * \param message the message typed unique_ptr used to return the message.
-   */
-  template<
-    typename MessageT, typename Alloc = std::allocator<void>,
-    typename Deleter = std::default_delete<MessageT>>
-  void
-  take_intra_process_message(
-    uint64_t intra_process_publisher_id,
-    uint64_t message_sequence_number,
-    uint64_t requesting_subscriptions_intra_process_id,
-    std::unique_ptr<MessageT, Deleter> & message)
-  {
-    using MRBMessageAlloc = typename std::allocator_traits<Alloc>::template rebind_alloc<MessageT>;
-    using TypedMRB = mapped_ring_buffer::MappedRingBuffer<MessageT, MRBMessageAlloc>;
-    message = nullptr;
-
-    size_t target_subs_size = 0;
-    std::lock_guard<std::mutex> lock(take_mutex_);
-    mapped_ring_buffer::MappedRingBufferBase::SharedPtr buffer = impl_->take_intra_process_message(
-      intra_process_publisher_id,
-      message_sequence_number,
-      requesting_subscriptions_intra_process_id,
-      target_subs_size
-    );
-    typename TypedMRB::SharedPtr typed_buffer = std::static_pointer_cast<TypedMRB>(buffer);
-    if (!typed_buffer) {
-      return;
-    }
-    // Return a copy or the unique_ptr (ownership) depending on how many subscriptions are left.
-    if (target_subs_size) {
-      // There are more subscriptions to serve, return a copy.
-      typed_buffer->get_copy_at_key(message_sequence_number, message);
-    } else {
-      // This is the last one to be returned, transfer ownership.
-      typed_buffer->pop_at_key(message_sequence_number, message);
-    }
-  }
-
-  /// Return true if the given rmw_gid_t matches any stored Publishers.
-  RCLCPP_PUBLIC
-  bool
-  matches_any_publishers(const rmw_gid_t * id) const;
-
-  /// Return the number of intraprocess subscriptions to a topic, given the publisher id.
-  RCLCPP_PUBLIC
-  size_t
-  get_subscription_count(uint64_t intra_process_publisher_id) const;
-
-private:
-  RCLCPP_PUBLIC
-  static uint64_t
-  get_next_unique_id();
-
-  IntraProcessManagerImplBase::SharedPtr impl_;
-  std::mutex take_mutex_;
-};
-
-}  // namespace intra_process_manager
-}  // namespace rclcpp
-
-#endif  // RCLCPP__INTRA_PROCESS_MANAGER_HPP_

rclcpp/include/rclcpp/intra_process_manager_impl.hpp

@@ -1,358 +0,0 @@
-// Copyright 2015 Open Source Robotics Foundation, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef RCLCPP__INTRA_PROCESS_MANAGER_IMPL_HPP_
-#define RCLCPP__INTRA_PROCESS_MANAGER_IMPL_HPP_
-
-#include <algorithm>
-#include <array>
-#include <atomic>
-#include <cstring>
-#include <functional>
-#include <limits>
-#include <map>
-#include <memory>
-#include <mutex>
-#include <set>
-#include <stdexcept>
-#include <string>
-#include <unordered_map>
-#include <utility>
-
-#include "rmw/validate_full_topic_name.h"
-
-#include "rclcpp/macros.hpp"
-#include "rclcpp/mapped_ring_buffer.hpp"
-#include "rclcpp/publisher.hpp"
-#include "rclcpp/subscription.hpp"
-#include "rclcpp/visibility_control.hpp"
-
-namespace rclcpp
-{
-namespace intra_process_manager
-{
-
-class IntraProcessManagerImplBase
-{
-public:
-  RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(IntraProcessManagerImplBase)
-
-  IntraProcessManagerImplBase() = default;
-  virtual ~IntraProcessManagerImplBase() = default;
-
-  virtual void
-  add_subscription(uint64_t id, SubscriptionBase::SharedPtr subscription) = 0;
-
-  virtual void
-  remove_subscription(uint64_t intra_process_subscription_id) = 0;
-
-  virtual void add_publisher(
-    uint64_t id,
-    PublisherBase::WeakPtr publisher,
-    mapped_ring_buffer::MappedRingBufferBase::SharedPtr mrb,
-    size_t size) = 0;
-
-  virtual void
-  remove_publisher(uint64_t intra_process_publisher_id) = 0;
-
-  virtual mapped_ring_buffer::MappedRingBufferBase::SharedPtr
-  get_publisher_info_for_id(
-    uint64_t intra_process_publisher_id,
-    uint64_t & message_seq) = 0;
-
-  virtual void
-  store_intra_process_message(uint64_t intra_process_publisher_id, uint64_t message_seq) = 0;
-
-  virtual mapped_ring_buffer::MappedRingBufferBase::SharedPtr
-  take_intra_process_message(
-    uint64_t intra_process_publisher_id,
-    uint64_t message_sequence_number,
-    uint64_t requesting_subscriptions_intra_process_id,
-    size_t & size) = 0;
-
-  virtual bool
-  matches_any_publishers(const rmw_gid_t * id) const = 0;
-
-  virtual size_t
-  get_subscription_count(uint64_t intra_process_publisher_id) const = 0;
-
-private:
-  RCLCPP_DISABLE_COPY(IntraProcessManagerImplBase)
-};
-
-template<typename Allocator = std::allocator<void>>
-class IntraProcessManagerImpl : public IntraProcessManagerImplBase
-{
-public:
-  IntraProcessManagerImpl() = default;
-  ~IntraProcessManagerImpl() = default;
-
-  void
-  add_subscription(uint64_t id, SubscriptionBase::SharedPtr subscription)
-  {
-    subscriptions_[id] = subscription;
-    subscription_ids_by_topic_[fixed_size_string(subscription->get_topic_name())].insert(id);
-  }
-
-  void
-  remove_subscription(uint64_t intra_process_subscription_id)
-  {
-    subscriptions_.erase(intra_process_subscription_id);
-    for (auto & pair : subscription_ids_by_topic_) {
-      pair.second.erase(intra_process_subscription_id);
-    }
-    // Iterate over all publisher infos and all stored subscription id's and
-    // remove references to this subscription's id.
-    for (auto & publisher_pair : publishers_) {
-      for (auto & sub_pair : publisher_pair.second.target_subscriptions_by_message_sequence) {
-        sub_pair.second.erase(intra_process_subscription_id);
-      }
-    }
-  }
-
-  void add_publisher(
-    uint64_t id,
-    PublisherBase::WeakPtr publisher,
-    mapped_ring_buffer::MappedRingBufferBase::SharedPtr mrb,
-    size_t size)
-  {
-    publishers_[id].publisher = publisher;
-    // As long as the size of the ring buffer is less than the max sequence number, we're safe.
-    if (size > std::numeric_limits<uint64_t>::max()) {
-      throw std::invalid_argument("the calculated buffer size is too large");
-    }
-    publishers_[id].sequence_number.store(0);
-
-    publishers_[id].buffer = mrb;
-    publishers_[id].target_subscriptions_by_message_sequence.reserve(size);
-  }
-
-  void
-  remove_publisher(uint64_t intra_process_publisher_id)
-  {
-    publishers_.erase(intra_process_publisher_id);
-  }
-
-  // return message_seq and mrb
-  mapped_ring_buffer::MappedRingBufferBase::SharedPtr
-  get_publisher_info_for_id(
-    uint64_t intra_process_publisher_id,
-    uint64_t & message_seq)
-  {
-    std::lock_guard<std::mutex> lock(runtime_mutex_);
-    auto it = publishers_.find(intra_process_publisher_id);
-    if (it == publishers_.end()) {
-      throw std::runtime_error("get_publisher_info_for_id called with invalid publisher id");
-    }
-    PublisherInfo & info = it->second;
-    // Calculate the next message sequence number.
-    message_seq = info.sequence_number.fetch_add(1);
-
-    return info.buffer;
-  }
-
-  void
-  store_intra_process_message(uint64_t intra_process_publisher_id, uint64_t message_seq)
-  {
-    std::lock_guard<std::mutex> lock(runtime_mutex_);
-    auto it = publishers_.find(intra_process_publisher_id);
-    if (it == publishers_.end()) {
-      throw std::runtime_error("store_intra_process_message called with invalid publisher id");
-    }
-    PublisherInfo & info = it->second;
-    auto publisher = info.publisher.lock();
-    if (!publisher) {
-      throw std::runtime_error("publisher has unexpectedly gone out of scope");
-    }
-
-    // Figure out what subscriptions should receive the message.
-    auto & destined_subscriptions =
-      subscription_ids_by_topic_[fixed_size_string(publisher->get_topic_name())];
-    // Store the list for later comparison.
-    if (info.target_subscriptions_by_message_sequence.count(message_seq) == 0) {
-      info.target_subscriptions_by_message_sequence.emplace(
-        message_seq, AllocSet(std::less<uint64_t>(), uint64_allocator));
-    } else {
-      info.target_subscriptions_by_message_sequence[message_seq].clear();
-    }
-    std::copy(
-      destined_subscriptions.begin(), destined_subscriptions.end(),
-      // Memory allocation occurs in info.target_subscriptions_by_message_sequence[message_seq]
-      std::inserter(
-        info.target_subscriptions_by_message_sequence[message_seq],
-        // This ends up only being a hint to std::set, could also be .begin().
-        info.target_subscriptions_by_message_sequence[message_seq].end()
-      )
-    );
-  }
-
-  mapped_ring_buffer::MappedRingBufferBase::SharedPtr
-  take_intra_process_message(
-    uint64_t intra_process_publisher_id,
-    uint64_t message_sequence_number,
-    uint64_t requesting_subscriptions_intra_process_id,
-    size_t & size
-  )
-  {
-    std::lock_guard<std::mutex> lock(runtime_mutex_);
-    PublisherInfo * info;
-    {
-      auto it = publishers_.find(intra_process_publisher_id);
-      if (it == publishers_.end()) {
-        // Publisher is either invalid or no longer exists.
-        return 0;
-      }
-      info = &it->second;
-    }
-    // Figure out how many subscriptions are left.
-    AllocSet * target_subs;
-    {
-      auto it = info->target_subscriptions_by_message_sequence.find(message_sequence_number);
-      if (it == info->target_subscriptions_by_message_sequence.end()) {
-        // Message is no longer being stored by this publisher.
-        return 0;
-      }
-      target_subs = &it->second;
-    }
-    {
-      auto it = std::find(
-        target_subs->begin(), target_subs->end(),
-        requesting_subscriptions_intra_process_id);
-      if (it == target_subs->end()) {
-        // This publisher id/message seq pair was not intended for this subscription.
-        return 0;
-      }
-      target_subs->erase(it);
-    }
-    size = target_subs->size();
-    return info->buffer;
-  }
-
-  bool
-  matches_any_publishers(const rmw_gid_t * id) const
-  {
-    for (auto & publisher_pair : publishers_) {
-      auto publisher = publisher_pair.second.publisher.lock();
-      if (!publisher) {
-        continue;
-      }
-      if (*publisher.get() == id) {
-        return true;
-      }
-    }
-    return false;
-  }
-
-  size_t
-  get_subscription_count(uint64_t intra_process_publisher_id) const
-  {
-    auto publisher_it = publishers_.find(intra_process_publisher_id);
-    if (publisher_it == publishers_.end()) {
-      // Publisher is either invalid or no longer exists.
-      return 0;
-    }
-    auto publisher = publisher_it->second.publisher.lock();
-    if (!publisher) {
-      throw std::runtime_error("publisher has unexpectedly gone out of scope");
-    }
-    auto sub_map_it =
-      subscription_ids_by_topic_.find(fixed_size_string(publisher->get_topic_name()));
-    if (sub_map_it == subscription_ids_by_topic_.end()) {
-      // No intraprocess subscribers
-      return 0;
-    }
-    return sub_map_it->second.size();
-  }
-
-private:
-  RCLCPP_DISABLE_COPY(IntraProcessManagerImpl)
-
-  using FixedSizeString = std::array<char, RMW_TOPIC_MAX_NAME_LENGTH + 1>;
-
-  FixedSizeString
-  fixed_size_string(const char * str) const
-  {
-    FixedSizeString ret;
-    size_t size = std::strlen(str) + 1;
-    if (size > ret.size()) {
-      throw std::runtime_error("failed to copy topic name");
-    }
-    std::memcpy(ret.data(), str, size);
-    return ret;
-  }
-  struct strcmp_wrapper
-  {
-    bool
-    operator()(const FixedSizeString lhs, const FixedSizeString rhs) const
-    {
-      return std::strcmp(lhs.data(), rhs.data()) < 0;
-    }
-  };
-
-  template<typename T>
-  using RebindAlloc = typename std::allocator_traits<Allocator>::template rebind_alloc<T>;
-
-  RebindAlloc<uint64_t> uint64_allocator;
-
-  using AllocSet = std::set<uint64_t, std::less<uint64_t>, RebindAlloc<uint64_t>>;
-  using SubscriptionMap = std::unordered_map<
-    uint64_t, SubscriptionBase::WeakPtr,
-    std::hash<uint64_t>, std::equal_to<uint64_t>,
-    RebindAlloc<std::pair<const uint64_t, SubscriptionBase::WeakPtr>>>;
-
-  using IDTopicMap = std::map<
-    FixedSizeString,
-    AllocSet,
-    strcmp_wrapper,
-    RebindAlloc<std::pair<const FixedSizeString, AllocSet>>>;
-
-  SubscriptionMap subscriptions_;
-
-  IDTopicMap subscription_ids_by_topic_;
-
-  struct PublisherInfo
-  {
-    RCLCPP_DISABLE_COPY(PublisherInfo)
-
-    PublisherInfo() = default;
-
-    PublisherBase::WeakPtr publisher;
-    std::atomic<uint64_t> sequence_number;
-    mapped_ring_buffer::MappedRingBufferBase::SharedPtr buffer;
-
-    using TargetSubscriptionsMap = std::unordered_map<
-      uint64_t, AllocSet,
-      std::hash<uint64_t>, std::equal_to<uint64_t>,
-      RebindAlloc<std::pair<const uint64_t, AllocSet>>>;
-    TargetSubscriptionsMap target_subscriptions_by_message_sequence;
-  };
-
-  using PublisherMap = std::unordered_map<
-    uint64_t, PublisherInfo,
-    std::hash<uint64_t>, std::equal_to<uint64_t>,
-    RebindAlloc<std::pair<const uint64_t, PublisherInfo>>>;
-
-  PublisherMap publishers_;
-
-  std::mutex runtime_mutex_;
-};
-
-RCLCPP_PUBLIC
-IntraProcessManagerImplBase::SharedPtr
-create_default_impl();
-
-}  // namespace intra_process_manager
-}  // namespace rclcpp
-
-#endif  // RCLCPP__INTRA_PROCESS_MANAGER_IMPL_HPP_

rclcpp/include/rclcpp/loaned_message.hpp

@@ -0,0 +1,207 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__LOANED_MESSAGE_HPP_
+#define RCLCPP__LOANED_MESSAGE_HPP_
+
+#include <memory>
+#include <utility>
+
+#include "rclcpp/allocator/allocator_common.hpp"
+#include "rclcpp/logging.hpp"
+#include "rclcpp/publisher_base.hpp"
+
+#include "rcl/allocator.h"
+#include "rcl/publisher.h"
+
+namespace rclcpp
+{
+
+template<typename MessageT, typename AllocatorT = std::allocator<void>>
+class LoanedMessage
+{
+  using MessageAllocatorTraits = rclcpp::allocator::AllocRebind<MessageT, AllocatorT>;
+  using MessageAllocator = typename MessageAllocatorTraits::allocator_type;
+
+public:
+  /// Constructor of the LoanedMessage class.
+  /**
+   * The constructor of this class allocates memory for a given message type
+   * and associates this with a given publisher.
+   *
+   * Given the publisher instance, a case differentiation is being performaned
+   * which decides whether the underlying middleware is able to allocate the appropriate
+   * memory for this message type or not.
+   * In the case that the middleware can not loan messages, the passed in allocator instance
+   * is being used to allocate the message within the scope of this class.
+   * Otherwise, the allocator is being ignored and the allocation is solely performaned
+   * in the underlying middleware with its appropriate allocation strategy.
+   * The need for this arises as the user code can be written explicitly targeting a middleware
+   * capable of loaning messages.
+   * However, this user code is ought to be usable even when dynamically linked against
+   * a middleware which doesn't support message loaning in which case the allocator will be used.
+   *
+   * \param pub rclcpp::Publisher instance to which the memory belongs
+   * \param allocator Allocator instance in case middleware can not allocate messages
+   */
+  LoanedMessage(
+    const rclcpp::PublisherBase & pub,
+    std::allocator<MessageT> allocator)
+  : pub_(pub),
+    message_(nullptr),
+    message_allocator_(std::move(allocator))
+  {
+    if (pub_.can_loan_messages()) {
+      void * message_ptr = nullptr;
+      auto ret = rcl_borrow_loaned_message(
+        pub_.get_publisher_handle(),
+        rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>(),
+        &message_ptr);
+      if (RCL_RET_OK != ret) {
+        rclcpp::exceptions::throw_from_rcl_error(ret);
+      }
+      message_ = static_cast<MessageT *>(message_ptr);
+    } else {
+      RCLCPP_INFO_ONCE(
+        rclcpp::get_logger("rclcpp"),
+        "Currently used middleware can't loan messages. Local allocator will be used.");
+      message_ = message_allocator_.allocate(1);
+      new (message_) MessageT();
+    }
+  }
+
+  /// Constructor of the LoanedMessage class.
+  /**
+   * The constructor of this class allocates memory for a given message type
+   * and associates this with a given publisher.
+   *
+   * Given the publisher instance, a case differentiation is being performaned
+   * which decides whether the underlying middleware is able to allocate the appropriate
+   * memory for this message type or not.
+   * In the case that the middleware can not loan messages, the passed in allocator instance
+   * is being used to allocate the message within the scope of this class.
+   * Otherwise, the allocator is being ignored and the allocation is solely performaned
+   * in the underlying middleware with its appropriate allocation strategy.
+   * The need for this arises as the user code can be written explicitly targeting a middleware
+   * capable of loaning messages.
+   * However, this user code is ought to be usable even when dynamically linked against
+   * a middleware which doesn't support message loaning in which case the allocator will be used.
+   *
+   * \param pub rclcpp::Publisher instance to which the memory belongs
+   * \param allocator Allocator instance in case middleware can not allocate messages
+   */
+  LoanedMessage(
+    const rclcpp::PublisherBase * pub,
+    std::shared_ptr<std::allocator<MessageT>> allocator)
+  : LoanedMessage(*pub, *allocator)
+  {}
+
+  /// Move semantic for RVO
+  LoanedMessage(LoanedMessage<MessageT> && other)
+  : pub_(std::move(other.pub_)),
+    message_(std::move(other.message_)),
+    message_allocator_(std::move(other.message_allocator_))
+  {}
+
+  /// Destructor of the LoanedMessage class.
+  /**
+   * The destructor has the explicit task to return the allocated memory for its message
+   * instance.
+   * If the message was previously allocated via the middleware, the message is getting
+   * returned to the middleware to cleanly destroy the allocation.
+   * In the case that the local allocator instance was used, the same instance is then
+   * being used to destroy the allocated memory.
+   *
+   * The contract here is that the memory for this message is valid as long as this instance
+   * of the LoanedMessage class is alive.
+   */
+  virtual ~LoanedMessage()
+  {
+    auto error_logger = rclcpp::get_logger("LoanedMessage");
+
+    if (message_ == nullptr) {
+      return;
+    }
+
+    if (pub_.can_loan_messages()) {
+      // return allocated memory to the middleware
+      auto ret =
+        rcl_return_loaned_message_from_publisher(pub_.get_publisher_handle(), message_);
+      if (ret != RCL_RET_OK) {
+        RCLCPP_ERROR(
+          error_logger, "rcl_deallocate_loaned_message failed: %s", rcl_get_error_string().str);
+        rcl_reset_error();
+      }
+    } else {
+      // call destructor before deallocating
+      message_->~MessageT();
+      message_allocator_.deallocate(message_, 1);
+    }
+    message_ = nullptr;
+  }
+
+  /// Validate if the message was correctly allocated.
+  /**
+   * The allocated memory might not be always consistent and valid.
+   * Reasons why this could fail is that an allocation step was failing,
+   * e.g. just like malloc could fail or a maximum amount of previously allocated
+   * messages is exceeded in which case the loaned messages have to be returned
+   * to the middleware prior to be able to allocate a new one.
+   */
+  bool is_valid() const
+  {
+    return message_ != nullptr;
+  }
+
+  /// Access the ROS message instance.
+  /**
+   * A call to `get()` will return a mutable reference to the underlying ROS message instance.
+   * This allows a user to modify the content of the message prior to publishing it.
+   *
+   * If this reference is copied, the memory for this copy is no longer managed
+   * by the LoanedMessage instance and has to be cleanup individually.
+   */
+  MessageT & get() const
+  {
+    return *message_;
+  }
+
+  /// Release ownership of the ROS message instance.
+  /**
+   * A call to `release()` will unmanage the memory for the ROS message.
+   * That means that the destructor of this class will not free the memory on scope exit.
+   *
+   * \return Raw pointer to the message instance.
+   */
+  MessageT * release()
+  {
+    auto msg = message_;
+    message_ = nullptr;
+    return msg;
+  }
+
+protected:
+  const rclcpp::PublisherBase & pub_;
+
+  MessageT * message_;
+
+  MessageAllocator message_allocator_;
+
+  /// Deleted copy constructor to preserve memory integrity.
+  LoanedMessage(const LoanedMessage<MessageT> & other) = delete;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__LOANED_MESSAGE_HPP_

rclcpp/include/rclcpp/macros.hpp

@@ -66,6 +66,7 @@
 #define RCLCPP_SMART_PTR_ALIASES_ONLY(...) \
   __RCLCPP_SHARED_PTR_ALIAS(__VA_ARGS__) \
   __RCLCPP_WEAK_PTR_ALIAS(__VA_ARGS__) \
+  __RCLCPP_UNIQUE_PTR_ALIAS(__VA_ARGS__) \
   __RCLCPP_MAKE_SHARED_DEFINITION(__VA_ARGS__)
 
 #define __RCLCPP_SHARED_PTR_ALIAS(...) \

rclcpp/include/rclcpp/mapped_ring_buffer.hpp

@@ -1,248 +0,0 @@
-// Copyright 2015 Open Source Robotics Foundation, Inc.
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-#ifndef RCLCPP__MAPPED_RING_BUFFER_HPP_
-#define RCLCPP__MAPPED_RING_BUFFER_HPP_
-
-#include <algorithm>
-#include <cstddef>
-#include <cstdint>
-#include <memory>
-#include <mutex>
-#include <utility>
-#include <vector>
-
-#include "rclcpp/allocator/allocator_common.hpp"
-#include "rclcpp/macros.hpp"
-#include "rclcpp/visibility_control.hpp"
-
-namespace rclcpp
-{
-namespace mapped_ring_buffer
-{
-
-class RCLCPP_PUBLIC MappedRingBufferBase
-{
-public:
-  RCLCPP_SMART_PTR_DEFINITIONS(MappedRingBufferBase)
-};
-
-/// Ring buffer container of unique_ptr's of T, which can be accessed by a key.
-/**
- * T must be a CopyConstructable and CopyAssignable.
- * This class can be used in a container by using the base class MappedRingBufferBase.
- * This class must have a positive, non-zero size.
- * This class cannot be resized nor can it reserve additional space after construction.
- * This class is not CopyConstructable nor CopyAssignable.
- *
- * The key's are not guaranteed to be unique because push_and_replace does not
- * check for colliding keys.
- * It is up to the user to only use unique keys.
- * A side effect of this is that when get_copy_at_key or pop_at_key are called,
- * they return the first encountered instance of the key.
- * But iteration does not begin with the ring buffer's head, and therefore
- * there is no guarantee on which value is returned if a key is used multiple
- * times.
- */
-template<typename T, typename Alloc = std::allocator<void>>
-class MappedRingBuffer : public MappedRingBufferBase
-{
-public:
-  RCLCPP_SMART_PTR_DEFINITIONS(MappedRingBuffer<T, Alloc>)
-  using ElemAllocTraits = allocator::AllocRebind<T, Alloc>;
-  using ElemAlloc = typename ElemAllocTraits::allocator_type;
-  using ElemDeleter = allocator::Deleter<ElemAlloc, T>;
-
-  using ElemUniquePtr = std::unique_ptr<T, ElemDeleter>;
-
-  /// Constructor.
-  /**
-   * The constructor will allocate memory while reserving space.
-   *
-   * \param size size of the ring buffer; must be positive and non-zero.
-   * \param allocator optional custom allocator
-   */
-  explicit MappedRingBuffer(size_t size, std::shared_ptr<Alloc> allocator = nullptr)
-  : elements_(size), head_(0)
-  {
-    if (size == 0) {
-      throw std::invalid_argument("size must be a positive, non-zero value");
-    }
-    if (!allocator) {
-      allocator_ = std::make_shared<ElemAlloc>();
-    } else {
-      allocator_ = std::make_shared<ElemAlloc>(*allocator.get());
-    }
-  }
-
-  virtual ~MappedRingBuffer() {}
-
-  /// Return a copy of the value stored in the ring buffer at the given key.
-  /**
-   * The key is matched if an element in the ring buffer has a matching key.
-   * This method will allocate in order to return a copy.
-   *
-   * The key is not guaranteed to be unique, see the class docs for more.
-   *
-   * The contents of value before the method is called are discarded.
-   *
-   * \param key the key associated with the stored value
-   * \param value if the key is found, the value is stored in this parameter
-   */
-  void
-  get_copy_at_key(uint64_t key, ElemUniquePtr & value)
-  {
-    std::lock_guard<std::mutex> lock(data_mutex_);
-    auto it = get_iterator_of_key(key);
-    value = nullptr;
-    if (it != elements_.end() && it->in_use) {
-      auto ptr = ElemAllocTraits::allocate(*allocator_.get(), 1);
-      ElemAllocTraits::construct(*allocator_.get(), ptr, *it->value);
-      value = ElemUniquePtr(ptr);
-    }
-  }
-
-  /// Return ownership of the value stored in the ring buffer, leaving a copy.
-  /**
-   * The key is matched if an element in the ring bufer has a matching key.
-   * This method will allocate in order to store a copy.
-   *
-   * The key is not guaranteed to be unique, see the class docs for more.
-   *
-   * The ownership of the currently stored object is returned, but a copy is
-   * made and stored in its place.
-   * This means that multiple calls to this function for a particular element
-   * will result in returning the copied and stored object not the original.
-   * This also means that later calls to pop_at_key will not return the
-   * originally stored object, since it was returned by the first call to this
-   * method.
-   *
-   * The contents of value before the method is called are discarded.
-   *
-   * \param key the key associated with the stored value
-   * \param value if the key is found, the value is stored in this parameter
-   */
-  void
-  get_ownership_at_key(uint64_t key, ElemUniquePtr & value)
-  {
-    std::lock_guard<std::mutex> lock(data_mutex_);
-    auto it = get_iterator_of_key(key);
-    value = nullptr;
-    if (it != elements_.end() && it->in_use) {
-      // Make a copy.
-      auto ptr = ElemAllocTraits::allocate(*allocator_.get(), 1);
-      ElemAllocTraits::construct(*allocator_.get(), ptr, *it->value);
-      auto copy = ElemUniquePtr(ptr);
-      // Return the original.
-      value.swap(it->value);
-      // Store the copy.
-      it->value.swap(copy);
-    }
-  }
-
-  /// Return ownership of the value stored in the ring buffer at the given key.
-  /**
-   * The key is matched if an element in the ring buffer has a matching key.
-   *
-   * The key is not guaranteed to be unique, see the class docs for more.
-   *
-   * The contents of value before the method is called are discarded.
-   *
-   * \param key the key associated with the stored value
-   * \param value if the key is found, the value is stored in this parameter
-   */
-  void
-  pop_at_key(uint64_t key, ElemUniquePtr & value)
-  {
-    std::lock_guard<std::mutex> lock(data_mutex_);
-    auto it = get_iterator_of_key(key);
-    value = nullptr;
-    if (it != elements_.end() && it->in_use) {
-      value.swap(it->value);
-      it->in_use = false;
-    }
-  }
-
-  /// Insert a key-value pair, displacing an existing pair if necessary.
-  /**
-   * The key's uniqueness is not checked on insertion.
-   * It is up to the user to ensure the key is unique.
-   * This method should not allocate memory.
-   *
-   * After insertion, if a pair was replaced, then value will contain ownership
-   * of that displaced value. Otherwise it will be a nullptr.
-   *
-   * \param key the key associated with the value to be stored
-   * \param value the value to store, and optionally the value displaced
-   */
-  bool
-  push_and_replace(uint64_t key, ElemUniquePtr & value)
-  {
-    std::lock_guard<std::mutex> lock(data_mutex_);
-    bool did_replace = elements_[head_].in_use;
-    elements_[head_].key = key;
-    elements_[head_].value.swap(value);
-    elements_[head_].in_use = true;
-    head_ = (head_ + 1) % elements_.size();
-    return did_replace;
-  }
-
-  bool
-  push_and_replace(uint64_t key, ElemUniquePtr && value)
-  {
-    ElemUniquePtr temp = std::move(value);
-    return push_and_replace(key, temp);
-  }
-
-  /// Return true if the key is found in the ring buffer, otherwise false.
-  bool
-  has_key(uint64_t key)
-  {
-    std::lock_guard<std::mutex> lock(data_mutex_);
-    return elements_.end() != get_iterator_of_key(key);
-  }
-
-private:
-  RCLCPP_DISABLE_COPY(MappedRingBuffer<T, Alloc>)
-
-  struct element
-  {
-    uint64_t key;
-    ElemUniquePtr value;
-    bool in_use;
-  };
-
-  using VectorAlloc = typename std::allocator_traits<Alloc>::template rebind_alloc<element>;
-
-  typename std::vector<element, VectorAlloc>::iterator
-  get_iterator_of_key(uint64_t key)
-  {
-    auto it = std::find_if(
-      elements_.begin(), elements_.end(),
-      [key](element & e) -> bool {
-        return e.key == key && e.in_use;
-      });
-    return it;
-  }
-
-  std::vector<element, VectorAlloc> elements_;
-  size_t head_;
-  std::shared_ptr<ElemAlloc> allocator_;
-  std::mutex data_mutex_;
-};
-
-}  // namespace mapped_ring_buffer
-}  // namespace rclcpp
-
-#endif  // RCLCPP__MAPPED_RING_BUFFER_HPP_

rclcpp/include/rclcpp/memory_strategy.hpp

@@ -15,8 +15,8 @@
 #ifndef RCLCPP__MEMORY_STRATEGY_HPP_
 #define RCLCPP__MEMORY_STRATEGY_HPP_
 
+#include <list>
 #include <memory>
-#include <vector>
 
 #include "rcl/allocator.h"
 #include "rcl/wait.h"
@@ -42,19 +42,21 @@ class RCLCPP_PUBLIC MemoryStrategy
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(MemoryStrategy)
-  using WeakNodeVector = std::vector<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>;
+  using WeakNodeList = std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>;
 
   virtual ~MemoryStrategy() = default;
 
-  virtual bool collect_entities(const WeakNodeVector & weak_nodes) = 0;
+  virtual bool collect_entities(const WeakNodeList & weak_nodes) = 0;
 
   virtual size_t number_of_ready_subscriptions() const = 0;
   virtual size_t number_of_ready_services() const = 0;
   virtual size_t number_of_ready_clients() const = 0;
+  virtual size_t number_of_ready_events() const = 0;
   virtual size_t number_of_ready_timers() const = 0;
   virtual size_t number_of_guard_conditions() const = 0;
   virtual size_t number_of_waitables() const = 0;
 
+  virtual void add_waitable_handle(const rclcpp::Waitable::SharedPtr & waitable) = 0;
   virtual bool add_handles_to_wait_set(rcl_wait_set_t * wait_set) = 0;
   virtual void clear_handles() = 0;
   virtual void remove_null_handles(rcl_wait_set_t * wait_set) = 0;
@@ -65,23 +67,28 @@ public:
 
   virtual void
   get_next_subscription(
-    rclcpp::executor::AnyExecutable & any_exec,
-    const WeakNodeVector & weak_nodes) = 0;
+    rclcpp::AnyExecutable & any_exec,
+    const WeakNodeList & weak_nodes) = 0;
 
   virtual void
   get_next_service(
-    rclcpp::executor::AnyExecutable & any_exec,
-    const WeakNodeVector & weak_nodes) = 0;
+    rclcpp::AnyExecutable & any_exec,
+    const WeakNodeList & weak_nodes) = 0;
 
   virtual void
   get_next_client(
-    rclcpp::executor::AnyExecutable & any_exec,
-    const WeakNodeVector & weak_nodes) = 0;
+    rclcpp::AnyExecutable & any_exec,
+    const WeakNodeList & weak_nodes) = 0;
+
+  virtual void
+  get_next_timer(
+    rclcpp::AnyExecutable & any_exec,
+    const WeakNodeList & weak_nodes) = 0;
 
   virtual void
   get_next_waitable(
-    rclcpp::executor::AnyExecutable & any_exec,
-    const WeakNodeVector & weak_nodes) = 0;
+    rclcpp::AnyExecutable & any_exec,
+    const WeakNodeList & weak_nodes) = 0;
 
   virtual rcl_allocator_t
   get_allocator() = 0;
@@ -89,42 +96,52 @@ public:
   static rclcpp::SubscriptionBase::SharedPtr
   get_subscription_by_handle(
     std::shared_ptr<const rcl_subscription_t> subscriber_handle,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 
   static rclcpp::ServiceBase::SharedPtr
   get_service_by_handle(
     std::shared_ptr<const rcl_service_t> service_handle,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 
   static rclcpp::ClientBase::SharedPtr
   get_client_by_handle(
     std::shared_ptr<const rcl_client_t> client_handle,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
+
+  static rclcpp::TimerBase::SharedPtr
+  get_timer_by_handle(
+    std::shared_ptr<const rcl_timer_t> timer_handle,
+    const WeakNodeList & weak_nodes);
 
   static rclcpp::node_interfaces::NodeBaseInterface::SharedPtr
   get_node_by_group(
-    rclcpp::callback_group::CallbackGroup::SharedPtr group,
-    const WeakNodeVector & weak_nodes);
+    rclcpp::CallbackGroup::SharedPtr group,
+    const WeakNodeList & weak_nodes);
 
-  static rclcpp::callback_group::CallbackGroup::SharedPtr
+  static rclcpp::CallbackGroup::SharedPtr
   get_group_by_subscription(
     rclcpp::SubscriptionBase::SharedPtr subscription,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 
-  static rclcpp::callback_group::CallbackGroup::SharedPtr
+  static rclcpp::CallbackGroup::SharedPtr
   get_group_by_service(
     rclcpp::ServiceBase::SharedPtr service,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 
-  static rclcpp::callback_group::CallbackGroup::SharedPtr
+  static rclcpp::CallbackGroup::SharedPtr
   get_group_by_client(
     rclcpp::ClientBase::SharedPtr client,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 
-  static rclcpp::callback_group::CallbackGroup::SharedPtr
+  static rclcpp::CallbackGroup::SharedPtr
+  get_group_by_timer(
+    rclcpp::TimerBase::SharedPtr timer,
+    const WeakNodeList & weak_nodes);
+
+  static rclcpp::CallbackGroup::SharedPtr
   get_group_by_waitable(
     rclcpp::Waitable::SharedPtr waitable,
-    const WeakNodeVector & weak_nodes);
+    const WeakNodeList & weak_nodes);
 };
 
 }  // namespace memory_strategy

rclcpp/include/rclcpp/message_info.hpp

@@ -0,0 +1,52 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__MESSAGE_INFO_HPP_
+#define RCLCPP__MESSAGE_INFO_HPP_
+
+#include "rmw/types.h"
+
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// Additional meta data about messages taken from subscriptions.
+class RCLCPP_PUBLIC MessageInfo
+{
+public:
+  /// Default empty constructor.
+  MessageInfo() = default;
+
+  /// Conversion constructor, which is intentionally not marked as explicit.
+  // cppcheck-suppress noExplicitConstructor
+  MessageInfo(const rmw_message_info_t & rmw_message_info);  // NOLINT(runtime/explicit)
+
+  virtual ~MessageInfo();
+
+  /// Return the message info as the underlying rmw message info type.
+  const rmw_message_info_t &
+  get_rmw_message_info() const;
+
+  /// Return the message info as the underlying rmw message info type.
+  rmw_message_info_t &
+  get_rmw_message_info();
+
+private:
+  rmw_message_info_t rmw_message_info_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__MESSAGE_INFO_HPP_

rclcpp/include/rclcpp/message_memory_strategy.hpp

@@ -95,16 +95,17 @@ public:
       rclcpp::exceptions::throw_from_rcl_error(ret);
     }
 
-    auto serialized_msg = std::shared_ptr<rcl_serialized_message_t>(msg,
-        [](rmw_serialized_message_t * msg) {
-          auto ret = rmw_serialized_message_fini(msg);
-          delete msg;
-          if (ret != RCL_RET_OK) {
-            RCUTILS_LOG_ERROR_NAMED(
-              "rclcpp",
-              "failed to destroy serialized message: %s", rcl_get_error_string().str);
-          }
-        });
+    auto serialized_msg = std::shared_ptr<rcl_serialized_message_t>(
+      msg,
+      [](rmw_serialized_message_t * msg) {
+        auto fini_ret = rmw_serialized_message_fini(msg);
+        delete msg;
+        if (fini_ret != RCL_RET_OK) {
+          RCUTILS_LOG_ERROR_NAMED(
+            "rclcpp",
+            "failed to destroy serialized message: %s", rcl_get_error_string().str);
+        }
+      });
 
     return serialized_msg;
   }

rclcpp/include/rclcpp/node_impl.hpp

@@ -33,14 +33,14 @@
 #include "rcl/publisher.h"
 #include "rcl/subscription.h"
 
-#include "rcl_interfaces/msg/intra_process_message.hpp"
-
 #include "rclcpp/contexts/default_context.hpp"
-#include "rclcpp/intra_process_manager.hpp"
-#include "rclcpp/parameter.hpp"
+#include "rclcpp/create_client.hpp"
 #include "rclcpp/create_publisher.hpp"
 #include "rclcpp/create_service.hpp"
 #include "rclcpp/create_subscription.hpp"
+#include "rclcpp/detail/resolve_enable_topic_statistics.hpp"
+#include "rclcpp/parameter.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -67,182 +67,38 @@ template<typename MessageT, typename AllocatorT, typename PublisherT>
 std::shared_ptr<PublisherT>
 Node::create_publisher(
   const std::string & topic_name,
-  size_t qos_history_depth,
+  const rclcpp::QoS & qos,
   const PublisherOptionsWithAllocator<AllocatorT> & options)
 {
-  std::shared_ptr<AllocatorT> allocator = options.allocator;
-  if (!allocator) {
-    allocator = std::make_shared<AllocatorT>();
-  }
-  rmw_qos_profile_t qos_profile = options.qos_profile;
-  qos_profile.depth = qos_history_depth;
-
-  bool use_intra_process;
-  switch (options.use_intra_process_comm) {
-    case IntraProcessSetting::Enable:
-      use_intra_process = true;
-      break;
-    case IntraProcessSetting::Disable:
-      use_intra_process = false;
-      break;
-    case IntraProcessSetting::NodeDefault:
-      use_intra_process = this->get_node_options().use_intra_process_comms();
-      break;
-    default:
-      throw std::runtime_error("Unrecognized IntraProcessSetting value");
-      break;
-  }
-
   return rclcpp::create_publisher<MessageT, AllocatorT, PublisherT>(
-    this->node_topics_.get(),
+    *this,
     extend_name_with_sub_namespace(topic_name, this->get_sub_namespace()),
-    qos_profile,
-    use_intra_process,
-    allocator);
-}
-
-template<typename MessageT, typename Alloc, typename PublisherT>
-std::shared_ptr<PublisherT>
-Node::create_publisher(
-  const std::string & topic_name, size_t qos_history_depth,
-  std::shared_ptr<Alloc> allocator,
-  IntraProcessSetting use_intra_process_comm)
-{
-  PublisherOptionsWithAllocator<Alloc> pub_options;
-  pub_options.allocator = allocator;
-  pub_options.use_intra_process_comm = use_intra_process_comm;
-  return this->create_publisher<MessageT, Alloc, PublisherT>(
-    topic_name, qos_history_depth, pub_options);
-}
-
-template<typename MessageT, typename Alloc, typename PublisherT>
-std::shared_ptr<PublisherT>
-Node::create_publisher(
-  const std::string & topic_name, const rmw_qos_profile_t & qos_profile,
-  std::shared_ptr<Alloc> allocator, IntraProcessSetting use_intra_process_comm)
-{
-  PublisherOptionsWithAllocator<Alloc> pub_options;
-  pub_options.qos_profile = qos_profile;
-  pub_options.allocator = allocator;
-  pub_options.use_intra_process_comm = use_intra_process_comm;
-  return this->create_publisher<MessageT, Alloc, PublisherT>(
-    topic_name, qos_profile.depth, pub_options);
+    qos,
+    options);
 }
 
 template<
   typename MessageT,
   typename CallbackT,
   typename AllocatorT,
-  typename SubscriptionT>
+  typename CallbackMessageT,
+  typename SubscriptionT,
+  typename MessageMemoryStrategyT>
 std::shared_ptr<SubscriptionT>
 Node::create_subscription(
   const std::string & topic_name,
+  const rclcpp::QoS & qos,
   CallbackT && callback,
-  size_t qos_history_depth,
   const SubscriptionOptionsWithAllocator<AllocatorT> & options,
-  typename rclcpp::message_memory_strategy::MessageMemoryStrategy<
-    typename rclcpp::subscription_traits::has_message_type<CallbackT>::type, AllocatorT>::SharedPtr
-  msg_mem_strat)
+  typename MessageMemoryStrategyT::SharedPtr msg_mem_strat)
 {
-  using CallbackMessageT = typename rclcpp::subscription_traits::has_message_type<CallbackT>::type;
-
-  std::shared_ptr<AllocatorT> allocator = options.allocator;
-  if (!allocator) {
-    allocator = std::make_shared<AllocatorT>();
-  }
-
-  rmw_qos_profile_t qos_profile = options.qos_profile;
-  qos_profile.depth = qos_history_depth;
-
-  if (!msg_mem_strat) {
-    using rclcpp::message_memory_strategy::MessageMemoryStrategy;
-    msg_mem_strat = MessageMemoryStrategy<CallbackMessageT, AllocatorT>::create_default();
-  }
-
-  bool use_intra_process;
-  switch (options.use_intra_process_comm) {
-    case IntraProcessSetting::Enable:
-      use_intra_process = true;
-      break;
-    case IntraProcessSetting::Disable:
-      use_intra_process = false;
-      break;
-    case IntraProcessSetting::NodeDefault:
-      use_intra_process = this->get_node_options().use_intra_process_comms();
-      break;
-    default:
-      throw std::runtime_error("Unrecognized IntraProcessSetting value");
-      break;
-  }
-
-  return rclcpp::create_subscription<
-    MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT>(
-    this->node_topics_.get(),
+  return rclcpp::create_subscription<MessageT>(
+    *this,
     extend_name_with_sub_namespace(topic_name, this->get_sub_namespace()),
+    qos,
     std::forward<CallbackT>(callback),
-    qos_profile,
-    options.callback_group,
-    options.ignore_local_publications,
-    use_intra_process,
-    msg_mem_strat,
-    allocator);
-}
-
-template<
-  typename MessageT,
-  typename CallbackT,
-  typename Alloc,
-  typename SubscriptionT>
-std::shared_ptr<SubscriptionT>
-Node::create_subscription(
-  const std::string & topic_name,
-  CallbackT && callback,
-  const rmw_qos_profile_t & qos_profile,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group,
-  bool ignore_local_publications,
-  typename rclcpp::message_memory_strategy::MessageMemoryStrategy<
-    typename rclcpp::subscription_traits::has_message_type<CallbackT>::type, Alloc>::SharedPtr
-  msg_mem_strat,
-  std::shared_ptr<Alloc> allocator,
-  IntraProcessSetting use_intra_process_comm)
-{
-  SubscriptionOptionsWithAllocator<Alloc> sub_options;
-  sub_options.qos_profile = qos_profile;
-  sub_options.callback_group = group;
-  sub_options.ignore_local_publications = ignore_local_publications;
-  sub_options.allocator = allocator;
-  sub_options.use_intra_process_comm = use_intra_process_comm;
-
-  return this->create_subscription<MessageT, CallbackT, Alloc, SubscriptionT>(
-    topic_name, std::forward<CallbackT>(callback), qos_profile.depth, sub_options, msg_mem_strat);
-}
-
-template<
-  typename MessageT,
-  typename CallbackT,
-  typename Alloc,
-  typename SubscriptionT>
-std::shared_ptr<SubscriptionT>
-Node::create_subscription(
-  const std::string & topic_name,
-  CallbackT && callback,
-  size_t qos_history_depth,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group,
-  bool ignore_local_publications,
-  typename rclcpp::message_memory_strategy::MessageMemoryStrategy<
-    typename rclcpp::subscription_traits::has_message_type<CallbackT>::type, Alloc>::SharedPtr
-  msg_mem_strat,
-  std::shared_ptr<Alloc> allocator,
-  IntraProcessSetting use_intra_process_comm)
-{
-  SubscriptionOptionsWithAllocator<Alloc> sub_options;
-  sub_options.callback_group = group;
-  sub_options.ignore_local_publications = ignore_local_publications;
-  sub_options.allocator = allocator;
-  sub_options.use_intra_process_comm = use_intra_process_comm;
-
-  return this->create_subscription<MessageT, CallbackT, Alloc, SubscriptionT>(
-    topic_name, std::forward<CallbackT>(callback), qos_history_depth, sub_options, msg_mem_strat);
+    options,
+    msg_mem_strat);
 }
 
 template<typename DurationRepT, typename DurationT, typename CallbackT>
@@ -250,7 +106,7 @@ typename rclcpp::WallTimer<CallbackT>::SharedPtr
 Node::create_wall_timer(
   std::chrono::duration<DurationRepT, DurationT> period,
   CallbackT callback,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group)
+  rclcpp::CallbackGroup::SharedPtr group)
 {
   auto timer = rclcpp::WallTimer<CallbackT>::make_shared(
     std::chrono::duration_cast<std::chrono::nanoseconds>(period),
@@ -265,23 +121,15 @@ typename Client<ServiceT>::SharedPtr
 Node::create_client(
   const std::string & service_name,
   const rmw_qos_profile_t & qos_profile,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group)
+  rclcpp::CallbackGroup::SharedPtr group)
 {
-  rcl_client_options_t options = rcl_client_get_default_options();
-  options.qos = qos_profile;
-
-  using rclcpp::Client;
-  using rclcpp::ClientBase;
-
-  auto cli = Client<ServiceT>::make_shared(
-    node_base_.get(),
+  return rclcpp::create_client<ServiceT>(
+    node_base_,
     node_graph_,
+    node_services_,
     extend_name_with_sub_namespace(service_name, this->get_sub_namespace()),
-    options);
-
-  auto cli_base_ptr = std::dynamic_pointer_cast<ClientBase>(cli);
-  node_services_->add_client(cli_base_ptr, group);
-  return cli;
+    qos_profile,
+    group);
 }
 
 template<typename ServiceT, typename CallbackT>
@@ -290,7 +138,7 @@ Node::create_service(
   const std::string & service_name,
   CallbackT && callback,
   const rmw_qos_profile_t & qos_profile,
-  rclcpp::callback_group::CallbackGroup::SharedPtr group)
+  rclcpp::CallbackGroup::SharedPtr group)
 {
   return rclcpp::create_service<ServiceT, CallbackT>(
     node_base_,
@@ -301,83 +149,86 @@ Node::create_service(
     group);
 }
 
-template<typename CallbackT>
-void
-Node::register_param_change_callback(CallbackT && callback)
-{
-  this->node_parameters_->register_param_change_callback(std::forward<CallbackT>(callback));
-}
-
 template<typename ParameterT>
-void
-Node::set_parameter_if_not_set(
+auto
+Node::declare_parameter(
   const std::string & name,
-  const ParameterT & value)
+  const ParameterT & default_value,
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
 {
-  std::string parameter_name_with_sub_namespace =
-    extend_name_with_sub_namespace(name, this->get_sub_namespace());
-
-  rclcpp::Parameter parameter;
-  if (!this->get_parameter(parameter_name_with_sub_namespace, parameter)) {
-    this->set_parameters({
-        rclcpp::Parameter(parameter_name_with_sub_namespace, value),
-      });
+  try {
+    return this->declare_parameter(
+      name,
+      rclcpp::ParameterValue(default_value),
+      parameter_descriptor,
+      ignore_override
+    ).get<ParameterT>();
+  } catch (const ParameterTypeException & ex) {
+    throw exceptions::InvalidParameterTypeException(name, ex.what());
   }
 }
 
-// this is a partially-specialized version of set_parameter_if_not_set above,
-// where our concrete type for ParameterT is std::map, but the to-be-determined
-// type is the value in the map.
-template<typename MapValueT>
-void
-Node::set_parameters_if_not_set(
-  const std::string & name,
-  const std::map<std::string, MapValueT> & values)
+template<typename ParameterT>
+std::vector<ParameterT>
+Node::declare_parameters(
+  const std::string & namespace_,
+  const std::map<std::string, ParameterT> & parameters,
+  bool ignore_overrides)
 {
-  std::vector<rclcpp::Parameter> params;
-
-  for (const auto & val : values) {
-    std::string param_name = name + "." + val.first;
-    rclcpp::Parameter parameter;
-    if (!this->get_parameter(param_name, parameter)) {
-      params.push_back(rclcpp::Parameter(param_name, val.second));
+  std::vector<ParameterT> result;
+  std::string normalized_namespace = namespace_.empty() ? "" : (namespace_ + ".");
+  std::transform(
+    parameters.begin(), parameters.end(), std::back_inserter(result),
+    [this, &normalized_namespace, ignore_overrides](auto element) {
+      return this->declare_parameter(
+        normalized_namespace + element.first,
+        element.second,
+        rcl_interfaces::msg::ParameterDescriptor(),
+        ignore_overrides);
     }
-  }
-
-  this->set_parameters(params);
-}
-
-template<typename ParameterT>
-bool
-Node::get_parameter(const std::string & name, ParameterT & value) const
-{
-  std::string sub_name = extend_name_with_sub_namespace(name, this->get_sub_namespace());
-
-  rclcpp::Parameter parameter;
-
-  bool result = get_parameter(sub_name, parameter);
-  if (result) {
-    value = parameter.get_value<ParameterT>();
-  }
-
+  );
   return result;
 }
 
-// this is a partially-specialized version of get_parameter above,
-// where our concrete type for ParameterT is std::map, but the to-be-determined
-// type is the value in the map.
-template<typename MapValueT>
-bool
-Node::get_parameters(
-  const std::string & name,
-  std::map<std::string, MapValueT> & values) const
+template<typename ParameterT>
+std::vector<ParameterT>
+Node::declare_parameters(
+  const std::string & namespace_,
+  const std::map<
+    std::string,
+    std::pair<ParameterT, rcl_interfaces::msg::ParameterDescriptor>
+  > & parameters,
+  bool ignore_overrides)
 {
-  std::map<std::string, rclcpp::Parameter> params;
-  bool result = node_parameters_->get_parameters_by_prefix(name, params);
-  if (result) {
-    for (const auto & param : params) {
-      values[param.first] = param.second.get_value<MapValueT>();
+  std::vector<ParameterT> result;
+  std::string normalized_namespace = namespace_.empty() ? "" : (namespace_ + ".");
+  std::transform(
+    parameters.begin(), parameters.end(), std::back_inserter(result),
+    [this, &normalized_namespace, ignore_overrides](auto element) {
+      return static_cast<ParameterT>(
+        this->declare_parameter(
+          normalized_namespace + element.first,
+          element.second.first,
+          element.second.second,
+          ignore_overrides)
+      );
     }
+  );
+  return result;
+}
+
+template<typename ParameterT>
+bool
+Node::get_parameter(const std::string & name, ParameterT & parameter) const
+{
+  std::string sub_name = extend_name_with_sub_namespace(name, this->get_sub_namespace());
+
+  rclcpp::Parameter parameter_variant;
+
+  bool result = get_parameter(sub_name, parameter_variant);
+  if (result) {
+    parameter = static_cast<ParameterT>(parameter_variant.get_value<ParameterT>());
   }
 
   return result;
@@ -387,34 +238,36 @@ template<typename ParameterT>
 bool
 Node::get_parameter_or(
   const std::string & name,
-  ParameterT & value,
+  ParameterT & parameter,
   const ParameterT & alternative_value) const
 {
   std::string sub_name = extend_name_with_sub_namespace(name, this->get_sub_namespace());
 
-  bool got_parameter = get_parameter(sub_name, value);
+  bool got_parameter = get_parameter(sub_name, parameter);
   if (!got_parameter) {
-    value = alternative_value;
+    parameter = alternative_value;
   }
   return got_parameter;
 }
 
+// this is a partially-specialized version of get_parameter above,
+// where our concrete type for ParameterT is std::map, but the to-be-determined
+// type is the value in the map.
 template<typename ParameterT>
-void
-Node::get_parameter_or_set(
-  const std::string & name,
-  ParameterT & value,
-  const ParameterT & alternative_value)
+bool
+Node::get_parameters(
+  const std::string & prefix,
+  std::map<std::string, ParameterT> & values) const
 {
-  std::string sub_name = extend_name_with_sub_namespace(name, this->get_sub_namespace());
-
-  bool got_parameter = get_parameter(sub_name, value);
-  if (!got_parameter) {
-    this->set_parameters({
-        rclcpp::Parameter(sub_name, alternative_value),
-      });
-    value = alternative_value;
+  std::map<std::string, rclcpp::Parameter> params;
+  bool result = node_parameters_->get_parameters_by_prefix(prefix, params);
+  if (result) {
+    for (const auto & param : params) {
+      values[param.first] = static_cast<ParameterT>(param.second.get_value<ParameterT>());
+    }
   }
+
+  return result;
 }
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/node_interfaces/get_node_base_interface.hpp

@@ -0,0 +1,149 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__NODE_INTERFACES__GET_NODE_BASE_INTERFACE_HPP_
+#define RCLCPP__NODE_INTERFACES__GET_NODE_BASE_INTERFACE_HPP_
+
+#include <memory>
+#include <utility>
+#include <type_traits>
+
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
+
+/// This header provides the get_node_base_interface() template function.
+/**
+ * This function is useful for getting the NodeBaseInterface pointer from
+ * various kinds of Node-like classes.
+ *
+ * It's able to get the NodeBaseInterface pointer so long as the class
+ * has a method called ``get_node_base_interface()`` which returns
+ * either a pointer (const or not) to a NodeBaseInterface or a
+ * std::shared_ptr to a NodeBaseInterface.
+ */
+
+namespace rclcpp
+{
+namespace node_interfaces
+{
+
+namespace detail
+{
+
+// This is a meta-programming checker for if a given Node-like object has a
+// getter called get_node_base_interface() which returns various types,
+// e.g. const pointer or a shared pointer.
+template<typename NodeType, typename ReturnType>
+struct has_get_node_base_interface
+{
+private:
+  template<typename T>
+  static constexpr
+  auto
+  check(T *)->typename std::is_same<
+    decltype(std::declval<T>().get_node_base_interface()),
+    ReturnType
+  >::type;
+
+  template<typename>
+  static constexpr
+  std::false_type
+  check(...);
+
+public:
+  using type = decltype(check<NodeType>(nullptr));
+  static constexpr bool value = type::value;
+};
+
+// If NodeType is a pointer to NodeBaseInterface already (just normal function overload).
+inline
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface_from_pointer(rclcpp::node_interfaces::NodeBaseInterface * pointer)
+{
+  return pointer;
+}
+
+// If NodeType has a method called get_node_base_interface() which returns a shared pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_base_interface<
+    typename std::remove_pointer<NodeType>::type,
+    std::shared_ptr<rclcpp::node_interfaces::NodeBaseInterface>
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_base_interface().get();
+}
+
+// If NodeType has a method called get_node_base_interface() which returns a pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_base_interface<
+    typename std::remove_pointer<NodeType>::type,
+    rclcpp::node_interfaces::NodeBaseInterface *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_base_interface();
+}
+
+// Forward shared_ptr's to const node pointer signatures.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_same<
+    NodeType,
+    typename std::shared_ptr<typename std::remove_pointer<NodeType>::type::element_type> *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface_from_pointer(NodeType node_shared_pointer)
+{
+  return get_node_base_interface_from_pointer(node_shared_pointer->get());
+}
+
+}  // namespace detail
+
+/// Get the NodeBaseInterface as a pointer from a pointer to a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_pointer<NodeType>::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface(NodeType node_pointer)
+{
+  // Forward pointers to detail implmentation directly.
+  return detail::get_node_base_interface_from_pointer(node_pointer);
+}
+
+/// Get the NodeBaseInterface as a pointer from a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<
+    !std::is_pointer<typename std::remove_reference<NodeType>::type>::value, int
+  >::type = 0
+>
+rclcpp::node_interfaces::NodeBaseInterface *
+get_node_base_interface(NodeType && node_reference)
+{
+  // Forward references to detail implmentation as a pointer.
+  return detail::get_node_base_interface_from_pointer(&node_reference);
+}
+
+}  // namespace node_interfaces
+}  // namespace rclcpp
+
+#endif  // RCLCPP__NODE_INTERFACES__GET_NODE_BASE_INTERFACE_HPP_

rclcpp/include/rclcpp/node_interfaces/get_node_timers_interface.hpp

@@ -0,0 +1,149 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__NODE_INTERFACES__GET_NODE_TIMERS_INTERFACE_HPP_
+#define RCLCPP__NODE_INTERFACES__GET_NODE_TIMERS_INTERFACE_HPP_
+
+#include <memory>
+#include <utility>
+#include <type_traits>
+
+#include "rclcpp/node_interfaces/node_timers_interface.hpp"
+
+/// This header provides the get_node_timers_interface() template function.
+/**
+ * This function is useful for getting the NodeTimersInterface pointer from
+ * various kinds of Node-like classes.
+ *
+ * It's able to get the NodeTimersInterface pointer so long as the class
+ * has a method called ``get_node_timers_interface()`` which returns
+ * either a pointer (const or not) to a NodeTimersInterface or a
+ * std::shared_ptr to a NodeTimersInterface.
+ */
+
+namespace rclcpp
+{
+namespace node_interfaces
+{
+
+namespace detail
+{
+
+// This is a meta-programming checker for if a given Node-like object has a
+// getter called get_node_timers_interface() which returns various types,
+// e.g. const pointer or a shared pointer.
+template<typename NodeType, typename ReturnType>
+struct has_get_node_timers_interface
+{
+private:
+  template<typename T>
+  static constexpr
+  auto
+  check(T *)->typename std::is_same<
+    decltype(std::declval<T>().get_node_timers_interface()),
+    ReturnType
+  >::type;
+
+  template<typename>
+  static constexpr
+  std::false_type
+  check(...);
+
+public:
+  using type = decltype(check<NodeType>(nullptr));
+  static constexpr bool value = type::value;
+};
+
+// If NodeType is a pointer to NodeTimersInterface already (just normal function overload).
+inline
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface_from_pointer(rclcpp::node_interfaces::NodeTimersInterface * pointer)
+{
+  return pointer;
+}
+
+// If NodeType has a method called get_node_timers_interface() which returns a shared pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_timers_interface<
+    typename std::remove_pointer<NodeType>::type,
+    std::shared_ptr<rclcpp::node_interfaces::NodeTimersInterface>
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_timers_interface().get();
+}
+
+// If NodeType has a method called get_node_timers_interface() which returns a pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_timers_interface<
+    typename std::remove_pointer<NodeType>::type,
+    rclcpp::node_interfaces::NodeTimersInterface *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_timers_interface();
+}
+
+// Forward shared_ptr's to const node pointer signatures.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_same<
+    NodeType,
+    typename std::shared_ptr<typename std::remove_pointer<NodeType>::type::element_type> *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface_from_pointer(NodeType node_shared_pointer)
+{
+  return get_node_timers_interface_from_pointer(node_shared_pointer->get());
+}
+
+}  // namespace detail
+
+/// Get the NodeTimersInterface as a pointer from a pointer to a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_pointer<NodeType>::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface(NodeType node_pointer)
+{
+  // Forward pointers to detail implmentation directly.
+  return detail::get_node_timers_interface_from_pointer(node_pointer);
+}
+
+/// Get the NodeTimersInterface as a pointer from a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<
+    !std::is_pointer<typename std::remove_reference<NodeType>::type>::value, int
+  >::type = 0
+>
+rclcpp::node_interfaces::NodeTimersInterface *
+get_node_timers_interface(NodeType && node_reference)
+{
+  // Forward references to detail implmentation as a pointer.
+  return detail::get_node_timers_interface_from_pointer(&node_reference);
+}
+
+}  // namespace node_interfaces
+}  // namespace rclcpp
+
+#endif  // RCLCPP__NODE_INTERFACES__GET_NODE_TIMERS_INTERFACE_HPP_

rclcpp/include/rclcpp/node_interfaces/get_node_topics_interface.hpp

@@ -0,0 +1,149 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__NODE_INTERFACES__GET_NODE_TOPICS_INTERFACE_HPP_
+#define RCLCPP__NODE_INTERFACES__GET_NODE_TOPICS_INTERFACE_HPP_
+
+#include <memory>
+#include <utility>
+#include <type_traits>
+
+#include "rclcpp/node_interfaces/node_topics_interface.hpp"
+
+/// This header provides the get_node_topics_interface() template function.
+/**
+ * This function is useful for getting the NodeTopicsInterface pointer from
+ * various kinds of Node-like classes.
+ *
+ * It's able to get the NodeTopicsInterface pointer so long as the class
+ * has a method called ``get_node_topics_interface()`` which returns
+ * either a pointer (const or not) to a NodeTopicsInterface or a
+ * std::shared_ptr to a NodeTopicsInterface.
+ */
+
+namespace rclcpp
+{
+namespace node_interfaces
+{
+
+namespace detail
+{
+
+// This is a meta-programming checker for if a given Node-like object has a
+// getter called get_node_topics_interface() which returns various types,
+// e.g. const pointer or a shared pointer.
+template<typename NodeType, typename ReturnType>
+struct has_get_node_topics_interface
+{
+private:
+  template<typename T>
+  static constexpr
+  auto
+  check(T *)->typename std::is_same<
+    decltype(std::declval<T>().get_node_topics_interface()),
+    ReturnType
+  >::type;
+
+  template<typename>
+  static constexpr
+  std::false_type
+  check(...);
+
+public:
+  using type = decltype(check<NodeType>(nullptr));
+  static constexpr bool value = type::value;
+};
+
+// If NodeType is a pointer to NodeTopicsInterface already (just normal function overload).
+inline
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface_from_pointer(rclcpp::node_interfaces::NodeTopicsInterface * pointer)
+{
+  return pointer;
+}
+
+// If NodeType has a method called get_node_topics_interface() which returns a shared pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_topics_interface<
+    typename std::remove_pointer<NodeType>::type,
+    std::shared_ptr<rclcpp::node_interfaces::NodeTopicsInterface>
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_topics_interface().get();
+}
+
+// If NodeType has a method called get_node_topics_interface() which returns a pointer.
+template<
+  typename NodeType,
+  typename std::enable_if<has_get_node_topics_interface<
+    typename std::remove_pointer<NodeType>::type,
+    rclcpp::node_interfaces::NodeTopicsInterface *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface_from_pointer(NodeType node_pointer)
+{
+  return node_pointer->get_node_topics_interface();
+}
+
+// Forward shared_ptr's to const node pointer signatures.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_same<
+    NodeType,
+    typename std::shared_ptr<typename std::remove_pointer<NodeType>::type::element_type> *
+  >::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface_from_pointer(NodeType node_shared_pointer)
+{
+  return get_node_topics_interface_from_pointer(node_shared_pointer->get());
+}
+
+}  // namespace detail
+
+/// Get the NodeTopicsInterface as a pointer from a pointer to a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<std::is_pointer<NodeType>::value, int>::type = 0
+>
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface(NodeType node_pointer)
+{
+  // Forward pointers to detail implmentation directly.
+  return detail::get_node_topics_interface_from_pointer(node_pointer);
+}
+
+/// Get the NodeTopicsInterface as a pointer from a "Node like" object.
+template<
+  typename NodeType,
+  typename std::enable_if<
+    !std::is_pointer<typename std::remove_reference<NodeType>::type>::value, int
+  >::type = 0
+>
+rclcpp::node_interfaces::NodeTopicsInterface *
+get_node_topics_interface(NodeType && node_reference)
+{
+  // Forward references to detail implmentation as a pointer.
+  return detail::get_node_topics_interface_from_pointer(&node_reference);
+}
+
+}  // namespace node_interfaces
+}  // namespace rclcpp
+
+#endif  // RCLCPP__NODE_INTERFACES__GET_NODE_TOPICS_INTERFACE_HPP_

rclcpp/include/rclcpp/node_interfaces/node_base.hpp

@@ -19,9 +19,9 @@
 #include <string>
 #include <vector>
 
+#include "rcl/node.h"
 #include "rclcpp/context.hpp"
 #include "rclcpp/macros.hpp"
-#include "rclcpp/node_options.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -34,102 +34,120 @@ namespace node_interfaces
 class NodeBase : public NodeBaseInterface
 {
 public:
-  RCLCPP_SMART_PTR_ALIASES_ONLY(NodeBaseInterface)
+  RCLCPP_SMART_PTR_ALIASES_ONLY(NodeBase)
 
   RCLCPP_PUBLIC
   NodeBase(
     const std::string & node_name,
     const std::string & namespace_,
-    const NodeOptions & options);
+    rclcpp::Context::SharedPtr context,
+    const rcl_node_options_t & rcl_node_options,
+    bool use_intra_process_default,
+    bool enable_topic_statistics_default);
 
   RCLCPP_PUBLIC
   virtual
   ~NodeBase();
 
   RCLCPP_PUBLIC
-  virtual
+
   const char *
-  get_name() const;
+  get_name() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   const char *
-  get_namespace() const;
+  get_namespace() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   const char *
-  get_fully_qualified_name() const;
+  get_fully_qualified_name() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   rclcpp::Context::SharedPtr
-  get_context();
+  get_context() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   rcl_node_t *
-  get_rcl_node_handle();
+  get_rcl_node_handle() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   const rcl_node_t *
-  get_rcl_node_handle() const;
+  get_rcl_node_handle() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::shared_ptr<rcl_node_t>
-  get_shared_rcl_node_handle();
+  get_shared_rcl_node_handle() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::shared_ptr<const rcl_node_t>
-  get_shared_rcl_node_handle() const;
+  get_shared_rcl_node_handle() const override;
 
   RCLCPP_PUBLIC
-  virtual
-  rclcpp::callback_group::CallbackGroup::SharedPtr
-  create_callback_group(rclcpp::callback_group::CallbackGroupType group_type);
 
-  RCLCPP_PUBLIC
-  virtual
-  rclcpp::callback_group::CallbackGroup::SharedPtr
-  get_default_callback_group();
-
-  RCLCPP_PUBLIC
-  virtual
   bool
-  callback_group_in_node(rclcpp::callback_group::CallbackGroup::SharedPtr group);
+  assert_liveliness() const override;
 
   RCLCPP_PUBLIC
-  virtual
-  const std::vector<rclcpp::callback_group::CallbackGroup::WeakPtr> &
-  get_callback_groups() const;
+
+  rclcpp::CallbackGroup::SharedPtr
+  create_callback_group(rclcpp::CallbackGroupType group_type) override;
 
   RCLCPP_PUBLIC
-  virtual
+
+  rclcpp::CallbackGroup::SharedPtr
+  get_default_callback_group() override;
+
+  RCLCPP_PUBLIC
+
+  bool
+  callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group) override;
+
+  RCLCPP_PUBLIC
+
+  const std::vector<rclcpp::CallbackGroup::WeakPtr> &
+  get_callback_groups() const override;
+
+  RCLCPP_PUBLIC
+
   std::atomic_bool &
-  get_associated_with_executor_atomic();
+  get_associated_with_executor_atomic() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   rcl_guard_condition_t *
-  get_notify_guard_condition();
+  get_notify_guard_condition() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::unique_lock<std::recursive_mutex>
-  acquire_notify_guard_condition_lock() const;
+  acquire_notify_guard_condition_lock() const override;
+
+  RCLCPP_PUBLIC
+
+  bool
+  get_use_intra_process_default() const override;
+
+  bool
+  get_enable_topic_statistics_default() const override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeBase)
 
   rclcpp::Context::SharedPtr context_;
+  bool use_intra_process_default_;
+  bool enable_topic_statistics_default_;
 
   std::shared_ptr<rcl_node_t> node_handle_;
 
-  rclcpp::callback_group::CallbackGroup::SharedPtr default_callback_group_;
-  std::vector<rclcpp::callback_group::CallbackGroup::WeakPtr> callback_groups_;
+  rclcpp::CallbackGroup::SharedPtr default_callback_group_;
+  std::vector<rclcpp::CallbackGroup::WeakPtr> callback_groups_;
 
   std::atomic_bool associated_with_executor_;
 

rclcpp/include/rclcpp/node_interfaces/node_base_interface.hpp

@@ -102,28 +102,34 @@ public:
   std::shared_ptr<const rcl_node_t>
   get_shared_rcl_node_handle() const = 0;
 
+  /// Manually assert that this Node is alive (for RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_NODE).
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  assert_liveliness() const = 0;
+
   /// Create and return a callback group.
   RCLCPP_PUBLIC
   virtual
-  rclcpp::callback_group::CallbackGroup::SharedPtr
-  create_callback_group(rclcpp::callback_group::CallbackGroupType group_type) = 0;
+  rclcpp::CallbackGroup::SharedPtr
+  create_callback_group(rclcpp::CallbackGroupType group_type) = 0;
 
   /// Return the default callback group.
   RCLCPP_PUBLIC
   virtual
-  rclcpp::callback_group::CallbackGroup::SharedPtr
+  rclcpp::CallbackGroup::SharedPtr
   get_default_callback_group() = 0;
 
   /// Return true if the given callback group is associated with this node.
   RCLCPP_PUBLIC
   virtual
   bool
-  callback_group_in_node(rclcpp::callback_group::CallbackGroup::SharedPtr group) = 0;
+  callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group) = 0;
 
   /// Return list of callback groups associated with this node.
   RCLCPP_PUBLIC
   virtual
-  const std::vector<rclcpp::callback_group::CallbackGroup::WeakPtr> &
+  const std::vector<rclcpp::CallbackGroup::WeakPtr> &
   get_callback_groups() const = 0;
 
   /// Return the atomic bool which is used to ensure only one executor is used.
@@ -149,6 +155,18 @@ public:
   virtual
   std::unique_lock<std::recursive_mutex>
   acquire_notify_guard_condition_lock() const = 0;
+
+  /// Return the default preference for using intra process communication.
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  get_use_intra_process_default() const = 0;
+
+  /// Return the default preference for enabling topic statistics collection.
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  get_enable_topic_statistics_default() const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_clock.hpp

@@ -15,14 +15,14 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_CLOCK_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_CLOCK_HPP_
 
-#include "rclcpp/callback_group.hpp"
 #include "rclcpp/clock.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_clock_interface.hpp"
-#include "rclcpp/node_interfaces/node_parameters_interface.hpp"
+#include "rclcpp/node_interfaces/node_graph_interface.hpp"
+#include "rclcpp/node_interfaces/node_logging_interface.hpp"
+#include "rclcpp/node_interfaces/node_services_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
-#include "rclcpp/time_source.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
@@ -50,9 +50,13 @@ public:
 
   /// Get a clock which will be kept up to date by the node.
   RCLCPP_PUBLIC
-  virtual
   rclcpp::Clock::SharedPtr
-  get_clock();
+  get_clock() override;
+
+  /// Get a clock which will be kept up to date by the node.
+  RCLCPP_PUBLIC
+  rclcpp::Clock::ConstSharedPtr
+  get_clock() const override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeClock)

rclcpp/include/rclcpp/node_interfaces/node_clock_interface.hpp

@@ -15,7 +15,6 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_CLOCK_INTERFACE_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_CLOCK_INTERFACE_HPP_
 
-#include "rclcpp/callback_group.hpp"
 #include "rclcpp/clock.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -40,6 +39,12 @@ public:
   virtual
   rclcpp::Clock::SharedPtr
   get_clock() = 0;
+
+  /// Get a const ROS clock which will be kept up to date by the node.
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::Clock::ConstSharedPtr
+  get_clock() const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_graph.hpp

@@ -30,6 +30,7 @@
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_graph_interface.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "rmw/topic_endpoint_info_array.h"
 
 namespace rclcpp
 {
@@ -56,66 +57,78 @@ public:
   ~NodeGraph();
 
   RCLCPP_PUBLIC
-  virtual
+
   std::map<std::string, std::vector<std::string>>
-  get_topic_names_and_types(bool no_demangle = false) const;
+  get_topic_names_and_types(bool no_demangle = false) const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::map<std::string, std::vector<std::string>>
-  get_service_names_and_types() const;
+  get_service_names_and_types() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::vector<std::string>
-  get_node_names() const;
+  get_node_names() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   std::vector<std::pair<std::string, std::string>>
-  get_node_names_and_namespaces() const;
+  get_node_names_and_namespaces() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   size_t
-  count_publishers(const std::string & topic_name) const;
+  count_publishers(const std::string & topic_name) const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   size_t
-  count_subscribers(const std::string & topic_name) const;
+  count_subscribers(const std::string & topic_name) const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   const rcl_guard_condition_t *
-  get_graph_guard_condition() const;
+  get_graph_guard_condition() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   void
-  notify_graph_change();
+  notify_graph_change() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   void
-  notify_shutdown();
+  notify_shutdown() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   rclcpp::Event::SharedPtr
-  get_graph_event();
+  get_graph_event() override;
 
   RCLCPP_PUBLIC
-  virtual
+
   void
   wait_for_graph_change(
     rclcpp::Event::SharedPtr event,
-    std::chrono::nanoseconds timeout);
+    std::chrono::nanoseconds timeout) override;
 
   RCLCPP_PUBLIC
-  virtual
+
   size_t
-  count_graph_users();
+  count_graph_users() override;
+
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::TopicEndpointInfo>
+  get_publishers_info_by_topic(
+    const std::string & topic_name,
+    bool no_mangle = false) const override;
+
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::TopicEndpointInfo>
+  get_subscriptions_info_by_topic(
+    const std::string & topic_name,
+    bool no_mangle = false) const override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeGraph)

rclcpp/include/rclcpp/node_interfaces/node_graph_interface.hpp

@@ -15,20 +15,120 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_GRAPH_INTERFACE_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_GRAPH_INTERFACE_HPP_
 
+#include <algorithm>
+#include <array>
 #include <chrono>
 #include <map>
 #include <string>
 #include <utility>
 #include <vector>
 
+#include "rcl/graph.h"
 #include "rcl/guard_condition.h"
 
 #include "rclcpp/event.hpp"
 #include "rclcpp/macros.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
 {
+
+enum class EndpointType
+{
+  Invalid = RMW_ENDPOINT_INVALID,
+  Publisher = RMW_ENDPOINT_PUBLISHER,
+  Subscription = RMW_ENDPOINT_SUBSCRIPTION
+};
+
+/**
+ * Struct that contains topic endpoint information like the associated node name, node namespace,
+ * topic type, endpoint type, endpoint GID, and its QoS.
+ */
+class TopicEndpointInfo
+{
+public:
+  /// Construct a TopicEndpointInfo from a rcl_topic_endpoint_info_t.
+  RCLCPP_PUBLIC
+  explicit TopicEndpointInfo(const rcl_topic_endpoint_info_t & info)
+  : node_name_(info.node_name),
+    node_namespace_(info.node_namespace),
+    topic_type_(info.topic_type),
+    endpoint_type_(static_cast<rclcpp::EndpointType>(info.endpoint_type)),
+    qos_profile_({info.qos_profile.history, info.qos_profile.depth}, info.qos_profile)
+  {
+    std::copy(info.endpoint_gid, info.endpoint_gid + RMW_GID_STORAGE_SIZE, endpoint_gid_.begin());
+  }
+
+  /// Get a mutable reference to the node name.
+  RCLCPP_PUBLIC
+  std::string &
+  node_name();
+
+  /// Get a const reference to the node name.
+  RCLCPP_PUBLIC
+  const std::string &
+  node_name() const;
+
+  /// Get a mutable reference to the node namespace.
+  RCLCPP_PUBLIC
+  std::string &
+  node_namespace();
+
+  /// Get a const reference to the node namespace.
+  RCLCPP_PUBLIC
+  const std::string &
+  node_namespace() const;
+
+  /// Get a mutable reference to the topic type string.
+  RCLCPP_PUBLIC
+  std::string &
+  topic_type();
+
+  /// Get a const reference to the topic type string.
+  RCLCPP_PUBLIC
+  const std::string &
+  topic_type() const;
+
+  /// Get a mutable reference to the topic endpoint type.
+  RCLCPP_PUBLIC
+  rclcpp::EndpointType &
+  endpoint_type();
+
+  /// Get a const reference to the topic endpoint type.
+  RCLCPP_PUBLIC
+  const rclcpp::EndpointType &
+  endpoint_type() const;
+
+  /// Get a mutable reference to the GID of the topic endpoint.
+  RCLCPP_PUBLIC
+  std::array<uint8_t, RMW_GID_STORAGE_SIZE> &
+  endpoint_gid();
+
+  /// Get a const reference to the GID of the topic endpoint.
+  RCLCPP_PUBLIC
+  const std::array<uint8_t, RMW_GID_STORAGE_SIZE> &
+  endpoint_gid() const;
+
+  /// Get a mutable reference to the QoS profile of the topic endpoint.
+  RCLCPP_PUBLIC
+  rclcpp::QoS &
+  qos_profile();
+
+  /// Get a const reference to the QoS profile of the topic endpoint.
+  RCLCPP_PUBLIC
+  const rclcpp::QoS &
+  qos_profile() const;
+
+private:
+  std::string node_name_;
+  std::string node_namespace_;
+  std::string topic_type_;
+  rclcpp::EndpointType endpoint_type_;
+  std::array<uint8_t, RMW_GID_STORAGE_SIZE> endpoint_gid_;
+  rclcpp::QoS qos_profile_;
+};
+
 namespace node_interfaces
 {
 
@@ -150,6 +250,24 @@ public:
   virtual
   size_t
   count_graph_users() = 0;
+
+  /// Return the topic endpoint information about publishers on a given topic.
+  /**
+   * \sa rclcpp::Node::get_publishers_info_by_topic
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<rclcpp::TopicEndpointInfo>
+  get_publishers_info_by_topic(const std::string & topic_name, bool no_mangle = false) const = 0;
+
+  /// Return the topic endpoint information about subscriptions on a given topic.
+  /**
+   * \sa rclcpp::Node::get_subscriptions_info_by_topic
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<rclcpp::TopicEndpointInfo>
+  get_subscriptions_info_by_topic(const std::string & topic_name, bool no_mangle = false) const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_logging.hpp

@@ -42,14 +42,14 @@ public:
   ~NodeLogging();
 
   RCLCPP_PUBLIC
-  virtual
+
   rclcpp::Logger
-  get_logger() const;
+  get_logger() const override;
 
   RCLCPP_PUBLIC
-  virtual
+
   const char *
-  get_logger_name() const;
+  get_logger_name() const override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeLogging)

rclcpp/include/rclcpp/node_interfaces/node_logging_interface.hpp

@@ -19,7 +19,6 @@
 
 #include "rclcpp/logger.hpp"
 #include "rclcpp/macros.hpp"
-#include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp

rclcpp/include/rclcpp/node_interfaces/node_parameters.hpp

@@ -17,6 +17,7 @@
 
 #include <map>
 #include <memory>
+#include <list>
 #include <string>
 #include <vector>
 
@@ -27,6 +28,7 @@
 
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/node_interfaces/node_logging_interface.hpp"
 #include "rclcpp/node_interfaces/node_parameters_interface.hpp"
 #include "rclcpp/node_interfaces/node_services_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
@@ -40,6 +42,40 @@ namespace rclcpp
 namespace node_interfaces
 {
 
+// Internal struct for holding useful info about parameters
+struct ParameterInfo
+{
+  /// Current value of the parameter.
+  rclcpp::ParameterValue value;
+
+  /// A description of the parameter
+  rcl_interfaces::msg::ParameterDescriptor descriptor;
+};
+
+// Internal RAII-style guard for mutation recursion
+class ParameterMutationRecursionGuard
+{
+public:
+  explicit ParameterMutationRecursionGuard(bool & allow_mod)
+  : allow_modification_(allow_mod)
+  {
+    if (!allow_modification_) {
+      throw rclcpp::exceptions::ParameterModifiedInCallbackException(
+              "cannot set or declare a parameter, or change the callback from within set callback");
+    }
+
+    allow_modification_ = false;
+  }
+
+  ~ParameterMutationRecursionGuard()
+  {
+    allow_modification_ = true;
+  }
+
+private:
+  bool & allow_modification_;
+};
+
 /// Implementation of the NodeParameters part of the Node API.
 class NodeParameters : public NodeParametersInterface
 {
@@ -49,83 +85,117 @@ public:
   RCLCPP_PUBLIC
   NodeParameters(
     const node_interfaces::NodeBaseInterface::SharedPtr node_base,
+    const node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
     const node_interfaces::NodeTopicsInterface::SharedPtr node_topics,
     const node_interfaces::NodeServicesInterface::SharedPtr node_services,
     const node_interfaces::NodeClockInterface::SharedPtr node_clock,
-    const std::vector<Parameter> & initial_parameters,
-    bool use_intra_process,
+    const std::vector<Parameter> & parameter_overrides,
     bool start_parameter_services,
     bool start_parameter_event_publisher,
-    const rmw_qos_profile_t & parameter_event_qos_profile);
+    const rclcpp::QoS & parameter_event_qos,
+    const rclcpp::PublisherOptionsBase & parameter_event_publisher_options,
+    bool allow_undeclared_parameters,
+    bool automatically_declare_parameters_from_overrides);
 
   RCLCPP_PUBLIC
   virtual
   ~NodeParameters();
 
   RCLCPP_PUBLIC
-  virtual
+  const rclcpp::ParameterValue &
+  declare_parameter(
+    const std::string & name,
+    const rclcpp::ParameterValue & default_value,
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+    bool ignore_override) override;
+
+  RCLCPP_PUBLIC
+  void
+  undeclare_parameter(const std::string & name) override;
+
+  RCLCPP_PUBLIC
+  bool
+  has_parameter(const std::string & name) const override;
+
+  RCLCPP_PUBLIC
   std::vector<rcl_interfaces::msg::SetParametersResult>
   set_parameters(
-    const std::vector<rclcpp::Parameter> & parameters);
+    const std::vector<rclcpp::Parameter> & parameters) override;
 
   RCLCPP_PUBLIC
-  virtual
   rcl_interfaces::msg::SetParametersResult
   set_parameters_atomically(
-    const std::vector<rclcpp::Parameter> & parameters);
+    const std::vector<rclcpp::Parameter> & parameters) override;
 
   RCLCPP_PUBLIC
-  virtual
   std::vector<rclcpp::Parameter>
-  get_parameters(const std::vector<std::string> & names) const;
+  get_parameters(const std::vector<std::string> & names) const override;
 
   RCLCPP_PUBLIC
-  virtual
   rclcpp::Parameter
-  get_parameter(const std::string & name) const;
+  get_parameter(const std::string & name) const override;
 
   RCLCPP_PUBLIC
-  virtual
   bool
   get_parameter(
     const std::string & name,
-    rclcpp::Parameter & parameter) const;
+    rclcpp::Parameter & parameter) const override;
 
   RCLCPP_PUBLIC
-  virtual
   bool
   get_parameters_by_prefix(
     const std::string & prefix,
-    std::map<std::string, rclcpp::Parameter> & parameters) const;
+    std::map<std::string, rclcpp::Parameter> & parameters) const override;
 
   RCLCPP_PUBLIC
-  virtual
   std::vector<rcl_interfaces::msg::ParameterDescriptor>
-  describe_parameters(const std::vector<std::string> & names) const;
+  describe_parameters(const std::vector<std::string> & names) const override;
 
   RCLCPP_PUBLIC
-  virtual
   std::vector<uint8_t>
-  get_parameter_types(const std::vector<std::string> & names) const;
+  get_parameter_types(const std::vector<std::string> & names) const override;
 
   RCLCPP_PUBLIC
-  virtual
   rcl_interfaces::msg::ListParametersResult
-  list_parameters(const std::vector<std::string> & prefixes, uint64_t depth) const;
+  list_parameters(const std::vector<std::string> & prefixes, uint64_t depth) const override;
+
+  RCLCPP_PUBLIC
+  OnSetParametersCallbackHandle::SharedPtr
+  add_on_set_parameters_callback(OnParametersSetCallbackType callback) override;
 
   RCLCPP_PUBLIC
-  virtual
   void
-  register_param_change_callback(ParametersCallbackFunction callback);
+  remove_on_set_parameters_callback(const OnSetParametersCallbackHandle * const handler) override;
+
+  RCLCPP_PUBLIC
+  OnParametersSetCallbackType
+  set_on_parameters_set_callback(OnParametersSetCallbackType callback) override;
+
+  RCLCPP_PUBLIC
+  const std::map<std::string, rclcpp::ParameterValue> &
+  get_parameter_overrides() const override;
+
+  using CallbacksContainerType = std::list<OnSetParametersCallbackHandle::WeakPtr>;
 
 private:
   RCLCPP_DISABLE_COPY(NodeParameters)
 
-  mutable std::mutex mutex_;
+  mutable std::recursive_mutex mutex_;
 
-  ParametersCallbackFunction parameters_callback_ = nullptr;
+  // There are times when we don't want to allow modifications to parameters
+  // (particularly when a set_parameter callback tries to call set_parameter,
+  // declare_parameter, etc).  In those cases, this will be set to false.
+  bool parameter_modification_enabled_{true};
 
-  std::map<std::string, rclcpp::Parameter> parameters_;
+  OnParametersSetCallbackType on_parameters_set_callback_ = nullptr;
+
+  CallbacksContainerType on_parameters_set_callback_container_;
+
+  std::map<std::string, ParameterInfo> parameters_;
+
+  std::map<std::string, rclcpp::ParameterValue> parameter_overrides_;
+
+  bool allow_undeclared_ = false;
 
   Publisher<rcl_interfaces::msg::ParameterEvent>::SharedPtr events_publisher_;
 
@@ -133,6 +203,7 @@ private:
 
   std::string combined_name_;
 
+  node_interfaces::NodeLoggingInterface::SharedPtr node_logging_;
   node_interfaces::NodeClockInterface::SharedPtr node_clock_;
 };
 

rclcpp/include/rclcpp/node_interfaces/node_parameters_interface.hpp

@@ -16,6 +16,7 @@
 #define RCLCPP__NODE_INTERFACES__NODE_PARAMETERS_INTERFACE_HPP_
 
 #include <map>
+#include <memory>
 #include <string>
 #include <vector>
 
@@ -32,6 +33,18 @@ namespace rclcpp
 namespace node_interfaces
 {
 
+struct OnSetParametersCallbackHandle
+{
+  RCLCPP_SMART_PTR_DEFINITIONS(OnSetParametersCallbackHandle)
+
+  using OnParametersSetCallbackType =
+    std::function<
+    rcl_interfaces::msg::SetParametersResult(
+      const std::vector<rclcpp::Parameter> &)>;
+
+  OnParametersSetCallbackType callback;
+};
+
 /// Pure virtual interface class for the NodeParameters part of the Node API.
 class NodeParametersInterface
 {
@@ -42,12 +55,51 @@ public:
   virtual
   ~NodeParametersInterface() = default;
 
+  /// Declare and initialize a parameter.
+  /**
+   * \sa rclcpp::Node::declare_parameter
+   */
+  RCLCPP_PUBLIC
+  virtual
+  const rclcpp::ParameterValue &
+  declare_parameter(
+    const std::string & name,
+    const rclcpp::ParameterValue & default_value = rclcpp::ParameterValue(),
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor(),
+    bool ignore_override = false) = 0;
+
+  /// Undeclare a parameter.
+  /**
+   * \sa rclcpp::Node::undeclare_parameter
+   */
+  RCLCPP_PUBLIC
+  virtual
+  void
+  undeclare_parameter(const std::string & name) = 0;
+
+  /// Return true if the parameter has been declared, otherwise false.
+  /**
+   * \sa rclcpp::Node::has_parameter
+   */
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  has_parameter(const std::string & name) const = 0;
+
+  /// Set one or more parameters, one at a time.
+  /**
+   * \sa rclcpp::Node::set_parameters
+   */
   RCLCPP_PUBLIC
   virtual
   std::vector<rcl_interfaces::msg::SetParametersResult>
-  set_parameters(
-    const std::vector<rclcpp::Parameter> & parameters) = 0;
+  set_parameters(const std::vector<rclcpp::Parameter> & parameters) = 0;
 
+  /// Set and initialize a parameter, all at once.
+  /**
+   * \sa rclcpp::Node::set_parameters_atomically
+   */
   RCLCPP_PUBLIC
   virtual
   rcl_interfaces::msg::SetParametersResult
@@ -119,14 +171,40 @@ public:
   rcl_interfaces::msg::ListParametersResult
   list_parameters(const std::vector<std::string> & prefixes, uint64_t depth) const = 0;
 
-  using ParametersCallbackFunction = std::function<
-    rcl_interfaces::msg::SetParametersResult(
-      const std::vector<rclcpp::Parameter> &)>;
+  using OnParametersSetCallbackType = OnSetParametersCallbackHandle::OnParametersSetCallbackType;
 
+  /// Add a callback for when parameters are being set.
+  /**
+   * \sa rclcpp::Node::add_on_set_parameters_callback
+   */
+  RCLCPP_PUBLIC
+  virtual
+  OnSetParametersCallbackHandle::SharedPtr
+  add_on_set_parameters_callback(OnParametersSetCallbackType callback) = 0;
+
+  /// Remove a callback registered with `add_on_set_parameters_callback`.
+  /**
+   * \sa rclcpp::Node::remove_on_set_parameters_callback
+   */
   RCLCPP_PUBLIC
   virtual
   void
-  register_param_change_callback(ParametersCallbackFunction callback) = 0;
+  remove_on_set_parameters_callback(const OnSetParametersCallbackHandle * const handler) = 0;
+
+  /// Register a callback for when parameters are being set, return an existing one.
+  /**
+   * \sa rclcpp::Node::set_on_parameters_set_callback
+   */
+  RCLCPP_PUBLIC
+  virtual
+  OnParametersSetCallbackType
+  set_on_parameters_set_callback(OnParametersSetCallbackType callback) = 0;
+
+  /// Return the initial parameter values used by the NodeParameters to override default values.
+  RCLCPP_PUBLIC
+  virtual
+  const std::map<std::string, rclcpp::ParameterValue> &
+  get_parameter_overrides() const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_services.hpp

@@ -42,18 +42,18 @@ public:
   ~NodeServices();
 
   RCLCPP_PUBLIC
-  virtual
+
   void
   add_client(
     rclcpp::ClientBase::SharedPtr client_base_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group);
+    rclcpp::CallbackGroup::SharedPtr group) override;
 
   RCLCPP_PUBLIC
-  virtual
+
   void
   add_service(
     rclcpp::ServiceBase::SharedPtr service_base_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group);
+    rclcpp::CallbackGroup::SharedPtr group) override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeServices)

rclcpp/include/rclcpp/node_interfaces/node_services_interface.hpp

@@ -41,14 +41,14 @@ public:
   void
   add_client(
     rclcpp::ClientBase::SharedPtr client_base_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group) = 0;
+    rclcpp::CallbackGroup::SharedPtr group) = 0;
 
   RCLCPP_PUBLIC
   virtual
   void
   add_service(
     rclcpp::ServiceBase::SharedPtr service_base_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group) = 0;
+    rclcpp::CallbackGroup::SharedPtr group) = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_time_source.hpp

@@ -15,12 +15,13 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_TIME_SOURCE_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_TIME_SOURCE_HPP_
 
-#include "rclcpp/callback_group.hpp"
-#include "rclcpp/clock.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_clock_interface.hpp"
+#include "rclcpp/node_interfaces/node_graph_interface.hpp"
+#include "rclcpp/node_interfaces/node_logging_interface.hpp"
 #include "rclcpp/node_interfaces/node_parameters_interface.hpp"
+#include "rclcpp/node_interfaces/node_services_interface.hpp"
 #include "rclcpp/node_interfaces/node_time_source_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
 #include "rclcpp/time_source.hpp"

rclcpp/include/rclcpp/node_interfaces/node_time_source_interface.hpp

@@ -15,8 +15,6 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_TIME_SOURCE_INTERFACE_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_TIME_SOURCE_INTERFACE_HPP_
 
-#include "rclcpp/callback_group.hpp"
-#include "rclcpp/clock.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/visibility_control.hpp"
 

rclcpp/include/rclcpp/node_interfaces/node_timers.hpp

@@ -42,11 +42,11 @@ public:
 
   /// Add a timer to the node.
   RCLCPP_PUBLIC
-  virtual
+
   void
   add_timer(
     rclcpp::TimerBase::SharedPtr timer,
-    rclcpp::callback_group::CallbackGroup::SharedPtr callback_group);
+    rclcpp::CallbackGroup::SharedPtr callback_group) override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeTimers)

rclcpp/include/rclcpp/node_interfaces/node_timers_interface.hpp

@@ -41,7 +41,7 @@ public:
   void
   add_timer(
     rclcpp::TimerBase::SharedPtr timer,
-    rclcpp::callback_group::CallbackGroup::SharedPtr callback_group) = 0;
+    rclcpp::CallbackGroup::SharedPtr callback_group) = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_topics.hpp

@@ -42,44 +42,42 @@ public:
   explicit NodeTopics(rclcpp::node_interfaces::NodeBaseInterface * node_base);
 
   RCLCPP_PUBLIC
-  virtual
-  ~NodeTopics();
+  ~NodeTopics() override;
 
   RCLCPP_PUBLIC
-  virtual
   rclcpp::PublisherBase::SharedPtr
   create_publisher(
     const std::string & topic_name,
     const rclcpp::PublisherFactory & publisher_factory,
-    rcl_publisher_options_t & publisher_options,
-    bool use_intra_process);
+    const rclcpp::QoS & qos) override;
 
   RCLCPP_PUBLIC
-  virtual
   void
   add_publisher(
-    rclcpp::PublisherBase::SharedPtr publisher);
+    rclcpp::PublisherBase::SharedPtr publisher,
+    rclcpp::CallbackGroup::SharedPtr callback_group) override;
 
   RCLCPP_PUBLIC
-  virtual
   rclcpp::SubscriptionBase::SharedPtr
   create_subscription(
     const std::string & topic_name,
     const rclcpp::SubscriptionFactory & subscription_factory,
-    rcl_subscription_options_t & subscription_options,
-    bool use_intra_process);
+    const rclcpp::QoS & qos) override;
 
   RCLCPP_PUBLIC
-  virtual
   void
   add_subscription(
     rclcpp::SubscriptionBase::SharedPtr subscription,
-    rclcpp::callback_group::CallbackGroup::SharedPtr callback_group);
+    rclcpp::CallbackGroup::SharedPtr callback_group) override;
+
+  RCLCPP_PUBLIC
+  rclcpp::node_interfaces::NodeBaseInterface *
+  get_node_base_interface() const override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeTopics)
 
-  NodeBaseInterface * node_base_;
+  rclcpp::node_interfaces::NodeBaseInterface * node_base_;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_topics_interface.hpp

@@ -22,7 +22,9 @@
 #include "rcl/publisher.h"
 #include "rcl/subscription.h"
 
+#include "rclcpp/callback_group.hpp"
 #include "rclcpp/macros.hpp"
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/publisher.hpp"
 #include "rclcpp/publisher_factory.hpp"
 #include "rclcpp/subscription.hpp"
@@ -50,14 +52,14 @@ public:
   create_publisher(
     const std::string & topic_name,
     const rclcpp::PublisherFactory & publisher_factory,
-    rcl_publisher_options_t & publisher_options,
-    bool use_intra_process) = 0;
+    const rclcpp::QoS & qos) = 0;
 
   RCLCPP_PUBLIC
   virtual
   void
   add_publisher(
-    rclcpp::PublisherBase::SharedPtr publisher) = 0;
+    rclcpp::PublisherBase::SharedPtr publisher,
+    rclcpp::CallbackGroup::SharedPtr callback_group) = 0;
 
   RCLCPP_PUBLIC
   virtual
@@ -65,15 +67,19 @@ public:
   create_subscription(
     const std::string & topic_name,
     const rclcpp::SubscriptionFactory & subscription_factory,
-    rcl_subscription_options_t & subscription_options,
-    bool use_intra_process) = 0;
+    const rclcpp::QoS & qos) = 0;
 
   RCLCPP_PUBLIC
   virtual
   void
   add_subscription(
     rclcpp::SubscriptionBase::SharedPtr subscription,
-    rclcpp::callback_group::CallbackGroup::SharedPtr callback_group) = 0;
+    rclcpp::CallbackGroup::SharedPtr callback_group) = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  rclcpp::node_interfaces::NodeBaseInterface *
+  get_node_base_interface() const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_waitables.hpp

@@ -16,7 +16,6 @@
 #define RCLCPP__NODE_INTERFACES__NODE_WAITABLES_HPP_
 
 #include "rclcpp/callback_group.hpp"
-#include "rclcpp/client.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_waitables_interface.hpp"
@@ -42,18 +41,18 @@ public:
   ~NodeWaitables();
 
   RCLCPP_PUBLIC
-  virtual
+
   void
   add_waitable(
     rclcpp::Waitable::SharedPtr waitable_base_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group);
+    rclcpp::CallbackGroup::SharedPtr group) override;
 
   RCLCPP_PUBLIC
-  virtual
+
   void
   remove_waitable(
     rclcpp::Waitable::SharedPtr waitable_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group) noexcept;
+    rclcpp::CallbackGroup::SharedPtr group) noexcept override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeWaitables)

rclcpp/include/rclcpp/node_interfaces/node_waitables_interface.hpp

@@ -40,7 +40,7 @@ public:
   void
   add_waitable(
     rclcpp::Waitable::SharedPtr waitable_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group) = 0;
+    rclcpp::CallbackGroup::SharedPtr group) = 0;
 
   /// \note this function should not throw because it may be called in destructors
   RCLCPP_PUBLIC
@@ -48,7 +48,7 @@ public:
   void
   remove_waitable(
     rclcpp::Waitable::SharedPtr waitable_ptr,
-    rclcpp::callback_group::CallbackGroup::SharedPtr group) noexcept = 0;
+    rclcpp::CallbackGroup::SharedPtr group) noexcept = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_options.hpp

@@ -23,6 +23,8 @@
 #include "rclcpp/context.hpp"
 #include "rclcpp/contexts/default_context.hpp"
 #include "rclcpp/parameter.hpp"
+#include "rclcpp/publisher_options.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
@@ -36,14 +38,19 @@ public:
   /**
    * Default values for the node options:
    *
-   *   - context = rclcpp::contexts::default_context::get_global_default_context()
+   *   - context = rclcpp::contexts::get_global_default_context()
    *   - arguments = {}
-   *   - initial_parameters = {}
+   *   - parameter_overrides = {}
    *   - use_global_arguments = true
    *   - use_intra_process_comms = false
+   *   - enable_topic_statistics = false
    *   - start_parameter_services = true
    *   - start_parameter_event_publisher = true
-   *   - parameter_event_qos_profile = rmw_qos_profile_parameter_events
+   *   - parameter_event_qos = rclcpp::ParameterEventQoS
+   *     - with history setting and depth from rmw_qos_profile_parameter_events
+   *   - parameter_event_publisher_options = rclcpp::PublisherOptionsBase
+   *   - allow_undeclared_parameters = false
+   *   - automatically_declare_parameters_from_overrides = false
    *   - allocator = rcl_get_default_allocator()
    *
    * \param[in] allocator allocator to use in construction of NodeOptions.
@@ -93,7 +100,7 @@ public:
   /// Set the arguments, return this for parameter idiom.
   /**
    * These arguments are used to extract remappings used by the node and other
-   * settings.
+   * ROS specific settings, as well as user defined non-ROS arguments.
    *
    * This will cause the internal rcl_node_options_t struct to be invalidated.
    */
@@ -101,37 +108,37 @@ public:
   NodeOptions &
   arguments(const std::vector<std::string> & arguments);
 
-  /// Return a reference to the list of initial parameters.
+  /// Return a reference to the list of parameter overrides.
   RCLCPP_PUBLIC
   std::vector<rclcpp::Parameter> &
-  initial_parameters();
+  parameter_overrides();
 
   RCLCPP_PUBLIC
   const std::vector<rclcpp::Parameter> &
-  initial_parameters() const;
+  parameter_overrides() const;
 
-  /// Set the initial parameters, return this for parameter idiom.
+  /// Set the parameters overrides, return this for parameter idiom.
   /**
-   * These initial parameter values are used to change the initial value
+   * These parameter overrides are used to change the initial value
    * of declared parameters within the node, overriding hard coded default
    * values if necessary.
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  initial_parameters(const std::vector<rclcpp::Parameter> & initial_parameters);
+  parameter_overrides(const std::vector<rclcpp::Parameter> & parameter_overrides);
 
-  /// Append a single initial parameter, parameter idiom style.
+  /// Append a single parameter override, parameter idiom style.
   template<typename ParameterT>
   NodeOptions &
-  append_initial_parameter(const std::string & name, const ParameterT & value)
+  append_parameter_override(const std::string & name, const ParameterT & value)
   {
-    this->initial_parameters().emplace_back(name, rclcpp::ParameterValue(value));
+    this->parameter_overrides().emplace_back(name, rclcpp::ParameterValue(value));
     return *this;
   }
 
-  /// Return a reference to the use_global_arguments flag.
+  /// Return the use_global_arguments flag.
   RCLCPP_PUBLIC
-  const bool &
+  bool
   use_global_arguments() const;
 
   /// Set the use_global_arguments flag, return this for parameter idiom.
@@ -144,11 +151,27 @@ public:
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  use_global_arguments(const bool & use_global_arguments);
+  use_global_arguments(bool use_global_arguments);
 
-  /// Return a reference to the use_intra_process_comms flag
+  /// Return the enable_rosout flag.
   RCLCPP_PUBLIC
-  const bool &
+  bool
+  enable_rosout() const;
+
+  /// Set the enable_rosout flag, return this for parameter idiom.
+  /**
+   * If false this will cause the node not to use rosout logging.
+   *
+   * Defaults to true for now, as there are still some cases where it is
+   * desirable.
+   */
+  RCLCPP_PUBLIC
+  NodeOptions &
+  enable_rosout(bool enable_rosout);
+
+  /// Return the use_intra_process_comms flag.
+  RCLCPP_PUBLIC
+  bool
   use_intra_process_comms() const;
 
   /// Set the use_intra_process_comms flag, return this for parameter idiom.
@@ -163,11 +186,28 @@ public:
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  use_intra_process_comms(const bool & use_intra_process_comms);
+  use_intra_process_comms(bool use_intra_process_comms);
 
-  /// Return a reference to the start_parameter_services flag
+  /// Return the enable_topic_statistics flag.
   RCLCPP_PUBLIC
-  const bool &
+  bool
+  enable_topic_statistics() const;
+
+  /// Set the enable_topic_statistics flag, return this for parameter idiom.
+  /**
+   * If true, topic statistics collection and publication will be enabled
+   * for all subscriptions.
+   * This can be used to override the global topic statistics setting.
+   *
+   * Defaults to false.
+   */
+  RCLCPP_PUBLIC
+  NodeOptions &
+  enable_topic_statistics(bool enable_topic_statistics);
+
+  /// Return the start_parameter_services flag.
+  RCLCPP_PUBLIC
+  bool
   start_parameter_services() const;
 
   /// Set the start_parameter_services flag, return this for parameter idiom.
@@ -182,11 +222,11 @@ public:
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  start_parameter_services(const bool & start_parameter_services);
+  start_parameter_services(bool start_parameter_services);
 
-  /// Return a reference to the start_parameter_event_publisher flag.
+  /// Return the start_parameter_event_publisher flag.
   RCLCPP_PUBLIC
-  const bool &
+  bool
   start_parameter_event_publisher() const;
 
   /// Set the start_parameter_event_publisher flag, return this for parameter idiom.
@@ -198,20 +238,78 @@ public:
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  start_parameter_event_publisher(const bool & start_parameter_event_publisher);
+  start_parameter_event_publisher(bool start_parameter_event_publisher);
 
-  /// Return a reference to the parameter_event_qos_profile QoS.
+  /// Return a reference to the parameter_event_qos QoS.
   RCLCPP_PUBLIC
-  const rmw_qos_profile_t &
-  parameter_event_qos_profile() const;
+  const rclcpp::QoS &
+  parameter_event_qos() const;
 
-  /// Set the parameter_event_qos_profile QoS, return this for parameter idiom.
+  /// Set the parameter_event_qos QoS, return this for parameter idiom.
   /**
    * The QoS settings to be used for the parameter event publisher, if enabled.
    */
   RCLCPP_PUBLIC
   NodeOptions &
-  parameter_event_qos_profile(const rmw_qos_profile_t & parameter_event_qos_profile);
+  parameter_event_qos(const rclcpp::QoS & parameter_event_qos);
+
+  /// Return a reference to the parameter_event_publisher_options.
+  RCLCPP_PUBLIC
+  const rclcpp::PublisherOptionsBase &
+  parameter_event_publisher_options() const;
+
+  /// Set the parameter_event_publisher_options, return this for parameter idiom.
+  /**
+   * The QoS settings to be used for the parameter event publisher, if enabled.
+   *
+   * \todo(wjwwood): make this take/store an instance of
+   *   rclcpp::PublisherOptionsWithAllocator<Allocator>, but to do that requires
+   *   NodeOptions to also be templated based on the Allocator type.
+   */
+  RCLCPP_PUBLIC
+  NodeOptions &
+  parameter_event_publisher_options(
+    const rclcpp::PublisherOptionsBase & parameter_event_publisher_options);
+
+  /// Return the allow_undeclared_parameters flag.
+  RCLCPP_PUBLIC
+  bool
+  allow_undeclared_parameters() const;
+
+  /// Set the allow_undeclared_parameters, return this for parameter idiom.
+  /**
+   * If true, allow any parameter name to be set on the node without first
+   * being declared.
+   * Otherwise, setting an undeclared parameter will raise an exception.
+   *
+   * This option being true does not affect parameter_overrides, as the first
+   * set action will implicitly declare the parameter and therefore consider
+   * any parameter overrides.
+   */
+  RCLCPP_PUBLIC
+  NodeOptions &
+  allow_undeclared_parameters(bool allow_undeclared_parameters);
+
+  /// Return the automatically_declare_parameters_from_overrides flag.
+  RCLCPP_PUBLIC
+  bool
+  automatically_declare_parameters_from_overrides() const;
+
+  /// Set the automatically_declare_parameters_from_overrides, return this.
+  /**
+   * If true, automatically iterate through the node's parameter overrides and
+   * implicitly declare any that have not already been declared.
+   * Otherwise, parameters passed to the node's parameter_overrides, and/or the
+   * global arguments (e.g. parameter overrides from a YAML file), which are
+   * not explicitly declared will not appear on the node at all, even if
+   * `allow_undeclared_parameters` is true.
+   * Already declared parameters will not be re-declared, and parameters
+   * declared in this way will use the default constructed ParameterDescriptor.
+   */
+  RCLCPP_PUBLIC
+  NodeOptions &
+  automatically_declare_parameters_from_overrides(
+    bool automatically_declare_parameters_from_overrides);
 
   /// Return the rcl_allocator_t to be used.
   RCLCPP_PUBLIC
@@ -240,21 +338,33 @@ private:
   // documentation in this class.
 
   rclcpp::Context::SharedPtr context_ {
-    rclcpp::contexts::default_context::get_global_default_context()};
+    rclcpp::contexts::get_global_default_context()};
 
   std::vector<std::string> arguments_ {};
 
-  std::vector<rclcpp::Parameter> initial_parameters_ {};
+  std::vector<rclcpp::Parameter> parameter_overrides_ {};
 
   bool use_global_arguments_ {true};
 
+  bool enable_rosout_ {true};
+
   bool use_intra_process_comms_ {false};
 
+  bool enable_topic_statistics_ {false};
+
   bool start_parameter_services_ {true};
 
   bool start_parameter_event_publisher_ {true};
 
-  rmw_qos_profile_t parameter_event_qos_profile_ {rmw_qos_profile_parameter_events};
+  rclcpp::QoS parameter_event_qos_ = rclcpp::ParameterEventsQoS(
+    rclcpp::QoSInitialization::from_rmw(rmw_qos_profile_parameter_events)
+  );
+
+  rclcpp::PublisherOptionsBase parameter_event_publisher_options_ = rclcpp::PublisherOptionsBase();
+
+  bool allow_undeclared_parameters_ {false};
+
+  bool automatically_declare_parameters_from_overrides_ {false};
 
   rcl_allocator_t allocator_ {rcl_get_default_allocator()};
 };

rclcpp/include/rclcpp/parameter.hpp

@@ -22,27 +22,66 @@
 #include <vector>
 
 #include "rcl_interfaces/msg/parameter.hpp"
+#include "rclcpp/exceptions.hpp"
 #include "rclcpp/parameter_value.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
 {
 
+class Parameter;
+
+namespace node_interfaces
+{
+struct ParameterInfo;
+}  // namespace node_interfaces
+
+namespace detail
+{
+
+// This helper function is required because you cannot do specialization on a
+// class method, so instead we specialize this template function and call it
+// from the unspecialized, but dependent, class method.
+template<typename T>
+auto
+get_value_helper(const rclcpp::Parameter * parameter);
+
+}  // namespace detail
+
 /// Structure to store an arbitrary parameter with templated get/set methods.
 class Parameter
 {
 public:
+  /// Construct with an empty name and a parameter value of type rclcpp::PARAMETER_NOT_SET.
   RCLCPP_PUBLIC
   Parameter();
 
+  /// Construct with given name and a parameter value of type rclcpp::PARAMETER_NOT_SET.
+  RCLCPP_PUBLIC
+  explicit Parameter(const std::string & name);
+
+  /// Construct with given name and given parameter value.
   RCLCPP_PUBLIC
   Parameter(const std::string & name, const ParameterValue & value);
 
+  /// Construct with given name and given parameter value.
   template<typename ValueTypeT>
-  explicit Parameter(const std::string & name, ValueTypeT value)
+  Parameter(const std::string & name, ValueTypeT value)
   : Parameter(name, ParameterValue(value))
-  {
-  }
+  {}
+
+  RCLCPP_PUBLIC
+  explicit Parameter(const rclcpp::node_interfaces::ParameterInfo & parameter_info);
+
+  /// Equal operator.
+  RCLCPP_PUBLIC
+  bool
+  operator==(const Parameter & rhs) const;
+
+  /// Not equal operator.
+  RCLCPP_PUBLIC
+  bool
+  operator!=(const Parameter & rhs) const;
 
   RCLCPP_PUBLIC
   ParameterType
@@ -60,6 +99,11 @@ public:
   rcl_interfaces::msg::ParameterValue
   get_value_message() const;
 
+  /// Get the internal storage for the parameter value.
+  RCLCPP_PUBLIC
+  const rclcpp::ParameterValue &
+  get_parameter_value() const;
+
   /// Get value of parameter using rclcpp::ParameterType as template argument.
   template<ParameterType ParamT>
   decltype(auto)
@@ -71,10 +115,7 @@ public:
   /// Get value of parameter using c++ types as template argument.
   template<typename T>
   decltype(auto)
-  get_value() const
-  {
-    return value_.get<T>();
-  }
+  get_value() const;
 
   RCLCPP_PUBLIC
   bool
@@ -142,6 +183,53 @@ RCLCPP_PUBLIC
 std::ostream &
 operator<<(std::ostream & os, const std::vector<Parameter> & parameters);
 
+namespace detail
+{
+
+template<typename T>
+auto
+get_value_helper(const rclcpp::Parameter * parameter)
+{
+  return parameter->get_parameter_value().get<T>();
+}
+
+// Specialization allowing Parameter::get() to return a const ref to the parameter value object.
+template<>
+inline
+auto
+get_value_helper<rclcpp::ParameterValue>(const rclcpp::Parameter * parameter)
+{
+  return parameter->get_parameter_value();
+}
+
+// Specialization allowing Parameter::get() to return a const ref to the parameter itself.
+template<>
+inline
+auto
+get_value_helper<rclcpp::Parameter>(const rclcpp::Parameter * parameter)
+{
+  // Use this lambda to ensure it's a const reference being returned (and not a copy).
+  auto type_enforcing_lambda =
+    [&parameter]() -> const rclcpp::Parameter & {
+      return *parameter;
+    };
+  return type_enforcing_lambda();
+}
+
+}  // namespace detail
+
+template<typename T>
+decltype(auto)
+Parameter::get_value() const
+{
+  try {
+    // use the helper to specialize for the ParameterValue and Parameter cases.
+    return detail::get_value_helper<T>(this);
+  } catch (const ParameterTypeException & ex) {
+    throw exceptions::InvalidParameterTypeException(this->name_, ex.what());
+  }
+}
+
 }  // namespace rclcpp
 
 namespace std

rclcpp/include/rclcpp/parameter_client.hpp

@@ -53,19 +53,22 @@ public:
     const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
     const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_interface,
     const std::string & remote_node_name = "",
-    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
+    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters,
+    rclcpp::CallbackGroup::SharedPtr group = nullptr);
 
   RCLCPP_PUBLIC
   AsyncParametersClient(
     const rclcpp::Node::SharedPtr node,
     const std::string & remote_node_name = "",
-    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
+    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters,
+    rclcpp::CallbackGroup::SharedPtr group = nullptr);
 
   RCLCPP_PUBLIC
   AsyncParametersClient(
     rclcpp::Node * node,
     const std::string & remote_node_name = "",
-    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
+    const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters,
+    rclcpp::CallbackGroup::SharedPtr group = nullptr);
 
   RCLCPP_PUBLIC
   std::shared_future<std::vector<rclcpp::Parameter>>
@@ -110,28 +113,50 @@ public:
 
   template<
     typename CallbackT,
-    typename Alloc = std::allocator<void>,
-    typename SubscriptionT =
-    rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent, Alloc>>
+    typename AllocatorT = std::allocator<void>>
   typename rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr
-  on_parameter_event(CallbackT && callback)
+  on_parameter_event(
+    CallbackT && callback,
+    const rclcpp::QoS & qos = (
+      rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(rmw_qos_profile_parameter_events))
+    ),
+    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options = (
+      rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>()
+  ))
   {
-    using rclcpp::message_memory_strategy::MessageMemoryStrategy;
-    auto msg_mem_strat =
-      MessageMemoryStrategy<rcl_interfaces::msg::ParameterEvent, Alloc>::create_default();
+    return this->on_parameter_event(
+      this->node_topics_interface_,
+      callback,
+      qos,
+      options);
+  }
 
-    using rcl_interfaces::msg::ParameterEvent;
-    return rclcpp::create_subscription<
-      ParameterEvent, CallbackT, Alloc, ParameterEvent, SubscriptionT>(
-      this->node_topics_interface_.get(),
+  /**
+   * The NodeT type only needs to have a method called get_node_topics_interface()
+   * which returns a shared_ptr to a NodeTopicsInterface, or be a
+   * NodeTopicsInterface pointer itself.
+   */
+  template<
+    typename CallbackT,
+    typename NodeT,
+    typename AllocatorT = std::allocator<void>>
+  static typename rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr
+  on_parameter_event(
+    NodeT && node,
+    CallbackT && callback,
+    const rclcpp::QoS & qos = (
+      rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(rmw_qos_profile_parameter_events))
+    ),
+    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options = (
+      rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>()
+  ))
+  {
+    return rclcpp::create_subscription<rcl_interfaces::msg::ParameterEvent>(
+      node,
       "parameter_events",
+      qos,
       std::forward<CallbackT>(callback),
-      rmw_qos_profile_default,
-      nullptr,  // group,
-      false,  // ignore_local_publications,
-      false,  // use_intra_process_comms_,
-      msg_mem_strat,
-      std::make_shared<Alloc>());
+      options);
   }
 
   RCLCPP_PUBLIC
@@ -154,7 +179,7 @@ protected:
   wait_for_service_nanoseconds(std::chrono::nanoseconds timeout);
 
 private:
-  const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface_;
+  rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface_;
   rclcpp::Client<rcl_interfaces::srv::GetParameters>::SharedPtr get_parameters_client_;
   rclcpp::Client<rcl_interfaces::srv::GetParameterTypes>::SharedPtr
     get_parameter_types_client_;
@@ -180,7 +205,7 @@ public:
 
   RCLCPP_PUBLIC
   SyncParametersClient(
-    rclcpp::executor::Executor::SharedPtr executor,
+    rclcpp::Executor::SharedPtr executor,
     rclcpp::Node::SharedPtr node,
     const std::string & remote_node_name = "",
     const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
@@ -193,14 +218,14 @@ public:
 
   RCLCPP_PUBLIC
   SyncParametersClient(
-    rclcpp::executor::Executor::SharedPtr executor,
+    rclcpp::Executor::SharedPtr executor,
     rclcpp::Node * node,
     const std::string & remote_node_name = "",
     const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
 
   RCLCPP_PUBLIC
   SyncParametersClient(
-    rclcpp::executor::Executor::SharedPtr executor,
+    rclcpp::Executor::SharedPtr executor,
     const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface,
     const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface,
     const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
@@ -246,7 +271,12 @@ public:
   {
     return get_parameter_impl(
       parameter_name,
-      std::function<T()>([]() -> T {throw std::runtime_error("Parameter not set");}));
+      std::function<T()>(
+        [&parameter_name]() -> T
+        {
+          throw std::runtime_error("Parameter '" + parameter_name + "' is not set");
+        })
+    );
   }
 
   RCLCPP_PUBLIC
@@ -271,7 +301,26 @@ public:
   typename rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr
   on_parameter_event(CallbackT && callback)
   {
-    return async_parameters_client_->on_parameter_event(std::forward<CallbackT>(callback));
+    return async_parameters_client_->on_parameter_event(
+      std::forward<CallbackT>(callback));
+  }
+
+  /**
+   * The NodeT type only needs to have a method called get_node_topics_interface()
+   * which returns a shared_ptr to a NodeTopicsInterface, or be a
+   * NodeTopicsInterface pointer itself.
+   */
+  template<
+    typename CallbackT,
+    typename NodeT>
+  static typename rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr
+  on_parameter_event(
+    NodeT && node,
+    CallbackT && callback)
+  {
+    return AsyncParametersClient::on_parameter_event(
+      node,
+      std::forward<CallbackT>(callback));
   }
 
   RCLCPP_PUBLIC
@@ -290,7 +339,7 @@ public:
   }
 
 private:
-  rclcpp::executor::Executor::SharedPtr executor_;
+  rclcpp::Executor::SharedPtr executor_;
   const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface_;
   AsyncParametersClient::SharedPtr async_parameters_client_;
 };

rclcpp/include/rclcpp/parameter_events_filter.hpp

@@ -44,16 +44,20 @@ public:
    * \param[in] event The parameter event message to filter.
    * \param[in] names A list of parameter names of interest.
    * \param[in] types A list of the types of parameter events of iterest.
-  *    EventType NEW, DELETED, or CHANGED
-  *
-  * Example Usage:
-  * If you have recieved a parameter event and are only interested in parameters foo and
-  * bar being added or changed but don't care about deletion.
-  *    auto res = rclcpp::ParameterEventsFilter(
-  *      event_shared_ptr,
-  *      {"foo", "bar"},
-  *      {rclcpp::ParameterEventsFilter::EventType::NEW, rclcpp::ParameterEventsFilter::EventType::CHANGED});
-  */
+   *    EventType NEW, DELETED, or CHANGED
+   *
+   * Example Usage:
+   *
+   * If you have recieved a parameter event and are only interested in parameters foo and
+   * bar being added or changed but don't care about deletion.
+   *
+   * ```cpp
+   * auto res = rclcpp::ParameterEventsFilter(
+   *   event_shared_ptr,
+   *   {"foo", "bar"},
+   *   {rclcpp::ParameterEventsFilter::EventType::NEW, rclcpp::ParameterEventsFilter::EventType::CHANGED});
+   * ```
+   */
   RCLCPP_PUBLIC
   ParameterEventsFilter(
     rcl_interfaces::msg::ParameterEvent::SharedPtr event,

rclcpp/include/rclcpp/parameter_service.hpp

@@ -43,7 +43,7 @@ public:
   explicit ParameterService(
     const std::shared_ptr<node_interfaces::NodeBaseInterface> node_base,
     const std::shared_ptr<node_interfaces::NodeServicesInterface> node_services,
-    node_interfaces::NodeParametersInterface * node_params,
+    rclcpp::node_interfaces::NodeParametersInterface * node_params,
     const rmw_qos_profile_t & qos_profile = rmw_qos_profile_parameters);
 
 private:

rclcpp/include/rclcpp/parameter_value.hpp

@@ -28,7 +28,8 @@
 
 namespace rclcpp
 {
-enum ParameterType
+
+enum ParameterType : uint8_t
 {
   PARAMETER_NOT_SET = rcl_interfaces::msg::ParameterType::PARAMETER_NOT_SET,
   PARAMETER_BOOL = rcl_interfaces::msg::ParameterType::PARAMETER_BOOL,
@@ -45,11 +46,11 @@ enum ParameterType
 /// Return the name of a parameter type
 RCLCPP_PUBLIC
 std::string
-to_string(const ParameterType type);
+to_string(ParameterType type);
 
 RCLCPP_PUBLIC
 std::ostream &
-operator<<(std::ostream & os, const ParameterType type);
+operator<<(std::ostream & os, ParameterType type);
 
 /// Indicate the parameter type does not match the expected type.
 class ParameterTypeException : public std::runtime_error
@@ -129,10 +130,21 @@ public:
   rcl_interfaces::msg::ParameterValue
   to_value_msg() const;
 
+  /// Equal operator.
+  RCLCPP_PUBLIC
+  bool
+  operator==(const ParameterValue & rhs) const;
+
+  /// Not equal operator.
+  RCLCPP_PUBLIC
+  bool
+  operator!=(const ParameterValue & rhs) const;
+
   // The following get() variants require the use of ParameterType
 
   template<ParameterType type>
-  typename std::enable_if<type == ParameterType::PARAMETER_BOOL, bool>::type
+  constexpr
+  typename std::enable_if<type == ParameterType::PARAMETER_BOOL, const bool &>::type
   get() const
   {
     if (value_.type != rcl_interfaces::msg::ParameterType::PARAMETER_BOOL) {
@@ -142,7 +154,8 @@ public:
   }
 
   template<ParameterType type>
-  typename std::enable_if<type == ParameterType::PARAMETER_INTEGER, int64_t>::type
+  constexpr
+  typename std::enable_if<type == ParameterType::PARAMETER_INTEGER, const int64_t &>::type
   get() const
   {
     if (value_.type != rcl_interfaces::msg::ParameterType::PARAMETER_INTEGER) {
@@ -152,7 +165,8 @@ public:
   }
 
   template<ParameterType type>
-  typename std::enable_if<type == ParameterType::PARAMETER_DOUBLE, double>::type
+  constexpr
+  typename std::enable_if<type == ParameterType::PARAMETER_DOUBLE, const double &>::type
   get() const
   {
     if (value_.type != rcl_interfaces::msg::ParameterType::PARAMETER_DOUBLE) {
@@ -162,6 +176,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<type == ParameterType::PARAMETER_STRING, const std::string &>::type
   get() const
   {
@@ -172,6 +187,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<
     type == ParameterType::PARAMETER_BYTE_ARRAY, const std::vector<uint8_t> &>::type
   get() const
@@ -183,6 +199,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<
     type == ParameterType::PARAMETER_BOOL_ARRAY, const std::vector<bool> &>::type
   get() const
@@ -194,6 +211,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<
     type == ParameterType::PARAMETER_INTEGER_ARRAY, const std::vector<int64_t> &>::type
   get() const
@@ -205,6 +223,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<
     type == ParameterType::PARAMETER_DOUBLE_ARRAY, const std::vector<double> &>::type
   get() const
@@ -216,6 +235,7 @@ public:
   }
 
   template<ParameterType type>
+  constexpr
   typename std::enable_if<
     type == ParameterType::PARAMETER_STRING_ARRAY, const std::vector<std::string> &>::type
   get() const
@@ -229,28 +249,32 @@ public:
   // The following get() variants allow the use of primitive types
 
   template<typename type>
-  typename std::enable_if<std::is_same<type, bool>::value, bool>::type
+  constexpr
+  typename std::enable_if<std::is_same<type, bool>::value, const bool &>::type
   get() const
   {
     return get<ParameterType::PARAMETER_BOOL>();
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
-    std::is_integral<type>::value && !std::is_same<type, bool>::value, int64_t>::type
+    std::is_integral<type>::value && !std::is_same<type, bool>::value, const int64_t &>::type
   get() const
   {
     return get<ParameterType::PARAMETER_INTEGER>();
   }
 
   template<typename type>
-  typename std::enable_if<std::is_floating_point<type>::value, double>::type
+  constexpr
+  typename std::enable_if<std::is_floating_point<type>::value, const double &>::type
   get() const
   {
     return get<ParameterType::PARAMETER_DOUBLE>();
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<std::is_convertible<type, std::string>::value, const std::string &>::type
   get() const
   {
@@ -258,6 +282,7 @@ public:
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
     std::is_convertible<
       type, const std::vector<uint8_t> &>::value, const std::vector<uint8_t> &>::type
@@ -267,6 +292,7 @@ public:
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
     std::is_convertible<
       type, const std::vector<bool> &>::value, const std::vector<bool> &>::type
@@ -276,6 +302,7 @@ public:
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
     std::is_convertible<
       type, const std::vector<int64_t> &>::value, const std::vector<int64_t> &>::type
@@ -285,6 +312,7 @@ public:
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
     std::is_convertible<
       type, const std::vector<double> &>::value, const std::vector<double> &>::type
@@ -294,6 +322,7 @@ public:
   }
 
   template<typename type>
+  constexpr
   typename std::enable_if<
     std::is_convertible<
       type, const std::vector<std::string> &>::value, const std::vector<std::string> &>::type

rclcpp/include/rclcpp/publisher.hpp

@@ -23,344 +23,247 @@
 #include <memory>
 #include <sstream>
 #include <string>
+#include <utility>
 
 #include "rcl/error_handling.h"
 #include "rcl/publisher.h"
 
-#include "rcl_interfaces/msg/intra_process_message.hpp"
-
 #include "rclcpp/allocator/allocator_common.hpp"
 #include "rclcpp/allocator/allocator_deleter.hpp"
+#include "rclcpp/detail/resolve_use_intra_process.hpp"
+#include "rclcpp/experimental/intra_process_manager.hpp"
+#include "rclcpp/loaned_message.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/publisher_base.hpp"
+#include "rclcpp/publisher_options.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
 {
 
-// Forward declaration is used for friend statement.
-namespace node_interfaces
-{
-class NodeTopicsInterface;
-}
-
-namespace intra_process_manager
-{
-/**
- * NOTE(ivanpauno): IntraProcessManager is forward declared here, avoiding a circular inclusion between intra_process_manager.hpp and publisher.hpp.
- * SharedPtr and WeakPtr of the IntraProcessManager are defined again here, to avoid a warning for accessing a member of a forward declared class.
- */
-class IntraProcessManager;
-}
-
-class PublisherBase
-{
-  friend ::rclcpp::node_interfaces::NodeTopicsInterface;
-
-public:
-  RCLCPP_SMART_PTR_DEFINITIONS(PublisherBase)
-
-  /// Default constructor.
-  /**
-   * Typically, a publisher is not created through this method, but instead is created through a
-   * call to `Node::create_publisher`.
-   * \param[in] node_base A pointer to the NodeBaseInterface for the parent node.
-   * \param[in] topic The topic that this publisher publishes on.
-   * \param[in] type_support The type support structure for the type to be published.
-   * \param[in] publisher_options QoS settings for this publisher.
-   */
-  RCLCPP_PUBLIC
-  PublisherBase(
-    rclcpp::node_interfaces::NodeBaseInterface * node_base,
-    const std::string & topic,
-    const rosidl_message_type_support_t & type_support,
-    const rcl_publisher_options_t & publisher_options);
-
-  RCLCPP_PUBLIC
-  virtual ~PublisherBase();
-
-  /// Get the topic that this publisher publishes on.
-  /** \return The topic name. */
-  RCLCPP_PUBLIC
-  const char *
-  get_topic_name() const;
-
-  /// Get the queue size for this publisher.
-  /** \return The queue size. */
-  RCLCPP_PUBLIC
-  size_t
-  get_queue_size() const;
-
-  /// Get the global identifier for this publisher (used in rmw and by DDS).
-  /** \return The gid. */
-  RCLCPP_PUBLIC
-  const rmw_gid_t &
-  get_gid() const;
-
-  /// Get the global identifier for this publisher used by intra-process communication.
-  /** \return The intra-process gid. */
-  RCLCPP_PUBLIC
-  const rmw_gid_t &
-  get_intra_process_gid() const;
-
-  /// Get the rcl publisher handle.
-  /** \return The rcl publisher handle. */
-  RCLCPP_PUBLIC
-  rcl_publisher_t *
-  get_publisher_handle();
-
-  /// Get the rcl publisher handle.
-  /** \return The rcl publisher handle. */
-  RCLCPP_PUBLIC
-  const rcl_publisher_t *
-  get_publisher_handle() const;
-
-  /// Get subscription count
-  /** \return The number of subscriptions. */
-  RCLCPP_PUBLIC
-  size_t
-  get_subscription_count() const;
-
-  /// Get intraprocess subscription count
-  /** \return The number of intraprocess subscriptions. */
-  RCLCPP_PUBLIC
-  size_t
-  get_intra_process_subscription_count() const;
-
-  /// Get the actual QoS settings, after the defaults have been determined.
-  /**
-   * The actual configuration applied when using RMW_QOS_POLICY_*_SYSTEM_DEFAULT
-   * can only be resolved after the creation of the publisher, and it
-   * depends on the underlying rmw implementation.
-   * If the underlying setting in use can't be represented in ROS terms,
-   * it will be set to RMW_QOS_POLICY_*_UNKNOWN.
-   * May throw runtime_error when an unexpected error occurs.
-   * \return The actual qos settings.
-   */
-  RCLCPP_PUBLIC
-  rmw_qos_profile_t
-  get_actual_qos() const;
-
-  /// Compare this publisher to a gid.
-  /**
-   * Note that this function calls the next function.
-   * \param[in] gid Reference to a gid.
-   * \return True if the publisher's gid matches the input.
-   */
-  RCLCPP_PUBLIC
-  bool
-  operator==(const rmw_gid_t & gid) const;
-
-  /// Compare this publisher to a pointer gid.
-  /**
-   * A wrapper for comparing this publisher's gid to the input using rmw_compare_gids_equal.
-   * \param[in] gid A pointer to a gid.
-   * \return True if this publisher's gid matches the input.
-   */
-  RCLCPP_PUBLIC
-  bool
-  operator==(const rmw_gid_t * gid) const;
-
-  using StoreMessageCallbackT = std::function<uint64_t(uint64_t, void *, const std::type_info &)>;
-  using IntraProcessManagerSharedPtr =
-    std::shared_ptr<rclcpp::intra_process_manager::IntraProcessManager>;
-
-  /// Implementation utility function used to setup intra process publishing after creation.
-  RCLCPP_PUBLIC
-  void
-  setup_intra_process(
-    uint64_t intra_process_publisher_id,
-    StoreMessageCallbackT store_callback,
-    IntraProcessManagerSharedPtr ipm,
-    const rcl_publisher_options_t & intra_process_options);
-
-protected:
-  std::shared_ptr<rcl_node_t> rcl_node_handle_;
-
-  rcl_publisher_t publisher_handle_ = rcl_get_zero_initialized_publisher();
-  rcl_publisher_t intra_process_publisher_handle_ = rcl_get_zero_initialized_publisher();
-
-  using IntraProcessManagerWeakPtr =
-    std::weak_ptr<rclcpp::intra_process_manager::IntraProcessManager>;
-  bool intra_process_is_enabled_;
-  IntraProcessManagerWeakPtr weak_ipm_;
-  uint64_t intra_process_publisher_id_;
-  StoreMessageCallbackT store_intra_process_message_;
-
-  rmw_gid_t rmw_gid_;
-  rmw_gid_t intra_process_rmw_gid_;
-};
+template<typename MessageT, typename AllocatorT>
+class LoanedMessage;
 
 /// A publisher publishes messages of any type to a topic.
-template<typename MessageT, typename Alloc = std::allocator<void>>
+template<typename MessageT, typename AllocatorT = std::allocator<void>>
 class Publisher : public PublisherBase
 {
 public:
-  using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
-  using MessageAlloc = typename MessageAllocTraits::allocator_type;
-  using MessageDeleter = allocator::Deleter<MessageAlloc, MessageT>;
+  using MessageAllocatorTraits = allocator::AllocRebind<MessageT, AllocatorT>;
+  using MessageAllocator = typename MessageAllocatorTraits::allocator_type;
+  using MessageDeleter = allocator::Deleter<MessageAllocator, MessageT>;
   using MessageUniquePtr = std::unique_ptr<MessageT, MessageDeleter>;
+  using MessageSharedPtr = std::shared_ptr<const MessageT>;
 
-  RCLCPP_SMART_PTR_DEFINITIONS(Publisher<MessageT, Alloc>)
+  RCLCPP_SMART_PTR_DEFINITIONS(Publisher<MessageT, AllocatorT>)
 
   Publisher(
     rclcpp::node_interfaces::NodeBaseInterface * node_base,
     const std::string & topic,
-    const rcl_publisher_options_t & publisher_options,
-    const std::shared_ptr<MessageAlloc> & allocator)
+    const rclcpp::QoS & qos,
+    const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options)
   : PublisherBase(
       node_base,
       topic,
       *rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>(),
-      publisher_options),
-    message_allocator_(allocator)
+      options.template to_rcl_publisher_options<MessageT>(qos)),
+    options_(options),
+    message_allocator_(new MessageAllocator(*options.get_allocator().get()))
   {
     allocator::set_allocator_for_deleter(&message_deleter_, message_allocator_.get());
+
+    if (options_.event_callbacks.deadline_callback) {
+      this->add_event_handler(
+        options_.event_callbacks.deadline_callback,
+        RCL_PUBLISHER_OFFERED_DEADLINE_MISSED);
+    }
+    if (options_.event_callbacks.liveliness_callback) {
+      this->add_event_handler(
+        options_.event_callbacks.liveliness_callback,
+        RCL_PUBLISHER_LIVELINESS_LOST);
+    }
+    if (options_.event_callbacks.incompatible_qos_callback) {
+      this->add_event_handler(
+        options_.event_callbacks.incompatible_qos_callback,
+        RCL_PUBLISHER_OFFERED_INCOMPATIBLE_QOS);
+    } else if (options_.use_default_callbacks) {
+      // Register default callback when not specified
+      try {
+        this->add_event_handler(
+          [this](QOSOfferedIncompatibleQoSInfo & info) {
+            this->default_incompatible_qos_callback(info);
+          },
+          RCL_PUBLISHER_OFFERED_INCOMPATIBLE_QOS);
+      } catch (UnsupportedEventTypeException & /*exc*/) {
+        // pass
+      }
+    }
+    // Setup continues in the post construction method, post_init_setup().
+  }
+
+  /// Called post construction, so that construction may continue after shared_from_this() works.
+  virtual
+  void
+  post_init_setup(
+    rclcpp::node_interfaces::NodeBaseInterface * node_base,
+    const std::string & topic,
+    const rclcpp::QoS & qos,
+    const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options)
+  {
+    // Topic is unused for now.
+    (void)topic;
+    (void)options;
+
+    // If needed, setup intra process communication.
+    if (rclcpp::detail::resolve_use_intra_process(options_, *node_base)) {
+      auto context = node_base->get_context();
+      // Get the intra process manager instance for this context.
+      auto ipm = context->get_sub_context<rclcpp::experimental::IntraProcessManager>();
+      // Register the publisher with the intra process manager.
+      if (qos.get_rmw_qos_profile().history == RMW_QOS_POLICY_HISTORY_KEEP_ALL) {
+        throw std::invalid_argument(
+                "intraprocess communication is not allowed with keep all history qos policy");
+      }
+      if (qos.get_rmw_qos_profile().depth == 0) {
+        throw std::invalid_argument(
+                "intraprocess communication is not allowed with a zero qos history depth value");
+      }
+      if (qos.get_rmw_qos_profile().durability != RMW_QOS_POLICY_DURABILITY_VOLATILE) {
+        throw std::invalid_argument(
+                "intraprocess communication allowed only with volatile durability");
+      }
+      uint64_t intra_process_publisher_id = ipm->add_publisher(this->shared_from_this());
+      this->setup_intra_process(
+        intra_process_publisher_id,
+        ipm);
+    }
   }
 
   virtual ~Publisher()
   {}
 
+  /// Borrow a loaned ROS message from the middleware.
+  /**
+   * If the middleware is capable of loaning memory for a ROS message instance,
+   * the loaned message will be directly allocated in the middleware.
+   * If not, the message allocator of this rclcpp::Publisher instance is being used.
+   *
+   * With a call to \sa `publish` the LoanedMessage instance is being returned to the middleware
+   * or free'd accordingly to the allocator.
+   * If the message is not being published but processed differently, the destructor of this
+   * class will either return the message to the middleware or deallocate it via the internal
+   * allocator.
+   * \sa rclcpp::LoanedMessage for details of the LoanedMessage class.
+   *
+   * \return LoanedMessage containing memory for a ROS message of type MessageT
+   */
+  rclcpp::LoanedMessage<MessageT, AllocatorT>
+  borrow_loaned_message()
+  {
+    return rclcpp::LoanedMessage<MessageT, AllocatorT>(this, this->get_allocator());
+  }
+
   /// Send a message to the topic for this publisher.
   /**
    * This function is templated on the input message type, MessageT.
    * \param[in] msg A shared pointer to the message to send.
    */
   virtual void
-  publish(std::unique_ptr<MessageT, MessageDeleter> & msg)
+  publish(std::unique_ptr<MessageT, MessageDeleter> msg)
   {
-    bool inter_process_subscriptions_exist =
+    if (!intra_process_is_enabled_) {
+      this->do_inter_process_publish(*msg);
+      return;
+    }
+    // If an interprocess subscription exist, then the unique_ptr is promoted
+    // to a shared_ptr and published.
+    // This allows doing the intraprocess publish first and then doing the
+    // interprocess publish, resulting in lower publish-to-subscribe latency.
+    // It's not possible to do that with an unique_ptr,
+    // as do_intra_process_publish takes the ownership of the message.
+    bool inter_process_publish_needed =
       get_subscription_count() > get_intra_process_subscription_count();
-    if (!intra_process_is_enabled_ || inter_process_subscriptions_exist) {
-      this->do_inter_process_publish(msg.get());
-    }
-    if (store_intra_process_message_) {
-      // Take the pointer from the unique_msg, release it and pass as a void *
-      // to the ipm. The ipm should then capture it again as a unique_ptr of
-      // the correct type.
-      // TODO(wjwwood):
-      //   investigate how to transfer the custom deleter (if there is one)
-      //   from the incoming unique_ptr through to the ipm's unique_ptr.
-      //   See: http://stackoverflow.com/questions/11002641/dynamic-casting-for-unique-ptr
-      MessageT * msg_ptr = msg.get();
-      msg.release();
-      uint64_t message_seq =
-        store_intra_process_message_(intra_process_publisher_id_, msg_ptr, typeid(MessageT));
-      rcl_interfaces::msg::IntraProcessMessage ipm;
-      ipm.publisher_id = intra_process_publisher_id_;
-      ipm.message_sequence = message_seq;
-      auto status = rcl_publish(&intra_process_publisher_handle_, &ipm);
-      if (RCL_RET_PUBLISHER_INVALID == status) {
-        rcl_reset_error();  // next call will reset error message if not context
-        if (rcl_publisher_is_valid_except_context(&intra_process_publisher_handle_)) {
-          rcl_context_t * context = rcl_publisher_get_context(&intra_process_publisher_handle_);
-          if (nullptr != context && !rcl_context_is_valid(context)) {
-            // publisher is invalid due to context being shutdown
-            return;
-          }
-        }
-      }
-      if (RCL_RET_OK != status) {
-        rclcpp::exceptions::throw_from_rcl_error(status, "failed to publish intra process message");
-      }
+
+    if (inter_process_publish_needed) {
+      auto shared_msg = this->do_intra_process_publish_and_return_shared(std::move(msg));
+      this->do_inter_process_publish(*shared_msg);
     } else {
-      // Always destroy the message, even if we don't consume it, for consistency.
-      msg.reset();
+      this->do_intra_process_publish(std::move(msg));
     }
   }
 
-  virtual void
-  publish(const std::shared_ptr<MessageT> & msg)
-  {
-    // Avoid allocating when not using intra process.
-    if (!store_intra_process_message_) {
-      // In this case we're not using intra process.
-      return this->do_inter_process_publish(msg.get());
-    }
-    // Otherwise we have to allocate memory in a unique_ptr and pass it along.
-    // TODO(wjwwood):
-    //   The intra process manager should probably also be able to store
-    //   shared_ptr's and do the "smart" thing based on other intra process
-    //   subscriptions. For now call the other publish().
-    auto ptr = MessageAllocTraits::allocate(*message_allocator_.get(), 1);
-    MessageAllocTraits::construct(*message_allocator_.get(), ptr, *msg.get());
-    MessageUniquePtr unique_msg(ptr, message_deleter_);
-    return this->publish(unique_msg);
-  }
-
-  virtual void
-  publish(std::shared_ptr<const MessageT> msg)
-  {
-    // Avoid allocating when not using intra process.
-    if (!store_intra_process_message_) {
-      // In this case we're not using intra process.
-      return this->do_inter_process_publish(msg.get());
-    }
-    // Otherwise we have to allocate memory in a unique_ptr and pass it along.
-    // TODO(wjwwood):
-    //   The intra process manager should probably also be able to store
-    //   shared_ptr's and do the "smart" thing based on other intra process
-    //   subscriptions. For now call the other publish().
-    auto ptr = MessageAllocTraits::allocate(*message_allocator_.get(), 1);
-    MessageAllocTraits::construct(*message_allocator_.get(), ptr, *msg.get());
-    MessageUniquePtr unique_msg(ptr, message_deleter_);
-    return this->publish(unique_msg);
-  }
-
   virtual void
   publish(const MessageT & msg)
   {
     // Avoid allocating when not using intra process.
-    if (!store_intra_process_message_) {
+    if (!intra_process_is_enabled_) {
       // In this case we're not using intra process.
-      return this->do_inter_process_publish(&msg);
+      return this->do_inter_process_publish(msg);
     }
     // Otherwise we have to allocate memory in a unique_ptr and pass it along.
-    auto ptr = MessageAllocTraits::allocate(*message_allocator_.get(), 1);
-    MessageAllocTraits::construct(*message_allocator_.get(), ptr, msg);
+    // As the message is not const, a copy should be made.
+    // A shared_ptr<const MessageT> could also be constructed here.
+    auto ptr = MessageAllocatorTraits::allocate(*message_allocator_.get(), 1);
+    MessageAllocatorTraits::construct(*message_allocator_.get(), ptr, msg);
     MessageUniquePtr unique_msg(ptr, message_deleter_);
-    return this->publish(unique_msg);
-  }
-
-  virtual void
-  publish(const MessageT * msg)
-  {
-    if (!msg) {
-      throw std::runtime_error("msg argument is nullptr");
-    }
-    return this->publish(*msg);
+    this->publish(std::move(unique_msg));
   }
 
   void
-  publish(const rcl_serialized_message_t * serialized_msg)
+  publish(const rcl_serialized_message_t & serialized_msg)
   {
-    if (store_intra_process_message_) {
-      // TODO(Karsten1987): support serialized message passed by intraprocess
-      throw std::runtime_error("storing serialized messages in intra process is not supported yet");
-    }
-    auto status = rcl_publish_serialized_message(&publisher_handle_, serialized_msg);
-    if (RCL_RET_OK != status) {
-      rclcpp::exceptions::throw_from_rcl_error(status, "failed to publish serialized message");
-    }
+    return this->do_serialized_publish(&serialized_msg);
   }
 
+  /// Publish an instance of a LoanedMessage.
+  /**
+   * When publishing a loaned message, the memory for this ROS message will be deallocated
+   * after being published.
+   * The instance of the loaned message is no longer valid after this call.
+   *
+   * \param loaned_msg The LoanedMessage instance to be published.
+   */
   void
-  publish(std::shared_ptr<const rcl_serialized_message_t> serialized_msg)
+  publish(rclcpp::LoanedMessage<MessageT, AllocatorT> && loaned_msg)
   {
-    return this->publish(serialized_msg.get());
+    if (!loaned_msg.is_valid()) {
+      throw std::runtime_error("loaned message is not valid");
+    }
+    if (intra_process_is_enabled_) {
+      // TODO(Karsten1987): support loaned message passed by intraprocess
+      throw std::runtime_error("storing loaned messages in intra process is not supported yet");
+    }
+
+    // verify that publisher supports loaned messages
+    // TODO(Karsten1987): This case separation has to be done in rclcpp
+    // otherwise we have to ensure that every middleware implements
+    // `rmw_publish_loaned_message` explicitly the same way as `rmw_publish`
+    // by taking a copy of the ros message.
+    if (this->can_loan_messages()) {
+      // we release the ownership from the rclpp::LoanedMessage instance
+      // and let the middleware clean up the memory.
+      this->do_loaned_message_publish(loaned_msg.release());
+    } else {
+      // we don't release the ownership, let the middleware copy the ros message
+      // and thus the destructor of rclcpp::LoanedMessage cleans up the memory.
+      this->do_inter_process_publish(loaned_msg.get());
+    }
   }
 
-  std::shared_ptr<MessageAlloc> get_allocator() const
+  std::shared_ptr<MessageAllocator>
+  get_allocator() const
   {
     return message_allocator_;
   }
 
 protected:
   void
-  do_inter_process_publish(const MessageT * msg)
+  do_inter_process_publish(const MessageT & msg)
   {
-    auto status = rcl_publish(&publisher_handle_, msg);
+    auto status = rcl_publish(&publisher_handle_, &msg, nullptr);
+
     if (RCL_RET_PUBLISHER_INVALID == status) {
       rcl_reset_error();  // next call will reset error message if not context
       if (rcl_publisher_is_valid_except_context(&publisher_handle_)) {
@@ -376,7 +279,83 @@ protected:
     }
   }
 
-  std::shared_ptr<MessageAlloc> message_allocator_;
+  void
+  do_serialized_publish(const rcl_serialized_message_t * serialized_msg)
+  {
+    if (intra_process_is_enabled_) {
+      // TODO(Karsten1987): support serialized message passed by intraprocess
+      throw std::runtime_error("storing serialized messages in intra process is not supported yet");
+    }
+    auto status = rcl_publish_serialized_message(&publisher_handle_, serialized_msg, nullptr);
+    if (RCL_RET_OK != status) {
+      rclcpp::exceptions::throw_from_rcl_error(status, "failed to publish serialized message");
+    }
+  }
+
+  void
+  do_loaned_message_publish(MessageT * msg)
+  {
+    auto status = rcl_publish_loaned_message(&publisher_handle_, msg, nullptr);
+
+    if (RCL_RET_PUBLISHER_INVALID == status) {
+      rcl_reset_error();  // next call will reset error message if not context
+      if (rcl_publisher_is_valid_except_context(&publisher_handle_)) {
+        rcl_context_t * context = rcl_publisher_get_context(&publisher_handle_);
+        if (nullptr != context && !rcl_context_is_valid(context)) {
+          // publisher is invalid due to context being shutdown
+          return;
+        }
+      }
+    }
+    if (RCL_RET_OK != status) {
+      rclcpp::exceptions::throw_from_rcl_error(status, "failed to publish message");
+    }
+  }
+
+  void
+  do_intra_process_publish(std::unique_ptr<MessageT, MessageDeleter> msg)
+  {
+    auto ipm = weak_ipm_.lock();
+    if (!ipm) {
+      throw std::runtime_error(
+              "intra process publish called after destruction of intra process manager");
+    }
+    if (!msg) {
+      throw std::runtime_error("cannot publish msg which is a null pointer");
+    }
+
+    ipm->template do_intra_process_publish<MessageT, AllocatorT>(
+      intra_process_publisher_id_,
+      std::move(msg),
+      message_allocator_);
+  }
+
+  std::shared_ptr<const MessageT>
+  do_intra_process_publish_and_return_shared(std::unique_ptr<MessageT, MessageDeleter> msg)
+  {
+    auto ipm = weak_ipm_.lock();
+    if (!ipm) {
+      throw std::runtime_error(
+              "intra process publish called after destruction of intra process manager");
+    }
+    if (!msg) {
+      throw std::runtime_error("cannot publish msg which is a null pointer");
+    }
+
+    return ipm->template do_intra_process_publish_and_return_shared<MessageT, AllocatorT>(
+      intra_process_publisher_id_,
+      std::move(msg),
+      message_allocator_);
+  }
+
+  /// Copy of original options passed during construction.
+  /**
+   * It is important to save a copy of this so that the rmw payload which it
+   * may contain is kept alive for the duration of the publisher.
+   */
+  const rclcpp::PublisherOptionsWithAllocator<AllocatorT> options_;
+
+  std::shared_ptr<MessageAllocator> message_allocator_;
 
   MessageDeleter message_deleter_;
 };

rclcpp/include/rclcpp/publisher_base.hpp

@@ -0,0 +1,231 @@
+// Copyright 2014 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__PUBLISHER_BASE_HPP_
+#define RCLCPP__PUBLISHER_BASE_HPP_
+
+#include <rmw/error_handling.h>
+#include <rmw/rmw.h>
+
+#include <functional>
+#include <iostream>
+#include <memory>
+#include <sstream>
+#include <string>
+#include <vector>
+
+#include "rcl/publisher.h"
+
+#include "rclcpp/macros.hpp"
+#include "rclcpp/qos.hpp"
+#include "rclcpp/qos_event.hpp"
+#include "rclcpp/type_support_decl.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+// Forward declaration is used for friend statement.
+namespace node_interfaces
+{
+class NodeBaseInterface;
+class NodeTopicsInterface;
+}  // namespace node_interfaces
+
+namespace experimental
+{
+/**
+ * IntraProcessManager is forward declared here, avoiding a circular inclusion between
+ * `intra_process_manager.hpp` and `publisher_base.hpp`.
+ */
+class IntraProcessManager;
+}  // namespace experimental
+
+class PublisherBase : public std::enable_shared_from_this<PublisherBase>
+{
+  friend ::rclcpp::node_interfaces::NodeTopicsInterface;
+
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(PublisherBase)
+
+  /// Default constructor.
+  /**
+   * Typically, a publisher is not created through this method, but instead is created through a
+   * call to `Node::create_publisher`.
+   * \param[in] node_base A pointer to the NodeBaseInterface for the parent node.
+   * \param[in] topic The topic that this publisher publishes on.
+   * \param[in] type_support The type support structure for the type to be published.
+   * \param[in] publisher_options QoS settings for this publisher.
+   */
+  RCLCPP_PUBLIC
+  PublisherBase(
+    rclcpp::node_interfaces::NodeBaseInterface * node_base,
+    const std::string & topic,
+    const rosidl_message_type_support_t & type_support,
+    const rcl_publisher_options_t & publisher_options);
+
+  RCLCPP_PUBLIC
+  virtual ~PublisherBase();
+
+  /// Get the topic that this publisher publishes on.
+  /** \return The topic name. */
+  RCLCPP_PUBLIC
+  const char *
+  get_topic_name() const;
+
+  /// Get the queue size for this publisher.
+  /** \return The queue size. */
+  RCLCPP_PUBLIC
+  size_t
+  get_queue_size() const;
+
+  /// Get the global identifier for this publisher (used in rmw and by DDS).
+  /** \return The gid. */
+  RCLCPP_PUBLIC
+  const rmw_gid_t &
+  get_gid() const;
+
+  /// Get the rcl publisher handle.
+  /** \return The rcl publisher handle. */
+  RCLCPP_PUBLIC
+  rcl_publisher_t *
+  get_publisher_handle();
+
+  /// Get the rcl publisher handle.
+  /** \return The rcl publisher handle. */
+  RCLCPP_PUBLIC
+  const rcl_publisher_t *
+  get_publisher_handle() const;
+
+  /// Get all the QoS event handlers associated with this publisher.
+  /** \return The vector of QoS event handlers. */
+  RCLCPP_PUBLIC
+  const std::vector<std::shared_ptr<rclcpp::QOSEventHandlerBase>> &
+  get_event_handlers() const;
+
+  /// Get subscription count
+  /** \return The number of subscriptions. */
+  RCLCPP_PUBLIC
+  size_t
+  get_subscription_count() const;
+
+  /// Get intraprocess subscription count
+  /** \return The number of intraprocess subscriptions. */
+  RCLCPP_PUBLIC
+  size_t
+  get_intra_process_subscription_count() const;
+
+  /// Manually assert that this Publisher is alive (for RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC).
+  /**
+   * If the rmw Liveliness policy is set to RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC, the creator
+   * of this publisher may manually call `assert_liveliness` at some point in time to signal to the
+   * rest of the system that this Node is still alive.
+   *
+   * \return `true` if the liveliness was asserted successfully, otherwise `false`
+   */
+  RCLCPP_PUBLIC
+  RCUTILS_WARN_UNUSED
+  bool
+  assert_liveliness() const;
+
+  /// Get the actual QoS settings, after the defaults have been determined.
+  /**
+   * The actual configuration applied when using RMW_QOS_POLICY_*_SYSTEM_DEFAULT
+   * can only be resolved after the creation of the publisher, and it
+   * depends on the underlying rmw implementation.
+   * If the underlying setting in use can't be represented in ROS terms,
+   * it will be set to RMW_QOS_POLICY_*_UNKNOWN.
+   * May throw runtime_error when an unexpected error occurs.
+   *
+   * \return The actual qos settings.
+   */
+  RCLCPP_PUBLIC
+  rclcpp::QoS
+  get_actual_qos() const;
+
+  /// Check if publisher instance can loan messages.
+  /**
+   * Depending on the middleware and the message type, this will return true if the middleware
+   * can allocate a ROS message instance.
+   */
+  RCLCPP_PUBLIC
+  bool
+  can_loan_messages() const;
+
+  /// Compare this publisher to a gid.
+  /**
+   * Note that this function calls the next function.
+   * \param[in] gid Reference to a gid.
+   * \return True if the publisher's gid matches the input.
+   */
+  RCLCPP_PUBLIC
+  bool
+  operator==(const rmw_gid_t & gid) const;
+
+  /// Compare this publisher to a pointer gid.
+  /**
+   * A wrapper for comparing this publisher's gid to the input using rmw_compare_gids_equal.
+   * \param[in] gid A pointer to a gid.
+   * \return True if this publisher's gid matches the input.
+   */
+  RCLCPP_PUBLIC
+  bool
+  operator==(const rmw_gid_t * gid) const;
+
+  using IntraProcessManagerSharedPtr =
+    std::shared_ptr<rclcpp::experimental::IntraProcessManager>;
+
+  /// Implementation utility function used to setup intra process publishing after creation.
+  RCLCPP_PUBLIC
+  void
+  setup_intra_process(
+    uint64_t intra_process_publisher_id,
+    IntraProcessManagerSharedPtr ipm);
+
+protected:
+  template<typename EventCallbackT>
+  void
+  add_event_handler(
+    const EventCallbackT & callback,
+    const rcl_publisher_event_type_t event_type)
+  {
+    auto handler = std::make_shared<QOSEventHandler<EventCallbackT>>(
+      callback,
+      rcl_publisher_event_init,
+      &publisher_handle_,
+      event_type);
+    event_handlers_.emplace_back(handler);
+  }
+
+  RCLCPP_PUBLIC
+  void default_incompatible_qos_callback(QOSOfferedIncompatibleQoSInfo & info) const;
+
+  std::shared_ptr<rcl_node_t> rcl_node_handle_;
+
+  rcl_publisher_t publisher_handle_ = rcl_get_zero_initialized_publisher();
+
+  std::vector<std::shared_ptr<rclcpp::QOSEventHandlerBase>> event_handlers_;
+
+  using IntraProcessManagerWeakPtr =
+    std::weak_ptr<rclcpp::experimental::IntraProcessManager>;
+  bool intra_process_is_enabled_;
+  IntraProcessManagerWeakPtr weak_ipm_;
+  uint64_t intra_process_publisher_id_;
+
+  rmw_gid_t rmw_gid_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__PUBLISHER_BASE_HPP_

rclcpp/include/rclcpp/publisher_factory.hpp

@@ -24,8 +24,10 @@
 #include "rosidl_typesupport_cpp/message_type_support.hpp"
 
 #include "rclcpp/publisher.hpp"
-#include "rclcpp/intra_process_manager.hpp"
+#include "rclcpp/publisher_base.hpp"
+#include "rclcpp/publisher_options.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/visibility_control.hpp"
 
 namespace rclcpp
@@ -41,6 +43,9 @@ namespace rclcpp
  * called from a templated "create_publisher" method on the Node class, and
  * is passed to the non-templated "create_publisher" method on the NodeTopics
  * class where it is used to create and setup the Publisher.
+ *
+ * It also handles the two step construction of Publishers, first calling
+ * the constructor and then the post_init_setup() method.
  */
 struct PublisherFactory
 {
@@ -49,95 +54,33 @@ struct PublisherFactory
     rclcpp::PublisherBase::SharedPtr(
       rclcpp::node_interfaces::NodeBaseInterface * node_base,
       const std::string & topic_name,
-      rcl_publisher_options_t & publisher_options)>;
+      const rclcpp::QoS & qos
+    )>;
 
-  PublisherFactoryFunction create_typed_publisher;
-
-  // Adds the PublisherBase to the intraprocess manager with the correctly
-  // templated call to IntraProcessManager::store_intra_process_message.
-  using AddPublisherToIntraProcessManagerFunction = std::function<
-    uint64_t(
-      rclcpp::intra_process_manager::IntraProcessManager * ipm,
-      rclcpp::PublisherBase::SharedPtr publisher)>;
-
-  AddPublisherToIntraProcessManagerFunction add_publisher_to_intra_process_manager;
-
-  // Creates the callback function which is called on each
-  // PublisherT::publish() and which handles the intra process transmission of
-  // the message being published.
-  using SharedPublishCallbackFactoryFunction = std::function<
-    rclcpp::PublisherBase::StoreMessageCallbackT(
-      rclcpp::intra_process_manager::IntraProcessManager::SharedPtr ipm)>;
-
-  SharedPublishCallbackFactoryFunction create_shared_publish_callback;
+  const PublisherFactoryFunction create_typed_publisher;
 };
 
-/// Return a PublisherFactory with functions setup for creating a PublisherT<MessageT, Alloc>.
-template<typename MessageT, typename Alloc, typename PublisherT>
+/// Return a PublisherFactory with functions setup for creating a PublisherT<MessageT, AllocatorT>.
+template<typename MessageT, typename AllocatorT, typename PublisherT>
 PublisherFactory
-create_publisher_factory(std::shared_ptr<Alloc> allocator)
+create_publisher_factory(const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options)
 {
-  PublisherFactory factory;
-
-  // factory function that creates a MessageT specific PublisherT
-  factory.create_typed_publisher =
-    [allocator](
-    rclcpp::node_interfaces::NodeBaseInterface * node_base,
-    const std::string & topic_name,
-    rcl_publisher_options_t & publisher_options) -> std::shared_ptr<PublisherT>
+  PublisherFactory factory {
+    // factory function that creates a MessageT specific PublisherT
+    [options](
+      rclcpp::node_interfaces::NodeBaseInterface * node_base,
+      const std::string & topic_name,
+      const rclcpp::QoS & qos
+    ) -> std::shared_ptr<PublisherT>
     {
-      auto message_alloc = std::make_shared<typename PublisherT::MessageAlloc>(*allocator.get());
-      publisher_options.allocator = allocator::get_rcl_allocator<MessageT>(*message_alloc.get());
-
-      return std::make_shared<PublisherT>(node_base, topic_name, publisher_options, message_alloc);
-    };
-
-  // function to add a publisher to the intra process manager
-  factory.add_publisher_to_intra_process_manager =
-    [](
-    rclcpp::intra_process_manager::IntraProcessManager * ipm,
-    rclcpp::PublisherBase::SharedPtr publisher) -> uint64_t
-    {
-      return ipm->add_publisher<MessageT, Alloc>(std::dynamic_pointer_cast<PublisherT>(publisher));
-    };
-
-  // function to create a shared publish callback std::function
-  using StoreMessageCallbackT = rclcpp::PublisherBase::StoreMessageCallbackT;
-  factory.create_shared_publish_callback =
-    [](rclcpp::intra_process_manager::IntraProcessManager::SharedPtr ipm) -> StoreMessageCallbackT
-    {
-      rclcpp::intra_process_manager::IntraProcessManager::WeakPtr weak_ipm = ipm;
-
-      // this function is called on each call to publish() and handles storing
-      // of the published message in the intra process manager
-      auto shared_publish_callback =
-        [weak_ipm](uint64_t publisher_id, void * msg, const std::type_info & type_info) -> uint64_t
-        {
-          auto ipm = weak_ipm.lock();
-          if (!ipm) {
-            // TODO(wjwwood): should this just return silently? Or maybe return with a warning?
-            throw std::runtime_error(
-                    "intra process publish called after destruction of intra process manager");
-          }
-          if (!msg) {
-            throw std::runtime_error("cannot publisher msg which is a null pointer");
-          }
-          auto & message_type_info = typeid(MessageT);
-          if (message_type_info != type_info) {
-            throw std::runtime_error(
-                    std::string("published type '") + type_info.name() +
-                    "' is incompatible from the publisher type '" + message_type_info.name() + "'");
-          }
-          MessageT * typed_message_ptr = static_cast<MessageT *>(msg);
-          using MessageDeleter = typename Publisher<MessageT, Alloc>::MessageDeleter;
-          std::unique_ptr<MessageT, MessageDeleter> unique_msg(typed_message_ptr);
-          uint64_t message_seq =
-            ipm->store_intra_process_message<MessageT, Alloc>(publisher_id, unique_msg);
-          return message_seq;
-        };
-
-      return shared_publish_callback;
-    };
+      auto publisher = std::make_shared<PublisherT>(node_base, topic_name, qos, options);
+      // This is used for setting up things like intra process comms which
+      // require this->shared_from_this() which cannot be called from
+      // the constructor.
+      publisher->post_init_setup(node_base, topic_name, qos, options);
+      return publisher;
+    }
+  };
 
   // return the factory now that it is populated
   return factory;

rclcpp/include/rclcpp/publisher_options.hpp

@@ -19,22 +19,88 @@
 #include <string>
 #include <vector>
 
+#include "rcl/publisher.h"
+
+#include "rclcpp/allocator/allocator_common.hpp"
+#include "rclcpp/detail/rmw_implementation_specific_publisher_payload.hpp"
 #include "rclcpp/intra_process_setting.hpp"
-#include "rclcpp/visibility_control.hpp"
+#include "rclcpp/qos.hpp"
+#include "rclcpp/qos_event.hpp"
 
 namespace rclcpp
 {
 
-/// Structure containing optional configuration for Publishers.
-template<typename Allocator>
-struct PublisherOptionsWithAllocator
+class CallbackGroup;
+
+/// Non-templated part of PublisherOptionsWithAllocator<Allocator>.
+struct PublisherOptionsBase
 {
-  /// The quality of service profile to pass on to the rmw implementation.
-  rmw_qos_profile_t qos_profile = rmw_qos_profile_default;
-  /// Optional custom allocator.
-  std::shared_ptr<Allocator> allocator = nullptr;
   /// Setting to explicitly set intraprocess communications.
   IntraProcessSetting use_intra_process_comm = IntraProcessSetting::NodeDefault;
+
+  /// Callbacks for various events related to publishers.
+  PublisherEventCallbacks event_callbacks;
+
+  /// Whether or not to use default callbacks when user doesn't supply any in event_callbacks
+  bool use_default_callbacks = true;
+
+  /// Callback group in which the waitable items from the publisher should be placed.
+  std::shared_ptr<rclcpp::CallbackGroup> callback_group;
+
+  /// Optional RMW implementation specific payload to be used during creation of the publisher.
+  std::shared_ptr<rclcpp::detail::RMWImplementationSpecificPublisherPayload>
+  rmw_implementation_payload = nullptr;
+};
+
+/// Structure containing optional configuration for Publishers.
+template<typename Allocator>
+struct PublisherOptionsWithAllocator : public PublisherOptionsBase
+{
+  /// Optional custom allocator.
+  std::shared_ptr<Allocator> allocator = nullptr;
+
+  PublisherOptionsWithAllocator<Allocator>() {}
+
+  /// Constructor using base class as input.
+  explicit PublisherOptionsWithAllocator(const PublisherOptionsBase & publisher_options_base)
+  : PublisherOptionsBase(publisher_options_base)
+  {}
+
+  /// Convert this class, and a rclcpp::QoS, into an rcl_publisher_options_t.
+  template<typename MessageT>
+  rcl_publisher_options_t
+  to_rcl_publisher_options(const rclcpp::QoS & qos) const
+  {
+    rcl_publisher_options_t result;
+    using AllocatorTraits = std::allocator_traits<Allocator>;
+    using MessageAllocatorT = typename AllocatorTraits::template rebind_alloc<MessageT>;
+    auto message_alloc = std::make_shared<MessageAllocatorT>(*this->get_allocator().get());
+    result.allocator = rclcpp::allocator::get_rcl_allocator<MessageT>(*message_alloc);
+    result.qos = qos.get_rmw_qos_profile();
+
+    // Apply payload to rcl_publisher_options if necessary.
+    if (rmw_implementation_payload && rmw_implementation_payload->has_been_customized()) {
+      rmw_implementation_payload->modify_rmw_publisher_options(result.rmw_publisher_options);
+    }
+
+    return result;
+  }
+
+
+  /// Get the allocator, creating one if needed.
+  std::shared_ptr<Allocator>
+  get_allocator() const
+  {
+    if (!this->allocator) {
+      // TODO(wjwwood): I would like to use the commented line instead, but
+      //   cppcheck 1.89 fails with:
+      //     Syntax Error: AST broken, binary operator '>' doesn't have two operands.
+      // return std::make_shared<Allocator>();
+      std::shared_ptr<Allocator> tmp(new Allocator());
+      return tmp;
+    }
+    return this->allocator;
+  }
 };
 
 using PublisherOptions = PublisherOptionsWithAllocator<std::allocator<void>>;

rclcpp/include/rclcpp/qos.hpp

@@ -0,0 +1,216 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__QOS_HPP_
+#define RCLCPP__QOS_HPP_
+
+#include <string>
+
+#include "rclcpp/duration.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rmw/incompatible_qos_events_statuses.h"
+#include "rmw/qos_profiles.h"
+#include "rmw/types.h"
+
+namespace rclcpp
+{
+
+std::string qos_policy_name_from_kind(rmw_qos_policy_kind_t policy_kind);
+
+/// QoS initialization values, cannot be created directly, use KeepAll or KeepLast instead.
+struct RCLCPP_PUBLIC QoSInitialization
+{
+  rmw_qos_history_policy_t history_policy;
+  size_t depth;
+
+  /// Constructor which takes both a history policy and a depth (even if it would be unused).
+  QoSInitialization(rmw_qos_history_policy_t history_policy_arg, size_t depth_arg);
+
+  /// Create a QoSInitialization from an existing rmw_qos_profile_t, using its history and depth.
+  static
+  QoSInitialization
+  from_rmw(const rmw_qos_profile_t & rmw_qos);
+};
+
+/// Use to initialize the QoS with the keep_all history setting.
+struct RCLCPP_PUBLIC KeepAll : public rclcpp::QoSInitialization
+{
+  KeepAll();
+};
+
+/// Use to initialize the QoS with the keep_last history setting and the given depth.
+struct RCLCPP_PUBLIC KeepLast : public rclcpp::QoSInitialization
+{
+  explicit KeepLast(size_t depth);
+};
+
+/// Encapsulation of Quality of Service settings.
+class RCLCPP_PUBLIC QoS
+{
+public:
+  /// Constructor which allows you to construct a QoS by giving the only required settings.
+  explicit
+  QoS(
+    const QoSInitialization & qos_initialization,
+    const rmw_qos_profile_t & initial_profile = rmw_qos_profile_default);
+
+  /// Conversion constructor to ease construction in the common case of just specifying depth.
+  /**
+   * Convenience constructor, equivalent to QoS(KeepLast(history_depth)).
+   */
+  // cppcheck-suppress noExplicitConstructor
+  QoS(size_t history_depth);  // NOLINT(runtime/explicit): conversion constructor
+
+  /// Return the rmw qos profile.
+  rmw_qos_profile_t &
+  get_rmw_qos_profile();
+
+  /// Return the rmw qos profile.
+  const rmw_qos_profile_t &
+  get_rmw_qos_profile() const;
+
+  /// Set the history policy.
+  QoS &
+  history(rmw_qos_history_policy_t history);
+
+  /// Set the history to keep last.
+  QoS &
+  keep_last(size_t depth);
+
+  /// Set the history to keep all.
+  QoS &
+  keep_all();
+
+  /// Set the reliability setting.
+  QoS &
+  reliability(rmw_qos_reliability_policy_t reliability);
+
+  /// Set the reliability setting to reliable.
+  QoS &
+  reliable();
+
+  /// Set the reliability setting to best effort.
+  QoS &
+  best_effort();
+
+  /// Set the durability setting.
+  QoS &
+  durability(rmw_qos_durability_policy_t durability);
+
+  /// Set the durability setting to volatile.
+  /**
+    * Note that this cannot be named `volatile` because it is a C++ keyword.
+    */
+  QoS &
+  durability_volatile();
+
+  /// Set the durability setting to transient local.
+  QoS &
+  transient_local();
+
+  /// Set the deadline setting.
+  QoS &
+  deadline(rmw_time_t deadline);
+
+  /// Set the deadline setting, rclcpp::Duration.
+  QoS &
+  deadline(const rclcpp::Duration & deadline);
+
+  /// Set the lifespan setting.
+  QoS &
+  lifespan(rmw_time_t lifespan);
+
+  /// Set the lifespan setting, rclcpp::Duration.
+  QoS &
+  lifespan(const rclcpp::Duration & lifespan);
+
+  /// Set the liveliness setting.
+  QoS &
+  liveliness(rmw_qos_liveliness_policy_t liveliness);
+
+  /// Set the liveliness_lease_duration setting.
+  QoS &
+  liveliness_lease_duration(rmw_time_t liveliness_lease_duration);
+
+  /// Set the liveliness_lease_duration setting, rclcpp::Duration.
+  QoS &
+  liveliness_lease_duration(const rclcpp::Duration & liveliness_lease_duration);
+
+  /// Set the avoid_ros_namespace_conventions setting.
+  QoS &
+  avoid_ros_namespace_conventions(bool avoid_ros_namespace_conventions);
+
+private:
+  rmw_qos_profile_t rmw_qos_profile_;
+};
+
+/// Check if two QoS profiles are exactly equal in all policy values.
+RCLCPP_PUBLIC
+bool operator==(const QoS & left, const QoS & right);
+RCLCPP_PUBLIC
+bool operator!=(const QoS & left, const QoS & right);
+
+class RCLCPP_PUBLIC SensorDataQoS : public QoS
+{
+public:
+  explicit
+  SensorDataQoS(
+    const QoSInitialization & qos_initialization = (
+      QoSInitialization::from_rmw(rmw_qos_profile_sensor_data)
+  ));
+};
+
+class RCLCPP_PUBLIC ParametersQoS : public QoS
+{
+public:
+  explicit
+  ParametersQoS(
+    const QoSInitialization & qos_initialization = (
+      QoSInitialization::from_rmw(rmw_qos_profile_parameters)
+  ));
+};
+
+class RCLCPP_PUBLIC ServicesQoS : public QoS
+{
+public:
+  explicit
+  ServicesQoS(
+    const QoSInitialization & qos_initialization = (
+      QoSInitialization::from_rmw(rmw_qos_profile_services_default)
+  ));
+};
+
+class RCLCPP_PUBLIC ParameterEventsQoS : public QoS
+{
+public:
+  explicit
+  ParameterEventsQoS(
+    const QoSInitialization & qos_initialization = (
+      QoSInitialization::from_rmw(rmw_qos_profile_parameter_events)
+  ));
+};
+
+class RCLCPP_PUBLIC SystemDefaultsQoS : public QoS
+{
+public:
+  explicit
+  SystemDefaultsQoS(
+    const QoSInitialization & qos_initialization = (
+      QoSInitialization::from_rmw(rmw_qos_profile_system_default)
+  ));
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__QOS_HPP_

rclcpp/include/rclcpp/qos_event.hpp

@@ -0,0 +1,156 @@
+// Copyright 2019 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__QOS_EVENT_HPP_
+#define RCLCPP__QOS_EVENT_HPP_
+
+#include <functional>
+#include <string>
+
+#include "rcl/error_handling.h"
+#include "rmw/incompatible_qos_events_statuses.h"
+
+#include "rcutils/logging_macros.h"
+
+#include "rclcpp/exceptions.hpp"
+#include "rclcpp/function_traits.hpp"
+#include "rclcpp/waitable.hpp"
+
+namespace rclcpp
+{
+
+using QOSDeadlineRequestedInfo = rmw_requested_deadline_missed_status_t;
+using QOSDeadlineOfferedInfo = rmw_offered_deadline_missed_status_t;
+using QOSLivelinessChangedInfo = rmw_liveliness_changed_status_t;
+using QOSLivelinessLostInfo = rmw_liveliness_lost_status_t;
+using QOSOfferedIncompatibleQoSInfo = rmw_offered_qos_incompatible_event_status_t;
+using QOSRequestedIncompatibleQoSInfo = rmw_requested_qos_incompatible_event_status_t;
+
+using QOSDeadlineRequestedCallbackType = std::function<void (QOSDeadlineRequestedInfo &)>;
+using QOSDeadlineOfferedCallbackType = std::function<void (QOSDeadlineOfferedInfo &)>;
+using QOSLivelinessChangedCallbackType = std::function<void (QOSLivelinessChangedInfo &)>;
+using QOSLivelinessLostCallbackType = std::function<void (QOSLivelinessLostInfo &)>;
+using QOSOfferedIncompatibleQoSCallbackType = std::function<void (QOSOfferedIncompatibleQoSInfo &)>;
+using QOSRequestedIncompatibleQoSCallbackType =
+  std::function<void (QOSRequestedIncompatibleQoSInfo &)>;
+
+/// Contains callbacks for various types of events a Publisher can receive from the middleware.
+struct PublisherEventCallbacks
+{
+  QOSDeadlineOfferedCallbackType deadline_callback;
+  QOSLivelinessLostCallbackType liveliness_callback;
+  QOSOfferedIncompatibleQoSCallbackType incompatible_qos_callback;
+};
+
+/// Contains callbacks for non-message events that a Subscription can receive from the middleware.
+struct SubscriptionEventCallbacks
+{
+  QOSDeadlineRequestedCallbackType deadline_callback;
+  QOSLivelinessChangedCallbackType liveliness_callback;
+  QOSRequestedIncompatibleQoSCallbackType incompatible_qos_callback;
+};
+
+class UnsupportedEventTypeException : public exceptions::RCLErrorBase, public std::runtime_error
+{
+public:
+  RCLCPP_PUBLIC
+  UnsupportedEventTypeException(
+    rcl_ret_t ret,
+    const rcl_error_state_t * error_state,
+    const std::string & prefix);
+
+  RCLCPP_PUBLIC
+  UnsupportedEventTypeException(
+    const exceptions::RCLErrorBase & base_exc,
+    const std::string & prefix);
+};
+
+class QOSEventHandlerBase : public Waitable
+{
+public:
+  RCLCPP_PUBLIC
+  virtual ~QOSEventHandlerBase();
+
+  /// Get the number of ready events
+  RCLCPP_PUBLIC
+  size_t
+  get_number_of_ready_events() override;
+
+  /// Add the Waitable to a wait set.
+  RCLCPP_PUBLIC
+  bool
+  add_to_wait_set(rcl_wait_set_t * wait_set) override;
+
+  /// Check if the Waitable is ready.
+  RCLCPP_PUBLIC
+  bool
+  is_ready(rcl_wait_set_t * wait_set) override;
+
+protected:
+  rcl_event_t event_handle_;
+  size_t wait_set_event_index_;
+};
+
+template<typename EventCallbackT>
+class QOSEventHandler : public QOSEventHandlerBase
+{
+public:
+  template<typename InitFuncT, typename ParentHandleT, typename EventTypeEnum>
+  QOSEventHandler(
+    const EventCallbackT & callback,
+    InitFuncT init_func,
+    ParentHandleT parent_handle,
+    EventTypeEnum event_type)
+  : event_callback_(callback)
+  {
+    event_handle_ = rcl_get_zero_initialized_event();
+    rcl_ret_t ret = init_func(&event_handle_, parent_handle, event_type);
+    if (ret != RCL_RET_OK) {
+      if (ret == RCL_RET_UNSUPPORTED) {
+        UnsupportedEventTypeException exc(ret, rcl_get_error_state(), "Failed to initialize event");
+        rcl_reset_error();
+        throw exc;
+      } else {
+        rclcpp::exceptions::throw_from_rcl_error(ret, "Failed to initialize event");
+      }
+    }
+  }
+
+  /// Execute any entities of the Waitable that are ready.
+  void
+  execute() override
+  {
+    EventCallbackInfoT callback_info;
+
+    rcl_ret_t ret = rcl_take_event(&event_handle_, &callback_info);
+    if (ret != RCL_RET_OK) {
+      RCUTILS_LOG_ERROR_NAMED(
+        "rclcpp",
+        "Couldn't take event info: %s", rcl_get_error_string().str);
+      return;
+    }
+
+    event_callback_(callback_info);
+  }
+
+private:
+  using EventCallbackInfoT = typename std::remove_reference<typename
+      rclcpp::function_traits::function_traits<EventCallbackT>::template argument_type<0>>::type;
+
+  EventCallbackT event_callback_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__QOS_EVENT_HPP_

rclcpp/include/rclcpp/rclcpp.hpp

@@ -48,7 +48,8 @@
  *   - rclcpp::Node::get_parameter()
  *   - rclcpp::Node::describe_parameters()
  *   - rclcpp::Node::list_parameters()
- *   - rclcpp::Node::register_param_change_callback()
+ *   - rclcpp::Node::add_on_set_parameters_callback()
+ *   - rclcpp::Node::remove_on_set_parameters_callback()
  *   - rclcpp::Parameter
  *   - rclcpp::ParameterValue
  *   - rclcpp::AsyncParametersClient
@@ -142,6 +143,7 @@
 #include <memory>
 
 #include "rclcpp/executors.hpp"
+#include "rclcpp/guard_condition.hpp"
 #include "rclcpp/logging.hpp"
 #include "rclcpp/node.hpp"
 #include "rclcpp/parameter.hpp"
@@ -151,6 +153,7 @@
 #include "rclcpp/time.hpp"
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "rclcpp/wait_set.hpp"
 #include "rclcpp/waitable.hpp"
 
 #endif  // RCLCPP__RCLCPP_HPP_

rclcpp/include/rclcpp/serialization.hpp

@@ -0,0 +1,102 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__SERIALIZATION_HPP_
+#define RCLCPP__SERIALIZATION_HPP_
+
+#include <memory>
+#include <stdexcept>
+#include <string>
+
+#include "rclcpp/visibility_control.hpp"
+
+#include "rcl/types.h"
+
+#include "rosidl_runtime_c/message_type_support_struct.h"
+
+#include "rosidl_typesupport_cpp/message_type_support.hpp"
+
+namespace rclcpp
+{
+
+class SerializedMessage;
+
+namespace serialization_traits
+{
+// trait to check if type is the object oriented serialized message
+template<typename T>
+struct is_serialized_message_class : std::false_type
+{};
+
+template<>
+struct is_serialized_message_class<rcl_serialized_message_t>: std::true_type
+{};
+
+template<>
+struct is_serialized_message_class<SerializedMessage>: std::true_type
+{};
+}  // namespace serialization_traits
+
+/// Interface to (de)serialize a message
+class RCLCPP_PUBLIC_TYPE SerializationBase
+{
+public:
+  /// Constructor of SerializationBase
+  /**
+   * \param[in] type_support handle for the message type support
+   * to be used for serialization and deserialization.
+   */
+  explicit SerializationBase(const rosidl_message_type_support_t * type_support);
+
+  /// Destructor of SerializationBase
+  virtual ~SerializationBase() = default;
+
+  /// Serialize a ROS2 message to a serialized stream
+  /**
+   * \param[in] message The ROS2 message which is read and serialized by rmw.
+   * \param[out] serialized_message The serialized message.
+   */
+  void serialize_message(
+    const void * ros_message, SerializedMessage * serialized_message) const;
+
+  /// Deserialize a serialized stream to a ROS message
+  /**
+   * \param[in] serialized_message The serialized message to be converted to ROS2 by rmw.
+   * \param[out] message The deserialized ROS2 message.
+   */
+  void deserialize_message(
+    const SerializedMessage * serialized_message, void * ros_message) const;
+
+private:
+  const rosidl_message_type_support_t * type_support_;
+};
+
+/// Default implementation to (de)serialize a message by using rmw_(de)serialize
+template<typename MessageT>
+class Serialization : public SerializationBase
+{
+public:
+  /// Constructor of Serialization
+  Serialization()
+  : SerializationBase(rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>())
+  {
+    static_assert(
+      !serialization_traits::is_serialized_message_class<MessageT>::value,
+      "Serialization of serialized message to serialized message is not possible.");
+  }
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__SERIALIZATION_HPP_

rclcpp/include/rclcpp/serialized_message.hpp

@@ -0,0 +1,107 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__SERIALIZED_MESSAGE_HPP_
+#define RCLCPP__SERIALIZED_MESSAGE_HPP_
+
+#include "rcl/allocator.h"
+#include "rcl/types.h"
+
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+
+/// Object oriented version of rcl_serialized_message_t with destructor to avoid memory leaks
+class RCLCPP_PUBLIC_TYPE SerializedMessage
+{
+public:
+  /// Default constructor for a SerializedMessage
+  /**
+   * Default constructs a serialized message and initalizes it
+   * with initial capacity of 0.
+   * The allocator defaults to `rcl_get_default_allocator()`.
+   *
+   * \param[in] allocator The allocator to be used for the initialization.
+   */
+  explicit SerializedMessage(
+    const rcl_allocator_t & allocator = rcl_get_default_allocator());
+
+  /// Default constructor for a SerializedMessage
+  /**
+   * Default constructs a serialized message and initalizes it
+   * with the provided capacity.
+   * The allocator defaults to `rcl_get_default_allocator()`.
+   *
+   * \param[in] initial_capacity The amount of memory to be allocated.
+   * \param[in] allocator The allocator to be used for the initialization.
+   */
+  SerializedMessage(
+    size_t initial_capacity,
+    const rcl_allocator_t & allocator = rcl_get_default_allocator());
+
+  /// Copy Constructor for a SerializedMessage
+  SerializedMessage(const SerializedMessage & other);
+
+  /// Constructor for a SerializedMessage from a rcl_serialized_message_t
+  explicit SerializedMessage(const rcl_serialized_message_t & other);
+
+  /// Move Constructor for a SerializedMessage
+  SerializedMessage(SerializedMessage && other);
+
+  /// Constructor for a SerializedMessage from a moved rcl_serialized_message_t
+  explicit SerializedMessage(rcl_serialized_message_t && other);
+
+  /// Copy assignment operator
+  SerializedMessage & operator=(const SerializedMessage & other);
+
+  /// Copy assignment operator from a rcl_serialized_message_t
+  SerializedMessage & operator=(const rcl_serialized_message_t & other);
+
+  /// Move assignment operator
+  SerializedMessage & operator=(SerializedMessage && other);
+
+  /// Move assignment operator from a rcl_serialized_message_t
+  SerializedMessage & operator=(rcl_serialized_message_t && other);
+
+  /// Destructor for a SerializedMessage
+  virtual ~SerializedMessage();
+
+  /// Get the underlying rcl_serialized_t handle
+  rcl_serialized_message_t & get_rcl_serialized_message();
+
+  // Get a const handle to the underlying rcl_serialized_message_t
+  const rcl_serialized_message_t & get_rcl_serialized_message() const;
+
+  /// Get the size of the serialized data buffer
+  /**
+   * Note, this is different from the actual amount of allocated memory.
+   * This can be obtained via a call to `capacity`.
+   */
+  size_t size() const;
+
+  /// Get the size of allocated memory for the data buffer
+  /**
+   * Note, this is different from the amount of content in the buffer.
+   * This can be obtained via a call to `size`.
+   */
+  size_t capacity() const;
+
+private:
+  rcl_serialized_message_t serialized_message_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__SERIALIZED_MESSAGE_HPP_