14.1.0

Signed-off-by: Chris Lalancette <clalancette@openrobotics.org>

rclcpp/CHANGELOG.rst

@@ -2,6 +2,120 @@
 Changelog for package rclcpp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+14.1.0 (2022-01-05)
+-------------------
+* Use UninitializedStaticallyTypedParameterException (`#1689 <https://github.com/ros2/rclcpp/issues/1689>`_)
+* Add wait_for_all_acked support (`#1662 <https://github.com/ros2/rclcpp/issues/1662>`_)
+* Add tests for function templates of declare_parameter (`#1747 <https://github.com/ros2/rclcpp/issues/1747>`_)
+* Contributors: Barry Xu, Bi0T1N, M. Mostafa Farzan
+
+14.0.0 (2021-12-17)
+-------------------
+* Fixes for uncrustify 0.72 (`#1844 <https://github.com/ros2/rclcpp/issues/1844>`_)
+* use private member to keep the all reference underneath. (`#1845 <https://github.com/ros2/rclcpp/issues/1845>`_)
+* Make node base sharable (`#1832 <https://github.com/ros2/rclcpp/issues/1832>`_)
+* Add Clock::sleep_for() (`#1828 <https://github.com/ros2/rclcpp/issues/1828>`_)
+* Synchronize rcl and std::chrono steady clocks in Clock::sleep_until (`#1830 <https://github.com/ros2/rclcpp/issues/1830>`_)
+* Use rclcpp::guard_condition (`#1612 <https://github.com/ros2/rclcpp/issues/1612>`_)
+* Call CMake function to generate version header (`#1805 <https://github.com/ros2/rclcpp/issues/1805>`_)
+* Use parantheses around logging macro parameter (`#1820 <https://github.com/ros2/rclcpp/issues/1820>`_)
+* Remove author by request (`#1818 <https://github.com/ros2/rclcpp/issues/1818>`_)
+* Update maintainers (`#1817 <https://github.com/ros2/rclcpp/issues/1817>`_)
+* min_forward & min_backward thresholds must not be disabled (`#1815 <https://github.com/ros2/rclcpp/issues/1815>`_)
+* Re-add Clock::sleep_until (`#1814 <https://github.com/ros2/rclcpp/issues/1814>`_)
+* Fix lifetime of context so it remains alive while its dependent node handles are still in use (`#1754 <https://github.com/ros2/rclcpp/issues/1754>`_)
+* Add the interface for pre-shutdown callback (`#1714 <https://github.com/ros2/rclcpp/issues/1714>`_)
+* Take message ownership from moved LoanedMessage (`#1808 <https://github.com/ros2/rclcpp/issues/1808>`_)
+* Suppress clang dead-store warnings in the benchmarks. (`#1802 <https://github.com/ros2/rclcpp/issues/1802>`_)
+* Wait for publisher and subscription to match (`#1777 <https://github.com/ros2/rclcpp/issues/1777>`_)
+* Fix unused QoS profile for clock subscription and make ClockQoS the default (`#1801 <https://github.com/ros2/rclcpp/issues/1801>`_)
+* Contributors: Abrar Rahman Protyasha, Barry Xu, Chen Lihui, Chris Lalancette, Grey, Jacob Perron, Nikolai Morin, Shane Loretz, Tomoya Fujita, mauropasse
+
+13.1.0 (2021-10-18)
+-------------------
+* Fix dangerous std::bind capture in TimeSource implementation. (`#1768 <https://github.com/ros2/rclcpp/issues/1768>`_)
+* Fix dangerous std::bind capture in ParameterEventHandler implementation. (`#1770 <https://github.com/ros2/rclcpp/issues/1770>`_)
+* Handle sigterm, in the same way sigint is being handled. (`#1771 <https://github.com/ros2/rclcpp/issues/1771>`_)
+* rclcpp::Node copy constructor: make copy of node_waitables\_ member. (`#1799 <https://github.com/ros2/rclcpp/issues/1799>`_)
+* Extend NodeGraph to match what rcl provides. (`#1484 <https://github.com/ros2/rclcpp/issues/1484>`_)
+* Context::sleep_for(): replace recursion with do-while to avoid potential stack-overflow. (`#1765 <https://github.com/ros2/rclcpp/issues/1765>`_)
+* extend_sub_namespace(): Verify string::empty() before calling string::front(). (`#1764 <https://github.com/ros2/rclcpp/issues/1764>`_)
+* Deprecate the `void shared_ptr<MessageT>` subscription callback signatures. (`#1713 <https://github.com/ros2/rclcpp/issues/1713>`_)
+* Contributors: Abrar Rahman Protyasha, Chris Lalancette, Emerson Knapp, Geoffrey Biggs, Ivan Santiago Paunovic, Jorge Perez, Tomoya Fujita, William Woodall, Yong-Hao Zou, livanov93
+
+13.0.0 (2021-08-23)
+-------------------
+* Remove can_be_nullptr assignment check for QNX case. (`#1752 <https://github.com/ros2/rclcpp/issues/1752>`_)
+* Update client API to be able to remove pending requests. (`#1734 <https://github.com/ros2/rclcpp/issues/1734>`_)
+* Fix: Allow to add a node while spinning in the StaticSingleThreadedExecutor. (`#1690 <https://github.com/ros2/rclcpp/issues/1690>`_)
+* Add tracing instrumentation for executor and message taking. (`#1738 <https://github.com/ros2/rclcpp/issues/1738>`_)
+* Fix: Reset timer trigger time before execute in StaticSingleThreadedExecutor. (`#1739 <https://github.com/ros2/rclcpp/issues/1739>`_)
+* Use FindPython3 and make python3 dependency explicit. (`#1745 <https://github.com/ros2/rclcpp/issues/1745>`_)
+* Use rosidl_get_typesupport_target(). (`#1729 <https://github.com/ros2/rclcpp/issues/1729>`_)
+* Fix returning invalid namespace if sub_namespace is empty. (`#1658 <https://github.com/ros2/rclcpp/issues/1658>`_)
+* Add free function to wait for a subscription message. (`#1705 <https://github.com/ros2/rclcpp/issues/1705>`_)
+* Use rcpputils/scope_exit.hpp and remove rclcpp/scope_exit.hpp. (`#1727 <https://github.com/ros2/rclcpp/issues/1727>`_)
+* Contributors: Ahmed Sobhy, Christophe Bedard, Ivan Santiago Paunovic, Karsten Knese, M. Hofstätter, Mauro Passerino, Shane Loretz, mauropasse
+
+12.0.0 (2021-07-26)
+-------------------
+* Remove unsafe get_callback_groups API.
+  Callers should change to using for_each_callback_group(), or
+  store the callback groups they need internally.
+* Add in callback_groups_for_each.
+  The main reason to add this method in is to make accesses to the
+  callback_groups\_ vector thread-safe.  By having a
+  callback_groups_for_each that accepts a std::function, we can
+  just have the callers give us the callback they are interested
+  in, and we can take care of the locking.
+  The rest of this fairly large PR is cleaning up all of the places
+  that use get_callback_groups() to instead use
+  callback_groups_for_each().
+* Use a different mechanism to avoid timers being scheduled multiple times by the MultiThreadedExecutor (`#1692 <https://github.com/ros2/rclcpp/issues/1692>`_)
+* Fix windows CI (`#1726 <https://github.com/ros2/rclcpp/issues/1726>`_)
+  Fix bug in AnyServiceCallback introduced in `#1709 <https://github.com/ros2/rclcpp/issues/1709>`_.
+* Contributors: Chris Lalancette, Ivan Santiago Paunovic
+
+11.2.0 (2021-07-21)
+-------------------
+* Support to defer to send a response in services. (`#1709 <https://github.com/ros2/rclcpp/issues/1709>`_)
+  Signed-off-by: Ivan Santiago Paunovic <ivanpauno@ekumenlabs.com>
+* Fix documentation bug. (`#1719 <https://github.com/ros2/rclcpp/issues/1719>`_)
+  Signed-off-by: William Woodall <william@osrfoundation.org>
+* Contributors: Ivan Santiago Paunovic, William Woodall
+
+11.1.0 (2021-07-13)
+-------------------
+* Removed left over ``is_initialized()`` implementation (`#1711 <https://github.com/ros2/rclcpp/issues/1711>`_)
+  Leftover from https://github.com/ros2/rclcpp/pull/1622
+* Fixed declare parameter methods for int and float vectors (`#1696 <https://github.com/ros2/rclcpp/issues/1696>`_)
+* Cleaned up implementation of the intra-process manager (`#1695 <https://github.com/ros2/rclcpp/issues/1695>`_)
+* Added the node name to an executor ``runtime_error`` (`#1686 <https://github.com/ros2/rclcpp/issues/1686>`_)
+* Fixed a typo "Attack" -> "Attach" (`#1687 <https://github.com/ros2/rclcpp/issues/1687>`_)
+* Removed use of std::allocator<>::rebind (`#1678 <https://github.com/ros2/rclcpp/issues/1678>`_)
+  rebind is deprecated in c++17 and removed in c++20
+* Contributors: Alberto Soragna, Chen Lihui, Chris Lalancette, Petter Nilsson, Steve Macenski, William Woodall
+
+11.0.0 (2021-05-18)
+-------------------
+* Allow declare uninitialized parameters (`#1673 <https://github.com/ros2/rclcpp/issues/1673>`_)
+* Fix syntax issue with gcc (`#1674 <https://github.com/ros2/rclcpp/issues/1674>`_)
+* [service] Don't use a weak_ptr to avoid leaking (`#1668 <https://github.com/ros2/rclcpp/issues/1668>`_)
+* Contributors: Ivan Santiago Paunovic, Jacob Perron, William Woodall
+
+10.0.0 (2021-05-11)
+-------------------
+* Fix doc typo (`#1663 <https://github.com/ros2/rclcpp/issues/1663>`_)
+* [rclcpp] Type Adaptation feature (`#1557 <https://github.com/ros2/rclcpp/issues/1557>`_)
+* Do not attempt to use void allocators for memory allocation. (`#1657 <https://github.com/ros2/rclcpp/issues/1657>`_)
+* Keep custom allocator in publisher and subscription options alive. (`#1647 <https://github.com/ros2/rclcpp/issues/1647>`_)
+* Fix get_publishers_subscriptions_info_by_topic test in test_node.cpp (`#1648 <https://github.com/ros2/rclcpp/issues/1648>`_)
+* Use OnShutdown callback handle instead of OnShutdown callback (`#1639 <https://github.com/ros2/rclcpp/issues/1639>`_)
+* use dynamic_pointer_cast to detect allocator mismatch in intra process manager (`#1643 <https://github.com/ros2/rclcpp/issues/1643>`_)
+* Increase cppcheck timeout to 500s (`#1634 <https://github.com/ros2/rclcpp/issues/1634>`_)
+* Clarify node parameters docs (`#1631 <https://github.com/ros2/rclcpp/issues/1631>`_)
+* Contributors: Audrow Nash, Barry Xu, Jacob Perron, Michel Hidalgo, Shane Loretz, William Woodall
+
 9.0.2 (2021-04-14)
 ------------------
 * Avoid returning loan when none was obtained. (`#1629 <https://github.com/ros2/rclcpp/issues/1629>`_)

rclcpp/CMakeLists.txt

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.5)
+cmake_minimum_required(VERSION 3.12)
 
 project(rclcpp)
 
@@ -41,7 +41,7 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/clock.cpp
   src/rclcpp/context.cpp
   src/rclcpp/contexts/default_context.cpp
-  src/rclcpp/detail/mutex_two_priorities.cpp
+  src/rclcpp/detail/add_guard_condition_to_rcl_wait_set.cpp
   src/rclcpp/detail/resolve_parameter_overrides.cpp
   src/rclcpp/detail/rmw_implementation_specific_payload.cpp
   src/rclcpp/detail/rmw_implementation_specific_publisher_payload.cpp
@@ -110,6 +110,8 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/waitable.cpp
 )
 
+find_package(Python3 REQUIRED COMPONENTS Interpreter)
+
 # "watch" template for changes
 configure_file(
   "resource/logging.hpp.em"
@@ -123,7 +125,7 @@ set(python_code_logging
 string(REPLACE ";" "$<SEMICOLON>" python_code_logging "${python_code_logging}")
 add_custom_command(OUTPUT include/rclcpp/logging.hpp
   COMMAND ${CMAKE_COMMAND} -E make_directory "include/rclcpp"
-  COMMAND ${PYTHON_EXECUTABLE} ARGS -c "${python_code_logging}"
+  COMMAND Python3::Interpreter ARGS -c "${python_code_logging}"
   DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/logging.hpp.em.watch"
   COMMENT "Expanding logging.hpp.em"
   VERBATIM
@@ -147,7 +149,7 @@ foreach(interface_file ${interface_files})
   string(REPLACE ";" "$<SEMICOLON>" python_${interface_name}_traits "${python_${interface_name}_traits}")
   add_custom_command(OUTPUT include/rclcpp/node_interfaces/${interface_name}_traits.hpp
     COMMAND ${CMAKE_COMMAND} -E make_directory "include/rclcpp/node_interfaces"
-    COMMAND ${PYTHON_EXECUTABLE} ARGS -c "${python_${interface_name}_traits}"
+    COMMAND Python3::Interpreter ARGS -c "${python_${interface_name}_traits}"
     DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/${interface_name}_traits.hpp.em.watch"
     COMMENT "Expanding interface_traits.hpp.em into ${interface_name}_traits.hpp"
     VERBATIM
@@ -167,7 +169,7 @@ foreach(interface_file ${interface_files})
   string(REPLACE ";" "$<SEMICOLON>" python_get_${interface_name} "${python_get_${interface_name}}")
   add_custom_command(OUTPUT include/rclcpp/node_interfaces/get_${interface_name}.hpp
     COMMAND ${CMAKE_COMMAND} -E make_directory "include/rclcpp/node_interfaces"
-    COMMAND ${PYTHON_EXECUTABLE} ARGS -c "${python_get_${interface_name}}"
+    COMMAND Python3::Interpreter ARGS -c "${python_get_${interface_name}}"
     DEPENDS "${CMAKE_CURRENT_BINARY_DIR}/get_${interface_name}.hpp.em.watch"
     COMMENT "Expanding get_interface.hpp.em into get_${interface_file}.hpp"
     VERBATIM
@@ -252,3 +254,5 @@ if(TEST cppcheck)
   # must set the property after ament_package()
   set_tests_properties(cppcheck PROPERTIES TIMEOUT 500)
 endif()
+
+ament_cmake_gen_version_h()

rclcpp/include/rclcpp/allocator/allocator_common.hpp

@@ -29,23 +29,71 @@ namespace allocator
 template<typename T, typename Alloc>
 using AllocRebind = typename std::allocator_traits<Alloc>::template rebind_traits<T>;
 
-/// Return the equivalent rcl_allocator_t for the C++ standard allocator.
-/**
- * This assumes that the user intent behind both allocators is the
- * same: Using system malloc for allocation.
- *
- * If you're using a custom allocator in ROS, you'll need to provide
- * your own overload for this function.
- */
-template<typename T>
-rcl_allocator_t get_rcl_allocator(std::allocator<T> allocator)
+template<typename Alloc>
+void * retyped_allocate(size_t size, void * untyped_allocator)
 {
+  auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
+  if (!typed_allocator) {
+    throw std::runtime_error("Received incorrect allocator type");
+  }
+  return std::allocator_traits<Alloc>::allocate(*typed_allocator, size);
+}
+
+template<typename T, typename Alloc>
+void retyped_deallocate(void * untyped_pointer, void * untyped_allocator)
+{
+  auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
+  if (!typed_allocator) {
+    throw std::runtime_error("Received incorrect allocator type");
+  }
+  auto typed_ptr = static_cast<T *>(untyped_pointer);
+  std::allocator_traits<Alloc>::deallocate(*typed_allocator, typed_ptr, 1);
+}
+
+template<typename T, typename Alloc>
+void * retyped_reallocate(void * untyped_pointer, size_t size, void * untyped_allocator)
+{
+  auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
+  if (!typed_allocator) {
+    throw std::runtime_error("Received incorrect allocator type");
+  }
+  auto typed_ptr = static_cast<T *>(untyped_pointer);
+  std::allocator_traits<Alloc>::deallocate(*typed_allocator, typed_ptr, 1);
+  return std::allocator_traits<Alloc>::allocate(*typed_allocator, size);
+}
+
+
+// Convert a std::allocator_traits-formatted Allocator into an rcl allocator
+template<
+  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)
+{
+  rcl_allocator_t rcl_allocator = rcl_get_default_allocator();
+#ifndef _WIN32
+  rcl_allocator.allocate = &retyped_allocate<Alloc>;
+  rcl_allocator.deallocate = &retyped_deallocate<T, Alloc>;
+  rcl_allocator.reallocate = &retyped_reallocate<T, Alloc>;
+  rcl_allocator.state = &allocator;
+#else
   (void)allocator;  // Remove warning
+#endif
+  return rcl_allocator;
+}
+
+// TODO(jacquelinekay) Workaround for an incomplete implementation of std::allocator<void>
+template<
+  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)
+{
+  (void)allocator;
   return rcl_get_default_allocator();
 }
 
 }  // namespace allocator
-
 }  // namespace rclcpp
 
 #endif  // RCLCPP__ALLOCATOR__ALLOCATOR_COMMON_HPP_

rclcpp/include/rclcpp/allocator/allocator_deleter.hpp

@@ -95,7 +95,7 @@ void set_allocator_for_deleter(AllocatorDeleter<T> * deleter, Alloc * alloc)
 template<typename Alloc, typename T>
 using Deleter = typename std::conditional<
   std::is_same<typename std::allocator_traits<Alloc>::template rebind_alloc<T>,
-  typename std::allocator<void>::template rebind<T>::other>::value,
+  std::allocator<T>>::value,
   std::default_delete<T>,
   AllocatorDeleter<Alloc>
   >::type;

rclcpp/include/rclcpp/any_service_callback.hpp

@@ -15,10 +15,12 @@
 #ifndef RCLCPP__ANY_SERVICE_CALLBACK_HPP_
 #define RCLCPP__ANY_SERVICE_CALLBACK_HPP_
 
+#include <variant>
 #include <functional>
 #include <memory>
 #include <stdexcept>
 #include <type_traits>
+#include <utility>
 
 #include "rclcpp/function_traits.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -29,93 +31,204 @@
 namespace rclcpp
 {
 
+namespace detail
+{
+template<typename T, typename = void>
+struct can_be_nullptr : std::false_type {};
+
+// Some lambdas define a comparison with nullptr,
+// but we see a warning that they can never be null when using it.
+// We also test if `T &` can be assigned to `nullptr` to avoid the issue.
+template<typename T>
+#ifdef __QNXNTO__
+struct can_be_nullptr<T, std::void_t<
+    decltype(std::declval<T>() == nullptr)>>: std::true_type {};
+#else
+struct can_be_nullptr<T, std::void_t<
+    decltype(std::declval<T>() == nullptr), decltype(std::declval<T &>() = nullptr)>>
+  : std::true_type {};
+#endif
+}  // namespace detail
+
+// Forward declare
+template<typename ServiceT>
+class Service;
+
 template<typename ServiceT>
 class AnyServiceCallback
 {
-private:
-  using SharedPtrCallback = std::function<
-    void (
-      const std::shared_ptr<typename ServiceT::Request>,
-      std::shared_ptr<typename ServiceT::Response>
-    )>;
-  using SharedPtrWithRequestHeaderCallback = std::function<
-    void (
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<typename ServiceT::Request>,
-      std::shared_ptr<typename ServiceT::Response>
-    )>;
-
-  SharedPtrCallback shared_ptr_callback_;
-  SharedPtrWithRequestHeaderCallback shared_ptr_with_request_header_callback_;
-
 public:
   AnyServiceCallback()
-  : shared_ptr_callback_(nullptr), shared_ptr_with_request_header_callback_(nullptr)
+  : callback_(std::monostate{})
   {}
 
-  AnyServiceCallback(const AnyServiceCallback &) = default;
-
   template<
     typename CallbackT,
-    typename std::enable_if<
+    typename std::enable_if_t<!detail::can_be_nullptr<CallbackT>::value, int> = 0>
+  void
+  set(CallbackT && callback)
+  {
+    // Workaround Windows issue with std::bind
+    if constexpr (
       rclcpp::function_traits::same_arguments<
         CallbackT,
         SharedPtrCallback
-      >::value
-    >::type * = nullptr
-  >
-  void set(CallbackT callback)
-  {
-    shared_ptr_callback_ = callback;
+      >::value)
+    {
+      callback_.template emplace<SharedPtrCallback>(callback);
+    } else if constexpr (  // NOLINT, can't satisfy both cpplint and uncrustify
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrWithRequestHeaderCallback
+      >::value)
+    {
+      callback_.template emplace<SharedPtrWithRequestHeaderCallback>(callback);
+    } else if constexpr (  // NOLINT
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrDeferResponseCallback
+      >::value)
+    {
+      callback_.template emplace<SharedPtrDeferResponseCallback>(callback);
+    } else if constexpr (  // NOLINT
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrDeferResponseCallbackWithServiceHandle
+      >::value)
+    {
+      callback_.template emplace<SharedPtrDeferResponseCallbackWithServiceHandle>(callback);
+    } else {
+      // the else clause is not needed, but anyways we should only be doing this instead
+      // of all the above workaround ...
+      callback_ = std::forward<CallbackT>(callback);
+    }
   }
 
   template<
     typename CallbackT,
-    typename std::enable_if<
+    typename std::enable_if_t<detail::can_be_nullptr<CallbackT>::value, int> = 0>
+  void
+  set(CallbackT && callback)
+  {
+    if (!callback) {
+      throw std::invalid_argument("AnyServiceCallback::set(): callback cannot be nullptr");
+    }
+    // Workaround Windows issue with std::bind
+    if constexpr (
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrCallback
+      >::value)
+    {
+      callback_.template emplace<SharedPtrCallback>(callback);
+    } else if constexpr (  // NOLINT
       rclcpp::function_traits::same_arguments<
         CallbackT,
         SharedPtrWithRequestHeaderCallback
-      >::value
-    >::type * = nullptr
-  >
-  void set(CallbackT callback)
-  {
-    shared_ptr_with_request_header_callback_ = callback;
+      >::value)
+    {
+      callback_.template emplace<SharedPtrWithRequestHeaderCallback>(callback);
+    } else if constexpr (  // NOLINT
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrDeferResponseCallback
+      >::value)
+    {
+      callback_.template emplace<SharedPtrDeferResponseCallback>(callback);
+    } else if constexpr (  // NOLINT
+      rclcpp::function_traits::same_arguments<
+        CallbackT,
+        SharedPtrDeferResponseCallbackWithServiceHandle
+      >::value)
+    {
+      callback_.template emplace<SharedPtrDeferResponseCallbackWithServiceHandle>(callback);
+    } else {
+      // the else clause is not needed, but anyways we should only be doing this instead
+      // of all the above workaround ...
+      callback_ = std::forward<CallbackT>(callback);
+    }
   }
 
-  void dispatch(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<typename ServiceT::Request> request,
-    std::shared_ptr<typename ServiceT::Response> response)
+  // template<typename Allocator = std::allocator<typename ServiceT::Response>>
+  std::shared_ptr<typename ServiceT::Response>
+  dispatch(
+    const std::shared_ptr<rclcpp::Service<ServiceT>> & service_handle,
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    std::shared_ptr<typename ServiceT::Request> request)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), false);
-    if (shared_ptr_callback_ != nullptr) {
+    if (std::holds_alternative<std::monostate>(callback_)) {
+      // TODO(ivanpauno): Remove the set method, and force the users of this class
+      // to pass a callback at construnciton.
+      throw std::runtime_error{"unexpected request without any callback set"};
+    }
+    if (std::holds_alternative<SharedPtrDeferResponseCallback>(callback_)) {
+      const auto & cb = std::get<SharedPtrDeferResponseCallback>(callback_);
+      cb(request_header, std::move(request));
+      return nullptr;
+    }
+    if (std::holds_alternative<SharedPtrDeferResponseCallbackWithServiceHandle>(callback_)) {
+      const auto & cb = std::get<SharedPtrDeferResponseCallbackWithServiceHandle>(callback_);
+      cb(service_handle, request_header, std::move(request));
+      return nullptr;
+    }
+    // auto response = allocate_shared<typename ServiceT::Response, Allocator>();
+    auto response = std::make_shared<typename ServiceT::Response>();
+    if (std::holds_alternative<SharedPtrCallback>(callback_)) {
       (void)request_header;
-      shared_ptr_callback_(request, response);
-    } else if (shared_ptr_with_request_header_callback_ != nullptr) {
-      shared_ptr_with_request_header_callback_(request_header, request, response);
-    } else {
-      throw std::runtime_error("unexpected request without any callback set");
+      const auto & cb = std::get<SharedPtrCallback>(callback_);
+      cb(std::move(request), response);
+    } else if (std::holds_alternative<SharedPtrWithRequestHeaderCallback>(callback_)) {
+      const auto & cb = std::get<SharedPtrWithRequestHeaderCallback>(callback_);
+      cb(request_header, std::move(request), response);
     }
     TRACEPOINT(callback_end, static_cast<const void *>(this));
+    return response;
   }
 
   void register_callback_for_tracing()
   {
 #ifndef TRACETOOLS_DISABLED
-    if (shared_ptr_callback_) {
-      TRACEPOINT(
-        rclcpp_callback_register,
-        static_cast<const void *>(this),
-        tracetools::get_symbol(shared_ptr_callback_));
-    } else if (shared_ptr_with_request_header_callback_) {
-      TRACEPOINT(
-        rclcpp_callback_register,
-        static_cast<const void *>(this),
-        tracetools::get_symbol(shared_ptr_with_request_header_callback_));
-    }
+    std::visit(
+      [this](auto && arg) {
+        TRACEPOINT(
+          rclcpp_callback_register,
+          static_cast<const void *>(this),
+          tracetools::get_symbol(arg));
+      }, callback_);
 #endif  // TRACETOOLS_DISABLED
   }
+
+private:
+  using SharedPtrCallback = std::function<
+    void (
+      std::shared_ptr<typename ServiceT::Request>,
+      std::shared_ptr<typename ServiceT::Response>
+    )>;
+  using SharedPtrWithRequestHeaderCallback = std::function<
+    void (
+      std::shared_ptr<rmw_request_id_t>,
+      std::shared_ptr<typename ServiceT::Request>,
+      std::shared_ptr<typename ServiceT::Response>
+    )>;
+  using SharedPtrDeferResponseCallback = std::function<
+    void (
+      std::shared_ptr<rmw_request_id_t>,
+      std::shared_ptr<typename ServiceT::Request>
+    )>;
+  using SharedPtrDeferResponseCallbackWithServiceHandle = std::function<
+    void (
+      std::shared_ptr<rclcpp::Service<ServiceT>>,
+      std::shared_ptr<rmw_request_id_t>,
+      std::shared_ptr<typename ServiceT::Request>
+    )>;
+
+  std::variant<
+    std::monostate,
+    SharedPtrCallback,
+    SharedPtrWithRequestHeaderCallback,
+    SharedPtrDeferResponseCallback,
+    SharedPtrDeferResponseCallbackWithServiceHandle> callback_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/any_subscription_callback.hpp

@@ -22,6 +22,7 @@
 #include <utility>
 #include <variant>  // NOLINT[build/include_order]
 
+#include "rosidl_runtime_cpp/traits.hpp"
 #include "tracetools/tracetools.h"
 #include "tracetools/utils.hpp"
 
@@ -29,6 +30,9 @@
 #include "rclcpp/detail/subscription_callback_type_helper.hpp"
 #include "rclcpp/function_traits.hpp"
 #include "rclcpp/message_info.hpp"
+#include "rclcpp/serialized_message.hpp"
+#include "rclcpp/type_adapter.hpp"
+
 
 template<class>
 inline constexpr bool always_false_v = false;
@@ -42,53 +46,189 @@ namespace detail
 template<typename MessageT, typename AllocatorT>
 struct MessageDeleterHelper
 {
-  using MessageAllocTraits = allocator::AllocRebind<MessageT, AllocatorT>;
-  using MessageAlloc = typename MessageAllocTraits::allocator_type;
-  using MessageDeleter = allocator::Deleter<MessageAlloc, MessageT>;
+  using AllocTraits = allocator::AllocRebind<MessageT, AllocatorT>;
+  using Alloc = typename AllocTraits::allocator_type;
+  using Deleter = allocator::Deleter<Alloc, MessageT>;
 };
 
+/// Struct which contains all possible callback signatures, with or without a TypeAdapter.s
 template<typename MessageT, typename AllocatorT>
-struct AnySubscriptionCallbackHelper
+struct AnySubscriptionCallbackPossibleTypes
 {
-  using MessageDeleter = typename MessageDeleterHelper<MessageT, AllocatorT>::MessageDeleter;
+  /// MessageT::custom_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using SubscribedType = typename rclcpp::TypeAdapter<MessageT>::custom_type;
+  /// MessageT::ros_message_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using ROSMessageType = typename rclcpp::TypeAdapter<MessageT>::ros_message_type;
+
+  using SubscribedMessageDeleter =
+    typename MessageDeleterHelper<SubscribedType, AllocatorT>::Deleter;
+  using ROSMessageDeleter =
+    typename MessageDeleterHelper<ROSMessageType, AllocatorT>::Deleter;
+  using SerializedMessageDeleter =
+    typename MessageDeleterHelper<rclcpp::SerializedMessage, AllocatorT>::Deleter;
 
   using ConstRefCallback =
-    std::function<void (const MessageT &)>;
+    std::function<void (const SubscribedType &)>;
+  using ConstRefROSMessageCallback =
+    std::function<void (const ROSMessageType &)>;
   using ConstRefWithInfoCallback =
-    std::function<void (const MessageT &, const rclcpp::MessageInfo &)>;
+    std::function<void (const SubscribedType &, const rclcpp::MessageInfo &)>;
+  using ConstRefWithInfoROSMessageCallback =
+    std::function<void (const ROSMessageType &, const rclcpp::MessageInfo &)>;
+  using ConstRefSerializedMessageCallback =
+    std::function<void (const rclcpp::SerializedMessage &)>;
+  using ConstRefSerializedMessageWithInfoCallback =
+    std::function<void (const rclcpp::SerializedMessage &, const rclcpp::MessageInfo &)>;
 
   using UniquePtrCallback =
-    std::function<void (std::unique_ptr<MessageT, MessageDeleter>)>;
+    std::function<void (std::unique_ptr<SubscribedType, SubscribedMessageDeleter>)>;
+  using UniquePtrROSMessageCallback =
+    std::function<void (std::unique_ptr<ROSMessageType, ROSMessageDeleter>)>;
   using UniquePtrWithInfoCallback =
-    std::function<void (std::unique_ptr<MessageT, MessageDeleter>, const rclcpp::MessageInfo &)>;
+    std::function<void (
+        std::unique_ptr<SubscribedType, SubscribedMessageDeleter>,
+        const rclcpp::MessageInfo &)>;
+  using UniquePtrWithInfoROSMessageCallback =
+    std::function<void (
+        std::unique_ptr<ROSMessageType, ROSMessageDeleter>,
+        const rclcpp::MessageInfo &)>;
+  using UniquePtrSerializedMessageCallback =
+    std::function<void (std::unique_ptr<rclcpp::SerializedMessage, SerializedMessageDeleter>)>;
+  using UniquePtrSerializedMessageWithInfoCallback =
+    std::function<void (
+        std::unique_ptr<rclcpp::SerializedMessage, SerializedMessageDeleter>,
+        const rclcpp::MessageInfo &)>;
 
   using SharedConstPtrCallback =
-    std::function<void (std::shared_ptr<const MessageT>)>;
+    std::function<void (std::shared_ptr<const SubscribedType>)>;
+  using SharedConstPtrROSMessageCallback =
+    std::function<void (std::shared_ptr<const ROSMessageType>)>;
   using SharedConstPtrWithInfoCallback =
-    std::function<void (std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)>;
+    std::function<void (
+        std::shared_ptr<const SubscribedType>,
+        const rclcpp::MessageInfo &)>;
+  using SharedConstPtrWithInfoROSMessageCallback =
+    std::function<void (
+        std::shared_ptr<const ROSMessageType>,
+        const rclcpp::MessageInfo &)>;
+  using SharedConstPtrSerializedMessageCallback =
+    std::function<void (std::shared_ptr<const rclcpp::SerializedMessage>)>;
+  using SharedConstPtrSerializedMessageWithInfoCallback =
+    std::function<void (
+        std::shared_ptr<const rclcpp::SerializedMessage>,
+        const rclcpp::MessageInfo &)>;
 
   using ConstRefSharedConstPtrCallback =
-    std::function<void (const std::shared_ptr<const MessageT> &)>;
+    std::function<void (const std::shared_ptr<const SubscribedType> &)>;
+  using ConstRefSharedConstPtrROSMessageCallback =
+    std::function<void (const std::shared_ptr<const ROSMessageType> &)>;
   using ConstRefSharedConstPtrWithInfoCallback =
-    std::function<void (const std::shared_ptr<const MessageT> &, const rclcpp::MessageInfo &)>;
+    std::function<void (
+        const std::shared_ptr<const SubscribedType> &,
+        const rclcpp::MessageInfo &)>;
+  using ConstRefSharedConstPtrWithInfoROSMessageCallback =
+    std::function<void (
+        const std::shared_ptr<const ROSMessageType> &,
+        const rclcpp::MessageInfo &)>;
+  using ConstRefSharedConstPtrSerializedMessageCallback =
+    std::function<void (const std::shared_ptr<const rclcpp::SerializedMessage> &)>;
+  using ConstRefSharedConstPtrSerializedMessageWithInfoCallback =
+    std::function<void (
+        const std::shared_ptr<const rclcpp::SerializedMessage> &,
+        const rclcpp::MessageInfo &)>;
 
   // Deprecated signatures:
   using SharedPtrCallback =
-    std::function<void (std::shared_ptr<MessageT>)>;
+    std::function<void (std::shared_ptr<SubscribedType>)>;
+  using SharedPtrROSMessageCallback =
+    std::function<void (std::shared_ptr<ROSMessageType>)>;
   using SharedPtrWithInfoCallback =
-    std::function<void (std::shared_ptr<MessageT>, const rclcpp::MessageInfo &)>;
+    std::function<void (std::shared_ptr<SubscribedType>, const rclcpp::MessageInfo &)>;
+  using SharedPtrWithInfoROSMessageCallback =
+    std::function<void (
+        std::shared_ptr<ROSMessageType>,
+        const rclcpp::MessageInfo &)>;
+  using SharedPtrSerializedMessageCallback =
+    std::function<void (std::shared_ptr<rclcpp::SerializedMessage>)>;
+  using SharedPtrSerializedMessageWithInfoCallback =
+    std::function<void (std::shared_ptr<rclcpp::SerializedMessage>, const rclcpp::MessageInfo &)>;
+};
+
+/// Template helper to select the variant type based on whether or not MessageT is a TypeAdapter.
+template<
+  typename MessageT,
+  typename AllocatorT,
+  bool is_adapted_type = rclcpp::TypeAdapter<MessageT>::is_specialized::value
+>
+struct AnySubscriptionCallbackHelper;
+
+/// Specialization for when MessageT is not a TypeAdapter.
+template<typename MessageT, typename AllocatorT>
+struct AnySubscriptionCallbackHelper<MessageT, AllocatorT, false>
+{
+  using CallbackTypes = AnySubscriptionCallbackPossibleTypes<MessageT, AllocatorT>;
 
   using variant_type = std::variant<
-    ConstRefCallback,
-    ConstRefWithInfoCallback,
-    UniquePtrCallback,
-    UniquePtrWithInfoCallback,
-    SharedConstPtrCallback,
-    SharedConstPtrWithInfoCallback,
-    ConstRefSharedConstPtrCallback,
-    ConstRefSharedConstPtrWithInfoCallback,
-    SharedPtrCallback,
-    SharedPtrWithInfoCallback
+    typename CallbackTypes::ConstRefCallback,
+    typename CallbackTypes::ConstRefWithInfoCallback,
+    typename CallbackTypes::ConstRefSerializedMessageCallback,
+    typename CallbackTypes::ConstRefSerializedMessageWithInfoCallback,
+    typename CallbackTypes::UniquePtrCallback,
+    typename CallbackTypes::UniquePtrWithInfoCallback,
+    typename CallbackTypes::UniquePtrSerializedMessageCallback,
+    typename CallbackTypes::UniquePtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::SharedConstPtrCallback,
+    typename CallbackTypes::SharedConstPtrWithInfoCallback,
+    typename CallbackTypes::SharedConstPtrSerializedMessageCallback,
+    typename CallbackTypes::SharedConstPtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrWithInfoCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::SharedPtrCallback,
+    typename CallbackTypes::SharedPtrWithInfoCallback,
+    typename CallbackTypes::SharedPtrSerializedMessageCallback,
+    typename CallbackTypes::SharedPtrSerializedMessageWithInfoCallback
+  >;
+};
+
+/// Specialization for when MessageT is a TypeAdapter.
+template<typename MessageT, typename AllocatorT>
+struct AnySubscriptionCallbackHelper<MessageT, AllocatorT, true>
+{
+  using CallbackTypes = AnySubscriptionCallbackPossibleTypes<MessageT, AllocatorT>;
+
+  using variant_type = std::variant<
+    typename CallbackTypes::ConstRefCallback,
+    typename CallbackTypes::ConstRefROSMessageCallback,
+    typename CallbackTypes::ConstRefWithInfoCallback,
+    typename CallbackTypes::ConstRefWithInfoROSMessageCallback,
+    typename CallbackTypes::ConstRefSerializedMessageCallback,
+    typename CallbackTypes::ConstRefSerializedMessageWithInfoCallback,
+    typename CallbackTypes::UniquePtrCallback,
+    typename CallbackTypes::UniquePtrROSMessageCallback,
+    typename CallbackTypes::UniquePtrWithInfoCallback,
+    typename CallbackTypes::UniquePtrWithInfoROSMessageCallback,
+    typename CallbackTypes::UniquePtrSerializedMessageCallback,
+    typename CallbackTypes::UniquePtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::SharedConstPtrCallback,
+    typename CallbackTypes::SharedConstPtrROSMessageCallback,
+    typename CallbackTypes::SharedConstPtrWithInfoCallback,
+    typename CallbackTypes::SharedConstPtrWithInfoROSMessageCallback,
+    typename CallbackTypes::SharedConstPtrSerializedMessageCallback,
+    typename CallbackTypes::SharedConstPtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrROSMessageCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrWithInfoCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrWithInfoROSMessageCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageCallback,
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageWithInfoCallback,
+    typename CallbackTypes::SharedPtrCallback,
+    typename CallbackTypes::SharedPtrROSMessageCallback,
+    typename CallbackTypes::SharedPtrWithInfoCallback,
+    typename CallbackTypes::SharedPtrWithInfoROSMessageCallback,
+    typename CallbackTypes::SharedPtrSerializedMessageCallback,
+    typename CallbackTypes::SharedPtrSerializedMessageWithInfoCallback
   >;
 };
 
@@ -101,49 +241,124 @@ template<
 class AnySubscriptionCallback
 {
 private:
+  /// MessageT::custom_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using SubscribedType = typename rclcpp::TypeAdapter<MessageT>::custom_type;
+  /// MessageT::ros_message_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using ROSMessageType = typename rclcpp::TypeAdapter<MessageT>::ros_message_type;
+
   using HelperT = typename rclcpp::detail::AnySubscriptionCallbackHelper<MessageT, AllocatorT>;
-  using MessageDeleterHelper = rclcpp::detail::MessageDeleterHelper<MessageT, AllocatorT>;
 
-  using MessageAllocTraits = typename MessageDeleterHelper::MessageAllocTraits;
-  using MessageAlloc = typename MessageDeleterHelper::MessageAlloc;
-  using MessageDeleter = typename MessageDeleterHelper::MessageDeleter;
+  using SubscribedTypeDeleterHelper =
+    rclcpp::detail::MessageDeleterHelper<SubscribedType, AllocatorT>;
+  using SubscribedTypeAllocatorTraits = typename SubscribedTypeDeleterHelper::AllocTraits;
+  using SubscribedTypeAllocator = typename SubscribedTypeDeleterHelper::Alloc;
+  using SubscribedTypeDeleter = typename SubscribedTypeDeleterHelper::Deleter;
 
-  // See AnySubscriptionCallbackHelper for the types of these.
-  using ConstRefCallback = typename HelperT::ConstRefCallback;
-  using ConstRefWithInfoCallback = typename HelperT::ConstRefWithInfoCallback;
+  using ROSMessageTypeDeleterHelper =
+    rclcpp::detail::MessageDeleterHelper<ROSMessageType, AllocatorT>;
+  using ROSMessageTypeAllocatorTraits = typename ROSMessageTypeDeleterHelper::AllocTraits;
+  using ROSMessageTypeAllocator = typename ROSMessageTypeDeleterHelper::Alloc;
+  using ROSMessageTypeDeleter = typename ROSMessageTypeDeleterHelper::Deleter;
 
-  using UniquePtrCallback = typename HelperT::UniquePtrCallback;
-  using UniquePtrWithInfoCallback = typename HelperT::UniquePtrWithInfoCallback;
+  using SerializedMessageDeleterHelper =
+    rclcpp::detail::MessageDeleterHelper<rclcpp::SerializedMessage, AllocatorT>;
+  using SerializedMessageAllocatorTraits = typename SerializedMessageDeleterHelper::AllocTraits;
+  using SerializedMessageAllocator = typename SerializedMessageDeleterHelper::Alloc;
+  using SerializedMessageDeleter = typename SerializedMessageDeleterHelper::Deleter;
 
-  using SharedConstPtrCallback = typename HelperT::SharedConstPtrCallback;
-  using SharedConstPtrWithInfoCallback = typename HelperT::SharedConstPtrWithInfoCallback;
+  // See AnySubscriptionCallbackPossibleTypes for the types of these.
+  using CallbackTypes = detail::AnySubscriptionCallbackPossibleTypes<MessageT, AllocatorT>;
 
+  using ConstRefCallback =
+    typename CallbackTypes::ConstRefCallback;
+  using ConstRefROSMessageCallback =
+    typename CallbackTypes::ConstRefROSMessageCallback;
+  using ConstRefWithInfoCallback =
+    typename CallbackTypes::ConstRefWithInfoCallback;
+  using ConstRefWithInfoROSMessageCallback =
+    typename CallbackTypes::ConstRefWithInfoROSMessageCallback;
+  using ConstRefSerializedMessageCallback =
+    typename CallbackTypes::ConstRefSerializedMessageCallback;
+  using ConstRefSerializedMessageWithInfoCallback =
+    typename CallbackTypes::ConstRefSerializedMessageWithInfoCallback;
+  using UniquePtrCallback =
+    typename CallbackTypes::UniquePtrCallback;
+  using UniquePtrROSMessageCallback =
+    typename CallbackTypes::UniquePtrROSMessageCallback;
+  using UniquePtrWithInfoCallback =
+    typename CallbackTypes::UniquePtrWithInfoCallback;
+  using UniquePtrWithInfoROSMessageCallback =
+    typename CallbackTypes::UniquePtrWithInfoROSMessageCallback;
+  using UniquePtrSerializedMessageCallback =
+    typename CallbackTypes::UniquePtrSerializedMessageCallback;
+  using UniquePtrSerializedMessageWithInfoCallback =
+    typename CallbackTypes::UniquePtrSerializedMessageWithInfoCallback;
+  using SharedConstPtrCallback =
+    typename CallbackTypes::SharedConstPtrCallback;
+  using SharedConstPtrROSMessageCallback =
+    typename CallbackTypes::SharedConstPtrROSMessageCallback;
+  using SharedConstPtrWithInfoCallback =
+    typename CallbackTypes::SharedConstPtrWithInfoCallback;
+  using SharedConstPtrWithInfoROSMessageCallback =
+    typename CallbackTypes::SharedConstPtrWithInfoROSMessageCallback;
+  using SharedConstPtrSerializedMessageCallback =
+    typename CallbackTypes::SharedConstPtrSerializedMessageCallback;
+  using SharedConstPtrSerializedMessageWithInfoCallback =
+    typename CallbackTypes::SharedConstPtrSerializedMessageWithInfoCallback;
   using ConstRefSharedConstPtrCallback =
-    typename HelperT::ConstRefSharedConstPtrCallback;
+    typename CallbackTypes::ConstRefSharedConstPtrCallback;
+  using ConstRefSharedConstPtrROSMessageCallback =
+    typename CallbackTypes::ConstRefSharedConstPtrROSMessageCallback;
   using ConstRefSharedConstPtrWithInfoCallback =
-    typename HelperT::ConstRefSharedConstPtrWithInfoCallback;
+    typename CallbackTypes::ConstRefSharedConstPtrWithInfoCallback;
+  using ConstRefSharedConstPtrWithInfoROSMessageCallback =
+    typename CallbackTypes::ConstRefSharedConstPtrWithInfoROSMessageCallback;
+  using ConstRefSharedConstPtrSerializedMessageCallback =
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageCallback;
+  using ConstRefSharedConstPtrSerializedMessageWithInfoCallback =
+    typename CallbackTypes::ConstRefSharedConstPtrSerializedMessageWithInfoCallback;
+  using SharedPtrCallback =
+    typename CallbackTypes::SharedPtrCallback;
+  using SharedPtrROSMessageCallback =
+    typename CallbackTypes::SharedPtrROSMessageCallback;
+  using SharedPtrWithInfoCallback =
+    typename CallbackTypes::SharedPtrWithInfoCallback;
+  using SharedPtrWithInfoROSMessageCallback =
+    typename CallbackTypes::SharedPtrWithInfoROSMessageCallback;
+  using SharedPtrSerializedMessageCallback =
+    typename CallbackTypes::SharedPtrSerializedMessageCallback;
+  using SharedPtrSerializedMessageWithInfoCallback =
+    typename CallbackTypes::SharedPtrSerializedMessageWithInfoCallback;
 
-  using SharedPtrCallback = typename HelperT::SharedPtrCallback;
-  using SharedPtrWithInfoCallback = typename HelperT::SharedPtrWithInfoCallback;
+  template<typename T>
+  struct NotNull
+  {
+    NotNull(const T * pointer_in, const char * msg)
+    : pointer(pointer_in)
+    {
+      if (pointer == nullptr) {
+        throw std::invalid_argument(msg);
+      }
+    }
+
+    const T * pointer;
+  };
 
 public:
   explicit
   AnySubscriptionCallback(const AllocatorT & allocator = AllocatorT())  // NOLINT[runtime/explicit]
+  : subscribed_type_allocator_(allocator),
+    ros_message_type_allocator_(allocator)
   {
-    message_allocator_ = allocator;
-    allocator::set_allocator_for_deleter(&message_deleter_, &message_allocator_);
+    allocator::set_allocator_for_deleter(&subscribed_type_deleter_, &subscribed_type_allocator_);
+    allocator::set_allocator_for_deleter(&ros_message_type_deleter_, &ros_message_type_allocator_);
   }
 
   [[deprecated("use AnySubscriptionCallback(const AllocatorT & allocator) instead")]]
   explicit
   AnySubscriptionCallback(std::shared_ptr<AllocatorT> allocator)  // NOLINT[runtime/explicit]
-  {
-    if (allocator == nullptr) {
-      throw std::runtime_error("invalid allocator");
-    }
-    message_allocator_ = *allocator;
-    allocator::set_allocator_for_deleter(&message_deleter_, &message_allocator_);
-  }
+  : AnySubscriptionCallback(*NotNull<AllocatorT>(allocator.get(), "invalid allocator").pointer)
+  {}
 
   AnySubscriptionCallback(const AnySubscriptionCallback &) = default;
 
@@ -190,40 +405,81 @@ public:
   }
 
   /// Function for shared_ptr to non-const MessageT, which is deprecated.
-  // TODO(wjwwood): enable this deprecation after Galactic
-  // [[deprecated(
-  //   "use 'void (std::shared_ptr<const MessageT>)' instead"
-  // )]]
+  template<typename SetT>
+#if !defined(RCLCPP_AVOID_DEPRECATIONS_FOR_UNIT_TESTS)
+  // suppress deprecation warnings in `test_any_subscription_callback.cpp`
+  [[deprecated("use 'void(std::shared_ptr<const MessageT>)' instead")]]
+#endif
   void
-  set_deprecated(std::function<void(std::shared_ptr<MessageT>)> callback)
-  // set(CallbackT callback)
+  set_deprecated(std::function<void(std::shared_ptr<SetT>)> callback)
   {
     callback_variant_ = callback;
   }
 
   /// Function for shared_ptr to non-const MessageT with MessageInfo, which is deprecated.
-  // TODO(wjwwood): enable this deprecation after Galactic
-  // [[deprecated(
-  //   "use 'void (std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)' instead"
-  // )]]
+  template<typename SetT>
+#if !defined(RCLCPP_AVOID_DEPRECATIONS_FOR_UNIT_TESTS)
+  // suppress deprecation warnings in `test_any_subscription_callback.cpp`
+  [[deprecated(
+          "use 'void(std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)' instead"
+  )]]
+#endif
   void
-  set_deprecated(
-    std::function<void(std::shared_ptr<MessageT>, const rclcpp::MessageInfo &)> callback)
+  set_deprecated(std::function<void(std::shared_ptr<SetT>, const rclcpp::MessageInfo &)> callback)
   {
     callback_variant_ = callback;
   }
 
-  std::unique_ptr<MessageT, MessageDeleter>
-  create_unique_ptr_from_shared_ptr_message(const std::shared_ptr<const MessageT> & message)
+  std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>
+  create_ros_unique_ptr_from_ros_shared_ptr_message(
+    const std::shared_ptr<const ROSMessageType> & message)
   {
-    auto ptr = MessageAllocTraits::allocate(message_allocator_, 1);
-    MessageAllocTraits::construct(message_allocator_, ptr, *message);
-    return std::unique_ptr<MessageT, MessageDeleter>(ptr, message_deleter_);
+    auto ptr = ROSMessageTypeAllocatorTraits::allocate(ros_message_type_allocator_, 1);
+    ROSMessageTypeAllocatorTraits::construct(ros_message_type_allocator_, ptr, *message);
+    return std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>(ptr, ros_message_type_deleter_);
   }
 
+  std::unique_ptr<rclcpp::SerializedMessage, SerializedMessageDeleter>
+  create_serialized_message_unique_ptr_from_shared_ptr(
+    const std::shared_ptr<const rclcpp::SerializedMessage> & serialized_message)
+  {
+    auto ptr = SerializedMessageAllocatorTraits::allocate(serialized_message_allocator_, 1);
+    SerializedMessageAllocatorTraits::construct(
+      serialized_message_allocator_, ptr, *serialized_message);
+    return std::unique_ptr<
+      rclcpp::SerializedMessage,
+      SerializedMessageDeleter
+    >(ptr, serialized_message_deleter_);
+  }
+
+  std::unique_ptr<SubscribedType, SubscribedTypeDeleter>
+  create_custom_unique_ptr_from_custom_shared_ptr_message(
+    const std::shared_ptr<const SubscribedType> & message)
+  {
+    auto ptr = SubscribedTypeAllocatorTraits::allocate(subscribed_type_allocator_, 1);
+    SubscribedTypeAllocatorTraits::construct(subscribed_type_allocator_, ptr, *message);
+    return std::unique_ptr<SubscribedType, SubscribedTypeDeleter>(ptr, subscribed_type_deleter_);
+  }
+
+  std::unique_ptr<SubscribedType, SubscribedTypeDeleter>
+  convert_ros_message_to_custom_type_unique_ptr(const ROSMessageType & msg)
+  {
+    if constexpr (rclcpp::TypeAdapter<MessageT>::is_specialized::value) {
+      auto ptr = SubscribedTypeAllocatorTraits::allocate(subscribed_type_allocator_, 1);
+      SubscribedTypeAllocatorTraits::construct(subscribed_type_allocator_, ptr);
+      rclcpp::TypeAdapter<MessageT>::convert_to_custom(msg, *ptr);
+      return std::unique_ptr<SubscribedType, SubscribedTypeDeleter>(ptr, subscribed_type_deleter_);
+    } else {
+      throw std::runtime_error(
+              "convert_ros_message_to_custom_type_unique_ptr "
+              "unexpectedly called without TypeAdapter");
+    }
+  }
+
+  // Dispatch when input is a ros message and the output could be anything.
   void
   dispatch(
-    std::shared_ptr<MessageT> message,
+    std::shared_ptr<ROSMessageType> message,
     const rclcpp::MessageInfo & message_info)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), false);
@@ -238,28 +494,162 @@ public:
     std::visit(
       [&message, &message_info, this](auto && callback) {
         using T = std::decay_t<decltype(callback)>;
+        static constexpr bool is_ta = rclcpp::TypeAdapter<MessageT>::is_specialized::value;
 
-        if constexpr (std::is_same_v<T, ConstRefCallback>) {
-          callback(*message);
-        } else if constexpr (std::is_same_v<T, ConstRefWithInfoCallback>) {
-          callback(*message, message_info);
-        } else if constexpr (std::is_same_v<T, UniquePtrCallback>) {
-          callback(create_unique_ptr_from_shared_ptr_message(message));
-        } else if constexpr (std::is_same_v<T, UniquePtrWithInfoCallback>) {
-          callback(create_unique_ptr_from_shared_ptr_message(message), message_info);
+        // conditions for output is custom message
+        if constexpr (is_ta && std::is_same_v<T, ConstRefCallback>) {
+          // TODO(wjwwood): consider avoiding heap allocation for small messages
+          //   maybe something like:
+          // if constexpr (rosidl_generator_traits::has_fixed_size<T> && sizeof(T) < N) {
+          //   ... on stack
+          // }
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message);
+        } else if constexpr (is_ta && std::is_same_v<T, ConstRefWithInfoCallback>) {  // NOLINT
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message, message_info);
+        } else if constexpr (is_ta && std::is_same_v<T, UniquePtrCallback>) {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (is_ta && std::is_same_v<T, UniquePtrWithInfoCallback>) {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, SharedConstPtrCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrCallback>||
-          std::is_same_v<T, SharedPtrCallback>)
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrCallback>||
+            std::is_same_v<T, SharedPtrCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrWithInfoCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>||
+            std::is_same_v<T, SharedPtrWithInfoCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
+        }
+        // conditions for output is ros message
+        else if constexpr (std::is_same_v<T, ConstRefROSMessageCallback>) {  // NOLINT
+          callback(*message);
+        } else if constexpr (std::is_same_v<T, ConstRefWithInfoROSMessageCallback>) {
+          callback(*message, message_info);
+        } else if constexpr (std::is_same_v<T, UniquePtrROSMessageCallback>) {
+          callback(create_ros_unique_ptr_from_ros_shared_ptr_message(message));
+        } else if constexpr (std::is_same_v<T, UniquePtrWithInfoROSMessageCallback>) {
+          callback(create_ros_unique_ptr_from_ros_shared_ptr_message(message), message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, SharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, SharedPtrROSMessageCallback>)
         {
           callback(message);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, SharedConstPtrWithInfoCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>||
-          std::is_same_v<T, SharedPtrWithInfoCallback>)
+          std::is_same_v<T, SharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, SharedPtrWithInfoROSMessageCallback>)
         {
           callback(message, message_info);
-        } else {
+        }
+        // condition to catch SerializedMessage types
+        else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, ConstRefSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageWithInfoCallback>)
+        {
+          throw std::runtime_error(
+            "Cannot dispatch std::shared_ptr<ROSMessageType> message "
+            "to rclcpp::SerializedMessage");
+        }
+        // condition to catch unhandled callback types
+        else {  // NOLINT[readability/braces]
+          static_assert(always_false_v<T>, "unhandled callback type");
+        }
+      }, callback_variant_);
+    TRACEPOINT(callback_end, static_cast<const void *>(this));
+  }
+
+  // Dispatch when input is a serialized message and the output could be anything.
+  void
+  dispatch(
+    std::shared_ptr<rclcpp::SerializedMessage> serialized_message,
+    const rclcpp::MessageInfo & message_info)
+  {
+    TRACEPOINT(callback_start, static_cast<const void *>(this), false);
+    // Check if the variant is "unset", throw if it is.
+    if (callback_variant_.index() == 0) {
+      if (std::get<0>(callback_variant_) == nullptr) {
+        // This can happen if it is default initialized, or if it is assigned nullptr.
+        throw std::runtime_error("dispatch called on an unset AnySubscriptionCallback");
+      }
+    }
+    // Dispatch.
+    std::visit(
+      [&serialized_message, &message_info, this](auto && callback) {
+        using T = std::decay_t<decltype(callback)>;
+
+        // condition to catch SerializedMessage types
+        if constexpr (std::is_same_v<T, ConstRefSerializedMessageCallback>) {
+          callback(*serialized_message);
+        } else if constexpr (std::is_same_v<T, ConstRefSerializedMessageWithInfoCallback>) {
+          callback(*serialized_message, message_info);
+        } else if constexpr (std::is_same_v<T, UniquePtrSerializedMessageCallback>) {
+          callback(create_serialized_message_unique_ptr_from_shared_ptr(serialized_message));
+        } else if constexpr (std::is_same_v<T, UniquePtrSerializedMessageWithInfoCallback>) {
+          callback(
+            create_serialized_message_unique_ptr_from_shared_ptr(serialized_message),
+            message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, SharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageCallback>)
+        {
+          callback(create_serialized_message_unique_ptr_from_shared_ptr(serialized_message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, SharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageWithInfoCallback>)
+        {
+          callback(
+            create_serialized_message_unique_ptr_from_shared_ptr(serialized_message),
+            message_info);
+        }
+        // conditions for output anything else
+        else if constexpr (  // NOLINT[whitespace/newline]
+          std::is_same_v<T, ConstRefCallback>||
+          std::is_same_v<T, ConstRefROSMessageCallback>||
+          std::is_same_v<T, ConstRefWithInfoCallback>||
+          std::is_same_v<T, ConstRefWithInfoROSMessageCallback>||
+          std::is_same_v<T, UniquePtrCallback>||
+          std::is_same_v<T, UniquePtrROSMessageCallback>||
+          std::is_same_v<T, UniquePtrWithInfoCallback>||
+          std::is_same_v<T, UniquePtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, SharedConstPtrCallback>||
+          std::is_same_v<T, SharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, SharedConstPtrWithInfoCallback>||
+          std::is_same_v<T, SharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, SharedPtrCallback>||
+          std::is_same_v<T, SharedPtrROSMessageCallback>||
+          std::is_same_v<T, SharedPtrWithInfoCallback>||
+          std::is_same_v<T, SharedPtrWithInfoROSMessageCallback>)
+        {
+          throw std::runtime_error(
+            "cannot dispatch rclcpp::SerializedMessage to "
+            "non-rclcpp::SerializedMessage callbacks");
+        }
+        // condition to catch unhandled callback types
+        else {  // NOLINT[readability/braces]
           static_assert(always_false_v<T>, "unhandled callback type");
         }
       }, callback_variant_);
@@ -268,7 +658,7 @@ public:
 
   void
   dispatch_intra_process(
-    std::shared_ptr<const MessageT> message,
+    std::shared_ptr<const ROSMessageType> message,
     const rclcpp::MessageInfo & message_info)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), true);
@@ -283,32 +673,89 @@ public:
     std::visit(
       [&message, &message_info, this](auto && callback) {
         using T = std::decay_t<decltype(callback)>;
+        static constexpr bool is_ta = rclcpp::TypeAdapter<MessageT>::is_specialized::value;
 
-        if constexpr (std::is_same_v<T, ConstRefCallback>) {
+        // conditions for custom type
+        if constexpr (is_ta && std::is_same_v<T, ConstRefCallback>) {
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message);
+        } else if constexpr (is_ta && std::is_same_v<T, ConstRefWithInfoCallback>) {  // NOLINT
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message, message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, UniquePtrCallback>||
+            std::is_same_v<T, SharedPtrCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, UniquePtrWithInfoCallback>||
+            std::is_same_v<T, SharedPtrWithInfoCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrWithInfoCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
+        }
+        // conditions for ros message type
+        else if constexpr (std::is_same_v<T, ConstRefROSMessageCallback>) {  // NOLINT
           callback(*message);
-        } else if constexpr (std::is_same_v<T, ConstRefWithInfoCallback>) {
+        } else if constexpr (std::is_same_v<T, ConstRefWithInfoROSMessageCallback>) {
           callback(*message, message_info);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, UniquePtrCallback>||
-          std::is_same_v<T, SharedPtrCallback>)
+          std::is_same_v<T, UniquePtrROSMessageCallback>||
+          std::is_same_v<T, SharedPtrROSMessageCallback>)
         {
-          callback(create_unique_ptr_from_shared_ptr_message(message));
+          callback(create_ros_unique_ptr_from_ros_shared_ptr_message(message));
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, UniquePtrWithInfoCallback>||
-          std::is_same_v<T, SharedPtrWithInfoCallback>)
+          std::is_same_v<T, UniquePtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, SharedPtrWithInfoROSMessageCallback>)
         {
-          callback(create_unique_ptr_from_shared_ptr_message(message), message_info);
+          callback(create_ros_unique_ptr_from_ros_shared_ptr_message(message), message_info);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, SharedConstPtrCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrCallback>)
+          std::is_same_v<T, SharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrROSMessageCallback>)
         {
           callback(message);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, SharedConstPtrWithInfoCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>)
+          std::is_same_v<T, SharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrWithInfoROSMessageCallback>)
         {
           callback(message, message_info);
-        } else {
+        }
+        // condition to catch SerializedMessage types
+        else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, ConstRefSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageWithInfoCallback>)
+        {
+          throw std::runtime_error(
+            "Cannot dispatch std::shared_ptr<const ROSMessageType> message "
+            "to rclcpp::SerializedMessage");
+        }
+        // condition to catch unhandled callback types
+        else {  // NOLINT[readability/braces]
           static_assert(always_false_v<T>, "unhandled callback type");
         }
       }, callback_variant_);
@@ -317,7 +764,7 @@ public:
 
   void
   dispatch_intra_process(
-    std::unique_ptr<MessageT, MessageDeleter> message,
+    std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter> message,
     const rclcpp::MessageInfo & message_info)
   {
     TRACEPOINT(callback_start, static_cast<const void *>(this), true);
@@ -330,28 +777,91 @@ public:
     }
     // Dispatch.
     std::visit(
-      [&message, &message_info](auto && callback) {
+      [&message, &message_info, this](auto && callback) {
         using T = std::decay_t<decltype(callback)>;
+        static constexpr bool is_ta = rclcpp::TypeAdapter<MessageT>::is_specialized::value;
 
-        if constexpr (std::is_same_v<T, ConstRefCallback>) {
+        // conditions for custom type
+        if constexpr (is_ta && std::is_same_v<T, ConstRefCallback>) {
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message);
+        } else if constexpr (is_ta && std::is_same_v<T, ConstRefWithInfoCallback>) {  // NOLINT
+          auto local_message = convert_ros_message_to_custom_type_unique_ptr(*message);
+          callback(*local_message, message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, UniquePtrCallback>||
+            std::is_same_v<T, SharedPtrCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, UniquePtrWithInfoCallback>||
+            std::is_same_v<T, SharedPtrWithInfoCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          is_ta && (
+            std::is_same_v<T, SharedConstPtrWithInfoCallback>||
+            std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>
+        ))
+        {
+          callback(convert_ros_message_to_custom_type_unique_ptr(*message), message_info);
+        }
+        // conditions for ros message type
+        else if constexpr (std::is_same_v<T, ConstRefROSMessageCallback>) {  // NOLINT
           callback(*message);
-        } else if constexpr (std::is_same_v<T, ConstRefWithInfoCallback>) {
+        } else if constexpr (std::is_same_v<T, ConstRefWithInfoROSMessageCallback>) {
           callback(*message, message_info);
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, UniquePtrCallback>||
-          std::is_same_v<T, SharedConstPtrCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrCallback>||
-          std::is_same_v<T, SharedPtrCallback>)
+          std::is_same_v<T, UniquePtrROSMessageCallback>||
+          std::is_same_v<T, SharedPtrROSMessageCallback>)
         {
           callback(std::move(message));
         } else if constexpr (  // NOLINT[readability/braces]
-          std::is_same_v<T, UniquePtrWithInfoCallback>||
-          std::is_same_v<T, SharedConstPtrWithInfoCallback>||
-          std::is_same_v<T, ConstRefSharedConstPtrWithInfoCallback>||
-          std::is_same_v<T, SharedPtrWithInfoCallback>)
+          std::is_same_v<T, UniquePtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, SharedPtrWithInfoROSMessageCallback>)
         {
           callback(std::move(message), message_info);
-        } else {
+        } else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, SharedConstPtrROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrROSMessageCallback>)
+        {
+          callback(std::move(message));
+        } else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, SharedConstPtrWithInfoROSMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrWithInfoROSMessageCallback>)
+        {
+          callback(std::move(message), message_info);
+        }
+        // condition to catch SerializedMessage types
+        else if constexpr (  // NOLINT[readability/braces]
+          std::is_same_v<T, ConstRefSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageCallback>||
+          std::is_same_v<T, UniquePtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageCallback>||
+          std::is_same_v<T, ConstRefSharedConstPtrSerializedMessageWithInfoCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageCallback>||
+          std::is_same_v<T, SharedPtrSerializedMessageWithInfoCallback>)
+        {
+          throw std::runtime_error(
+            "Cannot dispatch std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter> message "
+            "to rclcpp::SerializedMessage");
+        }
+        // condition to catch unhandled callback types
+        else {  // NOLINT[readability/braces]
           static_assert(always_false_v<T>, "unhandled callback type");
         }
       }, callback_variant_);
@@ -369,6 +879,18 @@ public:
       std::holds_alternative<ConstRefSharedConstPtrWithInfoCallback>(callback_variant_);
   }
 
+  constexpr
+  bool
+  is_serialized_message_callback() const
+  {
+    return
+      std::holds_alternative<ConstRefSerializedMessageCallback>(callback_variant_) ||
+      std::holds_alternative<UniquePtrSerializedMessageCallback>(callback_variant_) ||
+      std::holds_alternative<SharedConstPtrSerializedMessageCallback>(callback_variant_) ||
+      std::holds_alternative<ConstRefSharedConstPtrSerializedMessageCallback>(callback_variant_) ||
+      std::holds_alternative<SharedPtrSerializedMessageCallback>(callback_variant_);
+  }
+
   void
   register_callback_for_tracing()
   {
@@ -402,8 +924,12 @@ private:
   // For now, compose the variant into this class as a private attribute.
   typename HelperT::variant_type callback_variant_;
 
-  MessageAlloc message_allocator_;
-  MessageDeleter message_deleter_;
+  SubscribedTypeAllocator subscribed_type_allocator_;
+  SubscribedTypeDeleter subscribed_type_deleter_;
+  ROSMessageTypeAllocator ros_message_type_allocator_;
+  ROSMessageTypeDeleter ros_message_type_deleter_;
+  SerializedMessageAllocator serialized_message_allocator_;
+  SerializedMessageDeleter serialized_message_deleter_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/client.hpp

@@ -17,12 +17,15 @@
 
 #include <atomic>
 #include <future>
-#include <map>
+#include <unordered_map>
 #include <memory>
+#include <optional>  // NOLINT, cpplint doesn't think this is a cpp std header
 #include <sstream>
 #include <string>
 #include <tuple>
 #include <utility>
+#include <variant>  // NOLINT
+#include <vector>
 
 #include "rcl/client.h"
 #include "rcl/error_handling.h"
@@ -45,6 +48,68 @@
 namespace rclcpp
 {
 
+namespace detail
+{
+template<typename FutureT>
+struct FutureAndRequestId
+{
+  FutureT future;
+  int64_t request_id;
+
+  FutureAndRequestId(FutureT impl, int64_t req_id)
+  : future(std::move(impl)), request_id(req_id)
+  {}
+
+  /// Allow implicit conversions to `std::future` by reference.
+  operator FutureT &() {return this->future;}
+
+  /// Deprecated, use the `future` member variable instead.
+  /**
+   * Allow implicit conversions to `std::future` by value.
+   * \deprecated
+   */
+  [[deprecated("FutureAndRequestId: use .future instead of an implicit conversion")]]
+  operator FutureT() {return this->future;}
+
+  // delegate future like methods in the std::future impl_
+
+  /// See std::future::get().
+  auto get() {return this->future.get();}
+  /// See std::future::valid().
+  bool valid() const noexcept {return this->future.valid();}
+  /// See std::future::wait().
+  void wait() const {return this->future.wait();}
+  /// See std::future::wait_for().
+  template<class Rep, class Period>
+  std::future_status wait_for(
+    const std::chrono::duration<Rep, Period> & timeout_duration) const
+  {
+    return this->future.wait_for(timeout_duration);
+  }
+  /// See std::future::wait_until().
+  template<class Clock, class Duration>
+  std::future_status wait_until(
+    const std::chrono::time_point<Clock, Duration> & timeout_time) const
+  {
+    return this->future.wait_until(timeout_time);
+  }
+
+  // Rule of five, we could use the rule of zero here, but better be explicit as some of the
+  // methods are deleted.
+
+  /// Move constructor.
+  FutureAndRequestId(FutureAndRequestId && other) noexcept = default;
+  /// Deleted copy constructor, each instance is a unique owner of the future.
+  FutureAndRequestId(const FutureAndRequestId & other) = delete;
+  /// Move assignment.
+  FutureAndRequestId & operator=(FutureAndRequestId && other) noexcept = default;
+  /// Deleted copy assignment, each instance is a unique owner of the future.
+  FutureAndRequestId & operator=(const FutureAndRequestId & other) = delete;
+  /// Destructor.
+  ~FutureAndRequestId() = default;
+};
+}  // namespace detail
+
 namespace node_interfaces
 {
 class NodeBaseInterface;
@@ -178,6 +243,9 @@ template<typename ServiceT>
 class Client : public ClientBase
 {
 public:
+  using Request = typename ServiceT::Request;
+  using Response = typename ServiceT::Response;
+
   using SharedRequest = typename ServiceT::Request::SharedPtr;
   using SharedResponse = typename ServiceT::Response::SharedPtr;
 
@@ -187,6 +255,7 @@ public:
   using SharedPromise = std::shared_ptr<Promise>;
   using SharedPromiseWithRequest = std::shared_ptr<PromiseWithRequest>;
 
+  using Future = std::future<SharedResponse>;
   using SharedFuture = std::shared_future<SharedResponse>;
   using SharedFutureWithRequest = std::shared_future<std::pair<SharedRequest, SharedResponse>>;
 
@@ -195,6 +264,64 @@ public:
 
   RCLCPP_SMART_PTR_DEFINITIONS(Client)
 
+  /// A convenient Client::Future and request id pair.
+  /**
+   * Public members:
+   * - future: a std::future<SharedResponse>.
+   * - request_id: the request id associated with the future.
+   *
+   * All the other methods are equivalent to the ones std::future provides.
+   */
+  struct FutureAndRequestId
+    : detail::FutureAndRequestId<std::future<SharedResponse>>
+  {
+    using detail::FutureAndRequestId<std::future<SharedResponse>>::FutureAndRequestId;
+
+    /// Deprecated, use `.future.share()` instead.
+    /**
+     * Allow implicit conversions to `std::shared_future` by value.
+     * \deprecated
+     */
+    [[deprecated(
+      "FutureAndRequestId: use .future.share() instead of an implicit conversion")]]
+    operator SharedFuture() {return this->future.share();}
+
+    // delegate future like methods in the std::future impl_
+
+    /// See std::future::share().
+    SharedFuture share() noexcept {return this->future.share();}
+  };
+
+  /// A convenient Client::SharedFuture and request id pair.
+  /**
+   * Public members:
+   * - future: a std::shared_future<SharedResponse>.
+   * - request_id: the request id associated with the future.
+   *
+   * All the other methods are equivalent to the ones std::shared_future provides.
+   */
+  struct SharedFutureAndRequestId
+    : detail::FutureAndRequestId<std::shared_future<SharedResponse>>
+  {
+    using detail::FutureAndRequestId<std::shared_future<SharedResponse>>::FutureAndRequestId;
+  };
+
+  /// A convenient Client::SharedFutureWithRequest and request id pair.
+  /**
+   * Public members:
+   * - future: a std::shared_future<SharedResponse>.
+   * - request_id: the request id associated with the future.
+   *
+   * All the other methods are equivalent to the ones std::shared_future provides.
+   */
+  struct SharedFutureWithRequestAndRequestId
+    : detail::FutureAndRequestId<std::shared_future<std::pair<SharedRequest, SharedResponse>>>
+  {
+    using detail::FutureAndRequestId<
+      std::shared_future<std::pair<SharedRequest, SharedResponse>>
+    >::FutureAndRequestId;
+  };
+
   /// Default constructor.
   /**
    * The constructor for a Client is almost never called directly.
@@ -292,34 +419,89 @@ public:
     std::shared_ptr<rmw_request_id_t> request_header,
     std::shared_ptr<void> response) override
   {
-    std::unique_lock<std::mutex> lock(pending_requests_mutex_);
-    auto typed_response = std::static_pointer_cast<typename ServiceT::Response>(response);
-    int64_t sequence_number = request_header->sequence_number;
-    // TODO(esteve) this should throw instead since it is not expected to happen in the first place
-    if (this->pending_requests_.count(sequence_number) == 0) {
-      RCUTILS_LOG_ERROR_NAMED(
-        "rclcpp",
-        "Received invalid sequence number. Ignoring...");
+    std::optional<CallbackInfoVariant>
+    optional_pending_request = this->get_and_erase_pending_request(request_header->sequence_number);
+    if (!optional_pending_request) {
       return;
     }
-    auto tuple = this->pending_requests_[sequence_number];
-    auto call_promise = std::get<0>(tuple);
-    auto callback = std::get<1>(tuple);
-    auto future = std::get<2>(tuple);
-    this->pending_requests_.erase(sequence_number);
-    // Unlock here to allow the service to be called recursively from one of its callbacks.
-    lock.unlock();
-
-    call_promise->set_value(typed_response);
-    callback(future);
+    auto & value = *optional_pending_request;
+    auto typed_response = std::static_pointer_cast<typename ServiceT::Response>(
+      std::move(response));
+    if (std::holds_alternative<Promise>(value)) {
+      auto & promise = std::get<Promise>(value);
+      promise.set_value(std::move(typed_response));
+    } else if (std::holds_alternative<CallbackTypeValueVariant>(value)) {
+      auto & inner = std::get<CallbackTypeValueVariant>(value);
+      const auto & callback = std::get<CallbackType>(inner);
+      auto & promise = std::get<Promise>(inner);
+      auto & future = std::get<SharedFuture>(inner);
+      promise.set_value(std::move(typed_response));
+      callback(std::move(future));
+    } else if (std::holds_alternative<CallbackWithRequestTypeValueVariant>(value)) {
+      auto & inner = std::get<CallbackWithRequestTypeValueVariant>(value);
+      const auto & callback = std::get<CallbackWithRequestType>(inner);
+      auto & promise = std::get<PromiseWithRequest>(inner);
+      auto & future = std::get<SharedFutureWithRequest>(inner);
+      auto & request = std::get<SharedRequest>(inner);
+      promise.set_value(std::make_pair(std::move(request), std::move(typed_response)));
+      callback(std::move(future));
+    }
   }
 
-  SharedFuture
+  /// Send a request to the service server.
+  /**
+   * This method returns a `FutureAndRequestId` instance
+   * that can be passed to Executor::spin_until_future_complete() to
+   * wait until it has been completed.
+   *
+   * If the future never completes,
+   * e.g. the call to Executor::spin_until_future_complete() times out,
+   * Client::remove_pending_request() must be called to clean the client internal state.
+   * Not doing so will make the `Client` instance to use more memory each time a response is not
+   * received from the service server.
+   *
+   * ```cpp
+   * auto future = client->async_send_request(my_request);
+   * if (
+   *   rclcpp::FutureReturnCode::TIMEOUT ==
+   *   executor->spin_until_future_complete(future, timeout))
+   * {
+   *   client->remove_pending_request(future);
+   *   // handle timeout
+   * } else {
+   *   handle_response(future.get());
+   * }
+   * ```
+   *
+   * \param[in] request request to be send.
+   * \return a FutureAndRequestId instance.
+   */
+  FutureAndRequestId
   async_send_request(SharedRequest request)
   {
-    return async_send_request(request, [](SharedFuture) {});
+    Promise promise;
+    auto future = promise.get_future();
+    auto req_id = async_send_request_impl(
+      *request,
+      std::move(promise));
+    return FutureAndRequestId(std::move(future), req_id);
   }
 
+  /// Send a request to the service server and schedule a callback in the executor.
+  /**
+   * Similar to the previous overload, but a callback will automatically be called when a response is received.
+   *
+   * If the callback is never called, because we never got a reply for the service server, remove_pending_request()
+   * has to be called with the returned request id or prune_pending_requests().
+   * Not doing so will make the `Client` instance use more memory each time a response is not
+   * received from the service server.
+   * In this case, it's convenient to setup a timer to cleanup the pending requests.
+   * See for example the `examples_rclcpp_async_client` package in https://github.com/ros2/examples.
+   *
+   * \param[in] request request to be send.
+   * \param[in] cb callback that will be called when we get a response for this request.
+   * \return the request id representing the request just sent.
+   */
   template<
     typename CallbackT,
     typename std::enable_if<
@@ -329,23 +511,28 @@ public:
       >::value
     >::type * = nullptr
   >
-  SharedFuture
+  SharedFutureAndRequestId
   async_send_request(SharedRequest request, CallbackT && cb)
   {
-    std::lock_guard<std::mutex> lock(pending_requests_mutex_);
-    int64_t sequence_number;
-    rcl_ret_t ret = rcl_send_request(get_client_handle().get(), request.get(), &sequence_number);
-    if (RCL_RET_OK != ret) {
-      rclcpp::exceptions::throw_from_rcl_error(ret, "failed to send request");
-    }
-
-    SharedPromise call_promise = std::make_shared<Promise>();
-    SharedFuture f(call_promise->get_future());
-    pending_requests_[sequence_number] =
-      std::make_tuple(call_promise, std::forward<CallbackType>(cb), f);
-    return f;
+    Promise promise;
+    auto shared_future = promise.get_future().share();
+    auto req_id = async_send_request_impl(
+      *request,
+      std::make_tuple(
+        CallbackType{std::forward<CallbackT>(cb)},
+        shared_future,
+        std::move(promise)));
+    return SharedFutureAndRequestId{std::move(shared_future), req_id};
   }
 
+  /// Send a request to the service server and schedule a callback in the executor.
+  /**
+   * Similar to the previous method, but you can get both the request and response in the callback.
+   *
+   * \param[in] request request to be send.
+   * \param[in] cb callback that will be called when we get a response for this request.
+   * \return the request id representing the request just sent.
+   */
   template<
     typename CallbackT,
     typename std::enable_if<
@@ -355,28 +542,165 @@ public:
       >::value
     >::type * = nullptr
   >
-  SharedFutureWithRequest
+  SharedFutureWithRequestAndRequestId
   async_send_request(SharedRequest request, CallbackT && cb)
   {
-    SharedPromiseWithRequest promise = std::make_shared<PromiseWithRequest>();
-    SharedFutureWithRequest future_with_request(promise->get_future());
-
-    auto wrapping_cb = [future_with_request, promise, request,
-        cb = std::forward<CallbackWithRequestType>(cb)](SharedFuture future) {
-        auto response = future.get();
-        promise->set_value(std::make_pair(request, response));
-        cb(future_with_request);
-      };
-
-    async_send_request(request, wrapping_cb);
-
-    return future_with_request;
+    PromiseWithRequest promise;
+    auto shared_future = promise.get_future().share();
+    auto req_id = async_send_request_impl(
+      *request,
+      std::make_tuple(
+        CallbackWithRequestType{std::forward<CallbackT>(cb)},
+        request,
+        shared_future,
+        std::move(promise)));
+    return SharedFutureWithRequestAndRequestId{std::move(shared_future), req_id};
+  }
+
+  /// Cleanup a pending request.
+  /**
+   * This notifies the client that we have waited long enough for a response from the server
+   * to come, we have given up and we are not waiting for a response anymore.
+   *
+   * Not calling this will make the client start using more memory for each request
+   * that never got a reply from the server.
+   *
+   * \param[in] request_id request id returned by async_send_request().
+   * \return true when a pending request was removed, false if not (e.g. a response was received).
+   */
+  bool
+  remove_pending_request(int64_t request_id)
+  {
+    std::lock_guard guard(pending_requests_mutex_);
+    return pending_requests_.erase(request_id) != 0u;
+  }
+
+  /// Cleanup a pending request.
+  /**
+   * Convenient overload, same as:
+   *
+   * `Client::remove_pending_request(this, future.request_id)`.
+   */
+  bool
+  remove_pending_request(const FutureAndRequestId & future)
+  {
+    return this->remove_pending_request(future.request_id);
+  }
+
+  /// Cleanup a pending request.
+  /**
+   * Convenient overload, same as:
+   *
+   * `Client::remove_pending_request(this, future.request_id)`.
+   */
+  bool
+  remove_pending_request(const SharedFutureAndRequestId & future)
+  {
+    return this->remove_pending_request(future.request_id);
+  }
+
+  /// Cleanup a pending request.
+  /**
+   * Convenient overload, same as:
+   *
+   * `Client::remove_pending_request(this, future.request_id)`.
+   */
+  bool
+  remove_pending_request(const SharedFutureWithRequestAndRequestId & future)
+  {
+    return this->remove_pending_request(future.request_id);
+  }
+
+  /// Clean all pending requests.
+  /**
+   * \return number of pending requests that were removed.
+   */
+  size_t
+  prune_pending_requests()
+  {
+    std::lock_guard guard(pending_requests_mutex_);
+    auto ret = pending_requests_.size();
+    pending_requests_.clear();
+    return ret;
+  }
+
+  /// Clean all pending requests older than a time_point.
+  /**
+   * \param[in] time_point Requests that were sent before this point are going to be removed.
+   * \param[inout] pruned_requests Removed requests id will be pushed to the vector
+   *  if a pointer is provided.
+   * \return number of pending requests that were removed.
+   */
+  template<typename AllocatorT = std::allocator<int64_t>>
+  size_t
+  prune_requests_older_than(
+    std::chrono::time_point<std::chrono::system_clock> time_point,
+    std::vector<int64_t, AllocatorT> * pruned_requests = nullptr)
+  {
+    std::lock_guard guard(pending_requests_mutex_);
+    auto old_size = pending_requests_.size();
+    for (auto it = pending_requests_.begin(), last = pending_requests_.end(); it != last; ) {
+      if (it->second.first < time_point) {
+        pruned_requests->push_back(it->first);
+        it = pending_requests_.erase(it);
+      } else {
+        ++it;
+      }
+    }
+    return old_size - pending_requests_.size();
+  }
+
+protected:
+  using CallbackTypeValueVariant = std::tuple<CallbackType, SharedFuture, Promise>;
+  using CallbackWithRequestTypeValueVariant = std::tuple<
+    CallbackWithRequestType, SharedRequest, SharedFutureWithRequest, PromiseWithRequest>;
+
+  using CallbackInfoVariant = std::variant<
+    std::promise<SharedResponse>,
+    CallbackTypeValueVariant,
+    CallbackWithRequestTypeValueVariant>;
+
+  int64_t
+  async_send_request_impl(const Request & request, CallbackInfoVariant value)
+  {
+    int64_t sequence_number;
+    rcl_ret_t ret = rcl_send_request(get_client_handle().get(), &request, &sequence_number);
+    if (RCL_RET_OK != ret) {
+      rclcpp::exceptions::throw_from_rcl_error(ret, "failed to send request");
+    }
+    {
+      std::lock_guard<std::mutex> lock(pending_requests_mutex_);
+      pending_requests_.try_emplace(
+        sequence_number,
+        std::make_pair(std::chrono::system_clock::now(), std::move(value)));
+    }
+    return sequence_number;
+  }
+
+  std::optional<CallbackInfoVariant>
+  get_and_erase_pending_request(int64_t request_number)
+  {
+    std::unique_lock<std::mutex> lock(pending_requests_mutex_);
+    auto it = this->pending_requests_.find(request_number);
+    if (it == this->pending_requests_.end()) {
+      RCUTILS_LOG_DEBUG_NAMED(
+        "rclcpp",
+        "Received invalid sequence number. Ignoring...");
+      return std::nullopt;
+    }
+    auto value = std::move(it->second.second);
+    this->pending_requests_.erase(request_number);
+    return value;
   }
 
-private:
   RCLCPP_DISABLE_COPY(Client)
 
-  std::map<int64_t, std::tuple<SharedPromise, CallbackType, SharedFuture>> pending_requests_;
+  std::unordered_map<
+    int64_t,
+    std::pair<
+      std::chrono::time_point<std::chrono::system_clock>,
+      CallbackInfoVariant>>
+  pending_requests_;
   std::mutex pending_requests_mutex_;
 };
 

rclcpp/include/rclcpp/clock.hpp

@@ -19,6 +19,7 @@
 #include <memory>
 #include <mutex>
 
+#include "rclcpp/contexts/default_context.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/time.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -78,6 +79,64 @@ public:
   Time
   now();
 
+  /**
+   * Sleep until a specified Time, according to clock type.
+   *
+   * Notes for RCL_ROS_TIME clock type:
+   *   - Can sleep forever if ros time is active and received clock never reaches `until`
+   *   - If ROS time enabled state changes during the sleep, this method will immediately return
+   *     false. There is not a consistent choice of sleeping time when the time source changes,
+   *     so this is up to the caller to call again if needed.
+   *
+   * \warning When using gcc < 10 or when using gcc >= 10 and pthreads lacks the function
+   *    `pthread_cond_clockwait`, steady clocks may sleep using the system clock.
+   *    If so, steady clock sleep times can be affected by system clock time jumps.
+   *    Depending on the steady clock's epoch and resolution in comparison to the system clock's,
+   *    an overflow when converting steady clock durations to system clock times may cause
+   *    undefined behavior.
+   *    For more info see these issues:
+   *    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=41861
+   *    https://gcc.gnu.org/bugzilla/show_bug.cgi?id=58931
+   *
+   * \param until absolute time according to current clock type to sleep until.
+   * \param context the rclcpp context the clock should use to check that ROS is still initialized.
+   * \return true immediately if `until` is in the past
+   * \return true when the time `until` is reached
+   * \return false if time cannot be reached reliably, for example from shutdown or a change
+   *    of time source.
+   * \throws std::runtime_error if the context is invalid
+   * \throws std::runtime_error if `until` has a different clock type from this clock
+   */
+  RCLCPP_PUBLIC
+  bool
+  sleep_until(
+    Time until,
+    Context::SharedPtr context = contexts::get_global_default_context());
+
+  /**
+   * Sleep for a specified Duration.
+   *
+   * Equivalent to
+   *
+   * ```cpp
+   * clock->sleep_until(clock->now() + rel_time, context)
+   * ```
+   *
+   * The function will return immediately if `rel_time` is zero or negative.
+   *
+   * \param rel_time the length of time to sleep for.
+   * \param context the rclcpp context the clock should use to check that ROS is still initialized.
+   * \return true when the end time is reached
+   * \return false if time cannot be reached reliably, for example from shutdown or a change
+   *    of time source.
+   * \throws std::runtime_error if the context is invalid
+   */
+  RCLCPP_PUBLIC
+  bool
+  sleep_for(
+    Duration rel_time,
+    Context::SharedPtr context = contexts::get_global_default_context());
+
   /**
    * Returns the clock of the type `RCL_ROS_TIME` is active.
    *

rclcpp/include/rclcpp/context.hpp

@@ -23,6 +23,7 @@
 #include <typeindex>
 #include <typeinfo>
 #include <unordered_map>
+#include <unordered_set>
 #include <utility>
 #include <vector>
 
@@ -47,6 +48,20 @@ public:
 /// Forward declare WeakContextsWrapper
 class WeakContextsWrapper;
 
+class ShutdownCallbackHandle
+{
+  friend class Context;
+
+public:
+  using ShutdownCallbackType = std::function<void ()>;
+
+private:
+  std::weak_ptr<ShutdownCallbackType> callback;
+};
+
+using OnShutdownCallbackHandle = ShutdownCallbackHandle;
+using PreShutdownCallbackHandle = ShutdownCallbackHandle;
+
 /// Context which encapsulates shared state between nodes and other similar entities.
 /**
  * A context also represents the lifecycle between init and shutdown of rclcpp.
@@ -63,7 +78,7 @@ public:
    * Every context which is constructed is added to a global vector of contexts,
    * which is used by the signal handler to conditionally shutdown each context
    * on SIGINT.
-   * See the shutdown_on_sigint option in the InitOptions class.
+   * See the shutdown_on_signal option in the InitOptions class.
    */
   RCLCPP_PUBLIC
   Context();
@@ -80,8 +95,8 @@ public:
    *
    * Note that this function does not setup any signal handlers, so if you want
    * it to be shutdown by the signal handler, then you need to either install
-   * them manually with rclcpp::install_signal_handers() or use rclcpp::init().
-   * In addition to installing the signal handlers, the shutdown_on_sigint
+   * them manually with rclcpp::install_signal_handlers() or use rclcpp::init().
+   * In addition to installing the signal handlers, the shutdown_on_signal
    * of the InitOptions needs to be `true` for this context to be shutdown by
    * the signal handler, otherwise it will be passed over.
    *
@@ -177,7 +192,7 @@ public:
   bool
   shutdown(const std::string & reason);
 
-  using OnShutdownCallback = std::function<void ()>;
+  using OnShutdownCallback = OnShutdownCallbackHandle::ShutdownCallbackType;
 
   /// Add a on_shutdown callback to be called when shutdown is called for this context.
   /**
@@ -185,7 +200,7 @@ public:
    * to last step in shutdown().
    *
    * When shutdown occurs due to the signal handler, these callbacks are run
-   * asynchronoulsy in the dedicated singal handling thread.
+   * asynchronously in the dedicated singal handling thread.
    *
    * Also, shutdown() may be called from the destructor of this function.
    * Therefore, it is not safe to throw exceptions from these callbacks.
@@ -203,23 +218,82 @@ public:
   OnShutdownCallback
   on_shutdown(OnShutdownCallback callback);
 
-  /// Return the shutdown callbacks as const.
+  /// Add a on_shutdown callback to be called when shutdown is called for this context.
   /**
-   * Using the returned reference is not thread-safe with calls that modify
-   * the list of "on shutdown" callbacks, i.e. on_shutdown().
+   * These callbacks will be called in the order they are added as the second
+   * to last step in shutdown().
+   *
+   * When shutdown occurs due to the signal handler, these callbacks are run
+   * asynchronously in the dedicated signal handling thread.
+   *
+   * Also, shutdown() may be called from the destructor of this function.
+   * Therefore, it is not safe to throw exceptions from these callbacks.
+   * Instead, log errors or use some other mechanism to indicate an error has
+   * occurred.
+   *
+   * On shutdown callbacks may be registered before init and after shutdown,
+   * and persist on repeated init's.
+   *
+   * \param[in] callback the on_shutdown callback to be registered
+   * \return the created callback handle
    */
   RCLCPP_PUBLIC
-  const std::vector<OnShutdownCallback> &
-  get_on_shutdown_callbacks() const;
+  virtual
+  OnShutdownCallbackHandle
+  add_on_shutdown_callback(OnShutdownCallback callback);
+
+  /// Remove an registered on_shutdown callbacks.
+  /**
+   * \param[in] callback_handle the on_shutdown callback handle to be removed.
+   * \return true if the callback is found and removed, otherwise false.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  remove_on_shutdown_callback(const OnShutdownCallbackHandle & callback_handle);
+
+  using PreShutdownCallback = PreShutdownCallbackHandle::ShutdownCallbackType;
+
+  /// Add a pre_shutdown callback to be called before shutdown is called for this context.
+  /**
+   * These callbacks will be called in the order they are added.
+   *
+   * When shutdown occurs due to the signal handler, these callbacks are run
+   * asynchronously in the dedicated signal handling thread.
+   *
+   * \param[in] callback the pre_shutdown callback to be registered
+   * \return the created callback handle
+   */
+  RCLCPP_PUBLIC
+  virtual
+  PreShutdownCallbackHandle
+  add_pre_shutdown_callback(PreShutdownCallback callback);
+
+  /// Remove an registered pre_shutdown callback.
+  /**
+   * \param[in] callback_handle the pre_shutdown callback handle to be removed.
+   * \return true if the callback is found and removed, otherwise false.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  bool
+  remove_pre_shutdown_callback(const PreShutdownCallbackHandle & callback_handle);
 
   /// Return the shutdown callbacks.
   /**
-   * Using the returned reference is not thread-safe with calls that modify
-   * the list of "on shutdown" callbacks, i.e. on_shutdown().
+   * Returned callbacks are a copy of the registered callbacks.
    */
   RCLCPP_PUBLIC
-  std::vector<OnShutdownCallback> &
-  get_on_shutdown_callbacks();
+  std::vector<OnShutdownCallback>
+  get_on_shutdown_callbacks() const;
+
+  /// Return the pre-shutdown callbacks.
+  /**
+   * Returned callbacks are a copy of the registered callbacks.
+   */
+  RCLCPP_PUBLIC
+  std::vector<PreShutdownCallback>
+  get_pre_shutdown_callbacks() const;
 
   /// Return the internal rcl context.
   RCLCPP_PUBLIC
@@ -232,7 +306,7 @@ public:
    *
    *   - this context is shutdown()
    *   - this context is destructed (resulting in shutdown)
-   *   - this context has shutdown_on_sigint=true and SIGINT occurs (resulting in shutdown)
+   *   - this context has shutdown_on_signal=true and SIGINT/SIGTERM occurs (resulting in shutdown)
    *   - interrupt_all_sleep_for() is called
    *
    * \param[in] nanoseconds A std::chrono::duration representing how long to sleep for.
@@ -299,8 +373,11 @@ private:
   // attempt to acquire another sub context.
   std::recursive_mutex sub_contexts_mutex_;
 
-  std::vector<OnShutdownCallback> on_shutdown_callbacks_;
-  std::mutex on_shutdown_callbacks_mutex_;
+  std::unordered_set<std::shared_ptr<OnShutdownCallback>> on_shutdown_callbacks_;
+  mutable std::mutex on_shutdown_callbacks_mutex_;
+
+  std::unordered_set<std::shared_ptr<PreShutdownCallback>> pre_shutdown_callbacks_;
+  mutable std::mutex pre_shutdown_callbacks_mutex_;
 
   /// Condition variable for timed sleep (see sleep_for).
   std::condition_variable interrupt_condition_variable_;
@@ -309,6 +386,29 @@ private:
 
   /// Keep shared ownership of global vector of weak contexts
   std::shared_ptr<WeakContextsWrapper> weak_contexts_;
+
+  enum class ShutdownType
+  {
+    pre_shutdown,
+    on_shutdown
+  };
+
+  using ShutdownCallback = ShutdownCallbackHandle::ShutdownCallbackType;
+
+  RCLCPP_LOCAL
+  ShutdownCallbackHandle
+  add_shutdown_callback(
+    ShutdownType shutdown_type,
+    ShutdownCallback callback);
+
+  RCLCPP_LOCAL
+  bool
+  remove_shutdown_callback(
+    ShutdownType shutdown_type,
+    const ShutdownCallbackHandle & callback_handle);
+
+  std::vector<rclcpp::Context::ShutdownCallback>
+  get_shutdown_callback(ShutdownType shutdown_type) const;
 };
 
 /// Return a copy of the list of context shared pointers.

rclcpp/include/rclcpp/create_subscription.hpp

@@ -47,11 +47,11 @@ template<
   typename MessageT,
   typename CallbackT,
   typename AllocatorT,
-  typename CallbackMessageT,
   typename SubscriptionT,
   typename MessageMemoryStrategyT,
   typename NodeParametersT,
-  typename NodeTopicsT>
+  typename NodeTopicsT,
+  typename ROSMessageType = typename SubscriptionT::ROSMessageType>
 typename std::shared_ptr<SubscriptionT>
 create_subscription(
   NodeParametersT & node_parameters,
@@ -70,7 +70,7 @@ create_subscription(
   using rclcpp::node_interfaces::get_node_topics_interface;
   auto node_topics_interface = get_node_topics_interface(node_topics);
 
-  std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>>
+  std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<ROSMessageType>>
   subscription_topic_stats = nullptr;
 
   if (rclcpp::detail::resolve_enable_topic_statistics(
@@ -92,11 +92,11 @@ create_subscription(
       qos);
 
     subscription_topic_stats = std::make_shared<
-      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
+      rclcpp::topic_statistics::SubscriptionTopicStatistics<ROSMessageType>
       >(node_topics_interface->get_node_base_interface()->get_name(), publisher);
 
     std::weak_ptr<
-      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
+      rclcpp::topic_statistics::SubscriptionTopicStatistics<ROSMessageType>
     > weak_subscription_topic_stats(subscription_topic_stats);
     auto sub_call_back = [weak_subscription_topic_stats]() {
         auto subscription_topic_stats = weak_subscription_topic_stats.lock();
@@ -153,7 +153,6 @@ create_subscription(
  * \tparam MessageT
  * \tparam CallbackT
  * \tparam AllocatorT
- * \tparam CallbackMessageT
  * \tparam SubscriptionT
  * \tparam MessageMemoryStrategyT
  * \tparam NodeT
@@ -171,13 +170,8 @@ template<
   typename MessageT,
   typename CallbackT,
   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 SubscriptionT = rclcpp::Subscription<MessageT, AllocatorT>,
+  typename MessageMemoryStrategyT = typename SubscriptionT::MessageMemoryStrategyType,
   typename NodeT>
 typename std::shared_ptr<SubscriptionT>
 create_subscription(
@@ -194,7 +188,7 @@ create_subscription(
 )
 {
   return rclcpp::detail::create_subscription<
-    MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT, MessageMemoryStrategyT>(
+    MessageT, CallbackT, AllocatorT, SubscriptionT, MessageMemoryStrategyT>(
     node, node, topic_name, qos, std::forward<CallbackT>(callback), options, msg_mem_strat);
 }
 
@@ -206,13 +200,8 @@ template<
   typename MessageT,
   typename CallbackT,
   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 SubscriptionT = rclcpp::Subscription<MessageT, AllocatorT>,
+  typename MessageMemoryStrategyT = typename SubscriptionT::MessageMemoryStrategyType>
 typename std::shared_ptr<SubscriptionT>
 create_subscription(
   rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & node_parameters,
@@ -229,7 +218,7 @@ create_subscription(
 )
 {
   return rclcpp::detail::create_subscription<
-    MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT, MessageMemoryStrategyT>(
+    MessageT, CallbackT, AllocatorT, SubscriptionT, MessageMemoryStrategyT>(
     node_parameters, node_topics, topic_name, qos,
     std::forward<CallbackT>(callback), options, msg_mem_strat);
 }

rclcpp/include/rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp

@@ -0,0 +1,39 @@
+// Copyright 2021 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__ADD_GUARD_CONDITION_TO_RCL_WAIT_SET_HPP_
+#define RCLCPP__DETAIL__ADD_GUARD_CONDITION_TO_RCL_WAIT_SET_HPP_
+
+#include "rclcpp/guard_condition.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+/// Adds the guard condition to a waitset
+/**
+ * \param[in] wait_set reference to a wait set where to add the guard condition
+ * \param[in] guard_condition reference to the guard_condition to be added
+ */
+RCLCPP_PUBLIC
+void
+add_guard_condition_to_rcl_wait_set(
+  rcl_wait_set_t & wait_set,
+  const rclcpp::GuardCondition & guard_condition);
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__ADD_GUARD_CONDITION_TO_RCL_WAIT_SET_HPP_

rclcpp/include/rclcpp/detail/mutex_two_priorities.hpp

@@ -1,76 +0,0 @@
-// Copyright 2021 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__MUTEX_TWO_PRIORITIES_HPP_
-#define RCLCPP__DETAIL__MUTEX_TWO_PRIORITIES_HPP_
-
-#include <condition_variable>
-#include <mutex>
-
-namespace rclcpp
-{
-namespace detail
-{
-/// \internal A mutex that has two locking mechanism, one with higher priority than the other.
-/**
- * After the current mutex owner release the lock, a thread that used the high
- * priority mechanism will have priority over threads that used the low priority mechanism.
- */
-class MutexTwoPriorities
-{
-public:
-  class HighPriorityLockable
-  {
-public:
-    explicit HighPriorityLockable(MutexTwoPriorities & parent);
-
-    void lock();
-
-    void unlock();
-
-private:
-    MutexTwoPriorities & parent_;
-  };
-
-  class LowPriorityLockable
-  {
-public:
-    explicit LowPriorityLockable(MutexTwoPriorities & parent);
-
-    void lock();
-
-    void unlock();
-
-private:
-    MutexTwoPriorities & parent_;
-  };
-
-  HighPriorityLockable
-  get_high_priority_lockable();
-
-  LowPriorityLockable
-  get_low_priority_lockable();
-
-private:
-  std::condition_variable hp_cv_;
-  std::condition_variable lp_cv_;
-  std::mutex cv_mutex_;
-  size_t hp_waiting_count_{0u};
-  bool data_taken_{false};
-};
-
-}  // namespace detail
-}  // namespace rclcpp
-
-#endif  // RCLCPP__DETAIL__MUTEX_TWO_PRIORITIES_HPP_

rclcpp/include/rclcpp/exceptions/exceptions.hpp

@@ -254,6 +254,23 @@ public:
   {}
 };
 
+/// Thrown if user attempts to create an uninitialized statically typed parameter
+/**
+ * (see https://github.com/ros2/rclcpp/issues/1691)
+ */
+class UninitializedStaticallyTypedParameterException : public std::runtime_error
+{
+public:
+  /// Construct an instance.
+  /**
+   * \param[in] name the name of the parameter.
+   */
+  RCLCPP_PUBLIC
+  explicit UninitializedStaticallyTypedParameterException(const std::string & name)
+  : std::runtime_error("Statically typed parameter '" + name + "' must be initialized.")
+  {}
+};
+
 /// Thrown if parameter is already declared.
 class ParameterAlreadyDeclaredException : public std::runtime_error
 {
@@ -282,8 +299,8 @@ class ParameterModifiedInCallbackException : public std::runtime_error
   using std::runtime_error::runtime_error;
 };
 
-/// Thrown when a parameter override wasn't provided and one was required.
-class NoParameterOverrideProvided : public std::runtime_error
+/// Thrown when an uninitialized parameter is accessed.
+class ParameterUninitializedException : public std::runtime_error
 {
 public:
   /// Construct an instance.
@@ -291,8 +308,8 @@ public:
    * \param[in] name the name of the parameter.
    * \param[in] message custom exception message.
    */
-  explicit NoParameterOverrideProvided(const std::string & name)
-  : std::runtime_error("parameter '" + name + "' requires an user provided parameter override")
+  explicit ParameterUninitializedException(const std::string & name)
+  : std::runtime_error("parameter '" + name + "' is not initialized")
   {}
 };
 

rclcpp/include/rclcpp/executor.hpp

@@ -29,7 +29,9 @@
 
 #include "rcl/guard_condition.h"
 #include "rcl/wait.h"
+#include "rcpputils/scope_exit.hpp"
 
+#include "rclcpp/context.hpp"
 #include "rclcpp/contexts/default_context.hpp"
 #include "rclcpp/guard_condition.hpp"
 #include "rclcpp/executor_options.hpp"
@@ -39,7 +41,6 @@
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/visibility_control.hpp"
-#include "rclcpp/scope_exit.hpp"
 
 namespace rclcpp
 {
@@ -353,7 +354,7 @@ public:
     if (spinning.exchange(true)) {
       throw std::runtime_error("spin_until_future_complete() called while already spinning");
     }
-    RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+    RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
     while (rclcpp::ok(this->context_) && spinning.load()) {
       // Do one item of work.
       spin_once_impl(timeout_left);
@@ -524,7 +525,7 @@ protected:
   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_;
 
   std::shared_ptr<rclcpp::GuardCondition> shutdown_guard_condition_;
 
@@ -548,7 +549,7 @@ protected:
   spin_once_impl(std::chrono::nanoseconds timeout);
 
   typedef std::map<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr,
-      const rcl_guard_condition_t *,
+      const rclcpp::GuardCondition *,
       std::owner_less<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>>
     WeakNodesToGuardConditionsMap;
 
@@ -571,6 +572,9 @@ protected:
   /// nodes that are associated with the executor
   std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>
   weak_nodes_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
+
+  /// shutdown callback handle registered to Context
+  rclcpp::OnShutdownCallbackHandle shutdown_callback_handle_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/executors/multi_threaded_executor.hpp

@@ -22,7 +22,6 @@
 #include <thread>
 #include <unordered_map>
 
-#include "rclcpp/detail/mutex_two_priorities.hpp"
 #include "rclcpp/executor.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/memory_strategies.hpp"
@@ -82,12 +81,10 @@ protected:
 private:
   RCLCPP_DISABLE_COPY(MultiThreadedExecutor)
 
-  detail::MutexTwoPriorities wait_mutex_;
+  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_;
 };
 
 }  // namespace executors

rclcpp/include/rclcpp/executors/static_executor_entities_collector.hpp

@@ -57,15 +57,13 @@ public:
   /**
    * \param p_wait_set A reference to the wait set to be used in the executor
    * \param memory_strategy Shared pointer to the memory strategy to set.
-   * \param executor_guard_condition executor's guard condition
    * \throws std::runtime_error if memory strategy is null
    */
   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::memory_strategy::MemoryStrategy::SharedPtr memory_strategy);
 
   /// Finalize StaticExecutorEntitiesCollector to clear resources
   RCLCPP_PUBLIC
@@ -104,7 +102,7 @@ public:
    * \throws std::runtime_error if it couldn't add guard condition to wait set
    */
   RCLCPP_PUBLIC
-  bool
+  void
   add_to_wait_set(rcl_wait_set_t * wait_set) override;
 
   RCLCPP_PUBLIC
@@ -330,7 +328,7 @@ private:
   WeakCallbackGroupsToNodesMap weak_groups_to_nodes_associated_with_executor_;
 
   typedef std::map<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr,
-      const rcl_guard_condition_t *,
+      const rclcpp::GuardCondition *,
       std::owner_less<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>>
     WeakNodesToGuardConditionsMap;
   WeakNodesToGuardConditionsMap weak_nodes_to_guard_conditions_;
@@ -338,6 +336,10 @@ private:
   /// List of weak nodes registered in the static executor
   std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
 
+  // Mutex to protect vector of new nodes.
+  std::mutex new_nodes_mutex_;
+  std::vector<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> new_nodes_;
+
   /// Wait set for managing entities that the rmw layer waits on.
   rcl_wait_set_t * p_wait_set_ = nullptr;
 

rclcpp/include/rclcpp/experimental/create_intra_process_buffer.hpp

@@ -24,6 +24,7 @@
 #include "rclcpp/experimental/buffers/intra_process_buffer.hpp"
 #include "rclcpp/experimental/buffers/ring_buffer_implementation.hpp"
 #include "rclcpp/intra_process_buffer_type.hpp"
+#include "rclcpp/qos.hpp"
 
 namespace rclcpp
 {
@@ -37,13 +38,13 @@ template<
 typename rclcpp::experimental::buffers::IntraProcessBuffer<MessageT, Alloc, Deleter>::UniquePtr
 create_intra_process_buffer(
   IntraProcessBufferType buffer_type,
-  rmw_qos_profile_t qos,
+  const rclcpp::QoS & 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;
+  size_t buffer_size = qos.depth();
 
   using rclcpp::experimental::buffers::IntraProcessBuffer;
   typename IntraProcessBuffer<MessageT, Alloc, Deleter>::UniquePtr buffer;

rclcpp/include/rclcpp/experimental/intra_process_manager.hpp

@@ -33,6 +33,7 @@
 #include "rclcpp/allocator/allocator_deleter.hpp"
 #include "rclcpp/experimental/subscription_intra_process.hpp"
 #include "rclcpp/experimental/subscription_intra_process_base.hpp"
+#include "rclcpp/experimental/subscription_intra_process_buffer.hpp"
 #include "rclcpp/logger.hpp"
 #include "rclcpp/logging.hpp"
 #include "rclcpp/macros.hpp"
@@ -181,7 +182,7 @@ public:
   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)
+    typename allocator::AllocRebind<MessageT, Alloc>::allocator_type & allocator)
   {
     using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
     using MessageAllocatorT = typename MessageAllocTraits::allocator_type;
@@ -202,7 +203,8 @@ public:
       // 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);
+      this->template add_shared_msg_to_buffers<MessageT, Alloc, Deleter>(
+        msg, sub_ids.take_shared_subscriptions);
     } else if (!sub_ids.take_ownership_subscriptions.empty() && // NOLINT
       sub_ids.take_shared_subscriptions.size() <= 1)
     {
@@ -225,9 +227,9 @@ public:
     {
       // 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);
+      auto shared_msg = std::allocate_shared<MessageT, MessageAllocatorT>(allocator, *message);
 
-      this->template add_shared_msg_to_buffers<MessageT>(
+      this->template add_shared_msg_to_buffers<MessageT, Alloc, Deleter>(
         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);
@@ -242,7 +244,7 @@ public:
   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)
+    typename allocator::AllocRebind<MessageT, Alloc>::allocator_type & allocator)
   {
     using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
     using MessageAllocatorT = typename MessageAllocTraits::allocator_type;
@@ -263,17 +265,17 @@ public:
       // 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>(
+        this->template add_shared_msg_to_buffers<MessageT, Alloc, Deleter>(
           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);
+      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>(
+        this->template add_shared_msg_to_buffers<MessageT, Alloc, Deleter>(
           shared_msg,
           sub_ids.take_shared_subscriptions);
       }
@@ -303,25 +305,6 @@ public:
   get_subscription_intra_process(uint64_t intra_process_subscription_id);
 
 private:
-  struct SubscriptionInfo
-  {
-    SubscriptionInfo() = default;
-
-    rclcpp::experimental::SubscriptionIntraProcessBase::WeakPtr 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;
@@ -329,10 +312,10 @@ private:
   };
 
   using SubscriptionMap =
-    std::unordered_map<uint64_t, SubscriptionInfo>;
+    std::unordered_map<uint64_t, rclcpp::experimental::SubscriptionIntraProcessBase::WeakPtr>;
 
   using PublisherMap =
-    std::unordered_map<uint64_t, PublisherInfo>;
+    std::unordered_map<uint64_t, rclcpp::PublisherBase::WeakPtr>;
 
   using PublisherToSubscriptionIdsMap =
     std::unordered_map<uint64_t, SplittedSubscriptions>;
@@ -348,9 +331,14 @@ private:
 
   RCLCPP_PUBLIC
   bool
-  can_communicate(PublisherInfo pub_info, SubscriptionInfo sub_info) const;
+  can_communicate(
+    rclcpp::PublisherBase::SharedPtr pub,
+    rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr sub) const;
 
-  template<typename MessageT>
+  template<
+    typename MessageT,
+    typename Alloc,
+    typename Deleter>
   void
   add_shared_msg_to_buffers(
     std::shared_ptr<const MessageT> message,
@@ -361,11 +349,18 @@ private:
       if (subscription_it == subscriptions_.end()) {
         throw std::runtime_error("subscription has unexpectedly gone out of scope");
       }
-      auto subscription_base = subscription_it->second.subscription.lock();
+      auto subscription_base = subscription_it->second.lock();
       if (subscription_base) {
-        auto subscription = std::static_pointer_cast<
-          rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+        auto subscription = std::dynamic_pointer_cast<
+          rclcpp::experimental::SubscriptionIntraProcessBuffer<MessageT, Alloc, Deleter>
           >(subscription_base);
+        if (nullptr == subscription) {
+          throw std::runtime_error(
+                  "failed to dynamic cast SubscriptionIntraProcessBase to "
+                  "SubscriptionIntraProcessBuffer<MessageT, Alloc, Deleter>, which "
+                  "can happen when the publisher and subscription use different "
+                  "allocator types, which is not supported");
+        }
 
         subscription->provide_intra_process_message(message);
       } else {
@@ -382,7 +377,7 @@ private:
   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)
+    typename allocator::AllocRebind<MessageT, Alloc>::allocator_type & allocator)
   {
     using MessageAllocTraits = allocator::AllocRebind<MessageT, Alloc>;
     using MessageUniquePtr = std::unique_ptr<MessageT, Deleter>;
@@ -392,11 +387,18 @@ private:
       if (subscription_it == subscriptions_.end()) {
         throw std::runtime_error("subscription has unexpectedly gone out of scope");
       }
-      auto subscription_base = subscription_it->second.subscription.lock();
+      auto subscription_base = subscription_it->second.lock();
       if (subscription_base) {
-        auto subscription = std::static_pointer_cast<
-          rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+        auto subscription = std::dynamic_pointer_cast<
+          rclcpp::experimental::SubscriptionIntraProcessBuffer<MessageT, Alloc, Deleter>
           >(subscription_base);
+        if (nullptr == subscription) {
+          throw std::runtime_error(
+                  "failed to dynamic cast SubscriptionIntraProcessBase to "
+                  "SubscriptionIntraProcessBuffer<MessageT, Alloc, Deleter>, which "
+                  "can happen when the publisher and subscription use different "
+                  "allocator types, which is not supported");
+        }
 
         if (std::next(it) == subscription_ids.end()) {
           // If this is the last subscription, give up ownership
@@ -405,8 +407,8 @@ private:
           // 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);
+          auto ptr = MessageAllocTraits::allocate(allocator, 1);
+          MessageAllocTraits::construct(allocator, ptr, *message);
           copy_message = MessageUniquePtr(ptr, deleter);
 
           subscription->provide_intra_process_message(std::move(copy_message));

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -30,6 +30,8 @@
 #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/experimental/subscription_intra_process_buffer.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/waitable.hpp"
 #include "tracetools/tracetools.h"
@@ -44,54 +46,43 @@ template<
   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<
+class SubscriptionIntraProcess
+  : public SubscriptionIntraProcessBuffer<
     MessageT,
     Alloc,
     Deleter
-    >::UniquePtr;
+  >
+{
+  using SubscriptionIntraProcessBufferT = SubscriptionIntraProcessBuffer<
+    MessageT,
+    Alloc,
+    Deleter
+  >;
+
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(SubscriptionIntraProcess)
+
+  using MessageAllocTraits = typename SubscriptionIntraProcessBufferT::MessageAllocTraits;
+  using MessageAlloc = typename SubscriptionIntraProcessBufferT::MessageAlloc;
+  using ConstMessageSharedPtr = typename SubscriptionIntraProcessBufferT::ConstMessageSharedPtr;
+  using MessageUniquePtr = typename SubscriptionIntraProcessBufferT::MessageUniquePtr;
+  using BufferUniquePtr = typename SubscriptionIntraProcessBufferT::BufferUniquePtr;
 
   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,
+    const rclcpp::QoS & qos_profile,
     rclcpp::IntraProcessBufferType buffer_type)
-  : SubscriptionIntraProcessBase(topic_name, qos_profile),
+  : SubscriptionIntraProcessBuffer<MessageT, Alloc, Deleter>(
+      allocator,
+      context,
+      topic_name,
+      qos_profile,
+      buffer_type),
     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,
       static_cast<const void *>(this),
@@ -104,22 +95,7 @@ public:
 #endif
   }
 
-  ~SubscriptionIntraProcess()
-  {
-    if (rcl_guard_condition_fini(&gc_) != RCL_RET_OK) {
-      RCUTILS_LOG_ERROR_NAMED(
-        "rclcpp",
-        "Failed to destroy guard condition: %s",
-        rcutils_get_error_string().str);
-    }
-  }
-
-  bool
-  is_ready(rcl_wait_set_t * wait_set)
-  {
-    (void) wait_set;
-    return buffer_->has_data();
-  }
+  virtual ~SubscriptionIntraProcess() = default;
 
   std::shared_ptr<void>
   take_data()
@@ -128,9 +104,9 @@ public:
     MessageUniquePtr unique_msg;
 
     if (any_callback_.use_take_shared_method()) {
-      shared_msg = buffer_->consume_shared();
+      shared_msg = this->buffer_->consume_shared();
     } else {
-      unique_msg = buffer_->consume_unique();
+      unique_msg = this->buffer_->consume_unique();
     }
     return std::static_pointer_cast<void>(
       std::make_shared<std::pair<ConstMessageSharedPtr, MessageUniquePtr>>(
@@ -141,37 +117,10 @@ public:
 
   void execute(std::shared_ptr<void> & data)
   {
-    execute_impl<CallbackMessageT>(data);
-  }
-
-  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;
+    execute_impl<MessageT>(data);
   }
 
+protected:
   template<typename T>
   typename std::enable_if<std::is_same<T, rcl_serialized_message_t>::value, void>::type
   execute_impl(std::shared_ptr<void> & data)
@@ -206,7 +155,6 @@ private:
   }
 
   AnySubscriptionCallback<CallbackMessageT, Alloc> any_callback_;
-  BufferUniquePtr buffer_;
 };
 
 }  // namespace experimental

rclcpp/include/rclcpp/experimental/subscription_intra_process_base.hpp

@@ -25,6 +25,8 @@
 
 #include "rcl/error_handling.h"
 
+#include "rclcpp/guard_condition.hpp"
+#include "rclcpp/qos.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/waitable.hpp"
 
@@ -39,8 +41,11 @@ 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)
+  SubscriptionIntraProcessBase(
+    rclcpp::Context::SharedPtr context,
+    const std::string & topic_name,
+    const rclcpp::QoS & qos_profile)
+  : gc_(context), topic_name_(topic_name), qos_profile_(qos_profile)
   {}
 
   virtual ~SubscriptionIntraProcessBase() = default;
@@ -50,7 +55,7 @@ public:
   get_number_of_ready_guard_conditions() {return 1;}
 
   RCLCPP_PUBLIC
-  bool
+  void
   add_to_wait_set(rcl_wait_set_t * wait_set);
 
   virtual bool
@@ -71,19 +76,19 @@ public:
   get_topic_name() const;
 
   RCLCPP_PUBLIC
-  rmw_qos_profile_t
+  QoS
   get_actual_qos() const;
 
 protected:
   std::recursive_mutex reentrant_mutex_;
-  rcl_guard_condition_t gc_;
+  rclcpp::GuardCondition gc_;
 
 private:
   virtual void
   trigger_guard_condition() = 0;
 
   std::string topic_name_;
-  rmw_qos_profile_t qos_profile_;
+  QoS qos_profile_;
 };
 
 }  // namespace experimental

rclcpp/include/rclcpp/experimental/subscription_intra_process_buffer.hpp

@@ -0,0 +1,119 @@
+// Copyright 2021 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_BUFFER_HPP_
+#define RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_BUFFER_HPP_
+
+#include <rmw/rmw.h>
+
+#include <functional>
+#include <map>
+#include <memory>
+#include <stdexcept>
+#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/qos.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>
+>
+class SubscriptionIntraProcessBuffer : public SubscriptionIntraProcessBase
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(SubscriptionIntraProcessBuffer)
+
+  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;
+
+  SubscriptionIntraProcessBuffer(
+    std::shared_ptr<Alloc> allocator,
+    rclcpp::Context::SharedPtr context,
+    const std::string & topic_name,
+    const rclcpp::QoS & qos_profile,
+    rclcpp::IntraProcessBufferType buffer_type)
+  : SubscriptionIntraProcessBase(context, topic_name, qos_profile)
+  {
+    // Create the intra-process buffer.
+    buffer_ = rclcpp::experimental::create_intra_process_buffer<MessageT, Alloc, Deleter>(
+      buffer_type,
+      qos_profile,
+      allocator);
+  }
+
+  bool
+  is_ready(rcl_wait_set_t * wait_set)
+  {
+    (void) wait_set;
+    return buffer_->has_data();
+  }
+
+  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();
+  }
+
+protected:
+  void
+  trigger_guard_condition()
+  {
+    gc_.trigger();
+  }
+
+  BufferUniquePtr buffer_;
+};
+
+}  // namespace experimental
+}  // namespace rclcpp
+
+#endif  // RCLCPP__EXPERIMENTAL__SUBSCRIPTION_INTRA_PROCESS_BUFFER_HPP_

rclcpp/include/rclcpp/function_traits.hpp

@@ -83,7 +83,7 @@ template<typename ClassT, typename ReturnTypeT, typename ... Args, typename ...
 #if defined _LIBCPP_VERSION  // libc++ (Clang)
 struct function_traits<std::__bind<ReturnTypeT (ClassT::*)(Args ...), FArgs ...>>
 #elif defined _GLIBCXX_RELEASE  // glibc++ (GNU C++ >= 7.1)
-struct function_traits<std::_Bind<ReturnTypeT(ClassT::*(FArgs ...))(Args ...)>>
+struct function_traits<std::_Bind<ReturnTypeT(ClassT::* (FArgs ...))(Args ...)>>
 #elif defined __GLIBCXX__  // glibc++ (GNU C++)
 struct function_traits<std::_Bind<std::_Mem_fn<ReturnTypeT (ClassT::*)(Args ...)>(FArgs ...)>>
 #elif defined _MSC_VER  // MS Visual Studio
@@ -100,7 +100,7 @@ template<typename ClassT, typename ReturnTypeT, typename ... Args, typename ...
 #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>>
+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

rclcpp/include/rclcpp/generic_subscription.hpp

@@ -136,6 +136,13 @@ public:
   void handle_message(
     std::shared_ptr<void> & message, const rclcpp::MessageInfo & message_info) override;
 
+  /// Handle dispatching rclcpp::SerializedMessage to user callback.
+  RCLCPP_PUBLIC
+  void
+  handle_serialized_message(
+    const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
+    const rclcpp::MessageInfo & message_info) override;
+
   /// This function is currently not implemented.
   RCLCPP_PUBLIC
   void handle_loaned_message(

rclcpp/include/rclcpp/get_message_type_support_handle.hpp

@@ -0,0 +1,90 @@
+// Copyright 2021 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__GET_MESSAGE_TYPE_SUPPORT_HANDLE_HPP_
+#define RCLCPP__GET_MESSAGE_TYPE_SUPPORT_HANDLE_HPP_
+
+#include <type_traits>
+
+#include "rosidl_runtime_cpp/traits.hpp"
+#include "rosidl_runtime_cpp/message_type_support_decl.hpp"
+#include "rosidl_typesupport_cpp/message_type_support.hpp"
+
+#include "rclcpp/type_adapter.hpp"
+
+/// Versions of rosidl_typesupport_cpp::get_message_type_support_handle that handle adapted types.
+
+namespace rclcpp
+{
+
+/// Specialization for when MessageT is an actual ROS message type.
+template<typename MessageT>
+constexpr
+typename std::enable_if_t<
+  rosidl_generator_traits::is_message<MessageT>::value,
+  const rosidl_message_type_support_t &
+>
+get_message_type_support_handle()
+{
+  auto handle = rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>();
+  if (!handle) {
+    throw std::runtime_error("Type support handle unexpectedly nullptr");
+  }
+  return *handle;
+}
+
+/// Specialization for when MessageT is an adapted type using rclcpp::TypeAdapter.
+template<typename AdaptedType>
+constexpr
+typename std::enable_if_t<
+  !rosidl_generator_traits::is_message<AdaptedType>::value &&
+  rclcpp::TypeAdapter<AdaptedType>::is_specialized::value,
+  const rosidl_message_type_support_t &
+>
+get_message_type_support_handle()
+{
+  auto handle = rosidl_typesupport_cpp::get_message_type_support_handle<
+    typename TypeAdapter<AdaptedType>::ros_message_type
+    >();
+  if (!handle) {
+    throw std::runtime_error("Type support handle unexpectedly nullptr");
+  }
+  return *handle;
+}
+
+/// Specialization for when MessageT is not a ROS message nor an adapted type.
+/**
+ * This specialization is a pass through runtime check, which allows a better
+ * static_assert to catch this issue further down the line.
+ * This should never get to be called in practice, and is purely defensive.
+ */
+template<
+  typename AdaptedType
+>
+constexpr
+typename std::enable_if_t<
+  !rosidl_generator_traits::is_message<AdaptedType>::value &&
+  !TypeAdapter<AdaptedType>::is_specialized::value,
+  const rosidl_message_type_support_t &
+>
+get_message_type_support_handle()
+{
+  throw std::runtime_error(
+          "this specialization of rclcpp::get_message_type_support_handle() "
+          "should never be called");
+}
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__GET_MESSAGE_TYPE_SUPPORT_HANDLE_HPP_

rclcpp/include/rclcpp/graph_listener.hpp

@@ -24,6 +24,7 @@
 #include "rcl/guard_condition.h"
 #include "rcl/wait.h"
 #include "rclcpp/context.hpp"
+#include "rclcpp/guard_condition.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_graph_interface.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -187,7 +188,7 @@ private:
   mutable std::mutex node_graph_interfaces_mutex_;
   std::vector<rclcpp::node_interfaces::NodeGraphInterface *> node_graph_interfaces_;
 
-  rcl_guard_condition_t interrupt_guard_condition_ = rcl_get_zero_initialized_guard_condition();
+  rclcpp::GuardCondition interrupt_guard_condition_;
   rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
 };
 

rclcpp/include/rclcpp/guard_condition.hpp

@@ -47,7 +47,9 @@ public:
   RCLCPP_PUBLIC
   explicit GuardCondition(
     rclcpp::Context::SharedPtr context =
-    rclcpp::contexts::get_global_default_context());
+    rclcpp::contexts::get_global_default_context(),
+    rcl_guard_condition_options_t guard_condition_options =
+    rcl_guard_condition_get_default_options());
 
   RCLCPP_PUBLIC
   virtual
@@ -58,6 +60,11 @@ public:
   rclcpp::Context::SharedPtr
   get_context() const;
 
+  /// Return the underlying rcl guard condition structure.
+  RCLCPP_PUBLIC
+  rcl_guard_condition_t &
+  get_rcl_guard_condition();
+
   /// Return the underlying rcl guard condition structure.
   RCLCPP_PUBLIC
   const rcl_guard_condition_t &

rclcpp/include/rclcpp/init_options.hpp

@@ -29,7 +29,7 @@ class InitOptions
 {
 public:
   /// If true, the context will be shutdown on SIGINT by the signal handler (if it was installed).
-  bool shutdown_on_sigint = true;
+  bool shutdown_on_signal = true;
 
   /// Constructor
   /**

rclcpp/include/rclcpp/is_ros_compatible_type.hpp

@@ -0,0 +1,35 @@
+// Copyright 2021 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__IS_ROS_COMPATIBLE_TYPE_HPP_
+#define RCLCPP__IS_ROS_COMPATIBLE_TYPE_HPP_
+
+#include "rosidl_runtime_cpp/traits.hpp"
+
+#include "rclcpp/type_adapter.hpp"
+
+namespace rclcpp
+{
+
+template<typename T>
+struct is_ros_compatible_type
+{
+  static constexpr bool value =
+    rosidl_generator_traits::is_message<T>::value ||
+    rclcpp::TypeAdapter<T>::is_specialized::value;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__IS_ROS_COMPATIBLE_TYPE_HPP_

rclcpp/include/rclcpp/loaned_message.hpp

@@ -103,6 +103,9 @@ public:
    * \param[in] allocator Allocator instance in case middleware can not allocate messages
    * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
    */
+  [[
+    deprecated("used the LoanedMessage constructor that does not use a shared_ptr to the allocator")
+  ]]
   LoanedMessage(
     const rclcpp::PublisherBase * pub,
     std::shared_ptr<std::allocator<MessageT>> allocator)
@@ -114,7 +117,9 @@ public:
   : pub_(std::move(other.pub_)),
     message_(std::move(other.message_)),
     message_allocator_(std::move(other.message_allocator_))
-  {}
+  {
+    other.message_ = nullptr;
+  }
 
   /// Destructor of the LoanedMessage class.
   /**

rclcpp/include/rclcpp/memory_strategy.hpp

@@ -64,9 +64,11 @@ public:
   virtual void clear_handles() = 0;
   virtual void remove_null_handles(rcl_wait_set_t * wait_set) = 0;
 
-  virtual void add_guard_condition(const rcl_guard_condition_t * guard_condition) = 0;
+  virtual void
+  add_guard_condition(const rclcpp::GuardCondition & guard_condition) = 0;
 
-  virtual void remove_guard_condition(const rcl_guard_condition_t * guard_condition) = 0;
+  virtual void
+  remove_guard_condition(const rclcpp::GuardCondition * guard_condition) = 0;
 
   virtual void
   get_next_subscription(

rclcpp/include/rclcpp/message_memory_strategy.hpp

@@ -61,7 +61,7 @@ public:
     message_allocator_ = std::make_shared<MessageAlloc>();
     serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>();
     buffer_allocator_ = std::make_shared<BufferAlloc>();
-    rcutils_allocator_ = rclcpp::allocator::get_rcl_allocator(*buffer_allocator_.get());
+    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
   }
 
   explicit MessageMemoryStrategy(std::shared_ptr<Alloc> allocator)
@@ -69,7 +69,7 @@ public:
     message_allocator_ = std::make_shared<MessageAlloc>(*allocator.get());
     serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>(*allocator.get());
     buffer_allocator_ = std::make_shared<BufferAlloc>(*allocator.get());
-    rcutils_allocator_ = rclcpp::allocator::get_rcl_allocator(*buffer_allocator_.get());
+    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
   }
 
   virtual ~MessageMemoryStrategy() = default;

rclcpp/include/rclcpp/node.hpp

@@ -148,10 +148,16 @@ public:
     rclcpp::CallbackGroupType group_type,
     bool automatically_add_to_executor_with_node = true);
 
-  /// Return the list of callback groups in the node.
+  /// Iterate over the callback groups in the node, calling the given function on each valid one.
+  /**
+   * This method is called in a thread-safe way, and also makes sure to only call the given
+   * function on those items that are still valid.
+   *
+   * \param[in] func The callback function to call on each valid callback group.
+   */
   RCLCPP_PUBLIC
-  const std::vector<rclcpp::CallbackGroup::WeakPtr> &
-  get_callback_groups() const;
+  void
+  for_each_callback_group(const node_interfaces::NodeBaseInterface::CallbackGroupFunction & func);
 
   /// Create and return a Publisher.
   /**
@@ -206,13 +212,8 @@ public:
     typename MessageT,
     typename CallbackT,
     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 SubscriptionT = rclcpp::Subscription<MessageT, AllocatorT>,
+    typename MessageMemoryStrategyT = typename SubscriptionT::MessageMemoryStrategyType
   >
   std::shared_ptr<SubscriptionT>
   create_subscription(
@@ -984,12 +985,15 @@ public:
   std::map<std::string, std::vector<std::string>>
   get_service_names_and_types() const;
 
-  /// Return the number of publishers that are advertised on a given topic.
+  /// Return a map of existing service names to list of service types for a specific node.
   /**
-   * \param[in] node_name the node_name on which to count the publishers.
-   * \param[in] namespace_ the namespace of the node associated with the name
-   * \return number of publishers that are advertised on a given topic.
-   * \throws std::runtime_error if publishers could not be counted
+   * This function only considers services - not clients.
+   * The returned names are the actual names used and do not have remap rules applied.
+   *
+   * \param[in] node_name name of the node.
+   * \param[in] namespace_ namespace of the node.
+   * \return a map of existing service names to list of service types.
+   * \throws std::runtime_error anything that rcl_error can throw.
    */
   RCLCPP_PUBLIC
   std::map<std::string, std::vector<std::string>>

rclcpp/include/rclcpp/node_impl.hpp

@@ -86,7 +86,6 @@ template<
   typename MessageT,
   typename CallbackT,
   typename AllocatorT,
-  typename CallbackMessageT,
   typename SubscriptionT,
   typename MessageMemoryStrategyT>
 std::shared_ptr<SubscriptionT>
@@ -221,12 +220,16 @@ Node::declare_parameter(
   // get advantage of parameter value template magic to get
   // the correct rclcpp::ParameterType from ParameterT
   rclcpp::ParameterValue value{ParameterT{}};
-  return this->declare_parameter(
-    name,
-    value.get_type(),
-    parameter_descriptor,
-    ignore_override
-  ).get<ParameterT>();
+  try {
+    return this->declare_parameter(
+      name,
+      value.get_type(),
+      parameter_descriptor,
+      ignore_override
+    ).get<ParameterT>();
+  } catch (const ParameterTypeException &) {
+    throw exceptions::UninitializedStaticallyTypedParameterException(name);
+  }
 }
 
 template<typename ParameterT>

rclcpp/include/rclcpp/node_interfaces/node_base.hpp

@@ -15,11 +15,14 @@
 #ifndef RCLCPP__NODE_INTERFACES__NODE_BASE_HPP_
 #define RCLCPP__NODE_INTERFACES__NODE_BASE_HPP_
 
+#include <functional>
 #include <memory>
+#include <mutex>
 #include <string>
 #include <vector>
 
 #include "rcl/node.h"
+#include "rclcpp/callback_group.hpp"
 #include "rclcpp/context.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
@@ -31,7 +34,7 @@ namespace node_interfaces
 {
 
 /// Implementation of the NodeBase part of the Node API.
-class NodeBase : public NodeBaseInterface
+class NodeBase : public NodeBaseInterface, public std::enable_shared_from_this<NodeBase>
 {
 public:
   RCLCPP_SMART_PTR_ALIASES_ONLY(NodeBase)
@@ -95,22 +98,25 @@ public:
   bool
   callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group) override;
 
+  /// Iterate over the stored callback groups, calling the given function on each valid one.
+  /**
+   * This method is called in a thread-safe way, and also makes sure to only call the given
+   * function on those items that are still valid.
+   *
+   * \param[in] func The callback function to call on each valid callback group.
+   */
   RCLCPP_PUBLIC
-  const std::vector<rclcpp::CallbackGroup::WeakPtr> &
-  get_callback_groups() const override;
+  void
+  for_each_callback_group(const CallbackGroupFunction & func) override;
 
   RCLCPP_PUBLIC
   std::atomic_bool &
   get_associated_with_executor_atomic() override;
 
   RCLCPP_PUBLIC
-  rcl_guard_condition_t *
+  rclcpp::GuardCondition &
   get_notify_guard_condition() override;
 
-  RCLCPP_PUBLIC
-  std::unique_lock<std::recursive_mutex>
-  acquire_notify_guard_condition_lock() const override;
-
   RCLCPP_PUBLIC
   bool
   get_use_intra_process_default() const override;
@@ -132,13 +138,14 @@ private:
   std::shared_ptr<rcl_node_t> node_handle_;
 
   rclcpp::CallbackGroup::SharedPtr default_callback_group_;
+  std::mutex callback_groups_mutex_;
   std::vector<rclcpp::CallbackGroup::WeakPtr> callback_groups_;
 
   std::atomic_bool associated_with_executor_;
 
   /// Guard condition for notifying the Executor of changes to this node.
   mutable std::recursive_mutex notify_guard_condition_mutex_;
-  rcl_guard_condition_t notify_guard_condition_ = rcl_get_zero_initialized_guard_condition();
+  rclcpp::GuardCondition notify_guard_condition_;
   bool notify_guard_condition_is_valid_;
 };
 

rclcpp/include/rclcpp/node_interfaces/node_base_interface.hpp

@@ -24,6 +24,7 @@
 
 #include "rclcpp/callback_group.hpp"
 #include "rclcpp/context.hpp"
+#include "rclcpp/guard_condition.hpp"
 #include "rclcpp/macros.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -122,11 +123,19 @@ public:
   bool
   callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group) = 0;
 
-  /// Return list of callback groups associated with this node.
+  using CallbackGroupFunction = std::function<void (rclcpp::CallbackGroup::SharedPtr)>;
+
+  /// Iterate over the stored callback groups, calling the given function on each valid one.
+  /**
+   * This method is called in a thread-safe way, and also makes sure to only call the given
+   * function on those items that are still valid.
+   *
+   * \param[in] func The callback function to call on each valid callback group.
+   */
   RCLCPP_PUBLIC
   virtual
-  const std::vector<rclcpp::CallbackGroup::WeakPtr> &
-  get_callback_groups() const = 0;
+  void
+  for_each_callback_group(const CallbackGroupFunction & func) = 0;
 
   /// Return the atomic bool which is used to ensure only one executor is used.
   RCLCPP_PUBLIC
@@ -134,24 +143,17 @@ public:
   std::atomic_bool &
   get_associated_with_executor_atomic() = 0;
 
-  /// Return guard condition that should be notified when the internal node state changes.
+  /// Return a guard condition that should be notified when the internal node state changes.
   /**
    * For example, this should be notified when a publisher is added or removed.
    *
-   * \return the rcl_guard_condition_t if it is valid, else nullptr
+   * \return the GuardCondition if it is valid, else thow runtime error
    */
   RCLCPP_PUBLIC
   virtual
-  rcl_guard_condition_t *
+  rclcpp::GuardCondition &
   get_notify_guard_condition() = 0;
 
-  /// Acquire and return a scoped lock that protects the notify guard condition.
-  /** This should be used when triggering the notify guard condition. */
-  RCLCPP_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

rclcpp/include/rclcpp/node_interfaces/node_graph.hpp

@@ -20,6 +20,7 @@
 #include <memory>
 #include <mutex>
 #include <string>
+#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -70,10 +71,34 @@ public:
     const std::string & node_name,
     const std::string & namespace_) const override;
 
+  RCLCPP_PUBLIC
+  std::map<std::string, std::vector<std::string>>
+  get_client_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_) const override;
+
+  RCLCPP_PUBLIC
+  std::map<std::string, std::vector<std::string>>
+  get_publisher_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_,
+    bool no_demangle = false) const override;
+
+  RCLCPP_PUBLIC
+  std::map<std::string, std::vector<std::string>>
+  get_subscriber_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_,
+    bool no_demangle = false) const override;
+
   RCLCPP_PUBLIC
   std::vector<std::string>
   get_node_names() const override;
 
+  RCLCPP_PUBLIC
+  std::vector<std::tuple<std::string, std::string, std::string>>
+  get_node_names_with_enclaves() const override;
+
   RCLCPP_PUBLIC
   std::vector<std::pair<std::string, std::string>>
   get_node_names_and_namespaces() const override;

rclcpp/include/rclcpp/node_interfaces/node_graph_interface.hpp

@@ -20,6 +20,7 @@
 #include <chrono>
 #include <map>
 #include <string>
+#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -146,7 +147,9 @@ public:
   /**
    * A topic is considered to exist when at least one publisher or subscriber
    * exists for it, whether they be local or remote to this process.
-   * The returned names are the actual names used and do not have remap rules applied.
+   * The returned names are the actual names of the topics, either announced by another nodes or by this one.
+   * Attempting to create publishers or subscribers using names returned by this function may not
+   * result in the desired topic name being used depending on the remap rules in use.
    *
    * \param[in] no_demangle if true, topic names and types are not demangled
    */
@@ -160,7 +163,9 @@ public:
    * A service is considered to exist when at least one service server or
    * service client exists for it, whether they be local or remote to this
    * process.
-   * The returned names are the actual names used and do not have remap rules applied.
+   * The returned names are the actual names of the services, either announced by another nodes or by this one.
+   * Attempting to create clients or services using names returned by this function may not result in
+   * the desired service name being used depending on the remap rules in use.
    */
   RCLCPP_PUBLIC
   virtual
@@ -170,7 +175,9 @@ public:
   /// Return a map of existing service names to list of service types for a specific node.
   /**
    * This function only considers services - not clients.
-   * The returned names are the actual names used and do not have remap rules applied.
+   * The returned names are the actual names after remap rules applied.
+   * Attempting to create service clients using names returned by this function may not
+   * result in the desired service name being used depending on the remap rules in use.
    *
    * \param[in] node_name name of the node
    * \param[in] namespace_ namespace of the node
@@ -182,18 +189,85 @@ public:
     const std::string & node_name,
     const std::string & namespace_) const = 0;
 
+  /// Return a map of existing service names and types with a specific node.
+  /**
+   * This function only considers clients - not service servers.
+   * The returned names are the actual names after remap rules applied.
+   * Attempting to create service servers using names returned by this function may not
+   * result in the desired service name being used depending on the remap rules in use.
+   *
+   * \param[in] node_name name of the node
+   * \param[in] namespace_ namespace of the node
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::map<std::string, std::vector<std::string>>
+  get_client_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_) const = 0;
+
+  /// Return a map of existing topic names to list of topic types for a specific node.
+  /**
+   * This function only considers publishers - not subscribers.
+   * The returned names are the actual names after remap rules applied.
+   * Attempting to create publishers or subscribers using names returned by this function may not
+   * result in the desired topic name being used depending on the remap rules in use.
+   *
+   * \param[in] node_name name of the node
+   * \param[in] namespace_ namespace of the node
+   * \param[in] no_demangle if true, topic names and types are not demangled
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::map<std::string, std::vector<std::string>>
+  get_publisher_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_,
+    bool no_demangle = false) const = 0;
+
+  /// Return a map of existing topic names to list of topic types for a specific node.
+  /**
+   * This function only considers subscribers - not publishers.
+   * The returned names are the actual names after remap rules applied.
+   * Attempting to create publishers or subscribers using names returned by this function may not
+   * result in the desired topic name being used depending on the remap rules in use.
+   *
+   * \param[in] node_name name of the node
+   * \param[in] namespace_ namespace of the node
+   * \param[in] no_demangle if true, topic names and types are not demangled
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::map<std::string, std::vector<std::string>>
+  get_subscriber_names_and_types_by_node(
+    const std::string & node_name,
+    const std::string & namespace_,
+    bool no_demangle = false) const = 0;
+
   /// Return a vector of existing node names (string).
   /*
-   * The returned names are the actual names used and do not have remap rules applied.
+   * The returned names are the actual names after remap rules applied.
    */
   RCLCPP_PUBLIC
   virtual
   std::vector<std::string>
   get_node_names() const = 0;
 
+  /// Return a vector of existing node names, namespaces and enclaves (tuple of string).
+  /*
+   * The returned names are the actual names after remap rules applied.
+   * The enclaves contain the runtime security artifacts, those can be
+   * used to establish secured network.
+   * See https://design.ros2.org/articles/ros2_security_enclaves.html
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<std::tuple<std::string, std::string, std::string>>
+  get_node_names_with_enclaves() const = 0;
+
   /// Return a vector of existing node names and namespaces (pair of string).
   /*
-   * The returned names are the actual names used and do not have remap rules applied.
+   * The returned names are the actual names after remap rules applied.
    */
   RCLCPP_PUBLIC
   virtual

rclcpp/include/rclcpp/node_interfaces/node_time_source.hpp

@@ -48,7 +48,7 @@ public:
     rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
     rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock,
     rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters,
-    const rclcpp::QoS & qos = rclcpp::RosoutQoS(),
+    const rclcpp::QoS & qos = rclcpp::ClockQoS(),
     bool use_clock_thread = true
   );
 

rclcpp/include/rclcpp/node_options.hpp

@@ -349,6 +349,9 @@ public:
    * 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.
+   * Parameter declaration from overrides is done in the node's base constructor,
+   * so the user must take care to check if the parameter is already (e.g.
+   * automatically) declared before declaring it themselves.
    * Already declared parameters will not be re-declared, and parameters
    * declared in this way will use the default constructed ParameterDescriptor.
    */

rclcpp/include/rclcpp/parameter_event_handler.hpp

@@ -169,13 +169,17 @@ public:
     NodeT node,
     const rclcpp::QoS & qos =
     rclcpp::QoS(rclcpp::QoSInitialization::from_rmw(rmw_qos_profile_parameter_events)))
+  : node_base_(rclcpp::node_interfaces::get_node_base_interface(node))
   {
-    node_base_ = rclcpp::node_interfaces::get_node_base_interface(node);
     auto node_topics = rclcpp::node_interfaces::get_node_topics_interface(node);
 
+    callbacks_ = std::make_shared<Callbacks>();
+
     event_subscription_ = rclcpp::create_subscription<rcl_interfaces::msg::ParameterEvent>(
       node_topics, "/parameter_events", qos,
-      std::bind(&ParameterEventHandler::event_callback, this, std::placeholders::_1));
+      [callbacks = callbacks_](const rcl_interfaces::msg::ParameterEvent & event) {
+        callbacks->event_callback(event);
+      });
   }
 
   using ParameterEventCallbackType =
@@ -249,8 +253,8 @@ public:
   get_parameter_from_event(
     const rcl_interfaces::msg::ParameterEvent & event,
     rclcpp::Parameter & parameter,
-    const std::string parameter_name,
-    const std::string node_name = "");
+    const std::string & parameter_name,
+    const std::string & node_name = "");
 
   /// Get an rclcpp::Parameter from parameter event
   /**
@@ -269,8 +273,8 @@ public:
   static rclcpp::Parameter
   get_parameter_from_event(
     const rcl_interfaces::msg::ParameterEvent & event,
-    const std::string parameter_name,
-    const std::string node_name = "");
+    const std::string & parameter_name,
+    const std::string & node_name = "");
 
   /// Get all rclcpp::Parameter values from a parameter event
   /**
@@ -285,17 +289,6 @@ public:
   using CallbacksContainerType = std::list<ParameterCallbackHandle::WeakPtr>;
 
 protected:
-  /// Callback for parameter events subscriptions.
-  RCLCPP_PUBLIC
-  void
-  event_callback(const rcl_interfaces::msg::ParameterEvent & event);
-
-  // Utility function for resolving node path.
-  std::string resolve_path(const std::string & path);
-
-  // Node interface used for base functionality
-  std::shared_ptr<rclcpp::node_interfaces::NodeBaseInterface> node_base_;
-
   // *INDENT-OFF* Uncrustify doesn't handle indented public/private labels
   // Hash function for string pair required in std::unordered_map
   // See: https://stackoverflow.com/questions/35985960/c-why-is-boosthash-combine-the-best-way-to-combine-hash-values
@@ -319,18 +312,34 @@ protected:
   };
   // *INDENT-ON*
 
-  // Map container for registered parameters
-  std::unordered_map<
-    std::pair<std::string, std::string>,
-    CallbacksContainerType,
-    StringPairHash
-  > parameter_callbacks_;
+  struct Callbacks
+  {
+    std::recursive_mutex mutex_;
+
+    // Map container for registered parameters
+    std::unordered_map<
+      std::pair<std::string, std::string>,
+      CallbacksContainerType,
+      StringPairHash
+    > parameter_callbacks_;
+
+    std::list<ParameterEventCallbackHandle::WeakPtr> event_callbacks_;
+
+    /// Callback for parameter events subscriptions.
+    RCLCPP_PUBLIC
+    void
+    event_callback(const rcl_interfaces::msg::ParameterEvent & event);
+  };
+
+  std::shared_ptr<Callbacks> callbacks_;
+
+  // Utility function for resolving node path.
+  std::string resolve_path(const std::string & path);
+
+  // Node interface used for base functionality
+  std::shared_ptr<rclcpp::node_interfaces::NodeBaseInterface> node_base_;
 
   rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr event_subscription_;
-
-  std::list<ParameterEventCallbackHandle::WeakPtr> event_callbacks_;
-
-  std::recursive_mutex mutex_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/parameter_value.hpp

@@ -301,6 +301,16 @@ public:
     return get<ParameterType::PARAMETER_BOOL_ARRAY>();
   }
 
+  template<typename type>
+  constexpr
+  typename std::enable_if<
+    std::is_convertible<
+      type, const std::vector<int> &>::value, const std::vector<int64_t> &>::type
+  get() const
+  {
+    return get<ParameterType::PARAMETER_INTEGER_ARRAY>();
+  }
+
   template<typename type>
   constexpr
   typename std::enable_if<
@@ -311,6 +321,16 @@ public:
     return get<ParameterType::PARAMETER_INTEGER_ARRAY>();
   }
 
+  template<typename type>
+  constexpr
+  typename std::enable_if<
+    std::is_convertible<
+      type, const std::vector<float> &>::value, const std::vector<double> &>::type
+  get() const
+  {
+    return get<ParameterType::PARAMETER_DOUBLE_ARRAY>();
+  }
+
   template<typename type>
   constexpr
   typename std::enable_if<

rclcpp/include/rclcpp/publisher.hpp

@@ -15,9 +15,6 @@
 #ifndef RCLCPP__PUBLISHER_HPP_
 #define RCLCPP__PUBLISHER_HPP_
 
-#include <rmw/error_handling.h>
-#include <rmw/rmw.h>
-
 #include <functional>
 #include <iostream>
 #include <memory>
@@ -27,16 +24,21 @@
 
 #include "rcl/error_handling.h"
 #include "rcl/publisher.h"
+#include "rmw/error_handling.h"
+#include "rmw/rmw.h"
 
 #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/get_message_type_support_handle.hpp"
+#include "rclcpp/is_ros_compatible_type.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_adapter.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -49,15 +51,62 @@ template<typename MessageT, typename AllocatorT>
 class LoanedMessage;
 
 /// A publisher publishes messages of any type to a topic.
+/**
+ * MessageT must be a:
+ *
+ * - ROS message type with its own type support (e.g. std_msgs::msgs::String), or a
+ * - rclcpp::TypeAdapter<CustomType, ROSMessageType>
+ *   (e.g. rclcpp::TypeAdapter<std::string, std_msgs::msg::String), or a
+ * - custom type that has been setup as the implicit type for a ROS type using
+ *   RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE(custom_type, ros_message_type)
+ *
+ * In the case that MessageT is ROS message type (e.g. std_msgs::msg::String),
+ * both PublishedType and ROSMessageType will be that type.
+ * In the case that MessageT is a TypeAdapter<CustomType, ROSMessageType> type
+ * (e.g. TypeAdapter<std::string, std_msgs::msg::String>), PublishedType will
+ * be the custom type, and ROSMessageType will be the ros message type.
+ *
+ * This is achieved because of the "identity specialization" for TypeAdapter,
+ * which returns itself if it is already a TypeAdapter, and the default
+ * specialization which allows ROSMessageType to be void.
+ * \sa rclcpp::TypeAdapter for more details.
+ */
 template<typename MessageT, typename AllocatorT = std::allocator<void>>
 class Publisher : public PublisherBase
 {
 public:
-  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>;
+  static_assert(
+    rclcpp::is_ros_compatible_type<MessageT>::value,
+    "given message type is not compatible with ROS and cannot be used with a Publisher");
+
+  /// MessageT::custom_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using PublishedType = typename rclcpp::TypeAdapter<MessageT>::custom_type;
+  /// MessageT::ros_message_type if MessageT is a TypeAdapter, otherwise just MessageT.
+  using ROSMessageType = typename rclcpp::TypeAdapter<MessageT>::ros_message_type;
+
+  using PublishedTypeAllocatorTraits = allocator::AllocRebind<PublishedType, AllocatorT>;
+  using PublishedTypeAllocator = typename PublishedTypeAllocatorTraits::allocator_type;
+  using PublishedTypeDeleter = allocator::Deleter<PublishedTypeAllocator, PublishedType>;
+
+  using ROSMessageTypeAllocatorTraits = allocator::AllocRebind<ROSMessageType, AllocatorT>;
+  using ROSMessageTypeAllocator = typename ROSMessageTypeAllocatorTraits::allocator_type;
+  using ROSMessageTypeDeleter = allocator::Deleter<ROSMessageTypeAllocator, ROSMessageType>;
+
+  using MessageAllocatorTraits
+  [[deprecated("use PublishedTypeAllocatorTraits")]] =
+    PublishedTypeAllocatorTraits;
+  using MessageAllocator
+  [[deprecated("use PublishedTypeAllocator")]] =
+    PublishedTypeAllocator;
+  using MessageDeleter
+  [[deprecated("use PublishedTypeDeleter")]] =
+    PublishedTypeDeleter;
+  using MessageUniquePtr
+  [[deprecated("use std::unique_ptr<PublishedType, PublishedTypeDeleter>")]] =
+    std::unique_ptr<PublishedType, PublishedTypeDeleter>;
+  using MessageSharedPtr
+  [[deprecated("use std::shared_ptr<const PublishedType>")]] =
+    std::shared_ptr<const PublishedType>;
 
   RCLCPP_SMART_PTR_DEFINITIONS(Publisher<MessageT, AllocatorT>)
 
@@ -80,12 +129,14 @@ public:
   : PublisherBase(
       node_base,
       topic,
-      *rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>(),
+      rclcpp::get_message_type_support_handle<MessageT>(),
       options.template to_rcl_publisher_options<MessageT>(qos)),
     options_(options),
-    message_allocator_(new MessageAllocator(*options.get_allocator().get()))
+    published_type_allocator_(*options.get_allocator()),
+    ros_message_type_allocator_(*options.get_allocator())
   {
-    allocator::set_allocator_for_deleter(&message_deleter_, message_allocator_.get());
+    allocator::set_allocator_for_deleter(&published_type_deleter_, &published_type_allocator_);
+    allocator::set_allocator_for_deleter(&ros_message_type_deleter_, &ros_message_type_allocator_);
 
     if (options_.event_callbacks.deadline_callback) {
       this->add_event_handler(
@@ -135,15 +186,15 @@ public:
       // 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) {
+      if (qos.history() != rclcpp::HistoryPolicy::KeepLast) {
         throw std::invalid_argument(
-                "intraprocess communication is not allowed with keep all history qos policy");
+                "intraprocess communication allowed only with keep last history qos policy");
       }
-      if (qos.get_rmw_qos_profile().depth == 0) {
+      if (qos.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) {
+      if (qos.durability() != rclcpp::DurabilityPolicy::Volatile) {
         throw std::invalid_argument(
                 "intraprocess communication allowed only with volatile durability");
       }
@@ -170,21 +221,33 @@ public:
    * allocator.
    * \sa rclcpp::LoanedMessage for details of the LoanedMessage class.
    *
-   * \return LoanedMessage containing memory for a ROS message of type MessageT
+   * \return LoanedMessage containing memory for a ROS message of type ROSMessageType
    */
-  rclcpp::LoanedMessage<MessageT, AllocatorT>
+  rclcpp::LoanedMessage<ROSMessageType, AllocatorT>
   borrow_loaned_message()
   {
-    return rclcpp::LoanedMessage<MessageT, AllocatorT>(this, this->get_allocator());
+    return rclcpp::LoanedMessage<ROSMessageType, AllocatorT>(
+      *this,
+      this->get_ros_message_type_allocator());
   }
 
-  /// Send a message to the topic for this publisher.
+  /// Publish a message on the topic.
   /**
-   * This function is templated on the input message type, MessageT.
-   * \param[in] msg A shared pointer to the message to send.
+   * This signature is enabled if the element_type of the std::unique_ptr is
+   * a ROS message type, as opposed to the custom_type of a TypeAdapter, and
+   * that type matches the type given when creating the publisher.
+   *
+   * This signature allows the user to give ownership of the message to rclcpp,
+   * allowing for more efficient intra-process communication optimizations.
+   *
+   * \param[in] msg A unique pointer to the message to send.
    */
-  virtual void
-  publish(std::unique_ptr<MessageT, MessageDeleter> msg)
+  template<typename T>
+  typename std::enable_if_t<
+    rosidl_generator_traits::is_message<T>::value &&
+    std::is_same<T, ROSMessageType>::value
+  >
+  publish(std::unique_ptr<T, ROSMessageTypeDeleter> msg)
   {
     if (!intra_process_is_enabled_) {
       this->do_inter_process_publish(*msg);
@@ -207,8 +270,24 @@ public:
     }
   }
 
-  virtual void
-  publish(const MessageT & msg)
+  /// Publish a message on the topic.
+  /**
+   * This signature is enabled if the object being published is
+   * a ROS message type, as opposed to the custom_type of a TypeAdapter, and
+   * that type matches the type given when creating the publisher.
+   *
+   * This signature allows the user to give a reference to a message, which is
+   * copied onto the heap without modification so that a copy can be owned by
+   * rclcpp and ownership of the copy can be moved later if needed.
+   *
+   * \param[in] msg A const reference to the message to send.
+   */
+  template<typename T>
+  typename std::enable_if_t<
+    rosidl_generator_traits::is_message<T>::value &&
+    std::is_same<T, ROSMessageType>::value
+  >
+  publish(const T & msg)
   {
     // Avoid allocating when not using intra process.
     if (!intra_process_is_enabled_) {
@@ -218,12 +297,77 @@ public:
     // Otherwise we have to allocate memory in a unique_ptr and pass it along.
     // 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_);
+    auto unique_msg = this->duplicate_ros_message_as_unique_ptr(msg);
     this->publish(std::move(unique_msg));
   }
 
+  /// Publish a message on the topic.
+  /**
+   * This signature is enabled if this class was created with a TypeAdapter and
+   * the element_type of the std::unique_ptr matches the custom_type for the
+   * TypeAdapter used with this class.
+   *
+   * This signature allows the user to give ownership of the message to rclcpp,
+   * allowing for more efficient intra-process communication optimizations.
+   *
+   * \param[in] msg A unique pointer to the message to send.
+   */
+  template<typename T>
+  typename std::enable_if_t<
+    rclcpp::TypeAdapter<MessageT>::is_specialized::value &&
+    std::is_same<T, PublishedType>::value
+  >
+  publish(std::unique_ptr<T, PublishedTypeDeleter> msg)
+  {
+    // TODO(wjwwood): later update this to give the unique_ptr to the intra
+    // process manager and let it decide if it needs to be converted or not.
+    // For now, convert it unconditionally and pass it the ROSMessageType
+    // publish function specialization.
+    auto unique_ros_msg = this->create_ros_message_unique_ptr();
+    rclcpp::TypeAdapter<MessageT>::convert_to_ros_message(*msg, *unique_ros_msg);
+    this->publish(std::move(unique_ros_msg));
+  }
+
+  /// Publish a message on the topic.
+  /**
+   * This signature is enabled if this class was created with a TypeAdapter and
+   * the given type matches the custom_type of the TypeAdapter.
+   *
+   * This signature allows the user to give a reference to a message, which is
+   * copied onto the heap without modification so that a copy can be owned by
+   * rclcpp and ownership of the copy can be moved later if needed.
+   *
+   * \param[in] msg A const reference to the message to send.
+   */
+  template<typename T>
+  typename std::enable_if_t<
+    rclcpp::TypeAdapter<MessageT>::is_specialized::value &&
+    std::is_same<T, PublishedType>::value
+  >
+  publish(const T & msg)
+  {
+    // TODO(wjwwood): later update this to give the unique_ptr to the intra
+    // process manager and let it decide if it needs to be converted or not.
+    // For now, convert it unconditionally and pass it the ROSMessageType
+    // publish function specialization.
+
+    // Avoid allocating when not using intra process.
+    if (!intra_process_is_enabled_) {
+      // Convert to the ROS message equivalent and publish it.
+      ROSMessageType ros_msg;
+      rclcpp::TypeAdapter<MessageT>::convert_to_ros_message(msg, ros_msg);
+      // In this case we're not using intra process.
+      return this->do_inter_process_publish(ros_msg);
+    }
+    // Otherwise we have to allocate memory in a unique_ptr, convert it,
+    // and pass it along.
+    // As the message is not const, a copy should be made.
+    // A shared_ptr<const MessageT> could also be constructed here.
+    auto unique_ros_msg = this->create_ros_message_unique_ptr();
+    rclcpp::TypeAdapter<MessageT>::convert_to_ros_message(msg, *unique_ros_msg);
+    this->publish(std::move(unique_ros_msg));
+  }
+
   void
   publish(const rcl_serialized_message_t & serialized_msg)
   {
@@ -245,7 +389,7 @@ public:
    * \param loaned_msg The LoanedMessage instance to be published.
    */
   void
-  publish(rclcpp::LoanedMessage<MessageT, AllocatorT> && loaned_msg)
+  publish(rclcpp::LoanedMessage<ROSMessageType, AllocatorT> && loaned_msg)
   {
     if (!loaned_msg.is_valid()) {
       throw std::runtime_error("loaned message is not valid");
@@ -271,20 +415,30 @@ public:
     }
   }
 
-  std::shared_ptr<MessageAllocator>
+  [[deprecated("use get_published_type_allocator() or get_ros_message_type_allocator() instead")]]
+  std::shared_ptr<PublishedTypeAllocator>
   get_allocator() const
   {
-    return message_allocator_;
+    return std::make_shared<PublishedTypeAllocator>(published_type_allocator_);
+  }
+
+  PublishedTypeAllocator
+  get_published_type_allocator() const
+  {
+    return published_type_allocator_;
+  }
+
+  ROSMessageTypeAllocator
+  get_ros_message_type_allocator() const
+  {
+    return ros_message_type_allocator_;
   }
 
 protected:
   void
-  do_inter_process_publish(const MessageT & msg)
+  do_inter_process_publish(const ROSMessageType & msg)
   {
-    TRACEPOINT(
-      rclcpp_publish,
-      static_cast<const void *>(publisher_handle_.get()),
-      static_cast<const void *>(&msg));
+    TRACEPOINT(rclcpp_publish, nullptr, static_cast<const void *>(&msg));
     auto status = rcl_publish(publisher_handle_.get(), &msg, nullptr);
 
     if (RCL_RET_PUBLISHER_INVALID == status) {
@@ -316,7 +470,8 @@ protected:
   }
 
   void
-  do_loaned_message_publish(std::unique_ptr<MessageT, std::function<void(MessageT *)>> msg)
+  do_loaned_message_publish(
+    std::unique_ptr<ROSMessageType, std::function<void(ROSMessageType *)>> msg)
   {
     auto status = rcl_publish_loaned_message(publisher_handle_.get(), msg.get(), nullptr);
 
@@ -336,7 +491,7 @@ protected:
   }
 
   void
-  do_intra_process_publish(std::unique_ptr<MessageT, MessageDeleter> msg)
+  do_intra_process_publish(std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter> msg)
   {
     auto ipm = weak_ipm_.lock();
     if (!ipm) {
@@ -347,14 +502,15 @@ protected:
       throw std::runtime_error("cannot publish msg which is a null pointer");
     }
 
-    ipm->template do_intra_process_publish<MessageT, AllocatorT>(
+    ipm->template do_intra_process_publish<ROSMessageType, AllocatorT>(
       intra_process_publisher_id_,
       std::move(msg),
-      message_allocator_);
+      ros_message_type_allocator_);
   }
 
-  std::shared_ptr<const MessageT>
-  do_intra_process_publish_and_return_shared(std::unique_ptr<MessageT, MessageDeleter> msg)
+  std::shared_ptr<const ROSMessageType>
+  do_intra_process_publish_and_return_shared(
+    std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter> msg)
   {
     auto ipm = weak_ipm_.lock();
     if (!ipm) {
@@ -365,10 +521,29 @@ protected:
       throw std::runtime_error("cannot publish msg which is a null pointer");
     }
 
-    return ipm->template do_intra_process_publish_and_return_shared<MessageT, AllocatorT>(
+    return ipm->template do_intra_process_publish_and_return_shared<ROSMessageType,
+             AllocatorT>(
       intra_process_publisher_id_,
       std::move(msg),
-      message_allocator_);
+      ros_message_type_allocator_);
+  }
+
+  /// Return a new unique_ptr using the ROSMessageType of the publisher.
+  std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>
+  create_ros_message_unique_ptr()
+  {
+    auto ptr = ROSMessageTypeAllocatorTraits::allocate(ros_message_type_allocator_, 1);
+    ROSMessageTypeAllocatorTraits::construct(ros_message_type_allocator_, ptr);
+    return std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>(ptr, ros_message_type_deleter_);
+  }
+
+  /// Duplicate a given ros message as a unique_ptr.
+  std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>
+  duplicate_ros_message_as_unique_ptr(const ROSMessageType & msg)
+  {
+    auto ptr = ROSMessageTypeAllocatorTraits::allocate(ros_message_type_allocator_, 1);
+    ROSMessageTypeAllocatorTraits::construct(ros_message_type_allocator_, ptr, msg);
+    return std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>(ptr, ros_message_type_deleter_);
   }
 
   /// Copy of original options passed during construction.
@@ -378,9 +553,10 @@ protected:
    */
   const rclcpp::PublisherOptionsWithAllocator<AllocatorT> options_;
 
-  std::shared_ptr<MessageAllocator> message_allocator_;
-
-  MessageDeleter message_deleter_;
+  PublishedTypeAllocator published_type_allocator_;
+  PublishedTypeDeleter published_type_deleter_;
+  ROSMessageTypeAllocator ros_message_type_allocator_;
+  ROSMessageTypeDeleter ros_message_type_deleter_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/publisher_base.hpp

@@ -18,6 +18,7 @@
 #include <rmw/error_handling.h>
 #include <rmw/rmw.h>
 
+#include <chrono>
 #include <functional>
 #include <iostream>
 #include <memory>
@@ -33,6 +34,7 @@
 #include "rclcpp/qos_event.hpp"
 #include "rclcpp/type_support_decl.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "rcpputils/time.hpp"
 
 namespace rclcpp
 {
@@ -203,6 +205,46 @@ public:
   std::vector<rclcpp::NetworkFlowEndpoint>
   get_network_flow_endpoints() const;
 
+  /// Wait until all published messages are acknowledged or until the specified timeout elapses.
+  /**
+   * This method waits until all published messages are acknowledged by all matching
+   * subscriptions or the given timeout elapses.
+   *
+   * If the timeout is negative then this method will block indefinitely until all published
+   * messages are acknowledged.
+   * If the timeout is zero then this method will not block, it will check if all published
+   * messages are acknowledged and return immediately.
+   * If the timeout is greater than zero, this method will wait until all published messages are
+   * acknowledged or the timeout elapses.
+   *
+   * This method only waits for acknowledgments if the publisher's QoS profile is RELIABLE.
+   * Otherwise this method will immediately return `true`.
+   *
+   * \param[in] timeout the duration to wait for all published messages to be acknowledged.
+   * \return `true` if all published messages were acknowledged before the given timeout
+   *   elapsed, otherwise `false`.
+   * \throws rclcpp::exceptions::RCLError if middleware doesn't support or internal error occurs
+   * \throws std::invalid_argument if timeout is greater than std::chrono::nanoseconds::max() or
+   *   less than std::chrono::nanoseconds::min()
+   */
+  template<typename DurationRepT = int64_t, typename DurationT = std::milli>
+  bool
+  wait_for_all_acked(
+    std::chrono::duration<DurationRepT, DurationT> timeout =
+    std::chrono::duration<DurationRepT, DurationT>(-1)) const
+  {
+    rcl_duration_value_t rcl_timeout = rcpputils::convert_to_nanoseconds(timeout).count();
+
+    rcl_ret_t ret = rcl_publisher_wait_for_all_acked(publisher_handle_.get(), rcl_timeout);
+    if (ret == RCL_RET_OK) {
+      return true;
+    } else if (ret == RCL_RET_TIMEOUT) {
+      return false;
+    } else {
+      rclcpp::exceptions::throw_from_rcl_error(ret);
+    }
+  }
+
 protected:
   template<typename EventCallbackT>
   void

rclcpp/include/rclcpp/publisher_options.hpp

@@ -17,6 +17,7 @@
 
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <vector>
 
 #include "rcl/publisher.h"
@@ -64,6 +65,10 @@ struct PublisherOptionsBase
 template<typename Allocator>
 struct PublisherOptionsWithAllocator : public PublisherOptionsBase
 {
+  static_assert(
+    std::is_void_v<typename std::allocator_traits<Allocator>::value_type>,
+    "Publisher allocator value type must be void");
+
   /// Optional custom allocator.
   std::shared_ptr<Allocator> allocator = nullptr;
 
@@ -80,7 +85,7 @@ struct PublisherOptionsWithAllocator : public PublisherOptionsBase
   to_rcl_publisher_options(const rclcpp::QoS & qos) const
   {
     rcl_publisher_options_t result = rcl_publisher_get_default_options();
-    result.allocator = rclcpp::allocator::get_rcl_allocator(*this->get_allocator());
+    result.allocator = this->get_rcl_allocator();
     result.qos = qos.get_rmw_qos_profile();
     result.rmw_publisher_options.require_unique_network_flow_endpoints =
       this->require_unique_network_flow_endpoints;
@@ -99,10 +104,35 @@ struct PublisherOptionsWithAllocator : public PublisherOptionsBase
   get_allocator() const
   {
     if (!this->allocator) {
-      return std::make_shared<Allocator>();
+      if (!allocator_storage_) {
+        allocator_storage_ = std::make_shared<Allocator>();
+      }
+      return allocator_storage_;
     }
     return this->allocator;
   }
+
+private:
+  using PlainAllocator =
+    typename std::allocator_traits<Allocator>::template rebind_alloc<char>;
+
+  rcl_allocator_t
+  get_rcl_allocator() const
+  {
+    if (!plain_allocator_storage_) {
+      plain_allocator_storage_ =
+        std::make_shared<PlainAllocator>(*this->get_allocator());
+    }
+    return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
+  }
+
+  // This is a temporal workaround, to make sure that get_allocator()
+  // always returns a copy of the same allocator.
+  mutable std::shared_ptr<Allocator> allocator_storage_;
+
+  // This is a temporal workaround, to keep the plain allocator that backs
+  // up the rcl allocator returned in rcl_publisher_options_t alive.
+  mutable std::shared_ptr<PlainAllocator> plain_allocator_storage_;
 };
 
 using PublisherOptions = PublisherOptionsWithAllocator<std::allocator<void>>;

rclcpp/include/rclcpp/qos_event.hpp

@@ -94,7 +94,7 @@ public:
 
   /// Add the Waitable to a wait set.
   RCLCPP_PUBLIC
-  bool
+  void
   add_to_wait_set(rcl_wait_set_t * wait_set) override;
 
   /// Check if the Waitable is ready.

rclcpp/include/rclcpp/rclcpp.hpp

@@ -140,7 +140,6 @@
  *   - rclcpp/duration.hpp
  *   - rclcpp/function_traits.hpp
  *   - rclcpp/macros.hpp
- *   - rclcpp/scope_exit.hpp
  *   - rclcpp/time.hpp
  *   - rclcpp/utilities.hpp
  *   - rclcpp/typesupport_helpers.hpp

rclcpp/include/rclcpp/scope_exit.hpp

@@ -19,6 +19,10 @@
 #ifndef RCLCPP__SCOPE_EXIT_HPP_
 #define RCLCPP__SCOPE_EXIT_HPP_
 
+// TODO(christophebedard) remove this header completely in I-turtle
+
+#warning rclcpp/scope_exit.hpp has been deprecated, please use rcpputils/scope_exit.hpp instead
+
 #include <functional>
 
 #include "rclcpp/macros.hpp"

rclcpp/include/rclcpp/serialized_message.hpp

@@ -47,7 +47,7 @@ public:
    * \param[in] initial_capacity The amount of memory to be allocated.
    * \param[in] allocator The allocator to be used for the initialization.
    */
-  SerializedMessage(
+  explicit SerializedMessage(
     size_t initial_capacity,
     const rcl_allocator_t & allocator = rcl_get_default_allocator());
 

rclcpp/include/rclcpp/service.hpp

@@ -141,7 +141,9 @@ protected:
 };
 
 template<typename ServiceT>
-class Service : public ServiceBase
+class Service
+  : public ServiceBase,
+  public std::enable_shared_from_this<Service<ServiceT>>
 {
 public:
   using CallbackType = std::function<
@@ -177,25 +179,16 @@ public:
     using rosidl_typesupport_cpp::get_service_type_support_handle;
     auto service_type_support_handle = get_service_type_support_handle<ServiceT>();
 
-    std::weak_ptr<rcl_node_t> weak_node_handle(node_handle_);
     // rcl does the static memory allocation here
     service_handle_ = std::shared_ptr<rcl_service_t>(
-      new rcl_service_t, [weak_node_handle, service_name](rcl_service_t * service)
+      new rcl_service_t, [handle = node_handle_, service_name](rcl_service_t * service)
       {
-        auto handle = weak_node_handle.lock();
-        if (handle) {
-          if (rcl_service_fini(service, handle.get()) != RCL_RET_OK) {
-            RCLCPP_ERROR(
-              rclcpp::get_node_logger(handle.get()).get_child("rclcpp"),
-              "Error in destruction of rcl service handle: %s",
-              rcl_get_error_string().str);
-            rcl_reset_error();
-          }
-        } else {
-          RCLCPP_ERROR_STREAM(
-            rclcpp::get_logger("rclcpp"),
-            "Error in destruction of rcl service handle " << service_name <<
-              ": the Node Handle was destructed too early. You will leak memory");
+        if (rcl_service_fini(service, handle.get()) != RCL_RET_OK) {
+          RCLCPP_ERROR(
+            rclcpp::get_node_logger(handle.get()).get_child("rclcpp"),
+            "Error in destruction of rcl service handle: %s",
+            rcl_get_error_string().str);
+          rcl_reset_error();
         }
         delete service;
       });
@@ -344,9 +337,10 @@ public:
     std::shared_ptr<void> request) override
   {
     auto typed_request = std::static_pointer_cast<typename ServiceT::Request>(request);
-    auto response = std::make_shared<typename ServiceT::Response>();
-    any_callback_.dispatch(request_header, typed_request, response);
-    send_response(*request_header, *response);
+    auto response = any_callback_.dispatch(this->shared_from_this(), request_header, typed_request);
+    if (response) {
+      send_response(*request_header, *response);
+    }
   }
 
   void

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -21,6 +21,7 @@
 #include "rcl/allocator.h"
 
 #include "rclcpp/allocator/allocator_common.hpp"
+#include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
 #include "rclcpp/memory_strategy.hpp"
 #include "rclcpp/node.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -61,17 +62,17 @@ public:
     allocator_ = std::make_shared<VoidAlloc>();
   }
 
-  void add_guard_condition(const rcl_guard_condition_t * guard_condition) override
+  void add_guard_condition(const rclcpp::GuardCondition & guard_condition) override
   {
     for (const auto & existing_guard_condition : guard_conditions_) {
-      if (existing_guard_condition == guard_condition) {
+      if (existing_guard_condition == &guard_condition) {
         return;
       }
     }
-    guard_conditions_.push_back(guard_condition);
+    guard_conditions_.push_back(&guard_condition);
   }
 
-  void remove_guard_condition(const rcl_guard_condition_t * guard_condition) override
+  void remove_guard_condition(const rclcpp::GuardCondition * guard_condition) override
   {
     for (auto it = guard_conditions_.begin(); it != guard_conditions_.end(); ++it) {
       if (*it == guard_condition) {
@@ -240,22 +241,11 @@ public:
     }
 
     for (auto guard_condition : guard_conditions_) {
-      if (rcl_wait_set_add_guard_condition(wait_set, guard_condition, NULL) != RCL_RET_OK) {
-        RCUTILS_LOG_ERROR_NAMED(
-          "rclcpp",
-          "Couldn't add guard_condition to wait set: %s",
-          rcl_get_error_string().str);
-        return false;
-      }
+      detail::add_guard_condition_to_rcl_wait_set(*wait_set, *guard_condition);
     }
 
     for (auto waitable : waitable_handles_) {
-      if (!waitable->add_to_wait_set(wait_set)) {
-        RCUTILS_LOG_ERROR_NAMED(
-          "rclcpp",
-          "Couldn't add waitable to wait set: %s", rcl_get_error_string().str);
-        return false;
-      }
+      waitable->add_to_wait_set(wait_set);
     }
     return true;
   }
@@ -388,6 +378,11 @@ public:
           ++it;
           continue;
         }
+        if (!timer->call()) {
+          // timer was cancelled, skip it.
+          ++it;
+          continue;
+        }
         // Otherwise it is safe to set and return the any_exec
         any_exec.timer = timer;
         any_exec.callback_group = group;
@@ -395,7 +390,7 @@ public:
         timer_handles_.erase(it);
         return;
       }
-      // Else, the service is no longer valid, remove it and continue
+      // Else, the timer is no longer valid, remove it and continue
       it = timer_handles_.erase(it);
     }
   }
@@ -437,7 +432,7 @@ public:
 
   rcl_allocator_t get_allocator() override
   {
-    return rclcpp::allocator::get_rcl_allocator(*allocator_.get());
+    return rclcpp::allocator::get_rcl_allocator<void *, VoidAlloc>(*allocator_.get());
   }
 
   size_t number_of_ready_subscriptions() const override
@@ -504,7 +499,7 @@ private:
   using VectorRebind =
     std::vector<T, typename std::allocator_traits<Alloc>::template rebind_alloc<T>>;
 
-  VectorRebind<const rcl_guard_condition_t *> guard_conditions_;
+  VectorRebind<const rclcpp::GuardCondition *> guard_conditions_;
 
   VectorRebind<std::shared_ptr<const rcl_subscription_t>> subscription_handles_;
   VectorRebind<std::shared_ptr<const rcl_service_t>> service_handles_;

rclcpp/include/rclcpp/subscription.hpp

@@ -60,10 +60,16 @@ class NodeTopicsInterface;
 
 /// Subscription implementation, templated on the type of message this subscription receives.
 template<
-  typename CallbackMessageT,
+  typename MessageT,
   typename AllocatorT = std::allocator<void>,
+  /// MessageT::custom_type if MessageT is a TypeAdapter,
+  /// otherwise just MessageT.
+  typename SubscribedT = typename rclcpp::TypeAdapter<MessageT>::custom_type,
+  /// MessageT::ros_message_type if MessageT is a TypeAdapter,
+  /// otherwise just MessageT.
+  typename ROSMessageT = typename rclcpp::TypeAdapter<MessageT>::ros_message_type,
   typename MessageMemoryStrategyT = rclcpp::message_memory_strategy::MessageMemoryStrategy<
-    CallbackMessageT,
+    ROSMessageT,
     AllocatorT
   >>
 class Subscription : public SubscriptionBase
@@ -71,14 +77,36 @@ class Subscription : public SubscriptionBase
   friend class rclcpp::node_interfaces::NodeTopicsInterface;
 
 public:
-  using MessageAllocatorTraits = allocator::AllocRebind<CallbackMessageT, AllocatorT>;
-  using MessageAllocator = typename MessageAllocatorTraits::allocator_type;
-  using MessageDeleter = allocator::Deleter<MessageAllocator, CallbackMessageT>;
-  using ConstMessageSharedPtr = std::shared_ptr<const CallbackMessageT>;
-  using MessageUniquePtr = std::unique_ptr<CallbackMessageT, MessageDeleter>;
-  using SubscriptionTopicStatisticsSharedPtr =
-    std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>>;
+  // Redeclare these here to use outside of the class.
+  using SubscribedType = SubscribedT;
+  using ROSMessageType = ROSMessageT;
+  using MessageMemoryStrategyType = MessageMemoryStrategyT;
 
+  using SubscribedTypeAllocatorTraits = allocator::AllocRebind<SubscribedType, AllocatorT>;
+  using SubscribedTypeAllocator = typename SubscribedTypeAllocatorTraits::allocator_type;
+  using SubscribedTypeDeleter = allocator::Deleter<SubscribedTypeAllocator, SubscribedType>;
+
+  using ROSMessageTypeAllocatorTraits = allocator::AllocRebind<ROSMessageType, AllocatorT>;
+  using ROSMessageTypeAllocator = typename ROSMessageTypeAllocatorTraits::allocator_type;
+  using ROSMessageTypeDeleter = allocator::Deleter<ROSMessageTypeAllocator, ROSMessageType>;
+
+  using MessageAllocatorTraits [[deprecated("use ROSMessageTypeAllocatorTraits")]] =
+    ROSMessageTypeAllocatorTraits;
+  using MessageAllocator [[deprecated("use ROSMessageTypeAllocator")]] =
+    ROSMessageTypeAllocator;
+  using MessageDeleter [[deprecated("use ROSMessageTypeDeleter")]] =
+    ROSMessageTypeDeleter;
+
+  using ConstMessageSharedPtr [[deprecated]] = std::shared_ptr<const ROSMessageType>;
+  using MessageUniquePtr
+  [[deprecated("use std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter> instead")]] =
+    std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>;
+
+private:
+  using SubscriptionTopicStatisticsSharedPtr =
+    std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<ROSMessageType>>;
+
+public:
   RCLCPP_SMART_PTR_DEFINITIONS(Subscription)
 
   /// Default constructor.
@@ -104,7 +132,7 @@ public:
     const rosidl_message_type_support_t & type_support_handle,
     const std::string & topic_name,
     const rclcpp::QoS & qos,
-    AnySubscriptionCallback<CallbackMessageT, AllocatorT> callback,
+    AnySubscriptionCallback<MessageT, AllocatorT> callback,
     const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options,
     typename MessageMemoryStrategyT::SharedPtr message_memory_strategy,
     SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics = nullptr)
@@ -112,25 +140,25 @@ public:
       node_base,
       type_support_handle,
       topic_name,
-      options.template to_rcl_subscription_options<CallbackMessageT>(qos),
-      rclcpp::subscription_traits::is_serialized_subscription_argument<CallbackMessageT>::value),
+      options.template to_rcl_subscription_options<ROSMessageType>(qos),
+      callback.is_serialized_message_callback()),
     any_callback_(callback),
     options_(options),
     message_memory_strategy_(message_memory_strategy)
   {
-    if (options.event_callbacks.deadline_callback) {
+    if (options_.event_callbacks.deadline_callback) {
       this->add_event_handler(
-        options.event_callbacks.deadline_callback,
+        options_.event_callbacks.deadline_callback,
         RCL_SUBSCRIPTION_REQUESTED_DEADLINE_MISSED);
     }
-    if (options.event_callbacks.liveliness_callback) {
+    if (options_.event_callbacks.liveliness_callback) {
       this->add_event_handler(
-        options.event_callbacks.liveliness_callback,
+        options_.event_callbacks.liveliness_callback,
         RCL_SUBSCRIPTION_LIVELINESS_CHANGED);
     }
-    if (options.event_callbacks.incompatible_qos_callback) {
+    if (options_.event_callbacks.incompatible_qos_callback) {
       this->add_event_handler(
-        options.event_callbacks.incompatible_qos_callback,
+        options_.event_callbacks.incompatible_qos_callback,
         RCL_SUBSCRIPTION_REQUESTED_INCOMPATIBLE_QOS);
     } else if (options_.use_default_callbacks) {
       // Register default callback when not specified
@@ -144,27 +172,27 @@ public:
         // pass
       }
     }
-    if (options.event_callbacks.message_lost_callback) {
+    if (options_.event_callbacks.message_lost_callback) {
       this->add_event_handler(
-        options.event_callbacks.message_lost_callback,
+        options_.event_callbacks.message_lost_callback,
         RCL_SUBSCRIPTION_MESSAGE_LOST);
     }
 
     // Setup intra process publishing if requested.
-    if (rclcpp::detail::resolve_use_intra_process(options, *node_base)) {
+    if (rclcpp::detail::resolve_use_intra_process(options_, *node_base)) {
       using rclcpp::detail::resolve_intra_process_buffer_type;
 
       // Check if the QoS is compatible with intra-process.
-      rmw_qos_profile_t qos_profile = get_actual_qos().get_rmw_qos_profile();
-      if (qos_profile.history == RMW_QOS_POLICY_HISTORY_KEEP_ALL) {
+      auto qos_profile = get_actual_qos();
+      if (qos_profile.history() != rclcpp::HistoryPolicy::KeepLast) {
         throw std::invalid_argument(
-                "intraprocess communication is not allowed with keep all history qos policy");
+                "intraprocess communication allowed only with keep last history qos policy");
       }
-      if (qos_profile.depth == 0) {
+      if (qos_profile.depth() == 0) {
         throw std::invalid_argument(
                 "intraprocess communication is not allowed with 0 depth qos policy");
       }
-      if (qos_profile.durability != RMW_QOS_POLICY_DURABILITY_VOLATILE) {
+      if (qos_profile.durability() != rclcpp::DurabilityPolicy::Volatile) {
         throw std::invalid_argument(
                 "intraprocess communication allowed only with volatile durability");
       }
@@ -173,11 +201,11 @@ public:
       auto context = node_base->get_context();
       subscription_intra_process_ = std::make_shared<SubscriptionIntraProcessT>(
         callback,
-        options.get_allocator(),
+        options_.get_allocator(),
         context,
         this->get_topic_name(),  // important to get like this, as it has the fully-qualified name
         qos_profile,
-        resolve_intra_process_buffer_type(options.intra_process_buffer_type, callback));
+        resolve_intra_process_buffer_type(options_.intra_process_buffer_type, callback));
       TRACEPOINT(
         rclcpp_subscription_init,
         static_cast<const void *>(get_subscription_handle().get()),
@@ -241,11 +269,34 @@ public:
    * \throws any rcl errors from rcl_take, \sa rclcpp::exceptions::throw_from_rcl_error()
    */
   bool
-  take(CallbackMessageT & message_out, rclcpp::MessageInfo & message_info_out)
+  take(ROSMessageType & message_out, rclcpp::MessageInfo & message_info_out)
   {
     return this->take_type_erased(static_cast<void *>(&message_out), message_info_out);
   }
 
+  /// Take the next message from the inter-process subscription.
+  /**
+   * This verison takes a SubscribedType which is different frmo the
+   * ROSMessageType when a rclcpp::TypeAdapter is in used.
+   *
+   * \sa take(ROSMessageType &, rclcpp::MessageInfo &)
+   */
+  template<typename TakeT>
+  std::enable_if_t<
+    !rosidl_generator_traits::is_message<TakeT>::value &&
+    std::is_same_v<TakeT, SubscribedType>,
+    bool
+  >
+  take(TakeT & message_out, rclcpp::MessageInfo & message_info_out)
+  {
+    ROSMessageType local_message;
+    bool taken = this->take_type_erased(static_cast<void *>(&local_message), message_info_out);
+    if (taken) {
+      rclcpp::TypeAdapter<MessageT>::convert_to_custom(local_message, message_out);
+    }
+    return taken;
+  }
+
   std::shared_ptr<void>
   create_message() override
   {
@@ -272,7 +323,7 @@ public:
       // we should ignore this copy of the message.
       return;
     }
-    auto typed_message = std::static_pointer_cast<CallbackMessageT>(message);
+    auto typed_message = std::static_pointer_cast<ROSMessageType>(message);
 
     std::chrono::time_point<std::chrono::system_clock> now;
     if (subscription_topic_statistics_) {
@@ -290,15 +341,24 @@ public:
     }
   }
 
+  void
+  handle_serialized_message(
+    const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
+    const rclcpp::MessageInfo & message_info) override
+  {
+    // TODO(wjwwood): enable topic statistics for serialized messages
+    any_callback_.dispatch(serialized_message, message_info);
+  }
+
   void
   handle_loaned_message(
     void * loaned_message,
     const rclcpp::MessageInfo & message_info) override
   {
-    auto typed_message = static_cast<CallbackMessageT *>(loaned_message);
+    auto typed_message = static_cast<ROSMessageType *>(loaned_message);
     // message is loaned, so we have to make sure that the deleter does not deallocate the message
-    auto sptr = std::shared_ptr<CallbackMessageT>(
-      typed_message, [](CallbackMessageT * msg) {(void) msg;});
+    auto sptr = std::shared_ptr<ROSMessageType>(
+      typed_message, [](ROSMessageType * msg) {(void) msg;});
     any_callback_.dispatch(sptr, message_info);
   }
 
@@ -309,7 +369,7 @@ public:
   void
   return_message(std::shared_ptr<void> & message) override
   {
-    auto typed_message = std::static_pointer_cast<CallbackMessageT>(message);
+    auto typed_message = std::static_pointer_cast<ROSMessageType>(message);
     message_memory_strategy_->return_message(typed_message);
   }
 
@@ -332,21 +392,24 @@ public:
 private:
   RCLCPP_DISABLE_COPY(Subscription)
 
-  AnySubscriptionCallback<CallbackMessageT, AllocatorT> any_callback_;
+  AnySubscriptionCallback<MessageT, AllocatorT> any_callback_;
   /// 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 subscription.
    */
   const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> options_;
-  typename message_memory_strategy::MessageMemoryStrategy<CallbackMessageT, AllocatorT>::SharedPtr
+  typename message_memory_strategy::MessageMemoryStrategy<ROSMessageType, AllocatorT>::SharedPtr
     message_memory_strategy_;
+
   /// Component which computes and publishes topic statistics for this subscriber
   SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics_{nullptr};
+
   using SubscriptionIntraProcessT = rclcpp::experimental::SubscriptionIntraProcess<
-    CallbackMessageT,
+    ROSMessageType,
     AllocatorT,
-    typename MessageUniquePtr::deleter_type>;
+    ROSMessageTypeDeleter,
+    MessageT>;
   std::shared_ptr<SubscriptionIntraProcessT> subscription_intra_process_;
 };
 

rclcpp/include/rclcpp/subscription_base.hpp

@@ -107,7 +107,7 @@ public:
   /// 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
+   * can only be resolved after the creation of the subscription, 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.
@@ -183,6 +183,13 @@ public:
   void
   handle_message(std::shared_ptr<void> & message, const rclcpp::MessageInfo & message_info) = 0;
 
+  RCLCPP_PUBLIC
+  virtual
+  void
+  handle_serialized_message(
+    const std::shared_ptr<rclcpp::SerializedMessage> & serialized_message,
+    const rclcpp::MessageInfo & message_info) = 0;
+
   RCLCPP_PUBLIC
   virtual
   void

rclcpp/include/rclcpp/subscription_factory.hpp

@@ -25,6 +25,7 @@
 #include "rosidl_typesupport_cpp/message_type_support.hpp"
 
 #include "rclcpp/any_subscription_callback.hpp"
+#include "rclcpp/get_message_type_support_handle.hpp"
 #include "rclcpp/intra_process_buffer_type.hpp"
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/qos.hpp"
@@ -74,26 +75,23 @@ template<
   typename MessageT,
   typename CallbackT,
   typename AllocatorT,
-  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 SubscriptionT = rclcpp::Subscription<MessageT, AllocatorT>,
+  typename MessageMemoryStrategyT = typename SubscriptionT::MessageMemoryStrategyType,
+  typename ROSMessageType = typename SubscriptionT::ROSMessageType
+>
 SubscriptionFactory
 create_subscription_factory(
   CallbackT && callback,
   const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options,
   typename MessageMemoryStrategyT::SharedPtr msg_mem_strat,
-  std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>>
+  std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<ROSMessageType>>
   subscription_topic_stats = nullptr
 )
 {
   auto allocator = options.get_allocator();
 
   using rclcpp::AnySubscriptionCallback;
-  AnySubscriptionCallback<CallbackMessageT, AllocatorT> any_subscription_callback(*allocator);
+  AnySubscriptionCallback<MessageT, AllocatorT> any_subscription_callback(*allocator);
   any_subscription_callback.set(std::forward<CallbackT>(callback));
 
   SubscriptionFactory factory {
@@ -107,9 +105,9 @@ create_subscription_factory(
       using rclcpp::Subscription;
       using rclcpp::SubscriptionBase;
 
-      auto sub = Subscription<CallbackMessageT, AllocatorT>::make_shared(
+      auto sub = Subscription<MessageT, AllocatorT>::make_shared(
         node_base,
-        *rosidl_typesupport_cpp::get_message_type_support_handle<MessageT>(),
+        rclcpp::get_message_type_support_handle<MessageT>(),
         topic_name,
         qos,
         any_subscription_callback,

rclcpp/include/rclcpp/subscription_options.hpp

@@ -18,6 +18,7 @@
 #include <chrono>
 #include <memory>
 #include <string>
+#include <type_traits>
 #include <vector>
 
 #include "rclcpp/callback_group.hpp"
@@ -86,6 +87,10 @@ struct SubscriptionOptionsBase
 template<typename Allocator>
 struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
 {
+  static_assert(
+    std::is_void_v<typename std::allocator_traits<Allocator>::value_type>,
+    "Subscription allocator value type must be void");
+
   /// Optional custom allocator.
   std::shared_ptr<Allocator> allocator = nullptr;
 
@@ -107,7 +112,7 @@ struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
   to_rcl_subscription_options(const rclcpp::QoS & qos) const
   {
     rcl_subscription_options_t result = rcl_subscription_get_default_options();
-    result.allocator = rclcpp::allocator::get_rcl_allocator(*this->get_allocator());
+    result.allocator = this->get_rcl_allocator();
     result.qos = qos.get_rmw_qos_profile();
     result.rmw_subscription_options.ignore_local_publications = this->ignore_local_publications;
     result.rmw_subscription_options.require_unique_network_flow_endpoints =
@@ -121,15 +126,39 @@ struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
     return result;
   }
 
-  /// Get the allocator, creating one if needed.
   std::shared_ptr<Allocator>
   get_allocator() const
   {
     if (!this->allocator) {
-      return std::make_shared<Allocator>();
+      if (!allocator_storage_) {
+        allocator_storage_ = std::make_shared<Allocator>();
+      }
+      return allocator_storage_;
     }
     return this->allocator;
   }
+
+private:
+  using PlainAllocator =
+    typename std::allocator_traits<Allocator>::template rebind_alloc<char>;
+
+  rcl_allocator_t
+  get_rcl_allocator() const
+  {
+    if (!plain_allocator_storage_) {
+      plain_allocator_storage_ =
+        std::make_shared<PlainAllocator>(*this->get_allocator());
+    }
+    return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
+  }
+
+  // This is a temporal workaround, to make sure that get_allocator()
+  // always returns a copy of the same allocator.
+  mutable std::shared_ptr<Allocator> allocator_storage_;
+
+  // This is a temporal workaround, to keep the plain allocator that backs
+  // up the rcl allocator returned in rcl_subscription_options_t alive.
+  mutable std::shared_ptr<PlainAllocator> plain_allocator_storage_;
 };
 
 using SubscriptionOptions = SubscriptionOptionsWithAllocator<std::allocator<void>>;

rclcpp/include/rclcpp/time_source.hpp

@@ -74,14 +74,22 @@ public:
     const rclcpp::QoS & qos = rclcpp::ClockQoS(),
     bool use_clock_thread = true);
 
-  /// Attack node to the time source.
+  // The TimeSource is uncopyable
+  TimeSource(const TimeSource &) = delete;
+  TimeSource & operator=(const TimeSource &) = delete;
+
+  // The TimeSource is moveable
+  TimeSource(TimeSource &&) = default;
+  TimeSource & operator=(TimeSource &&) = default;
+
+  /// Attach node to the time source.
   /**
    * \param node std::shared pointer to a initialized node
    */
   RCLCPP_PUBLIC
   void attachNode(rclcpp::Node::SharedPtr node);
 
-  /// Attack node to the time source.
+  /// Attach node to the time source.
   /**
    * If the parameter `use_sim_time` is `true` then the source time is the simulation time,
    * otherwise the source time is defined by the system.
@@ -116,89 +124,36 @@ public:
   RCLCPP_PUBLIC
   void attachClock(rclcpp::Clock::SharedPtr clock);
 
-  /// Detach a clock to the time source
+  /// Detach a clock from the time source
   RCLCPP_PUBLIC
   void detachClock(rclcpp::Clock::SharedPtr clock);
 
+  /// Get whether a separate clock thread is used or not
+  RCLCPP_PUBLIC
+  bool get_use_clock_thread();
+
+  /// Set whether to use a separate clock thread or not
+  RCLCPP_PUBLIC
+  void set_use_clock_thread(bool use_clock_thread);
+
+  /// Check if the clock thread is joinable
+  RCLCPP_PUBLIC
+  bool clock_thread_is_joinable();
+
   /// TimeSource Destructor
   RCLCPP_PUBLIC
   ~TimeSource();
 
-protected:
-  // Dedicated thread for clock subscription.
-  bool use_clock_thread_;
-  std::thread clock_executor_thread_;
-
 private:
-  // Preserve the node reference
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_;
-  rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_;
-  rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_;
-  rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_;
-  rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging_;
-  rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock_;
-  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters_;
+  class ClocksState;
+  std::shared_ptr<ClocksState> clocks_state_;
 
-  // Store (and update on node attach) logger for logging.
-  Logger logger_;
+  class NodeState;
+  std::shared_ptr<NodeState> node_state_;
 
-  // QoS of the clock subscription.
-  rclcpp::QoS qos_;
-
-  // The subscription for the clock callback
-  using MessageT = rosgraph_msgs::msg::Clock;
-  using Alloc = std::allocator<void>;
-  using SubscriptionT = rclcpp::Subscription<MessageT, Alloc>;
-  std::shared_ptr<SubscriptionT> clock_subscription_{nullptr};
-  std::mutex clock_sub_lock_;
-  rclcpp::CallbackGroup::SharedPtr clock_callback_group_;
-  rclcpp::executors::SingleThreadedExecutor::SharedPtr clock_executor_;
-  std::promise<void> cancel_clock_executor_promise_;
-
-  // The clock callback itself
-  void clock_cb(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg);
-
-  // Create the subscription for the clock topic
-  void create_clock_sub();
-
-  // Destroy the subscription for the clock topic
-  void destroy_clock_sub();
-
-  // Parameter Event subscription
-  using ParamMessageT = rcl_interfaces::msg::ParameterEvent;
-  using ParamSubscriptionT = rclcpp::Subscription<ParamMessageT, Alloc>;
-  std::shared_ptr<ParamSubscriptionT> parameter_subscription_;
-
-  // Callback for parameter updates
-  void on_parameter_event(std::shared_ptr<const rcl_interfaces::msg::ParameterEvent> event);
-
-  // An enum to hold the parameter state
-  enum UseSimTimeParameterState {UNSET, SET_TRUE, SET_FALSE};
-  UseSimTimeParameterState parameter_state_;
-
-  // An internal method to use in the clock callback that iterates and enables all clocks
-  void enable_ros_time();
-  // An internal method to use in the clock callback that iterates and disables all clocks
-  void disable_ros_time();
-
-  // Internal helper functions used inside iterators
-  static void set_clock(
-    const builtin_interfaces::msg::Time::SharedPtr msg,
-    bool set_ros_time_enabled,
-    rclcpp::Clock::SharedPtr clock);
-
-  // Local storage of validity of ROS time
-  // This is needed when new clocks are added.
-  bool ros_time_active_{false};
-  // Last set message to be passed to newly registered clocks
-  std::shared_ptr<const rosgraph_msgs::msg::Clock> last_msg_set_;
-
-  // A lock to protect iterating the associated_clocks_ field.
-  std::mutex clock_list_lock_;
-  // A vector to store references to associated clocks.
-  std::vector<rclcpp::Clock::SharedPtr> associated_clocks_;
-  // A handler for the use_sim_time parameter callback.
-  rclcpp::node_interfaces::OnSetParametersCallbackHandle::SharedPtr sim_time_cb_handler_{nullptr};
+  // Preserve the arguments received by the constructor for reuse at runtime
+  bool constructed_use_clock_thread_;
+  rclcpp::QoS constructed_qos_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/timer.hpp

@@ -91,6 +91,17 @@ public:
   void
   reset();
 
+  /// Indicate that we're about to execute the callback.
+  /**
+   * The multithreaded executor takes advantage of this to avoid scheduling
+   * the callback multiple times.
+   *
+   * \return `true` if the callback should be executed, `false` if the timer was canceled.
+   */
+  RCLCPP_PUBLIC
+  virtual bool
+  call() = 0;
+
   /// Call the callback function when the timer signal is emitted.
   RCLCPP_PUBLIC
   virtual void
@@ -192,19 +203,28 @@ public:
   }
 
   /**
-   * \sa rclcpp::TimerBase::execute_callback
-   * \throws std::runtime_error if it failed to notify timer that callback occurred
+   * \sa rclcpp::TimerBase::call
+   * \throws std::runtime_error if it failed to notify timer that callback will occurr
    */
-  void
-  execute_callback() override
+  bool
+  call() override
   {
     rcl_ret_t ret = rcl_timer_call(timer_handle_.get());
     if (ret == RCL_RET_TIMER_CANCELED) {
-      return;
+      return false;
     }
     if (ret != RCL_RET_OK) {
       throw std::runtime_error("Failed to notify timer that callback occurred");
     }
+    return true;
+  }
+
+  /**
+   * \sa rclcpp::TimerBase::execute_callback
+   */
+  void
+  execute_callback() override
+  {
     TRACEPOINT(callback_start, static_cast<const void *>(&callback_), false);
     execute_callback_delegate<>();
     TRACEPOINT(callback_end, static_cast<const void *>(&callback_));

rclcpp/include/rclcpp/type_adapter.hpp

@@ -0,0 +1,201 @@
+// Copyright 2021 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__TYPE_ADAPTER_HPP_
+#define RCLCPP__TYPE_ADAPTER_HPP_
+
+#include <type_traits>
+
+namespace rclcpp
+{
+
+/// Template structure used to adapt custom, user-defined types to ROS types.
+/**
+ * Adapting a custom, user-defined type to a ROS type allows that custom type
+ * to be used when publishing and subscribing in ROS.
+ *
+ * In order to adapt a custom type to a ROS type, the user must create a
+ * template specialization of this structure for the custom type.
+ * In that specialization they must:
+ *
+ *   - change `is_specialized` to `std::true_type`,
+ *   - specify the custom type with `using custom_type = ...`,
+ *   - specify the ROS type with `using ros_message_type = ...`,
+ *   - provide static convert functions with the signatures:
+ *     - static void convert_to_ros(const custom_type &, ros_message_type &)
+ *     - static void convert_to_custom(const ros_message_type &, custom_type &)
+ *
+ * The convert functions must convert from one type to the other.
+ *
+ * For example, here is a theoretical example for adapting `std::string` to the
+ * `std_msgs::msg::String` ROS message type:
+ *
+ *     template<>
+ *     struct rclcpp::TypeAdapter<std::string, std_msgs::msg::String>
+ *     {
+ *       using is_specialized = std::true_type;
+ *       using custom_type = std::string;
+ *       using ros_message_type = std_msgs::msg::String;
+ *
+ *       static
+ *       void
+ *       convert_to_ros_message(
+ *         const custom_type & source,
+ *         ros_message_type & destination)
+ *       {
+ *         destination.data = source;
+ *       }
+ *
+ *       static
+ *       void
+ *       convert_to_custom(
+ *         const ros_message_type & source,
+ *         custom_type & destination)
+ *       {
+ *         destination = source.data;
+ *       }
+ *     };
+ *
+ * The adapter can then be used when creating a publisher or subscription,
+ * e.g.:
+ *
+ *     using MyAdaptedType = TypeAdapter<std::string, std_msgs::msg::String>;
+ *     auto pub = node->create_publisher<MyAdaptedType>("topic", 10);
+ *     auto sub = node->create_subscription<MyAdaptedType>(
+ *       "topic",
+ *       10,
+ *       [](const std::string & msg) {...});
+ *
+ * You can also be more declarative by using the adapt_type::as metafunctions,
+ * which are a bit less ambiguous to read:
+ *
+ *     using AdaptedType = rclcpp::adapt_type<std::string>::as<std_msgs::msg::String>;
+ *     auto pub = node->create_publisher<AdaptedType>(...);
+ *
+ * If you wish, you may associate a custom type with a single ROS message type,
+ * allowing you to be a bit more brief when creating entities, e.g.:
+ *
+ *     // First you must declare the association, this is similar to how you
+ *     // would avoid using the namespace in C++ by doing `using std::vector;`.
+ *     RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE(std::string, std_msgs::msg::String);
+ *
+ *     // Then you can create things with just the custom type, and the ROS
+ *     // message type is implied based on the previous statement.
+ *     auto pub = node->create_publisher<std::string>(...);
+ */
+template<typename CustomType, typename ROSMessageType = void, class Enable = void>
+struct TypeAdapter
+{
+  using is_specialized = std::false_type;
+  using custom_type = CustomType;
+  // In this case, the CustomType is the only thing given, or there is no specialization.
+  // Assign ros_message_type to CustomType for the former case.
+  using ros_message_type = CustomType;
+};
+
+/// Helper template to determine if a type is a TypeAdapter, false specialization.
+template<typename T>
+struct is_type_adapter : std::false_type {};
+
+/// Helper template to determine if a type is a TypeAdapter, true specialization.
+template<typename ... Ts>
+struct is_type_adapter<TypeAdapter<Ts...>>: std::true_type {};
+
+/// Identity specialization for TypeAdapter.
+template<typename T>
+struct TypeAdapter<T, void, std::enable_if_t<is_type_adapter<T>::value>>: T {};
+
+namespace detail
+{
+
+template<typename CustomType, typename ROSMessageType>
+struct assert_type_pair_is_specialized_type_adapter
+{
+  using type_adapter = TypeAdapter<CustomType, ROSMessageType>;
+  static_assert(
+    type_adapter::is_specialized::value,
+    "No type adapter for this custom type/ros message type pair");
+};
+
+}  // namespace detail
+
+/// Template metafunction that can make the type being adapted explicit.
+template<typename CustomType>
+struct adapt_type
+{
+  template<typename ROSMessageType>
+  using as = typename ::rclcpp::detail::assert_type_pair_is_specialized_type_adapter<
+    CustomType,
+    ROSMessageType
+    >::type_adapter;
+};
+
+/// Implicit type adapter used as a short hand way to create something with just the custom type.
+/**
+ * This is used when creating a publisher or subscription using just the custom
+ * type in conjunction with RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE().
+ * For example:
+ *
+ *     #include "type_adapter_for_std_string_to_std_msgs_String.hpp"
+ *
+ *     RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE(std::string, std_msgs::msg::String);
+ *
+ *     int main(...) {
+ *       // ...
+ *       auto pub = node->create_publisher<std::string>(...);
+ *     }
+ *
+ * \sa TypeAdapter for more examples.
+ */
+template<typename CustomType>
+struct ImplicitTypeAdapter
+{
+  using is_specialized = std::false_type;
+};
+
+/// Specialization of TypeAdapter for ImplicitTypeAdapter.
+/**
+ * This allows for things like this:
+ *
+ *    RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE(std::string, std_msgs::msg::String);
+ *    auto pub = node->create_publisher<std::string>("topic", 10);
+ *
+ */
+template<typename T>
+struct TypeAdapter<T, void, std::enable_if_t<ImplicitTypeAdapter<T>::is_specialized::value>>
+  : ImplicitTypeAdapter<T>
+{};
+
+/// Assigns the custom type implicitly to the given custom type/ros message type pair.
+/**
+ * Note: this macro needs to be used in the root namespace.
+ * We cannot use ::rclcpp to protect against this, due to how GCC interprets the
+ * syntax, see: https://stackoverflow.com/a/2781537
+ *
+ * \sa TypeAdapter
+ * \sa ImplicitTypeAdapter
+ */
+#define RCLCPP_USING_CUSTOM_TYPE_AS_ROS_MESSAGE_TYPE(CustomType, ROSMessageType) \
+  template<> \
+  struct rclcpp::ImplicitTypeAdapter<CustomType> \
+    : public rclcpp::TypeAdapter<CustomType, ROSMessageType> \
+  { \
+    static_assert( \
+      is_specialized::value, \
+      "Cannot use custom type as ros type when there is no TypeAdapter for that pair"); \
+  }
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__TYPE_ADAPTER_HPP_

rclcpp/include/rclcpp/utilities.hpp

@@ -42,6 +42,20 @@ std::string to_string(T value)
 
 namespace rclcpp
 {
+
+/// Option to indicate which signal handlers rclcpp should install.
+enum class SignalHandlerOptions
+{
+  /// Install both sigint and sigterm, this is the default behavior.
+  All,
+  /// Install only a sigint handler.
+  SigInt,
+  /// Install only a sigterm handler.
+  SigTerm,
+  /// Do not install any signal handler.
+  None,
+};
+
 /// Initialize communications via the rmw implementation and set up a global signal handler.
 /**
  * Initializes the global context which is accessible via the function
@@ -50,10 +64,16 @@ namespace rclcpp
  * rclcpp::install_signal_handlers().
  *
  * \sa rclcpp::Context::init() for more details on arguments and possible exceptions
+ *
+ * \param signal_handler_options option to indicate which signal handlers should be installed.
  */
 RCLCPP_PUBLIC
 void
-init(int argc, char const * const argv[], const InitOptions & init_options = InitOptions());
+init(
+  int argc,
+  char const * const argv[],
+  const InitOptions & init_options = InitOptions(),
+  SignalHandlerOptions signal_handler_options = SignalHandlerOptions::All);
 
 /// Install the global signal handler for rclcpp.
 /**
@@ -67,17 +87,26 @@ init(int argc, char const * const argv[], const InitOptions & init_options = Ini
  *
  * This function is thread-safe.
  *
+ * \param signal_handler_options option to indicate which signal handlers should be installed.
  * \return true if signal handler was installed by this function, false if already installed.
  */
 RCLCPP_PUBLIC
 bool
-install_signal_handlers();
+install_signal_handlers(SignalHandlerOptions signal_handler_options = SignalHandlerOptions::All);
 
 /// Return true if the signal handlers are installed, otherwise false.
 RCLCPP_PUBLIC
 bool
 signal_handlers_installed();
 
+/// Get the current signal handler options.
+/**
+ * If no signal handler is installed, SignalHandlerOptions::None is returned.
+ */
+RCLCPP_PUBLIC
+SignalHandlerOptions
+get_current_signal_handler_options();
+
 /// Uninstall the global signal handler for rclcpp.
 /**
  * This function does not necessarily need to be called, but can be used to

rclcpp/include/rclcpp/wait_for_message.hpp

@@ -0,0 +1,100 @@
+// Copyright 2021 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__WAIT_FOR_MESSAGE_HPP_
+#define RCLCPP__WAIT_FOR_MESSAGE_HPP_
+
+#include <memory>
+#include <string>
+
+#include "rclcpp/node.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rclcpp/wait_set.hpp"
+
+namespace rclcpp
+{
+/// Wait for the next incoming message.
+/**
+ * Given an already initialized subscription,
+ * wait for the next incoming message to arrive before the specified timeout.
+ *
+ * \param[out] out is the message to be filled when a new message is arriving.
+ * \param[in] subscription shared pointer to a previously initialized subscription.
+ * \param[in] context shared pointer to a context to watch for SIGINT requests.
+ * \param[in] time_to_wait parameter specifying the timeout before returning.
+ * \return true if a message was successfully received, false if message could not
+ * be obtained or shutdown was triggered asynchronously on the context.
+ */
+template<class MsgT, class Rep = int64_t, class Period = std::milli>
+bool wait_for_message(
+  MsgT & out,
+  std::shared_ptr<rclcpp::Subscription<MsgT>> subscription,
+  std::shared_ptr<rclcpp::Context> context,
+  std::chrono::duration<Rep, Period> time_to_wait = std::chrono::duration<Rep, Period>(-1))
+{
+  auto gc = std::make_shared<rclcpp::GuardCondition>(context);
+  auto shutdown_callback_handle = context->add_on_shutdown_callback(
+    [weak_gc = std::weak_ptr<rclcpp::GuardCondition>{gc}]() {
+      auto strong_gc = weak_gc.lock();
+      if (strong_gc) {
+        strong_gc->trigger();
+      }
+    });
+
+  rclcpp::WaitSet wait_set;
+  wait_set.add_subscription(subscription);
+  wait_set.add_guard_condition(gc);
+  auto ret = wait_set.wait(time_to_wait);
+  if (ret.kind() != rclcpp::WaitResultKind::Ready) {
+    return false;
+  }
+
+  if (wait_set.get_rcl_wait_set().guard_conditions[0]) {
+    return false;
+  }
+
+  rclcpp::MessageInfo info;
+  if (!subscription->take(out, info)) {
+    return false;
+  }
+
+  return true;
+}
+
+/// Wait for the next incoming message.
+/**
+ * Wait for the next incoming message to arrive on a specified topic before the specified timeout.
+ *
+ * \param[out] out is the message to be filled when a new message is arriving.
+ * \param[in] node the node pointer to initialize the subscription on.
+ * \param[in] topic the topic to wait for messages.
+ * \param[in] time_to_wait parameter specifying the timeout before returning.
+ * \return true if a message was successfully received, false if message could not
+ * be obtained or shutdown was triggered asynchronously on the context.
+ */
+template<class MsgT, class Rep = int64_t, class Period = std::milli>
+bool wait_for_message(
+  MsgT & out,
+  rclcpp::Node::SharedPtr node,
+  const std::string & topic,
+  std::chrono::duration<Rep, Period> time_to_wait = std::chrono::duration<Rep, Period>(-1))
+{
+  auto sub = node->create_subscription<MsgT>(topic, 1, [](const std::shared_ptr<const MsgT>) {});
+  return wait_for_message<MsgT, Rep, Period>(
+    out, sub, node->get_node_options().context(), time_to_wait);
+}
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__WAIT_FOR_MESSAGE_HPP_

rclcpp/include/rclcpp/wait_set_policies/detail/storage_policy_common.hpp

@@ -383,10 +383,7 @@ protected:
         continue;
       }
       rclcpp::Waitable & waitable = *waitable_ptr_pair.second;
-      bool successful = waitable.add_to_wait_set(&rcl_wait_set_);
-      if (!successful) {
-        throw std::runtime_error("waitable unexpectedly failed to be added to wait set");
-      }
+      waitable.add_to_wait_set(&rcl_wait_set_);
     }
   }
 

rclcpp/include/rclcpp/wait_set_policies/sequential_synchronization.hpp

@@ -203,7 +203,7 @@ protected:
     std::shared_ptr<rclcpp::Waitable> && waitable,
     std::shared_ptr<void> && associated_entity,
     std::function<
-      void(std::shared_ptr<rclcpp::Waitable>&&, std::shared_ptr<void>&&)
+      void(std::shared_ptr<rclcpp::Waitable>&&, std::shared_ptr<void> &&)
     > add_waitable_function)
   {
     // Explicitly no thread synchronization.

rclcpp/include/rclcpp/wait_set_policies/thread_safe_synchronization.hpp

@@ -216,7 +216,7 @@ protected:
     std::shared_ptr<rclcpp::Waitable> && waitable,
     std::shared_ptr<void> && associated_entity,
     std::function<
-      void(std::shared_ptr<rclcpp::Waitable>&&, std::shared_ptr<void>&&)
+      void(std::shared_ptr<rclcpp::Waitable>&&, std::shared_ptr<void> &&)
     > add_waitable_function)
   {
     using rclcpp::wait_set_policies::detail::WritePreferringReadWriteLock;

rclcpp/include/rclcpp/wait_set_template.hpp

@@ -20,13 +20,13 @@
 #include <utility>
 
 #include "rcl/wait.h"
+#include "rcpputils/scope_exit.hpp"
 
 #include "rclcpp/client.hpp"
 #include "rclcpp/context.hpp"
 #include "rclcpp/contexts/default_context.hpp"
 #include "rclcpp/guard_condition.hpp"
 #include "rclcpp/macros.hpp"
-#include "rclcpp/scope_exit.hpp"
 #include "rclcpp/service.hpp"
 #include "rclcpp/subscription_base.hpp"
 #include "rclcpp/subscription_wait_set_mask.hpp"
@@ -657,7 +657,7 @@ public:
 
     // ensure the ownership of the entities in the wait set is shared for the duration of wait
     this->storage_acquire_ownerships();
-    RCLCPP_SCOPE_EXIT({this->storage_release_ownerships();});
+    RCPPUTILS_SCOPE_EXIT({this->storage_release_ownerships();});
 
     // this method comes from the SynchronizationPolicy
     return this->template sync_wait<WaitResult<WaitSetTemplate>>(

rclcpp/include/rclcpp/waitable.hpp

@@ -103,12 +103,11 @@ public:
   /// Add the Waitable to a wait set.
   /**
    * \param[in] wait_set A handle to the wait set to add the Waitable to.
-   * \return `true` if the Waitable is added successfully, `false` otherwise.
    * \throws rclcpp::execptions::RCLError from rcl_wait_set_add_*()
    */
   RCLCPP_PUBLIC
   virtual
-  bool
+  void
   add_to_wait_set(rcl_wait_set_t * wait_set) = 0;
 
   /// Check if the Waitable is ready.
@@ -145,8 +144,7 @@ public:
    * ```cpp
    * // ... create a wait set and a Waitable
    * // Add the Waitable to the wait set
-   * bool add_ret = waitable.add_to_wait_set(wait_set);
-   * // ... error handling
+   * waitable.add_to_wait_set(wait_set);
    * // Wait
    * rcl_ret_t wait_ret = rcl_wait(wait_set);
    * // ... error handling
@@ -172,8 +170,7 @@ public:
    * ```cpp
    * // ... create a wait set and a Waitable
    * // Add the Waitable to the wait set
-   * bool add_ret = waitable.add_to_wait_set(wait_set);
-   * // ... error handling
+   * waitable.add_to_wait_set(wait_set);
    * // Wait
    * rcl_ret_t wait_ret = rcl_wait(wait_set);
    * // ... error handling

rclcpp/package.xml

@@ -2,15 +2,17 @@
 <?xml-model href="http://download.ros.org/schema/package_format2.xsd" schematypens="http://www.w3.org/2001/XMLSchema"?>
 <package format="2">
   <name>rclcpp</name>
-  <version>9.0.2</version>
+  <version>14.1.0</version>
   <description>The ROS client library in C++.</description>
   <maintainer email="ivanpauno@ekumenlabs.com">Ivan Paunovic</maintainer>
-  <maintainer email="mabel@openrobotics.org">Mabel Zhang</maintainer>
+  <maintainer email="jacob@openrobotics.org">Jacob Perron</maintainer>
   <maintainer email="william@openrobotics.org">William Woodall</maintainer>
   <license>Apache License 2.0</license>
   <author email="dthomas@openrobotics.org">Dirk Thomas</author>
 
   <buildtool_depend>ament_cmake_ros</buildtool_depend>
+  <buildtool_depend>ament_cmake_gen_version_h</buildtool_depend>
+  <buildtool_depend>python3</buildtool_depend>
 
   <build_depend>ament_index_cpp</build_depend>
   <build_depend>builtin_interfaces</build_depend>

rclcpp/resource/logging.hpp.em

@@ -149,7 +149,7 @@ def get_rclcpp_suffix_from_features(features):
 @[ if params]@
 @(''.join(['      ' + p + ', \\\n' for p in params if p != stream_arg]))@
 @[ end if]@
-      logger.get_name(), \
+      (logger).get_name(), \
 @[ if 'stream' not in feature_combination]@
       __VA_ARGS__); \
 @[ else]@

rclcpp/src/rclcpp/clock.cpp

@@ -14,11 +14,14 @@
 
 #include "rclcpp/clock.hpp"
 
+#include <condition_variable>
 #include <memory>
 #include <thread>
 
 #include "rclcpp/exceptions.hpp"
+#include "rclcpp/utilities.hpp"
 
+#include "rcpputils/scope_exit.hpp"
 #include "rcutils/logging_macros.h"
 
 namespace rclcpp
@@ -76,6 +79,109 @@ Clock::now()
   return now;
 }
 
+bool
+Clock::sleep_until(Time until, Context::SharedPtr context)
+{
+  if (!context || !context->is_valid()) {
+    throw std::runtime_error("context cannot be slept with because it's invalid");
+  }
+  const auto this_clock_type = get_clock_type();
+  if (until.get_clock_type() != this_clock_type) {
+    throw std::runtime_error("until's clock type does not match this clock's type");
+  }
+  bool time_source_changed = false;
+
+  std::condition_variable cv;
+
+  // Wake this thread if the context is shutdown
+  rclcpp::OnShutdownCallbackHandle shutdown_cb_handle = context->add_on_shutdown_callback(
+    [&cv]() {
+      cv.notify_one();
+    });
+  // No longer need the shutdown callback when this function exits
+  auto callback_remover = rcpputils::scope_exit(
+    [context, &shutdown_cb_handle]() {
+      context->remove_on_shutdown_callback(shutdown_cb_handle);
+    });
+
+  if (this_clock_type == RCL_STEADY_TIME) {
+    // Synchronize because RCL steady clock epoch might differ from chrono::steady_clock epoch
+    const Time rcl_entry = now();
+    const std::chrono::steady_clock::time_point chrono_entry = std::chrono::steady_clock::now();
+    const Duration delta_t = until - rcl_entry;
+    const std::chrono::steady_clock::time_point chrono_until =
+      chrono_entry + std::chrono::nanoseconds(delta_t.nanoseconds());
+
+    // loop over spurious wakeups but notice shutdown
+    std::unique_lock lock(impl_->clock_mutex_);
+    while (now() < until && context->is_valid()) {
+      cv.wait_until(lock, chrono_until);
+    }
+  } else if (this_clock_type == RCL_SYSTEM_TIME) {
+    auto system_time = std::chrono::system_clock::time_point(
+      // Cast because system clock resolution is too big for nanoseconds on some systems
+      std::chrono::duration_cast<std::chrono::system_clock::duration>(
+        std::chrono::nanoseconds(until.nanoseconds())));
+
+    // loop over spurious wakeups but notice shutdown
+    std::unique_lock lock(impl_->clock_mutex_);
+    while (now() < until && context->is_valid()) {
+      cv.wait_until(lock, system_time);
+    }
+  } else if (this_clock_type == RCL_ROS_TIME) {
+    // Install jump handler for any amount of time change, for two purposes:
+    // - if ROS time is active, check if time reached on each new clock sample
+    // - Trigger via on_clock_change to detect if time source changes, to invalidate sleep
+    rcl_jump_threshold_t threshold;
+    threshold.on_clock_change = true;
+    // 0 is disable, so -1 and 1 are smallest possible time changes
+    threshold.min_backward.nanoseconds = -1;
+    threshold.min_forward.nanoseconds = 1;
+    auto clock_handler = create_jump_callback(
+      nullptr,
+      [&cv, &time_source_changed](const rcl_time_jump_t & jump) {
+        if (jump.clock_change != RCL_ROS_TIME_NO_CHANGE) {
+          time_source_changed = true;
+        }
+        cv.notify_one();
+      },
+      threshold);
+
+    if (!ros_time_is_active()) {
+      auto system_time = std::chrono::system_clock::time_point(
+        // Cast because system clock resolution is too big for nanoseconds on some systems
+        std::chrono::duration_cast<std::chrono::system_clock::duration>(
+          std::chrono::nanoseconds(until.nanoseconds())));
+
+      // loop over spurious wakeups but notice shutdown or time source change
+      std::unique_lock lock(impl_->clock_mutex_);
+      while (now() < until && context->is_valid() && !time_source_changed) {
+        cv.wait_until(lock, system_time);
+      }
+    } else {
+      // RCL_ROS_TIME with ros_time_is_active.
+      // Just wait without "until" because installed
+      // jump callbacks wake the cv on every new sample.
+      std::unique_lock lock(impl_->clock_mutex_);
+      while (now() < until && context->is_valid() && !time_source_changed) {
+        cv.wait(lock);
+      }
+    }
+  }
+
+  if (!context->is_valid() || time_source_changed) {
+    return false;
+  }
+
+  return now() >= until;
+}
+
+bool
+Clock::sleep_for(Duration rel_time, Context::SharedPtr context)
+{
+  return sleep_until(now() + rel_time, context);
+}
+
 bool
 Clock::ros_time_is_active()
 {

rclcpp/src/rclcpp/context.cpp

@@ -19,6 +19,7 @@
 #include <sstream>
 #include <string>
 #include <vector>
+#include <unordered_set>
 #include <utility>
 
 #include "rcl/init.h"
@@ -307,6 +308,15 @@ Context::shutdown(const std::string & reason)
     // if it is not valid, then it cannot be shutdown
     return false;
   }
+
+  // call each pre-shutdown callback
+  {
+    std::lock_guard<std::mutex> lock{pre_shutdown_callbacks_mutex_};
+    for (const auto & callback : pre_shutdown_callbacks_) {
+      (*callback)();
+    }
+  }
+
   // rcl shutdown
   rcl_ret_t ret = rcl_shutdown(rcl_context_.get());
   if (RCL_RET_OK != ret) {
@@ -315,9 +325,13 @@ Context::shutdown(const std::string & reason)
   // set shutdown reason
   shutdown_reason_ = reason;
   // call each shutdown callback
-  for (const auto & callback : on_shutdown_callbacks_) {
-    callback();
+  {
+    std::lock_guard<std::mutex> lock(on_shutdown_callbacks_mutex_);
+    for (const auto & callback : on_shutdown_callbacks_) {
+      (*callback)();
+    }
   }
+
   // interrupt all blocking sleep_for() and all blocking executors or wait sets
   this->interrupt_all_sleep_for();
   // remove self from the global contexts
@@ -344,20 +358,130 @@ Context::shutdown(const std::string & reason)
 rclcpp::Context::OnShutdownCallback
 Context::on_shutdown(OnShutdownCallback callback)
 {
-  on_shutdown_callbacks_.push_back(callback);
+  add_on_shutdown_callback(callback);
   return callback;
 }
 
-const std::vector<rclcpp::Context::OnShutdownCallback> &
-Context::get_on_shutdown_callbacks() const
+rclcpp::OnShutdownCallbackHandle
+Context::add_on_shutdown_callback(OnShutdownCallback callback)
 {
-  return on_shutdown_callbacks_;
+  return add_shutdown_callback(ShutdownType::on_shutdown, callback);
 }
 
-std::vector<rclcpp::Context::OnShutdownCallback> &
-Context::get_on_shutdown_callbacks()
+bool
+Context::remove_on_shutdown_callback(const OnShutdownCallbackHandle & callback_handle)
 {
-  return on_shutdown_callbacks_;
+  return remove_shutdown_callback(ShutdownType::on_shutdown, callback_handle);
+}
+
+rclcpp::PreShutdownCallbackHandle
+Context::add_pre_shutdown_callback(PreShutdownCallback callback)
+{
+  return add_shutdown_callback(ShutdownType::pre_shutdown, callback);
+}
+
+bool
+Context::remove_pre_shutdown_callback(
+  const PreShutdownCallbackHandle & callback_handle)
+{
+  return remove_shutdown_callback(ShutdownType::pre_shutdown, callback_handle);
+}
+
+rclcpp::ShutdownCallbackHandle
+Context::add_shutdown_callback(
+  ShutdownType shutdown_type,
+  ShutdownCallback callback)
+{
+  auto callback_shared_ptr =
+    std::make_shared<ShutdownCallbackHandle::ShutdownCallbackType>(callback);
+
+  switch (shutdown_type) {
+    case ShutdownType::pre_shutdown:
+      {
+        std::lock_guard<std::mutex> lock(pre_shutdown_callbacks_mutex_);
+        pre_shutdown_callbacks_.emplace(callback_shared_ptr);
+      }
+      break;
+    case ShutdownType::on_shutdown:
+      {
+        std::lock_guard<std::mutex> lock(on_shutdown_callbacks_mutex_);
+        on_shutdown_callbacks_.emplace(callback_shared_ptr);
+      }
+      break;
+  }
+
+  ShutdownCallbackHandle callback_handle;
+  callback_handle.callback = callback_shared_ptr;
+  return callback_handle;
+}
+
+bool
+Context::remove_shutdown_callback(
+  ShutdownType shutdown_type,
+  const ShutdownCallbackHandle & callback_handle)
+{
+  std::mutex * mutex_ptr = nullptr;
+  std::unordered_set<
+    std::shared_ptr<ShutdownCallbackHandle::ShutdownCallbackType>> * callback_list_ptr;
+
+  switch (shutdown_type) {
+    case ShutdownType::pre_shutdown:
+      mutex_ptr = &pre_shutdown_callbacks_mutex_;
+      callback_list_ptr = &pre_shutdown_callbacks_;
+      break;
+    case ShutdownType::on_shutdown:
+      mutex_ptr = &on_shutdown_callbacks_mutex_;
+      callback_list_ptr = &on_shutdown_callbacks_;
+      break;
+  }
+
+  std::lock_guard<std::mutex> lock(*mutex_ptr);
+  auto callback_shared_ptr = callback_handle.callback.lock();
+  if (callback_shared_ptr == nullptr) {
+    return false;
+  }
+  return callback_list_ptr->erase(callback_shared_ptr) == 1;
+}
+
+std::vector<rclcpp::Context::OnShutdownCallback>
+Context::get_on_shutdown_callbacks() const
+{
+  return get_shutdown_callback(ShutdownType::on_shutdown);
+}
+
+std::vector<rclcpp::Context::PreShutdownCallback>
+Context::get_pre_shutdown_callbacks() const
+{
+  return get_shutdown_callback(ShutdownType::pre_shutdown);
+}
+
+std::vector<rclcpp::Context::ShutdownCallback>
+Context::get_shutdown_callback(ShutdownType shutdown_type) const
+{
+  std::mutex * mutex_ptr = nullptr;
+  const std::unordered_set<
+    std::shared_ptr<ShutdownCallbackHandle::ShutdownCallbackType>> * callback_list_ptr;
+
+  switch (shutdown_type) {
+    case ShutdownType::pre_shutdown:
+      mutex_ptr = &pre_shutdown_callbacks_mutex_;
+      callback_list_ptr = &pre_shutdown_callbacks_;
+      break;
+    case ShutdownType::on_shutdown:
+      mutex_ptr = &on_shutdown_callbacks_mutex_;
+      callback_list_ptr = &on_shutdown_callbacks_;
+      break;
+  }
+
+  std::vector<rclcpp::Context::ShutdownCallback> callbacks;
+  {
+    std::lock_guard<std::mutex> lock(*mutex_ptr);
+    for (auto & iter : *callback_list_ptr) {
+      callbacks.emplace_back(*iter);
+    }
+  }
+
+  return callbacks;
 }
 
 std::shared_ptr<rcl_context_t>
@@ -370,16 +494,15 @@ bool
 Context::sleep_for(const std::chrono::nanoseconds & nanoseconds)
 {
   std::chrono::nanoseconds time_left = nanoseconds;
-  {
-    std::unique_lock<std::mutex> lock(interrupt_mutex_);
-    auto start = std::chrono::steady_clock::now();
-    // this will release the lock while waiting
-    interrupt_condition_variable_.wait_for(lock, nanoseconds);
-    time_left -= std::chrono::steady_clock::now() - start;
-  }
-  if (time_left > std::chrono::nanoseconds::zero() && this->is_valid()) {
-    return sleep_for(time_left);
-  }
+  do {
+    {
+      std::unique_lock<std::mutex> lock(interrupt_mutex_);
+      auto start = std::chrono::steady_clock::now();
+      // this will release the lock while waiting
+      interrupt_condition_variable_.wait_for(lock, nanoseconds);
+      time_left -= std::chrono::steady_clock::now() - start;
+    }
+  } while (time_left > std::chrono::nanoseconds::zero() && this->is_valid());
   // Return true if the timeout elapsed successfully, otherwise false.
   return this->is_valid();
 }

rclcpp/src/rclcpp/detail/add_guard_condition_to_rcl_wait_set.cpp

@@ -0,0 +1,39 @@
+// Copyright 2021 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.
+
+#include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
+#include "rclcpp/exceptions.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+void
+add_guard_condition_to_rcl_wait_set(
+  rcl_wait_set_t & wait_set,
+  const rclcpp::GuardCondition & guard_condition)
+{
+  const auto & gc = guard_condition.get_rcl_guard_condition();
+
+  rcl_ret_t ret = rcl_wait_set_add_guard_condition(&wait_set, &gc, NULL);
+
+  if (RCL_RET_OK != ret) {
+    rclcpp::exceptions::throw_from_rcl_error(
+      ret, "failed to add guard condition to wait set");
+  }
+}
+
+}  // namespace detail
+}  // namespace rclcpp

rclcpp/src/rclcpp/detail/mutex_two_priorities.cpp

@@ -1,104 +0,0 @@
-// Copyright 2021 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.
-
-#include "rclcpp/detail/mutex_two_priorities.hpp"
-
-#include <mutex>
-
-namespace rclcpp
-{
-namespace detail
-{
-
-using LowPriorityLockable = MutexTwoPriorities::LowPriorityLockable;
-using HighPriorityLockable = MutexTwoPriorities::HighPriorityLockable;
-
-HighPriorityLockable::HighPriorityLockable(MutexTwoPriorities & parent)
-: parent_(parent)
-{}
-
-void
-HighPriorityLockable::lock()
-{
-  std::unique_lock<std::mutex> guard{parent_.cv_mutex_};
-  if (parent_.data_taken_) {
-    ++parent_.hp_waiting_count_;
-    while (parent_.data_taken_) {
-      parent_.hp_cv_.wait(guard);
-    }
-    --parent_.hp_waiting_count_;
-  }
-  parent_.data_taken_ = true;
-}
-
-void
-HighPriorityLockable::unlock()
-{
-  bool notify_lp{false};
-  {
-    std::lock_guard<std::mutex> guard{parent_.cv_mutex_};
-    parent_.data_taken_ = false;
-    notify_lp = 0u == parent_.hp_waiting_count_;
-  }
-  if (notify_lp) {
-    parent_.lp_cv_.notify_one();
-  } else {
-    parent_.hp_cv_.notify_one();
-  }
-}
-
-LowPriorityLockable::LowPriorityLockable(MutexTwoPriorities & parent)
-: parent_(parent)
-{}
-
-void
-LowPriorityLockable::lock()
-{
-  std::unique_lock<std::mutex> guard{parent_.cv_mutex_};
-  while (parent_.data_taken_ || parent_.hp_waiting_count_) {
-    parent_.lp_cv_.wait(guard);
-  }
-  parent_.data_taken_ = true;
-}
-
-void
-LowPriorityLockable::unlock()
-{
-  bool notify_lp{false};
-  {
-    std::lock_guard<std::mutex> guard{parent_.cv_mutex_};
-    parent_.data_taken_ = false;
-    notify_lp = 0u == parent_.hp_waiting_count_;
-  }
-  if (notify_lp) {
-    parent_.lp_cv_.notify_one();
-  } else {
-    parent_.hp_cv_.notify_one();
-  }
-}
-
-HighPriorityLockable
-MutexTwoPriorities::get_high_priority_lockable()
-{
-  return HighPriorityLockable{*this};
-}
-
-LowPriorityLockable
-MutexTwoPriorities::get_low_priority_lockable()
-{
-  return LowPriorityLockable{*this};
-}
-
-}  // namespace detail
-}  // namespace rclcpp

rclcpp/src/rclcpp/detail/resolve_parameter_overrides.cpp

@@ -19,8 +19,8 @@
 #include <vector>
 
 #include "rcl_yaml_param_parser/parser.h"
+#include "rcpputils/scope_exit.hpp"
 
-#include "rclcpp/scope_exit.hpp"
 #include "rclcpp/parameter_map.hpp"
 
 std::map<std::string, rclcpp::ParameterValue>
@@ -47,7 +47,7 @@ rclcpp::detail::resolve_parameter_overrides(
       rclcpp::exceptions::throw_from_rcl_error(ret);
     }
     if (params) {
-      auto cleanup_params = make_scope_exit(
+      auto cleanup_params = rcpputils::make_scope_exit(
         [params]() {
           rcl_yaml_node_struct_fini(params);
         });

rclcpp/src/rclcpp/executor.cpp

@@ -22,17 +22,19 @@
 
 #include "rcl/allocator.h"
 #include "rcl/error_handling.h"
+#include "rcpputils/scope_exit.hpp"
 
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/executor.hpp"
 #include "rclcpp/guard_condition.hpp"
 #include "rclcpp/memory_strategy.hpp"
 #include "rclcpp/node.hpp"
-#include "rclcpp/scope_exit.hpp"
 #include "rclcpp/utilities.hpp"
 
 #include "rcutils/logging_macros.h"
 
+#include "tracetools/tracetools.h"
+
 using namespace std::chrono_literals;
 
 using rclcpp::exceptions::throw_from_rcl_error;
@@ -43,20 +45,14 @@ using rclcpp::FutureReturnCode;
 
 Executor::Executor(const rclcpp::ExecutorOptions & options)
 : spinning(false),
+  interrupt_guard_condition_(options.context),
   shutdown_guard_condition_(std::make_shared<rclcpp::GuardCondition>(options.context)),
   memory_strategy_(options.memory_strategy)
 {
   // Store the context for later use.
   context_ = options.context;
 
-  rcl_guard_condition_options_t guard_condition_options = rcl_guard_condition_get_default_options();
-  rcl_ret_t ret = rcl_guard_condition_init(
-    &interrupt_guard_condition_, context_->get_rcl_context().get(), guard_condition_options);
-  if (RCL_RET_OK != ret) {
-    throw_from_rcl_error(ret, "Failed to create interrupt guard condition in Executor constructor");
-  }
-
-  context_->on_shutdown(
+  shutdown_callback_handle_ = context_->add_on_shutdown_callback(
     [weak_gc = std::weak_ptr<rclcpp::GuardCondition>{shutdown_guard_condition_}]() {
       auto strong_gc = weak_gc.lock();
       if (strong_gc) {
@@ -66,13 +62,13 @@ Executor::Executor(const rclcpp::ExecutorOptions & options)
 
   // The number of guard conditions is always at least 2: 1 for the ctrl-c guard cond,
   // and one for the executor's guard cond (interrupt_guard_condition_)
-  memory_strategy_->add_guard_condition(&shutdown_guard_condition_->get_rcl_guard_condition());
+  memory_strategy_->add_guard_condition(*shutdown_guard_condition_.get());
 
   // Put the executor's guard condition in
-  memory_strategy_->add_guard_condition(&interrupt_guard_condition_);
+  memory_strategy_->add_guard_condition(interrupt_guard_condition_);
   rcl_allocator_t allocator = memory_strategy_->get_allocator();
 
-  ret = rcl_wait_set_init(
+  rcl_ret_t ret = rcl_wait_set_init(
     &wait_set_,
     0, 2, 0, 0, 0, 0,
     context_->get_rcl_context().get(),
@@ -82,12 +78,6 @@ Executor::Executor(const rclcpp::ExecutorOptions & options)
       "rclcpp",
       "failed to create wait set: %s", rcl_get_error_string().str);
     rcl_reset_error();
-    if (rcl_guard_condition_fini(&interrupt_guard_condition_) != RCL_RET_OK) {
-      RCUTILS_LOG_ERROR_NAMED(
-        "rclcpp",
-        "failed to destroy guard condition: %s", rcl_get_error_string().str);
-      rcl_reset_error();
-    }
     throw_from_rcl_error(ret, "Failed to create wait set in Executor constructor");
   }
 }
@@ -117,7 +107,7 @@ Executor::~Executor()
   weak_groups_to_nodes_associated_with_executor_.clear();
   weak_groups_to_nodes_.clear();
   for (const auto & pair : weak_nodes_to_guard_conditions_) {
-    auto & guard_condition = pair.second;
+    auto guard_condition = pair.second;
     memory_strategy_->remove_guard_condition(guard_condition);
   }
   weak_nodes_to_guard_conditions_.clear();
@@ -129,15 +119,17 @@ Executor::~Executor()
       "failed to destroy wait set: %s", rcl_get_error_string().str);
     rcl_reset_error();
   }
-  // Finalize the interrupt guard condition.
-  if (rcl_guard_condition_fini(&interrupt_guard_condition_) != RCL_RET_OK) {
+  // Remove and release the sigint guard condition
+  memory_strategy_->remove_guard_condition(shutdown_guard_condition_.get());
+  memory_strategy_->remove_guard_condition(&interrupt_guard_condition_);
+
+  // Remove shutdown callback handle registered to Context
+  if (!context_->remove_on_shutdown_callback(shutdown_callback_handle_)) {
     RCUTILS_LOG_ERROR_NAMED(
       "rclcpp",
-      "failed to destroy guard condition: %s", rcl_get_error_string().str);
+      "failed to remove registered on_shutdown callback");
     rcl_reset_error();
   }
-  // Remove and release the sigint guard condition
-  memory_strategy_->remove_guard_condition(&shutdown_guard_condition_->get_rcl_guard_condition());
 }
 
 std::vector<rclcpp::CallbackGroup::WeakPtr>
@@ -182,14 +174,12 @@ Executor::add_callback_groups_from_nodes_associated_to_executor()
   for (auto & weak_node : weak_nodes_) {
     auto node = weak_node.lock();
     if (node) {
-      auto group_ptrs = node->get_callback_groups();
-      std::for_each(
-        group_ptrs.begin(), group_ptrs.end(),
-        [this, node](rclcpp::CallbackGroup::WeakPtr group_ptr)
+      node->for_each_callback_group(
+        [this, node](rclcpp::CallbackGroup::SharedPtr shared_group_ptr)
         {
-          auto shared_group_ptr = group_ptr.lock();
-          if (shared_group_ptr && shared_group_ptr->automatically_add_to_executor_with_node() &&
-          !shared_group_ptr->get_associated_with_executor_atomic().load())
+          if (
+            shared_group_ptr->automatically_add_to_executor_with_node() &&
+            !shared_group_ptr->get_associated_with_executor_atomic().load())
           {
             this->add_callback_group_to_map(
               shared_group_ptr,
@@ -226,17 +216,20 @@ Executor::add_callback_group_to_map(
   // Also add to the map that contains all callback groups
   weak_groups_to_nodes_.insert(std::make_pair(weak_group_ptr, node_ptr));
   if (is_new_node) {
-    rclcpp::node_interfaces::NodeBaseInterface::WeakPtr node_weak_ptr(node_ptr);
-    weak_nodes_to_guard_conditions_[node_weak_ptr] = node_ptr->get_notify_guard_condition();
+    const auto & gc = node_ptr->get_notify_guard_condition();
+    weak_nodes_to_guard_conditions_[node_ptr] = &gc;
     if (notify) {
       // Interrupt waiting to handle new node
-      rcl_ret_t ret = rcl_trigger_guard_condition(&interrupt_guard_condition_);
-      if (ret != RCL_RET_OK) {
-        throw_from_rcl_error(ret, "Failed to trigger guard condition on callback group add");
+      try {
+        interrupt_guard_condition_.trigger();
+      } catch (const rclcpp::exceptions::RCLError & ex) {
+        throw std::runtime_error(
+                std::string(
+                  "Failed to trigger guard condition on callback group add: ") + ex.what());
       }
     }
     // Add the node's notify condition to the guard condition handles
-    memory_strategy_->add_guard_condition(node_ptr->get_notify_guard_condition());
+    memory_strategy_->add_guard_condition(gc);
   }
 }
 
@@ -260,21 +253,25 @@ Executor::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_pt
   // If the node already has an executor
   std::atomic_bool & has_executor = node_ptr->get_associated_with_executor_atomic();
   if (has_executor.exchange(true)) {
-    throw std::runtime_error("Node has already been added to an executor.");
+    throw std::runtime_error(
+            std::string("Node '") + node_ptr->get_fully_qualified_name() +
+            "' has already been added to an executor.");
   }
   std::lock_guard<std::mutex> guard{mutex_};
-  for (auto & weak_group : node_ptr->get_callback_groups()) {
-    auto group_ptr = weak_group.lock();
-    if (group_ptr != nullptr && !group_ptr->get_associated_with_executor_atomic().load() &&
-      group_ptr->automatically_add_to_executor_with_node())
+  node_ptr->for_each_callback_group(
+    [this, node_ptr, notify](rclcpp::CallbackGroup::SharedPtr group_ptr)
     {
-      this->add_callback_group_to_map(
-        group_ptr,
-        node_ptr,
-        weak_groups_to_nodes_associated_with_executor_,
-        notify);
-    }
-  }
+      if (!group_ptr->get_associated_with_executor_atomic().load() &&
+      group_ptr->automatically_add_to_executor_with_node())
+      {
+        this->add_callback_group_to_map(
+          group_ptr,
+          node_ptr,
+          weak_groups_to_nodes_associated_with_executor_,
+          notify);
+      }
+    });
+
   weak_nodes_.push_back(node_ptr);
 }
 
@@ -303,15 +300,17 @@ Executor::remove_callback_group_from_map(
   if (!has_node(node_ptr, weak_groups_to_nodes_associated_with_executor_) &&
     !has_node(node_ptr, weak_groups_associated_with_executor_to_nodes_))
   {
-    rclcpp::node_interfaces::NodeBaseInterface::WeakPtr node_weak_ptr(node_ptr);
-    weak_nodes_to_guard_conditions_.erase(node_weak_ptr);
+    weak_nodes_to_guard_conditions_.erase(node_ptr);
     if (notify) {
-      rcl_ret_t ret = rcl_trigger_guard_condition(&interrupt_guard_condition_);
-      if (ret != RCL_RET_OK) {
-        throw_from_rcl_error(ret, "Failed to trigger guard condition on callback group remove");
+      try {
+        interrupt_guard_condition_.trigger();
+      } catch (const rclcpp::exceptions::RCLError & ex) {
+        throw std::runtime_error(
+                std::string(
+                  "Failed to trigger guard condition on callback group remove: ") + ex.what());
       }
     }
-    memory_strategy_->remove_guard_condition(node_ptr->get_notify_guard_condition());
+    memory_strategy_->remove_guard_condition(&node_ptr->get_notify_guard_condition());
   }
 }
 
@@ -440,7 +439,7 @@ Executor::spin_some_impl(std::chrono::nanoseconds max_duration, bool exhaustive)
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin_some() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
   bool work_available = false;
   while (rclcpp::ok(context_) && spinning.load() && max_duration_not_elapsed()) {
     AnyExecutable any_exec;
@@ -474,7 +473,7 @@ Executor::spin_once(std::chrono::nanoseconds timeout)
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin_once() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
   spin_once_impl(timeout);
 }
 
@@ -482,9 +481,11 @@ void
 Executor::cancel()
 {
   spinning.store(false);
-  rcl_ret_t ret = rcl_trigger_guard_condition(&interrupt_guard_condition_);
-  if (ret != RCL_RET_OK) {
-    throw_from_rcl_error(ret, "Failed to trigger guard condition in cancel");
+  try {
+    interrupt_guard_condition_.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("Failed to trigger guard condition in cancel: ") + ex.what());
   }
 }
 
@@ -505,9 +506,15 @@ Executor::execute_any_executable(AnyExecutable & any_exec)
     return;
   }
   if (any_exec.timer) {
+    TRACEPOINT(
+      rclcpp_executor_execute,
+      static_cast<const void *>(any_exec.timer->get_timer_handle().get()));
     execute_timer(any_exec.timer);
   }
   if (any_exec.subscription) {
+    TRACEPOINT(
+      rclcpp_executor_execute,
+      static_cast<const void *>(any_exec.subscription->get_subscription_handle().get()));
     execute_subscription(any_exec.subscription);
   }
   if (any_exec.service) {
@@ -523,9 +530,12 @@ Executor::execute_any_executable(AnyExecutable & any_exec)
   any_exec.callback_group->can_be_taken_from().store(true);
   // Wake the wait, because it may need to be recalculated or work that
   // was previously blocked is now available.
-  rcl_ret_t ret = rcl_trigger_guard_condition(&interrupt_guard_condition_);
-  if (ret != RCL_RET_OK) {
-    throw_from_rcl_error(ret, "Failed to trigger guard condition from execute_any_executable");
+  try {
+    interrupt_guard_condition_.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string(
+              "Failed to trigger guard condition from execute_any_executable: ") + ex.what());
   }
 }
 
@@ -581,8 +591,7 @@ Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
       [&]() {return subscription->take_serialized(*serialized_msg.get(), message_info);},
       [&]()
       {
-        auto void_serialized_msg = std::static_pointer_cast<void>(serialized_msg);
-        subscription->handle_message(void_serialized_msg, message_info);
+        subscription->handle_serialized_message(serialized_msg, message_info);
       });
     subscription->return_serialized_message(serialized_msg);
   } else if (subscription->can_loan_messages()) {
@@ -669,6 +678,7 @@ Executor::execute_client(
 void
 Executor::wait_for_work(std::chrono::nanoseconds timeout)
 {
+  TRACEPOINT(rclcpp_executor_wait_for_work, timeout.count());
   {
     std::lock_guard<std::mutex> guard(mutex_);
 
@@ -818,6 +828,7 @@ Executor::get_next_ready_executable_from_map(
   const rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap &
   weak_groups_to_nodes)
 {
+  TRACEPOINT(rclcpp_executor_get_next_ready);
   bool success = false;
   std::lock_guard<std::mutex> guard{mutex_};
   // Check the timers to see if there are any that are ready

rclcpp/src/rclcpp/executors/multi_threaded_executor.cpp

@@ -19,10 +19,10 @@
 #include <memory>
 #include <vector>
 
-#include "rclcpp/utilities.hpp"
-#include "rclcpp/scope_exit.hpp"
+#include "rcpputils/scope_exit.hpp"
+
+#include "rclcpp/utilities.hpp"
 
-using rclcpp::detail::MutexTwoPriorities;
 using rclcpp::executors::MultiThreadedExecutor;
 
 MultiThreadedExecutor::MultiThreadedExecutor(
@@ -48,12 +48,11 @@ MultiThreadedExecutor::spin()
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
   std::vector<std::thread> threads;
   size_t thread_id = 0;
   {
-    auto low_priority_wait_mutex = wait_mutex_.get_low_priority_lockable();
-    std::lock_guard<MutexTwoPriorities::LowPriorityLockable> wait_lock(low_priority_wait_mutex);
+    std::lock_guard wait_lock{wait_mutex_};
     for (; thread_id < number_of_threads_ - 1; ++thread_id) {
       auto func = std::bind(&MultiThreadedExecutor::run, this, thread_id);
       threads.emplace_back(func);
@@ -78,26 +77,13 @@ MultiThreadedExecutor::run(size_t)
   while (rclcpp::ok(this->context_) && spinning.load()) {
     rclcpp::AnyExecutable any_exec;
     {
-      auto low_priority_wait_mutex = wait_mutex_.get_low_priority_lockable();
-      std::lock_guard<MutexTwoPriorities::LowPriorityLockable> wait_lock(low_priority_wait_mutex);
+      std::lock_guard wait_lock{wait_mutex_};
       if (!rclcpp::ok(this->context_) || !spinning.load()) {
         return;
       }
       if (!get_next_executable(any_exec, next_exec_timeout_)) {
         continue;
       }
-      if (any_exec.timer) {
-        // Guard against multiple threads getting the same timer.
-        if (scheduled_timers_.count(any_exec.timer) != 0) {
-          // Make sure that any_exec's callback group is reset before
-          // the lock is released.
-          if (any_exec.callback_group) {
-            any_exec.callback_group->can_be_taken_from().store(true);
-          }
-          continue;
-        }
-        scheduled_timers_.insert(any_exec.timer);
-      }
     }
     if (yield_before_execute_) {
       std::this_thread::yield();
@@ -105,14 +91,6 @@ MultiThreadedExecutor::run(size_t)
 
     execute_any_executable(any_exec);
 
-    if (any_exec.timer) {
-      auto high_priority_wait_mutex = wait_mutex_.get_high_priority_lockable();
-      std::lock_guard<MutexTwoPriorities::HighPriorityLockable> wait_lock(high_priority_wait_mutex);
-      auto it = scheduled_timers_.find(any_exec.timer);
-      if (it != scheduled_timers_.end()) {
-        scheduled_timers_.erase(it);
-      }
-    }
     // Clear the callback_group to prevent the AnyExecutable destructor from
     // resetting the callback group `can_be_taken_from`
     any_exec.callback_group.reset();

rclcpp/src/rclcpp/executors/single_threaded_executor.cpp

@@ -12,9 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+#include "rcpputils/scope_exit.hpp"
+
 #include "rclcpp/executors/single_threaded_executor.hpp"
 #include "rclcpp/any_executable.hpp"
-#include "rclcpp/scope_exit.hpp"
 
 using rclcpp::executors::SingleThreadedExecutor;
 
@@ -29,7 +30,7 @@ SingleThreadedExecutor::spin()
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
   while (rclcpp::ok(this->context_) && spinning.load()) {
     rclcpp::AnyExecutable any_executable;
     if (get_next_executable(any_executable)) {

rclcpp/src/rclcpp/executors/static_executor_entities_collector.cpp

@@ -23,6 +23,7 @@
 
 #include "rclcpp/memory_strategy.hpp"
 #include "rclcpp/executors/static_single_threaded_executor.hpp"
+#include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
 
 using rclcpp::executors::StaticExecutorEntitiesCollector;
 
@@ -61,8 +62,7 @@ StaticExecutorEntitiesCollector::~StaticExecutorEntitiesCollector()
 void
 StaticExecutorEntitiesCollector::init(
   rcl_wait_set_t * p_wait_set,
-  rclcpp::memory_strategy::MemoryStrategy::SharedPtr memory_strategy,
-  rcl_guard_condition_t * executor_guard_condition)
+  rclcpp::memory_strategy::MemoryStrategy::SharedPtr memory_strategy)
 {
   // Empty initialize executable list
   exec_list_ = rclcpp::experimental::ExecutableList();
@@ -74,9 +74,6 @@ StaticExecutorEntitiesCollector::init(
   }
   memory_strategy_ = memory_strategy;
 
-  // Add executor's guard condition
-  memory_strategy_->add_guard_condition(executor_guard_condition);
-
   // Get memory strategy and executable list. Prepare wait_set_
   std::shared_ptr<void> shared_ptr;
   execute(shared_ptr);
@@ -108,6 +105,15 @@ StaticExecutorEntitiesCollector::execute(std::shared_ptr<void> & data)
   fill_executable_list();
   // Resize the wait_set_ based on memory_strategy handles (rcl_wait_set_resize)
   prepare_wait_set();
+  // Add new nodes guard conditions to map
+  std::lock_guard<std::mutex> guard{new_nodes_mutex_};
+  for (const auto & weak_node : new_nodes_) {
+    if (auto node_ptr = weak_node.lock()) {
+      const auto & gc = node_ptr->get_notify_guard_condition();
+      weak_nodes_to_guard_conditions_[node_ptr] = &gc;
+    }
+  }
+  new_nodes_.clear();
 }
 
 void
@@ -261,23 +267,20 @@ StaticExecutorEntitiesCollector::refresh_wait_set(std::chrono::nanoseconds timeo
   }
 }
 
-bool
+void
 StaticExecutorEntitiesCollector::add_to_wait_set(rcl_wait_set_t * wait_set)
 {
   // Add waitable guard conditions (one for each registered node) into the wait set.
   for (const auto & pair : weak_nodes_to_guard_conditions_) {
     auto & gc = pair.second;
-    rcl_ret_t ret = rcl_wait_set_add_guard_condition(wait_set, gc, NULL);
-    if (ret != RCL_RET_OK) {
-      throw std::runtime_error("Executor waitable: couldn't add guard condition to wait set");
-    }
+    detail::add_guard_condition_to_rcl_wait_set(*wait_set, *gc);
   }
-  return true;
 }
 
 size_t StaticExecutorEntitiesCollector::get_number_of_ready_guard_conditions()
 {
-  return weak_nodes_to_guard_conditions_.size();
+  std::lock_guard<std::mutex> guard{new_nodes_mutex_};
+  return weak_nodes_to_guard_conditions_.size() + new_nodes_.size();
 }
 
 bool
@@ -290,18 +293,20 @@ StaticExecutorEntitiesCollector::add_node(
   if (has_executor.exchange(true)) {
     throw std::runtime_error("Node has already been added to an executor.");
   }
-  for (const auto & weak_group : node_ptr->get_callback_groups()) {
-    auto group_ptr = weak_group.lock();
-    if (group_ptr != nullptr && !group_ptr->get_associated_with_executor_atomic().load() &&
-      group_ptr->automatically_add_to_executor_with_node())
+  node_ptr->for_each_callback_group(
+    [this, node_ptr, &is_new_node](rclcpp::CallbackGroup::SharedPtr group_ptr)
     {
-      is_new_node = (add_callback_group(
+      if (
+        !group_ptr->get_associated_with_executor_atomic().load() &&
+        group_ptr->automatically_add_to_executor_with_node())
+      {
+        is_new_node = (add_callback_group(
           group_ptr,
           node_ptr,
           weak_groups_to_nodes_associated_with_executor_) ||
         is_new_node);
-    }
-  }
+      }
+    });
   weak_nodes_.push_back(node_ptr);
   return is_new_node;
 }
@@ -327,7 +332,8 @@ StaticExecutorEntitiesCollector::add_callback_group(
     throw std::runtime_error("Callback group was already added to executor.");
   }
   if (is_new_node) {
-    weak_nodes_to_guard_conditions_[node_ptr] = node_ptr->get_notify_guard_condition();
+    std::lock_guard<std::mutex> guard{new_nodes_mutex_};
+    new_nodes_.push_back(node_ptr);
     return true;
   }
   return false;
@@ -433,8 +439,9 @@ StaticExecutorEntitiesCollector::is_ready(rcl_wait_set_t * p_wait_set)
       auto found_guard_condition = std::find_if(
         weak_nodes_to_guard_conditions_.begin(), weak_nodes_to_guard_conditions_.end(),
         [&](std::pair<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr,
-        const rcl_guard_condition_t *> pair) -> bool {
-          return pair.second == p_wait_set->guard_conditions[i];
+        const GuardCondition *> pair) -> bool {
+          const rcl_guard_condition_t & rcl_gc = pair.second->get_rcl_guard_condition();
+          return &rcl_gc == p_wait_set->guard_conditions[i];
         });
       if (found_guard_condition != weak_nodes_to_guard_conditions_.end()) {
         return true;
@@ -467,13 +474,10 @@ StaticExecutorEntitiesCollector::add_callback_groups_from_nodes_associated_to_ex
   for (const auto & weak_node : weak_nodes_) {
     auto node = weak_node.lock();
     if (node) {
-      auto group_ptrs = node->get_callback_groups();
-      std::for_each(
-        group_ptrs.begin(), group_ptrs.end(),
-        [this, node](rclcpp::CallbackGroup::WeakPtr group_ptr)
+      node->for_each_callback_group(
+        [this, node](rclcpp::CallbackGroup::SharedPtr shared_group_ptr)
         {
-          auto shared_group_ptr = group_ptr.lock();
-          if (shared_group_ptr && shared_group_ptr->automatically_add_to_executor_with_node() &&
+          if (shared_group_ptr->automatically_add_to_executor_with_node() &&
           !shared_group_ptr->get_associated_with_executor_atomic().load())
           {
             add_callback_group(

rclcpp/src/rclcpp/executors/static_single_threaded_executor.cpp

@@ -16,9 +16,10 @@
 
 #include <chrono>
 #include <memory>
+#include <utility>
 #include <vector>
 
-#include "rclcpp/scope_exit.hpp"
+#include "rcpputils/scope_exit.hpp"
 
 using rclcpp::executors::StaticSingleThreadedExecutor;
 using rclcpp::experimental::ExecutableList;
@@ -43,11 +44,11 @@ StaticSingleThreadedExecutor::spin()
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
 
   // Set memory_strategy_ and exec_list_ based on weak_nodes_
   // Prepare wait_set_ based on memory_strategy_
-  entities_collector_->init(&wait_set_, memory_strategy_, &interrupt_guard_condition_);
+  entities_collector_->init(&wait_set_, memory_strategy_);
 
   while (rclcpp::ok(this->context_) && spinning.load()) {
     // Refresh wait set and wait for work
@@ -81,7 +82,7 @@ StaticSingleThreadedExecutor::spin_some_impl(std::chrono::nanoseconds max_durati
 {
   // Make sure the entities collector has been initialized
   if (!entities_collector_->is_init()) {
-    entities_collector_->init(&wait_set_, memory_strategy_, &interrupt_guard_condition_);
+    entities_collector_->init(&wait_set_, memory_strategy_);
   }
 
   auto start = std::chrono::steady_clock::now();
@@ -100,7 +101,7 @@ StaticSingleThreadedExecutor::spin_some_impl(std::chrono::nanoseconds max_durati
   if (spinning.exchange(true)) {
     throw std::runtime_error("spin_some() called while already spinning");
   }
-  RCLCPP_SCOPE_EXIT(this->spinning.store(false); );
+  RCPPUTILS_SCOPE_EXIT(this->spinning.store(false); );
 
   while (rclcpp::ok(context_) && spinning.load() && max_duration_not_elapsed()) {
     // Get executables that are ready now
@@ -118,7 +119,7 @@ StaticSingleThreadedExecutor::spin_once_impl(std::chrono::nanoseconds timeout)
 {
   // Make sure the entities collector has been initialized
   if (!entities_collector_->is_init()) {
-    entities_collector_->init(&wait_set_, memory_strategy_, &interrupt_guard_condition_);
+    entities_collector_->init(&wait_set_, memory_strategy_);
   }
 
   if (rclcpp::ok(context_) && spinning.load()) {
@@ -138,9 +139,7 @@ StaticSingleThreadedExecutor::add_callback_group(
   bool is_new_node = entities_collector_->add_callback_group(group_ptr, node_ptr);
   if (is_new_node && notify) {
     // Interrupt waiting to handle new node
-    if (rcl_trigger_guard_condition(&interrupt_guard_condition_) != RCL_RET_OK) {
-      throw std::runtime_error(rcl_get_error_string().str);
-    }
+    interrupt_guard_condition_.trigger();
   }
 }
 
@@ -151,9 +150,7 @@ StaticSingleThreadedExecutor::add_node(
   bool is_new_node = entities_collector_->add_node(node_ptr);
   if (is_new_node && notify) {
     // Interrupt waiting to handle new node
-    if (rcl_trigger_guard_condition(&interrupt_guard_condition_) != RCL_RET_OK) {
-      throw std::runtime_error(rcl_get_error_string().str);
-    }
+    interrupt_guard_condition_.trigger();
   }
 }
 
@@ -170,9 +167,7 @@ StaticSingleThreadedExecutor::remove_callback_group(
   bool node_removed = entities_collector_->remove_callback_group(group_ptr);
   // If the node was matched and removed, interrupt waiting
   if (node_removed && notify) {
-    if (rcl_trigger_guard_condition(&interrupt_guard_condition_) != RCL_RET_OK) {
-      throw std::runtime_error(rcl_get_error_string().str);
-    }
+    interrupt_guard_condition_.trigger();
   }
 }
 
@@ -186,9 +181,7 @@ StaticSingleThreadedExecutor::remove_node(
   }
   // If the node was matched and removed, interrupt waiting
   if (notify) {
-    if (rcl_trigger_guard_condition(&interrupt_guard_condition_) != RCL_RET_OK) {
-      throw std::runtime_error(rcl_get_error_string().str);
-    }
+    interrupt_guard_condition_.trigger();
   }
 }
 
@@ -237,7 +230,9 @@ StaticSingleThreadedExecutor::execute_ready_executables(bool spin_once)
   for (size_t i = 0; i < wait_set_.size_of_timers; ++i) {
     if (i < entities_collector_->get_number_of_timers()) {
       if (wait_set_.timers[i] && entities_collector_->get_timer(i)->is_ready()) {
-        execute_timer(entities_collector_->get_timer(i));
+        auto timer = entities_collector_->get_timer(i);
+        timer->call();
+        execute_timer(std::move(timer));
         if (spin_once) {
           return true;
         }

rclcpp/src/rclcpp/expand_topic_or_service_name.cpp

@@ -19,7 +19,6 @@
 #include "rcl/expand_topic_name.h"
 #include "rcl/validate_topic_name.h"
 #include "rclcpp/exceptions.hpp"
-#include "rclcpp/scope_exit.hpp"
 #include "rcutils/logging_macros.h"
 #include "rcutils/types/string_map.h"
 #include "rmw/error_handling.h"

rclcpp/src/rclcpp/generic_subscription.cpp

@@ -36,11 +36,19 @@ std::shared_ptr<rclcpp::SerializedMessage> GenericSubscription::create_serialize
 }
 
 void GenericSubscription::handle_message(
-  std::shared_ptr<void> & message, const rclcpp::MessageInfo & message_info)
+  std::shared_ptr<void> &,
+  const rclcpp::MessageInfo &)
 {
-  (void) message_info;
-  auto typed_message = std::static_pointer_cast<rclcpp::SerializedMessage>(message);
-  callback_(typed_message);
+  throw rclcpp::exceptions::UnimplementedError(
+          "handle_message is not implemented for GenericSubscription");
+}
+
+void
+GenericSubscription::handle_serialized_message(
+  const std::shared_ptr<rclcpp::SerializedMessage> & message,
+  const rclcpp::MessageInfo &)
+{
+  callback_(message);
 }
 
 void GenericSubscription::handle_loaned_message(

rclcpp/src/rclcpp/graph_listener.cpp

@@ -22,6 +22,7 @@
 
 #include "rcl/error_handling.h"
 #include "rcl/types.h"
+#include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/logging.hpp"
 #include "rclcpp/node.hpp"
@@ -40,19 +41,9 @@ GraphListener::GraphListener(const std::shared_ptr<Context> & parent_context)
 : weak_parent_context_(parent_context),
   rcl_parent_context_(parent_context->get_rcl_context()),
   is_started_(false),
-  is_shutdown_(false)
+  is_shutdown_(false),
+  interrupt_guard_condition_(parent_context)
 {
-  // TODO(wjwwood): make a guard condition class in rclcpp so this can be tracked
-  //   automatically with the rcl guard condition
-  // hold on to this context to prevent it from going out of scope while this
-  // guard condition is using it.
-  rcl_ret_t ret = rcl_guard_condition_init(
-    &interrupt_guard_condition_,
-    rcl_parent_context_.get(),
-    rcl_guard_condition_get_default_options());
-  if (RCL_RET_OK != ret) {
-    throw_from_rcl_error(ret, "failed to create interrupt guard condition");
-  }
 }
 
 GraphListener::~GraphListener()
@@ -159,10 +150,7 @@ GraphListener::run_loop()
       throw_from_rcl_error(ret, "failed to clear wait set");
     }
     // Put the interrupt guard condition in the wait set.
-    ret = rcl_wait_set_add_guard_condition(&wait_set_, &interrupt_guard_condition_, NULL);
-    if (RCL_RET_OK != ret) {
-      throw_from_rcl_error(ret, "failed to add interrupt guard condition to wait set");
-    }
+    detail::add_guard_condition_to_rcl_wait_set(wait_set_, interrupt_guard_condition_);
 
     // Put graph guard conditions for each node into the wait set.
     std::vector<size_t> graph_gc_indexes(node_graph_interfaces_size, 0u);
@@ -211,19 +199,16 @@ GraphListener::run_loop()
 }
 
 static void
-interrupt_(rcl_guard_condition_t * interrupt_guard_condition)
+interrupt_(GuardCondition * interrupt_guard_condition)
 {
-  rcl_ret_t ret = rcl_trigger_guard_condition(interrupt_guard_condition);
-  if (RCL_RET_OK != ret) {
-    throw_from_rcl_error(ret, "failed to trigger the interrupt guard condition");
-  }
+  interrupt_guard_condition->trigger();
 }
 
 static void
 acquire_nodes_lock_(
   std::mutex * node_graph_interfaces_barrier_mutex,
   std::mutex * node_graph_interfaces_mutex,
-  rcl_guard_condition_t * interrupt_guard_condition)
+  GuardCondition * interrupt_guard_condition)
 {
   {
     // Acquire this lock to prevent the run loop from re-locking the
@@ -351,10 +336,6 @@ GraphListener::__shutdown()
       interrupt_(&interrupt_guard_condition_);
       listener_thread_.join();
     }
-    rcl_ret_t ret = rcl_guard_condition_fini(&interrupt_guard_condition_);
-    if (RCL_RET_OK != ret) {
-      throw_from_rcl_error(ret, "failed to finalize interrupt guard condition");
-    }
     if (is_started_) {
       cleanup_wait_set();
     }

rclcpp/src/rclcpp/guard_condition.cpp

@@ -20,19 +20,20 @@
 namespace rclcpp
 {
 
-GuardCondition::GuardCondition(rclcpp::Context::SharedPtr context)
+GuardCondition::GuardCondition(
+  rclcpp::Context::SharedPtr context,
+  rcl_guard_condition_options_t guard_condition_options)
 : context_(context), rcl_guard_condition_{rcl_get_zero_initialized_guard_condition()}
 {
   if (!context_) {
     throw std::invalid_argument("context argument unexpectedly nullptr");
   }
-  rcl_guard_condition_options_t guard_condition_options = rcl_guard_condition_get_default_options();
   rcl_ret_t ret = rcl_guard_condition_init(
     &this->rcl_guard_condition_,
     context_->get_rcl_context().get(),
     guard_condition_options);
   if (RCL_RET_OK != ret) {
-    rclcpp::exceptions::throw_from_rcl_error(ret);
+    rclcpp::exceptions::throw_from_rcl_error(ret, "failed to create guard condition");
   }
 }
 
@@ -45,7 +46,7 @@ GuardCondition::~GuardCondition()
     } catch (const std::exception & exception) {
       RCLCPP_ERROR(
         rclcpp::get_logger("rclcpp"),
-        "Error in destruction of rcl guard condition: %s", exception.what());
+        "failed to finalize guard condition: %s", exception.what());
     }
   }
 }
@@ -56,6 +57,12 @@ GuardCondition::get_context() const
   return context_;
 }
 
+rcl_guard_condition_t &
+GuardCondition::get_rcl_guard_condition()
+{
+  return rcl_guard_condition_;
+}
+
 const rcl_guard_condition_t &
 GuardCondition::get_rcl_guard_condition() const
 {

rclcpp/src/rclcpp/init_options.cpp

@@ -43,7 +43,7 @@ InitOptions::InitOptions(const rcl_init_options_t & init_options)
 InitOptions::InitOptions(const InitOptions & other)
 : InitOptions(*other.get_rcl_init_options())
 {
-  shutdown_on_sigint = other.shutdown_on_sigint;
+  shutdown_on_signal = other.shutdown_on_signal;
   initialize_logging_ = other.initialize_logging_;
 }
 
@@ -70,7 +70,7 @@ InitOptions::operator=(const InitOptions & other)
     if (RCL_RET_OK != ret) {
       rclcpp::exceptions::throw_from_rcl_error(ret, "failed to copy rcl init options");
     }
-    this->shutdown_on_sigint = other.shutdown_on_sigint;
+    this->shutdown_on_signal = other.shutdown_on_signal;
     this->initialize_logging_ = other.initialize_logging_;
   }
   return *this;

rclcpp/src/rclcpp/intra_process_manager.cpp

@@ -36,23 +36,26 @@ IntraProcessManager::add_publisher(rclcpp::PublisherBase::SharedPtr publisher)
 {
   std::unique_lock<std::shared_timed_mutex> lock(mutex_);
 
-  auto id = IntraProcessManager::get_next_unique_id();
+  uint64_t pub_id = IntraProcessManager::get_next_unique_id();
 
-  publishers_[id].publisher = publisher;
-  publishers_[id].topic_name = publisher->get_topic_name();
-  publishers_[id].qos = publisher->get_actual_qos().get_rmw_qos_profile();
+  publishers_[pub_id] = publisher;
 
   // Initialize the subscriptions storage for this publisher.
-  pub_to_subs_[id] = SplittedSubscriptions();
+  pub_to_subs_[pub_id] = SplittedSubscriptions();
 
   // create an entry for the publisher id and populate with already existing subscriptions
   for (auto & pair : subscriptions_) {
-    if (can_communicate(publishers_[id], pair.second)) {
-      insert_sub_id_for_pub(pair.first, id, pair.second.use_take_shared_method);
+    auto subscription = pair.second.lock();
+    if (!subscription) {
+      continue;
+    }
+    if (can_communicate(publisher, subscription)) {
+      uint64_t sub_id = pair.first;
+      insert_sub_id_for_pub(sub_id, pub_id, subscription->use_take_shared_method());
     }
   }
 
-  return id;
+  return pub_id;
 }
 
 uint64_t
@@ -60,21 +63,23 @@ IntraProcessManager::add_subscription(SubscriptionIntraProcessBase::SharedPtr su
 {
   std::unique_lock<std::shared_timed_mutex> lock(mutex_);
 
-  auto id = IntraProcessManager::get_next_unique_id();
+  uint64_t sub_id = IntraProcessManager::get_next_unique_id();
 
-  subscriptions_[id].subscription = subscription;
-  subscriptions_[id].topic_name = subscription->get_topic_name();
-  subscriptions_[id].qos = subscription->get_actual_qos();
-  subscriptions_[id].use_take_shared_method = subscription->use_take_shared_method();
+  subscriptions_[sub_id] = subscription;
 
   // adds the subscription id to all the matchable publishers
   for (auto & pair : publishers_) {
-    if (can_communicate(pair.second, subscriptions_[id])) {
-      insert_sub_id_for_pub(id, pair.first, subscriptions_[id].use_take_shared_method);
+    auto publisher = pair.second.lock();
+    if (!publisher) {
+      continue;
+    }
+    if (can_communicate(publisher, subscription)) {
+      uint64_t pub_id = pair.first;
+      insert_sub_id_for_pub(sub_id, pub_id, subscription->use_take_shared_method());
     }
   }
 
-  return id;
+  return sub_id;
 }
 
 void
@@ -116,7 +121,7 @@ IntraProcessManager::matches_any_publishers(const rmw_gid_t * id) const
   std::shared_lock<std::shared_timed_mutex> lock(mutex_);
 
   for (auto & publisher_pair : publishers_) {
-    auto publisher = publisher_pair.second.publisher.lock();
+    auto publisher = publisher_pair.second.lock();
     if (!publisher) {
       continue;
     }
@@ -157,7 +162,7 @@ IntraProcessManager::get_subscription_intra_process(uint64_t intra_process_subsc
   if (subscription_it == subscriptions_.end()) {
     return nullptr;
   } else {
-    auto subscription = subscription_it->second.subscription.lock();
+    auto subscription = subscription_it->second.lock();
     if (subscription) {
       return subscription;
     } else {
@@ -204,25 +209,16 @@ IntraProcessManager::insert_sub_id_for_pub(
 
 bool
 IntraProcessManager::can_communicate(
-  PublisherInfo pub_info,
-  SubscriptionInfo sub_info) const
+  rclcpp::PublisherBase::SharedPtr pub,
+  rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr sub) const
 {
   // publisher and subscription must be on the same topic
-  if (strcmp(pub_info.topic_name, sub_info.topic_name) != 0) {
+  if (strcmp(pub->get_topic_name(), sub->get_topic_name()) != 0) {
     return false;
   }
 
-  // TODO(alsora): the following checks for qos compatibility should be provided by the RMW
-  // a reliable subscription can't be connected with a best effort publisher
-  if (
-    sub_info.qos.reliability == RMW_QOS_POLICY_RELIABILITY_RELIABLE &&
-    pub_info.qos.reliability == RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT)
-  {
-    return false;
-  }
-
-  // a publisher and a subscription with different durability can't communicate
-  if (sub_info.qos.durability != pub_info.qos.durability) {
+  auto check_result = rclcpp::qos_check_compatible(pub->get_actual_qos(), sub->get_actual_qos());
+  if (check_result.compatibility == rclcpp::QoSCompatibility::Error) {
     return false;
   }
 

rclcpp/src/rclcpp/node.cpp

@@ -47,6 +47,9 @@ using rclcpp::Node;
 using rclcpp::NodeOptions;
 using rclcpp::exceptions::throw_from_rcl_error;
 
+namespace
+{
+
 RCLCPP_LOCAL
 std::string
 extend_sub_namespace(const std::string & existing_sub_namespace, const std::string & extension)
@@ -54,8 +57,14 @@ extend_sub_namespace(const std::string & existing_sub_namespace, const std::stri
   // Assumption is that the existing_sub_namespace does not need checking
   // because it would be checked already when it was set with this function.
 
-  // check if the new sub-namespace extension is absolute
-  if (extension.front() == '/') {
+  if (extension.empty()) {
+    throw rclcpp::exceptions::NameValidationError(
+            "sub_namespace",
+            extension.c_str(),
+            "sub-nodes should not extend nodes by an empty sub-namespace",
+            0);
+  } else if (extension.front() == '/') {
+    // check if the new sub-namespace extension is absolute
     throw rclcpp::exceptions::NameValidationError(
             "sub_namespace",
             extension.c_str(),
@@ -70,7 +79,7 @@ extend_sub_namespace(const std::string & existing_sub_namespace, const std::stri
     new_sub_namespace = existing_sub_namespace + "/" + extension;
   }
 
-  // remove any trailing `/` so that new extensions do no result in `//`
+  // remove any trailing `/` so that new extensions do not result in `//`
   if (new_sub_namespace.back() == '/') {
     new_sub_namespace = new_sub_namespace.substr(0, new_sub_namespace.size() - 1);
   }
@@ -86,7 +95,11 @@ create_effective_namespace(const std::string & node_namespace, const std::string
   // and do not need trimming of `/` and other things, as they were validated
   // in other functions already.
 
-  if (node_namespace.back() == '/') {
+  // A node may not have a sub_namespace if it is no sub_node. In this case,
+  // just return the original namespace
+  if (sub_namespace.empty()) {
+    return node_namespace;
+  } else if (node_namespace.back() == '/') {
     // this is the special case where node_namespace is just `/`
     return node_namespace + sub_namespace;
   } else {
@@ -94,6 +107,8 @@ create_effective_namespace(const std::string & node_namespace, const std::string
   }
 }
 
+}  // namespace
+
 Node::Node(
   const std::string & node_name,
   const NodeOptions & options)
@@ -222,6 +237,8 @@ Node::Node(
   node_services_(other.node_services_),
   node_clock_(other.node_clock_),
   node_parameters_(other.node_parameters_),
+  node_time_source_(other.node_time_source_),
+  node_waitables_(other.node_waitables_),
   node_options_(other.node_options_),
   sub_namespace_(extend_sub_namespace(other.get_sub_namespace(), sub_namespace)),
   effective_namespace_(create_effective_namespace(other.get_namespace(), sub_namespace_))
@@ -482,10 +499,11 @@ Node::get_subscriptions_info_by_topic(const std::string & topic_name, bool no_ma
   return node_graph_->get_subscriptions_info_by_topic(topic_name, no_mangle);
 }
 
-const std::vector<rclcpp::CallbackGroup::WeakPtr> &
-Node::get_callback_groups() const
+void
+Node::for_each_callback_group(
+  const node_interfaces::NodeBaseInterface::CallbackGroupFunction & func)
 {
-  return node_base_->get_callback_groups();
+  node_base_->for_each_callback_group(func);
 }
 
 rclcpp::Event::SharedPtr

rclcpp/src/rclcpp/node_interfaces/node_base.cpp

@@ -44,30 +44,15 @@ NodeBase::NodeBase(
   node_handle_(nullptr),
   default_callback_group_(nullptr),
   associated_with_executor_(false),
+  notify_guard_condition_(context),
   notify_guard_condition_is_valid_(false)
 {
-  // Setup the guard condition that is notified when changes occur in the graph.
-  rcl_guard_condition_options_t guard_condition_options = rcl_guard_condition_get_default_options();
-  rcl_ret_t ret = rcl_guard_condition_init(
-    &notify_guard_condition_, context_->get_rcl_context().get(), guard_condition_options);
-  if (ret != RCL_RET_OK) {
-    throw_from_rcl_error(ret, "failed to create interrupt guard condition");
-  }
-
-  // Setup a safe exit lamda to clean up the guard condition in case of an error here.
-  auto finalize_notify_guard_condition = [this]() {
-      // Finalize the interrupt guard condition.
-      if (rcl_guard_condition_fini(&notify_guard_condition_) != RCL_RET_OK) {
-        RCUTILS_LOG_ERROR_NAMED(
-          "rclcpp",
-          "failed to destroy guard condition: %s", rcl_get_error_string().str);
-      }
-    };
-
   // Create the rcl node and store it in a shared_ptr with a custom destructor.
   std::unique_ptr<rcl_node_t> rcl_node(new rcl_node_t(rcl_get_zero_initialized_node()));
 
   std::shared_ptr<std::recursive_mutex> logging_mutex = get_global_logging_mutex();
+
+  rcl_ret_t ret;
   {
     std::lock_guard<std::recursive_mutex> guard(*logging_mutex);
     // TODO(ivanpauno): /rosout Qos should be reconfigurable.
@@ -80,9 +65,6 @@ NodeBase::NodeBase(
       context_->get_rcl_context().get(), &rcl_node_options);
   }
   if (ret != RCL_RET_OK) {
-    // Finalize the interrupt guard condition.
-    finalize_notify_guard_condition();
-
     if (ret == RCL_RET_NODE_INVALID_NAME) {
       rcl_reset_error();  // discard rcl_node_init error
       int validation_result;
@@ -160,11 +142,6 @@ NodeBase::~NodeBase()
   {
     std::lock_guard<std::recursive_mutex> notify_condition_lock(notify_guard_condition_mutex_);
     notify_guard_condition_is_valid_ = false;
-    if (rcl_guard_condition_fini(&notify_guard_condition_) != RCL_RET_OK) {
-      RCUTILS_LOG_ERROR_NAMED(
-        "rclcpp",
-        "failed to destroy guard condition: %s", rcl_get_error_string().str);
-    }
   }
 }
 
@@ -207,13 +184,13 @@ NodeBase::get_rcl_node_handle() const
 std::shared_ptr<rcl_node_t>
 NodeBase::get_shared_rcl_node_handle()
 {
-  return node_handle_;
+  return std::shared_ptr<rcl_node_t>(shared_from_this(), node_handle_.get());
 }
 
 std::shared_ptr<const rcl_node_t>
 NodeBase::get_shared_rcl_node_handle() const
 {
-  return node_handle_;
+  return std::shared_ptr<const rcl_node_t>(shared_from_this(), node_handle_.get());
 }
 
 rclcpp::CallbackGroup::SharedPtr
@@ -221,12 +198,10 @@ NodeBase::create_callback_group(
   rclcpp::CallbackGroupType group_type,
   bool automatically_add_to_executor_with_node)
 {
-  using rclcpp::CallbackGroup;
-  using rclcpp::CallbackGroupType;
-  auto group = CallbackGroup::SharedPtr(
-    new CallbackGroup(
-      group_type,
-      automatically_add_to_executor_with_node));
+  auto group = std::make_shared<rclcpp::CallbackGroup>(
+    group_type,
+    automatically_add_to_executor_with_node);
+  std::lock_guard<std::mutex> lock(callback_groups_mutex_);
   callback_groups_.push_back(group);
   return group;
 }
@@ -240,20 +215,25 @@ NodeBase::get_default_callback_group()
 bool
 NodeBase::callback_group_in_node(rclcpp::CallbackGroup::SharedPtr group)
 {
-  bool group_belongs_to_this_node = false;
+  std::lock_guard<std::mutex> lock(callback_groups_mutex_);
   for (auto & weak_group : this->callback_groups_) {
     auto cur_group = weak_group.lock();
     if (cur_group && (cur_group == group)) {
-      group_belongs_to_this_node = true;
+      return true;
     }
   }
-  return group_belongs_to_this_node;
+  return false;
 }
 
-const std::vector<rclcpp::CallbackGroup::WeakPtr> &
-NodeBase::get_callback_groups() const
+void NodeBase::for_each_callback_group(const CallbackGroupFunction & func)
 {
-  return callback_groups_;
+  std::lock_guard<std::mutex> lock(callback_groups_mutex_);
+  for (rclcpp::CallbackGroup::WeakPtr & weak_group : this->callback_groups_) {
+    rclcpp::CallbackGroup::SharedPtr group = weak_group.lock();
+    if (group) {
+      func(group);
+    }
+  }
 }
 
 std::atomic_bool &
@@ -262,20 +242,14 @@ NodeBase::get_associated_with_executor_atomic()
   return associated_with_executor_;
 }
 
-rcl_guard_condition_t *
+rclcpp::GuardCondition &
 NodeBase::get_notify_guard_condition()
 {
   std::lock_guard<std::recursive_mutex> notify_condition_lock(notify_guard_condition_mutex_);
   if (!notify_guard_condition_is_valid_) {
-    return nullptr;
+    throw std::runtime_error("failed to get notify guard condition because it is invalid");
   }
-  return &notify_guard_condition_;
-}
-
-std::unique_lock<std::recursive_mutex>
-NodeBase::acquire_notify_guard_condition_lock() const
-{
-  return std::unique_lock<std::recursive_mutex>(notify_guard_condition_mutex_);
+  return notify_guard_condition_;
 }
 
 bool

rclcpp/src/rclcpp/node_interfaces/node_graph.cpp

@@ -17,6 +17,7 @@
 #include <algorithm>
 #include <map>
 #include <string>
+#include <tuple>
 #include <utility>
 #include <vector>
 
@@ -27,6 +28,7 @@
 #include "rclcpp/expand_topic_or_service_name.hpp"
 #include "rclcpp/graph_listener.hpp"
 #include "rclcpp/node_interfaces/node_graph_interface.hpp"
+#include "rcpputils/scope_exit.hpp"
 
 using rclcpp::node_interfaces::NodeGraph;
 using rclcpp::exceptions::throw_from_rcl_error;
@@ -178,6 +180,115 @@ NodeGraph::get_service_names_and_types_by_node(
   return services_and_types;
 }
 
+std::map<std::string, std::vector<std::string>>
+NodeGraph::get_client_names_and_types_by_node(
+  const std::string & node_name,
+  const std::string & namespace_) const
+{
+  rcl_names_and_types_t service_names_and_types = rcl_get_zero_initialized_names_and_types();
+  auto service_names_and_types_finalizer = rcpputils::make_scope_exit(
+    [&service_names_and_types]() {
+      if (rcl_names_and_types_fini(&service_names_and_types) != RCL_RET_OK) {
+        RCLCPP_ERROR(
+          rclcpp::get_logger("rclcpp"), "could not destroy service names and types");
+      }
+    });
+  rcl_allocator_t allocator = rcl_get_default_allocator();
+  rcl_ret_t ret = rcl_get_client_names_and_types_by_node(
+    node_base_->get_rcl_node_handle(),
+    &allocator,
+    node_name.c_str(),
+    namespace_.c_str(),
+    &service_names_and_types);
+  if (ret != RCL_RET_OK) {
+    throw_from_rcl_error(ret, "failed to get service names and types by node");
+  }
+
+  std::map<std::string, std::vector<std::string>> services_and_types;
+  for (size_t i = 0; i < service_names_and_types.names.size; ++i) {
+    std::string service_name = service_names_and_types.names.data[i];
+    for (size_t j = 0; j < service_names_and_types.types[i].size; ++j) {
+      services_and_types[service_name].emplace_back(service_names_and_types.types[i].data[j]);
+    }
+  }
+
+  return services_and_types;
+}
+
+std::map<std::string, std::vector<std::string>>
+NodeGraph::get_publisher_names_and_types_by_node(
+  const std::string & node_name,
+  const std::string & namespace_,
+  bool no_demangle) const
+{
+  rcl_names_and_types_t topic_names_and_types = rcl_get_zero_initialized_names_and_types();
+  auto topic_names_and_types_finalizer = rcpputils::make_scope_exit(
+    [&topic_names_and_types]() {
+      if (rcl_names_and_types_fini(&topic_names_and_types) != RCL_RET_OK) {
+        RCLCPP_ERROR(
+          rclcpp::get_logger("rclcpp"), "could not destroy topic names and types");
+      }
+    });
+  rcl_allocator_t allocator = rcl_get_default_allocator();
+  rcl_ret_t ret = rcl_get_publisher_names_and_types_by_node(
+    node_base_->get_rcl_node_handle(),
+    &allocator,
+    no_demangle,
+    node_name.c_str(),
+    namespace_.c_str(),
+    &topic_names_and_types);
+  if (ret != RCL_RET_OK) {
+    throw_from_rcl_error(ret, "failed to get topic names and types by node");
+  }
+
+  std::map<std::string, std::vector<std::string>> topics_and_types;
+  for (size_t i = 0; i < topic_names_and_types.names.size; ++i) {
+    std::string topic_name = topic_names_and_types.names.data[i];
+    for (size_t j = 0; j < topic_names_and_types.types[i].size; ++j) {
+      topics_and_types[topic_name].emplace_back(topic_names_and_types.types[i].data[j]);
+    }
+  }
+
+  return topics_and_types;
+}
+
+std::map<std::string, std::vector<std::string>>
+NodeGraph::get_subscriber_names_and_types_by_node(
+  const std::string & node_name,
+  const std::string & namespace_,
+  bool no_demangle) const
+{
+  rcl_names_and_types_t topic_names_and_types = rcl_get_zero_initialized_names_and_types();
+  auto topic_names_and_types_finalizer = rcpputils::make_scope_exit(
+    [&topic_names_and_types]() {
+      if (rcl_names_and_types_fini(&topic_names_and_types) != RCL_RET_OK) {
+        RCLCPP_ERROR(
+          rclcpp::get_logger("rclcpp"), "could not destroy topic names and types");
+      }
+    });
+  rcl_allocator_t allocator = rcl_get_default_allocator();
+  rcl_ret_t ret = rcl_get_subscriber_names_and_types_by_node(
+    node_base_->get_rcl_node_handle(),
+    &allocator,
+    no_demangle,
+    node_name.c_str(),
+    namespace_.c_str(),
+    &topic_names_and_types);
+  if (ret != RCL_RET_OK) {
+    throw_from_rcl_error(ret, "failed to get topic names and types by node");
+  }
+
+  std::map<std::string, std::vector<std::string>> topics_and_types;
+  for (size_t i = 0; i < topic_names_and_types.names.size; ++i) {
+    std::string topic_name = topic_names_and_types.names.data[i];
+    for (size_t j = 0; j < topic_names_and_types.types[i].size; ++j) {
+      topics_and_types[topic_name].emplace_back(topic_names_and_types.types[i].data[j]);
+    }
+  }
+
+  return topics_and_types;
+}
+
 std::vector<std::string>
 NodeGraph::get_node_names() const
 {
@@ -206,6 +317,81 @@ NodeGraph::get_node_names() const
   return nodes;
 }
 
+std::vector<std::tuple<std::string, std::string, std::string>>
+NodeGraph::get_node_names_with_enclaves() const
+{
+  rcutils_string_array_t node_names_c =
+    rcutils_get_zero_initialized_string_array();
+  rcutils_string_array_t node_namespaces_c =
+    rcutils_get_zero_initialized_string_array();
+  rcutils_string_array_t node_enclaves_c =
+    rcutils_get_zero_initialized_string_array();
+
+  auto allocator = rcl_get_default_allocator();
+  auto ret = rcl_get_node_names_with_enclaves(
+    node_base_->get_rcl_node_handle(),
+    allocator,
+    &node_names_c,
+    &node_namespaces_c,
+    &node_enclaves_c);
+  if (ret != RCL_RET_OK) {
+    auto error_msg =
+      std::string("failed to get node names with enclaves: ") + rcl_get_error_string().str;
+    rcl_reset_error();
+    if (rcutils_string_array_fini(&node_names_c) != RCUTILS_RET_OK) {
+      error_msg += std::string(", failed also to cleanup node names, leaking memory: ") +
+        rcl_get_error_string().str;
+      rcl_reset_error();
+    }
+    if (rcutils_string_array_fini(&node_namespaces_c) != RCUTILS_RET_OK) {
+      error_msg += std::string(", failed also to cleanup node namespaces, leaking memory: ") +
+        rcl_get_error_string().str;
+      rcl_reset_error();
+    }
+    if (rcutils_string_array_fini(&node_enclaves_c) != RCUTILS_RET_OK) {
+      error_msg += std::string(", failed also to cleanup node enclaves, leaking memory: ") +
+        rcl_get_error_string().str;
+      rcl_reset_error();
+    }
+    throw std::runtime_error(error_msg);
+  }
+
+  std::vector<std::tuple<std::string, std::string, std::string>> node_tuples;
+  for (size_t i = 0; i < node_names_c.size; ++i) {
+    if (node_names_c.data[i] && node_namespaces_c.data[i] && node_enclaves_c.data[i]) {
+      node_tuples.emplace_back(
+        std::make_tuple(node_names_c.data[i], node_namespaces_c.data[i], node_enclaves_c.data[i]));
+    }
+  }
+
+  std::string error("failed to finalize array");
+  rcl_ret_t ret_names = rcutils_string_array_fini(&node_names_c);
+  if (ret_names != RCUTILS_RET_OK) {
+    error += std::string(", could not destroy node names, leaking memory: ") +
+      rcl_get_error_string().str;
+    rcl_reset_error();
+  }
+  rcl_ret_t ret_ns = rcutils_string_array_fini(&node_namespaces_c);
+  if (ret_ns != RCUTILS_RET_OK) {
+    error += std::string(", could not destroy node namespaces, leaking memory: ") +
+      rcl_get_error_string().str;
+    rcl_reset_error();
+  }
+
+  rcl_ret_t ret_ecv = rcutils_string_array_fini(&node_enclaves_c);
+  if (ret_ecv != RCUTILS_RET_OK) {
+    error += std::string(", could not destroy node enclaves, leaking memory: ") +
+      rcl_get_error_string().str;
+    rcl_reset_error();
+  }
+
+  if (ret_names != RCUTILS_RET_OK || ret_ns != RCUTILS_RET_OK || ret_ecv != RCUTILS_RET_OK) {
+    throw std::runtime_error(error);
+  }
+
+  return node_tuples;
+}
+
 std::vector<std::pair<std::string, std::string>>
 NodeGraph::get_node_names_and_namespaces() const
 {
@@ -237,7 +423,6 @@ NodeGraph::get_node_names_and_namespaces() const
     throw std::runtime_error(error_msg);
   }
 
-
   std::vector<std::pair<std::string, std::string>> node_names;
   node_names.reserve(node_names_c.size);
   for (size_t i = 0; i < node_names_c.size; ++i) {
@@ -348,12 +533,12 @@ NodeGraph::notify_graph_change()
     }
   }
   graph_cv_.notify_all();
-  {
-    auto notify_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    rcl_ret_t ret = rcl_trigger_guard_condition(node_base_->get_notify_guard_condition());
-    if (RCL_RET_OK != ret) {
-      throw_from_rcl_error(ret, "failed to trigger notify guard condition");
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on graph change: ") + ex.what());
   }
 }
 

rclcpp/src/rclcpp/node_interfaces/node_parameters.cpp

@@ -32,7 +32,6 @@
 #include "rcl_interfaces/srv/list_parameters.hpp"
 #include "rclcpp/create_publisher.hpp"
 #include "rclcpp/parameter_map.hpp"
-#include "rclcpp/scope_exit.hpp"
 #include "rcutils/logging_macros.h"
 #include "rmw/qos_profiles.h"
 
@@ -349,6 +348,21 @@ __declare_parameter_common(
     initial_value = &overrides_it->second;
   }
 
+  // If there is no initial value, then skip initialization
+  if (initial_value->get_type() == rclcpp::PARAMETER_NOT_SET) {
+    // Add declared parameters to storage (without a value)
+    parameter_infos[name].descriptor.name = name;
+    if (parameter_descriptor.dynamic_typing) {
+      parameter_infos[name].descriptor.type = rclcpp::PARAMETER_NOT_SET;
+    } else {
+      parameter_infos[name].descriptor.type = parameter_descriptor.type;
+    }
+    parameters_out[name] = parameter_infos.at(name);
+    rcl_interfaces::msg::SetParametersResult result;
+    result.successful = true;
+    return result;
+  }
+
   // Check with the user's callback to see if the initial value can be set.
   std::vector<rclcpp::Parameter> parameter_wrappers {rclcpp::Parameter(name, *initial_value)};
   // This function also takes care of default vs initial value.
@@ -413,14 +427,6 @@ declare_parameter_helper(
     parameter_descriptor.type = static_cast<uint8_t>(type);
   }
 
-  if (
-    rclcpp::PARAMETER_NOT_SET == default_value.get_type() &&
-    overrides.find(name) == overrides.end() &&
-    parameter_descriptor.dynamic_typing == false)
-  {
-    throw rclcpp::exceptions::NoParameterOverrideProvided(name);
-  }
-
   rcl_interfaces::msg::ParameterEvent parameter_event;
   auto result = __declare_parameter_common(
     name,
@@ -806,14 +812,21 @@ NodeParameters::get_parameters(const std::vector<std::string> & names) const
 rclcpp::Parameter
 NodeParameters::get_parameter(const std::string & name) const
 {
-  rclcpp::Parameter parameter;
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
 
-  if (get_parameter(name, parameter)) {
-    return parameter;
+  auto param_iter = parameters_.find(name);
+  if (
+    parameters_.end() != param_iter &&
+    (param_iter->second.value.get_type() != rclcpp::ParameterType::PARAMETER_NOT_SET ||
+    param_iter->second.descriptor.dynamic_typing))
+  {
+    return rclcpp::Parameter{name, param_iter->second.value};
   } else if (this->allow_undeclared_) {
-    return parameter;
-  } else {
+    return rclcpp::Parameter{};
+  } else if (parameters_.end() == param_iter) {
     throw rclcpp::exceptions::ParameterNotDeclaredException(name);
+  } else {
+    throw rclcpp::exceptions::ParameterUninitializedException(name);
   }
 }
 

rclcpp/src/rclcpp/node_interfaces/node_services.cpp

@@ -41,14 +41,12 @@ NodeServices::add_service(
   }
 
   // Notify the executor that a new service was created using the parent Node.
-  {
-    auto notify_guard_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    if (rcl_trigger_guard_condition(node_base_->get_notify_guard_condition()) != RCL_RET_OK) {
-      throw std::runtime_error(
-              std::string("Failed to notify wait set on service creation: ") +
-              rmw_get_error_string().str
-      );
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on service creation: ") + ex.what());
   }
 }
 
@@ -68,14 +66,12 @@ NodeServices::add_client(
   }
 
   // Notify the executor that a new client was created using the parent Node.
-  {
-    auto notify_guard_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    if (rcl_trigger_guard_condition(node_base_->get_notify_guard_condition()) != RCL_RET_OK) {
-      throw std::runtime_error(
-              std::string("Failed to notify wait set on client creation: ") +
-              rmw_get_error_string().str
-      );
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on client creation: ") + ex.what());
   }
 }
 

rclcpp/src/rclcpp/node_interfaces/node_timers.cpp

@@ -41,11 +41,15 @@ NodeTimers::add_timer(
   } else {
     node_base_->get_default_callback_group()->add_timer(timer);
   }
-  if (rcl_trigger_guard_condition(node_base_->get_notify_guard_condition()) != RCL_RET_OK) {
+
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
     throw std::runtime_error(
-            std::string("Failed to notify wait set on timer creation: ") +
-            rmw_get_error_string().str);
+            std::string("failed to notify wait set on timer creation: ") + ex.what());
   }
+
   TRACEPOINT(
     rclcpp_timer_link_node,
     static_cast<const void *>(timer->get_timer_handle().get()),

rclcpp/src/rclcpp/node_interfaces/node_topics.cpp

@@ -60,13 +60,12 @@ NodeTopics::add_publisher(
   }
 
   // Notify the executor that a new publisher was created using the parent Node.
-  {
-    auto notify_guard_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    if (rcl_trigger_guard_condition(node_base_->get_notify_guard_condition()) != RCL_RET_OK) {
-      throw std::runtime_error(
-              std::string("Failed to notify wait set on publisher creation: ") +
-              rmw_get_error_string().str);
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on publisher creation: ") + ex.what());
   }
 }
 
@@ -108,13 +107,12 @@ NodeTopics::add_subscription(
   }
 
   // Notify the executor that a new subscription was created using the parent Node.
-  {
-    auto notify_guard_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    auto ret = rcl_trigger_guard_condition(node_base_->get_notify_guard_condition());
-    if (ret != RCL_RET_OK) {
-      using rclcpp::exceptions::throw_from_rcl_error;
-      throw_from_rcl_error(ret, "failed to notify wait set on subscription creation");
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on subscription creation: ") + ex.what());
   }
 }
 

rclcpp/src/rclcpp/node_interfaces/node_waitables.cpp

@@ -41,14 +41,12 @@ NodeWaitables::add_waitable(
   }
 
   // Notify the executor that a new waitable was created using the parent Node.
-  {
-    auto notify_guard_condition_lock = node_base_->acquire_notify_guard_condition_lock();
-    if (rcl_trigger_guard_condition(node_base_->get_notify_guard_condition()) != RCL_RET_OK) {
-      throw std::runtime_error(
-              std::string("Failed to notify wait set on waitable creation: ") +
-              rmw_get_error_string().str
-      );
-    }
+  auto & node_gc = node_base_->get_notify_guard_condition();
+  try {
+    node_gc.trigger();
+  } catch (const rclcpp::exceptions::RCLError & ex) {
+    throw std::runtime_error(
+            std::string("failed to notify wait set on waitable creation: ") + ex.what());
   }
 }
 

rclcpp/src/rclcpp/parameter_event_handler.cpp

@@ -29,10 +29,10 @@ ParameterEventCallbackHandle::SharedPtr
 ParameterEventHandler::add_parameter_event_callback(
   ParameterEventCallbackType callback)
 {
-  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto handle = std::make_shared<ParameterEventCallbackHandle>();
   handle->callback = callback;
-  event_callbacks_.emplace_front(handle);
+  callbacks_->event_callbacks_.emplace_front(handle);
 
   return handle;
 }
@@ -41,15 +41,15 @@ void
 ParameterEventHandler::remove_parameter_event_callback(
   ParameterEventCallbackHandle::SharedPtr callback_handle)
 {
-  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto it = std::find_if(
-    event_callbacks_.begin(),
-    event_callbacks_.end(),
+    callbacks_->event_callbacks_.begin(),
+    callbacks_->event_callbacks_.end(),
     [callback_handle](const auto & weak_handle) {
       return callback_handle.get() == weak_handle.lock().get();
     });
-  if (it != event_callbacks_.end()) {
-    event_callbacks_.erase(it);
+  if (it != callbacks_->event_callbacks_.end()) {
+    callbacks_->event_callbacks_.erase(it);
   } else {
     throw std::runtime_error("Callback doesn't exist");
   }
@@ -61,7 +61,7 @@ ParameterEventHandler::add_parameter_callback(
   ParameterCallbackType callback,
   const std::string & node_name)
 {
-  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto full_node_name = resolve_path(node_name);
 
   auto handle = std::make_shared<ParameterCallbackHandle>();
@@ -69,7 +69,7 @@ ParameterEventHandler::add_parameter_callback(
   handle->parameter_name = parameter_name;
   handle->node_name = full_node_name;
   // the last callback registered is executed first.
-  parameter_callbacks_[{parameter_name, full_node_name}].emplace_front(handle);
+  callbacks_->parameter_callbacks_[{parameter_name, full_node_name}].emplace_front(handle);
 
   return handle;
 }
@@ -78,9 +78,9 @@ void
 ParameterEventHandler::remove_parameter_callback(
   ParameterCallbackHandle::SharedPtr callback_handle)
 {
-  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto handle = callback_handle.get();
-  auto & container = parameter_callbacks_[{handle->parameter_name, handle->node_name}];
+  auto & container = callbacks_->parameter_callbacks_[{handle->parameter_name, handle->node_name}];
   auto it = std::find_if(
     container.begin(),
     container.end(),
@@ -90,7 +90,7 @@ ParameterEventHandler::remove_parameter_callback(
   if (it != container.end()) {
     container.erase(it);
     if (container.empty()) {
-      parameter_callbacks_.erase({handle->parameter_name, handle->node_name});
+      callbacks_->parameter_callbacks_.erase({handle->parameter_name, handle->node_name});
     }
   } else {
     throw std::runtime_error("Callback doesn't exist");
@@ -101,8 +101,8 @@ bool
 ParameterEventHandler::get_parameter_from_event(
   const rcl_interfaces::msg::ParameterEvent & event,
   rclcpp::Parameter & parameter,
-  const std::string parameter_name,
-  const std::string node_name)
+  const std::string & parameter_name,
+  const std::string & node_name)
 {
   if (event.node != node_name) {
     return false;
@@ -128,8 +128,8 @@ ParameterEventHandler::get_parameter_from_event(
 rclcpp::Parameter
 ParameterEventHandler::get_parameter_from_event(
   const rcl_interfaces::msg::ParameterEvent & event,
-  const std::string parameter_name,
-  const std::string node_name)
+  const std::string & parameter_name,
+  const std::string & node_name)
 {
   rclcpp::Parameter p;
   if (!get_parameter_from_event(event, p, parameter_name, node_name)) {
@@ -158,7 +158,7 @@ ParameterEventHandler::get_parameters_from_event(
 }
 
 void
-ParameterEventHandler::event_callback(const rcl_interfaces::msg::ParameterEvent & event)
+ParameterEventHandler::Callbacks::event_callback(const rcl_interfaces::msg::ParameterEvent & event)
 {
   std::lock_guard<std::recursive_mutex> lock(mutex_);
 

rclcpp/src/rclcpp/qos_event.cpp

@@ -51,14 +51,13 @@ QOSEventHandlerBase::get_number_of_ready_events()
 }
 
 /// Add the Waitable to a wait set.
-bool
+void
 QOSEventHandlerBase::add_to_wait_set(rcl_wait_set_t * wait_set)
 {
   rcl_ret_t ret = rcl_wait_set_add_event(wait_set, &event_handle_, &wait_set_event_index_);
   if (RCL_RET_OK != ret) {
     exceptions::throw_from_rcl_error(ret, "Couldn't add event to wait set");
   }
-  return true;
 }
 
 /// Check if the Waitable is ready.

rclcpp/src/rclcpp/signal_handler.cpp

@@ -30,80 +30,131 @@
 #endif
 
 #include "rclcpp/logging.hpp"
+#include "rclcpp/utilities.hpp"
 #include "rcutils/strerror.h"
 #include "rmw/impl/cpp/demangle.hpp"
 
 using rclcpp::SignalHandler;
+using rclcpp::SignalHandlerOptions;
 
-// initialize static storage in SignalHandler class
-SignalHandler::signal_handler_type SignalHandler::old_signal_handler_;
-std::atomic_bool SignalHandler::signal_received_ = ATOMIC_VAR_INIT(false);
-std::atomic_bool SignalHandler::wait_for_signal_is_setup_ = ATOMIC_VAR_INIT(false);
-#if defined(_WIN32)
-HANDLE SignalHandler::signal_handler_sem_;
-#elif defined(__APPLE__)
-dispatch_semaphore_t SignalHandler::signal_handler_sem_;
-#else  // posix
-sem_t SignalHandler::signal_handler_sem_;
+SignalHandler::signal_handler_type
+SignalHandler::set_signal_handler(
+  int signal_value,
+  const SignalHandler::signal_handler_type & signal_handler)
+{
+  bool signal_handler_install_failed;
+  SignalHandler::signal_handler_type old_signal_handler;
+#if defined(RCLCPP_HAS_SIGACTION)
+  ssize_t ret = sigaction(signal_value, &signal_handler, &old_signal_handler);
+  signal_handler_install_failed = (ret == -1);
+#else
+  old_signal_handler = std::signal(signal_value, signal_handler);
+  signal_handler_install_failed = (old_signal_handler == SIG_ERR);
 #endif
+  if (signal_handler_install_failed) {
+    char error_string[1024];
+    rcutils_strerror(error_string, sizeof(error_string));
+    auto msg =
+      "Failed to set signal handler (" + std::to_string(errno) + "): " + error_string;
+    throw std::runtime_error(msg);
+  }
+  return old_signal_handler;
+}
 
-// The logger must be initialized before the local static variable signal_handler,
-// from the method get_global_signal_handler(), so that it is destructed after
-// it, because the destructor of SignalHandler uses this logger object.
-static rclcpp::Logger g_logger = rclcpp::get_logger("rclcpp");
+// Unfortunately macros (or duplicated code) are needed here,
+// as the signal handler must be a function pointer.
+#if defined(RCLCPP_HAS_SIGACTION)
+void
+SignalHandler::signal_handler(
+  int signum, siginfo_t * siginfo, void * context)
+{
+  RCLCPP_INFO(SignalHandler::get_logger(), "signal_handler(signum=%d)", signum);
+  auto & instance = SignalHandler::get_global_signal_handler();
+
+  auto old_signal_handler = instance.get_old_signal_handler(signum);
+  if (old_signal_handler.sa_flags & SA_SIGINFO) {
+    if (old_signal_handler.sa_sigaction != NULL) {
+      old_signal_handler.sa_sigaction(signum, siginfo, context);
+    }
+  } else {
+    if (
+      old_signal_handler.sa_handler != NULL &&  /* Is set */
+      old_signal_handler.sa_handler != SIG_DFL &&  /* Is not default*/
+      old_signal_handler.sa_handler != SIG_IGN)  /* Is not ignored */
+    {
+      old_signal_handler.sa_handler(signum);
+    }
+  }
+  instance.signal_handler_common();
+}
+#else
+void
+SignalHandler::signal_handler(int signum)
+{
+  RCLCPP_INFO(SignalHandler::get_logger(), "signal_handler(signum=%d)", signum);
+  auto & instance = SignalHandler::get_global_signal_handler();
+  auto old_signal_handler = instance.get_old_signal_handler(signum);
+  if (
+    SIG_ERR != old_signal_handler && SIG_IGN != old_signal_handler &&
+    SIG_DFL != old_signal_handler)
+  {
+    old_signal_handler(signum);
+  }
+  instance.signal_handler_common();
+}
+#endif
 
 rclcpp::Logger &
 SignalHandler::get_logger()
 {
-  return g_logger;
+  return SignalHandler::get_global_signal_handler().logger_;
 }
 
 SignalHandler &
 SignalHandler::get_global_signal_handler()
 {
-  // This is initialized after the g_logger static global, ensuring
-  // SignalHandler::get_logger() may be called from the destructor of
-  // SignalHandler, according to this:
-  //
-  //   Variables declared at block scope with the specifier static have static
-  //   storage duration but are initialized the first time control passes
-  //   through their declaration (unless their initialization is zero- or
-  //   constant-initialization, which can be performed before the block is
-  //   first entered). On all further calls, the declaration is skipped.
-  //
-  // -- https://en.cppreference.com/w/cpp/language/storage_duration#Static_local_variables
-  //
-  // Which is guaranteed to occur after static initialization for global (see:
-  // https://en.cppreference.com/w/cpp/language/initialization#Static_initialization),
-  // which is when g_logger will be initialized.
-  // And destruction will occur in the reverse order.
   static SignalHandler signal_handler;
   return signal_handler;
 }
 
 bool
-SignalHandler::install()
+SignalHandler::install(SignalHandlerOptions signal_handler_options)
 {
   std::lock_guard<std::mutex> lock(install_mutex_);
   bool already_installed = installed_.exchange(true);
   if (already_installed) {
     return false;
   }
+  if (signal_handler_options == SignalHandlerOptions::None) {
+    return true;
+  }
+  signal_handlers_options_ = signal_handler_options;
   try {
     setup_wait_for_signal();
     signal_received_.store(false);
 
-    SignalHandler::signal_handler_type signal_handler_argument;
+    SignalHandler::signal_handler_type handler_argument;
 #if defined(RCLCPP_HAS_SIGACTION)
-    memset(&signal_handler_argument, 0, sizeof(signal_handler_argument));
-    sigemptyset(&signal_handler_argument.sa_mask);
-    signal_handler_argument.sa_sigaction = signal_handler;
-    signal_handler_argument.sa_flags = SA_SIGINFO;
+    memset(&handler_argument, 0, sizeof(handler_argument));
+    sigemptyset(&handler_argument.sa_mask);
+    handler_argument.sa_sigaction = &this->signal_handler;
+    handler_argument.sa_flags = SA_SIGINFO;
 #else
-    signal_handler_argument = signal_handler;
+    handler_argument = &this->signal_handler;
 #endif
+    if (
+      signal_handler_options == SignalHandlerOptions::SigInt ||
+      signal_handler_options == SignalHandlerOptions::All)
+    {
+      old_sigint_handler_ = set_signal_handler(SIGINT, handler_argument);
+    }
 
-    old_signal_handler_ = SignalHandler::set_signal_handler(SIGINT, signal_handler_argument);
+    if (
+      signal_handler_options == SignalHandlerOptions::SigTerm ||
+      signal_handler_options == SignalHandlerOptions::All)
+    {
+      old_sigterm_handler_ = set_signal_handler(SIGTERM, handler_argument);
+    }
 
     signal_handler_thread_ = std::thread(&SignalHandler::deferred_signal_handler, this);
   } catch (...) {
@@ -125,7 +176,19 @@ SignalHandler::uninstall()
   try {
     // TODO(wjwwood): what happens if someone overrides our signal handler then calls uninstall?
     //   I think we need to assert that we're the current signal handler, and mitigate if not.
-    set_signal_handler(SIGINT, old_signal_handler_);
+    if (
+      SignalHandlerOptions::SigInt == signal_handlers_options_ ||
+      SignalHandlerOptions::All == signal_handlers_options_)
+    {
+      set_signal_handler(SIGINT, old_sigint_handler_);
+    }
+    if (
+      SignalHandlerOptions::SigTerm == signal_handlers_options_ ||
+      SignalHandlerOptions::All == signal_handlers_options_)
+    {
+      set_signal_handler(SIGTERM, old_sigterm_handler_);
+    }
+    signal_handlers_options_ = SignalHandlerOptions::None;
     RCLCPP_DEBUG(get_logger(), "SignalHandler::uninstall(): notifying deferred signal handler");
     notify_signal_handler();
     signal_handler_thread_.join();
@@ -151,98 +214,57 @@ SignalHandler::~SignalHandler()
   } catch (const std::exception & exc) {
     RCLCPP_ERROR(
       get_logger(),
-      "caught %s exception when uninstalling the sigint handler in rclcpp::~SignalHandler: %s",
+      "caught %s exception when uninstalling signal handlers in rclcpp::~SignalHandler: %s",
       rmw::impl::cpp::demangle(exc).c_str(), exc.what());
   } catch (...) {
     RCLCPP_ERROR(
       get_logger(),
-      "caught unknown exception when uninstalling the sigint handler in rclcpp::~SignalHandler");
+      "caught unknown exception when uninstalling signal handlers in rclcpp::~SignalHandler");
   }
 }
 
 SignalHandler::signal_handler_type
-SignalHandler::set_signal_handler(
-  int signal_value,
-  const SignalHandler::signal_handler_type & signal_handler)
+SignalHandler::get_old_signal_handler(int signum)
 {
-  bool signal_handler_install_failed;
-  SignalHandler::signal_handler_type old_signal_handler;
-#if defined(RCLCPP_HAS_SIGACTION)
-  ssize_t ret = sigaction(signal_value, &signal_handler, &old_signal_handler);
-  signal_handler_install_failed = (ret == -1);
-#else
-  old_signal_handler = std::signal(signal_value, signal_handler);
-  signal_handler_install_failed = (old_signal_handler == SIG_ERR);
-#endif
-  if (signal_handler_install_failed) {
-    char error_string[1024];
-    rcutils_strerror(error_string, sizeof(error_string));
-    auto msg =
-      "Failed to set SIGINT signal handler (" + std::to_string(errno) + "): " + error_string;
-    throw std::runtime_error(msg);
+  if (SIGINT == signum) {
+    return old_sigint_handler_;
+  } else if (SIGTERM == signum) {
+    return old_sigterm_handler_;
   }
-
-  return old_signal_handler;
+#if defined(RCLCPP_HAS_SIGACTION)
+  SignalHandler::signal_handler_type ret;
+  memset(&ret, 0, sizeof(ret));
+  sigemptyset(&ret.sa_mask);
+  ret.sa_handler = SIG_DFL;
+  return ret;
+#else
+  return SIG_DFL;
+#endif
 }
 
 void
 SignalHandler::signal_handler_common()
 {
-  signal_received_.store(true);
+  auto & instance = SignalHandler::get_global_signal_handler();
+  instance.signal_received_.store(true);
   RCLCPP_DEBUG(
     get_logger(),
-    "signal_handler(): SIGINT received, notifying deferred signal handler");
-  notify_signal_handler();
+    "signal_handler(): notifying deferred signal handler");
+  instance.notify_signal_handler();
 }
 
-#if defined(RCLCPP_HAS_SIGACTION)
-void
-SignalHandler::signal_handler(int signal_value, siginfo_t * siginfo, void * context)
-{
-  RCLCPP_INFO(get_logger(), "signal_handler(signal_value=%d)", signal_value);
-
-  if (old_signal_handler_.sa_flags & SA_SIGINFO) {
-    if (old_signal_handler_.sa_sigaction != NULL) {
-      old_signal_handler_.sa_sigaction(signal_value, siginfo, context);
-    }
-  } else {
-    if (
-      old_signal_handler_.sa_handler != NULL &&  // Is set
-      old_signal_handler_.sa_handler != SIG_DFL &&  // Is not default
-      old_signal_handler_.sa_handler != SIG_IGN)  // Is not ignored
-    {
-      old_signal_handler_.sa_handler(signal_value);
-    }
-  }
-
-  signal_handler_common();
-}
-#else
-void
-SignalHandler::signal_handler(int signal_value)
-{
-  RCLCPP_INFO(get_logger(), "signal_handler(signal_value=%d)", signal_value);
-
-  if (old_signal_handler_) {
-    old_signal_handler_(signal_value);
-  }
-
-  signal_handler_common();
-}
-#endif
-
 void
 SignalHandler::deferred_signal_handler()
 {
   while (true) {
     if (signal_received_.exchange(false)) {
-      RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): SIGINT received, shutting down");
+      RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): shutting down");
       for (auto context_ptr : rclcpp::get_contexts()) {
-        if (context_ptr->get_init_options().shutdown_on_sigint) {
+        if (context_ptr->get_init_options().shutdown_on_signal) {
           RCLCPP_DEBUG(
             get_logger(),
             "deferred_signal_handler(): "
-            "shutting down rclcpp::Context @ %p, because it had shutdown_on_sigint == true",
+            "shutting down rclcpp::Context @ %p, because it had shutdown_on_signal == true",
             static_cast<void *>(context_ptr.get()));
           context_ptr->shutdown("signal handler");
         }
@@ -252,9 +274,11 @@ SignalHandler::deferred_signal_handler()
       RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): signal handling uninstalled");
       break;
     }
-    RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): waiting for SIGINT or uninstall");
+    RCLCPP_DEBUG(
+      get_logger(), "deferred_signal_handler(): waiting for SIGINT/SIGTERM or uninstall");
     wait_for_signal();
-    RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): woken up due to SIGINT or uninstall");
+    RCLCPP_DEBUG(
+      get_logger(), "deferred_signal_handler(): woken up due to SIGINT/SIGTERM or uninstall");
   }
 }
 
@@ -356,3 +380,9 @@ SignalHandler::notify_signal_handler() noexcept
   }
 #endif
 }
+
+rclcpp::SignalHandlerOptions
+SignalHandler::get_current_signal_handler_options()
+{
+  return signal_handlers_options_;
+}

rclcpp/src/rclcpp/signal_handler.hpp

@@ -21,6 +21,7 @@
 #include <thread>
 
 #include "rclcpp/logging.hpp"
+#include "rclcpp/utilities.hpp"
 
 // includes for semaphore notification code
 #if defined(_WIN32)
@@ -39,14 +40,14 @@
 namespace rclcpp
 {
 
-/// Responsible for manaaging the SIGINT signal handling.
+/// Responsible for managing the SIGINT/SIGTERM signal handling.
 /**
  * This class is responsible for:
  *
- * - installing the signal handler for SIGINT
- * - uninstalling the signal handler for SIGINT
- * - creating a thread to execute "on sigint" work outside of the signal handler
- * - safely notifying the dedicated signal handling thread when receiving SIGINT
+ * - installing the signal handler for SIGINT/SIGTERM
+ * - uninstalling the signal handler for SIGINT/SIGTERM
+ * - creating a thread to execute "on signal" work outside of the signal handler
+ * - safely notifying the dedicated signal handling thread when receiving SIGINT/SIGTERM
  * - implementation of all of the signal handling work, like shutting down contexts
  *
  * \internal
@@ -64,15 +65,18 @@ public:
   rclcpp::Logger &
   get_logger();
 
-  /// Install the signal handler for SIGINT and start the dedicated signal handling thread.
+  /// Install the signal handler for SIGINT/SIGTERM and start the dedicated signal handling thread.
   /**
-   * Also stores the current signal handler to be called on SIGINT and to
+   * Also stores the current signal handler to be called on signal and to
    * restore when uninstalling this signal handler.
+   *
+   * \param signal_handler_options option to indicate which signal handlers should be installed.
    */
   bool
-  install();
+  install(SignalHandlerOptions signal_handler_options = SignalHandlerOptions::All);
 
-  /// Uninstall the signal handler for SIGINT and join the dedicated singal handling thread.
+  /// Uninstall the signal handler for SIGINT/SIGTERM and join the dedicated singal handling
+  /// thread.
   /**
    * Also restores the previous signal handler.
    */
@@ -83,26 +87,34 @@ public:
   bool
   is_installed();
 
+  /// Get the current signal handler options.
+  /**
+   * If no signal handler is installed, SignalHandlerOptions::None is returned.
+   */
+  rclcpp::SignalHandlerOptions
+  get_current_signal_handler_options();
+
 private:
-  SignalHandler() = default;
-
-  ~SignalHandler();
-
+  /// Signal handler type, platform dependent.
 #if defined(RCLCPP_HAS_SIGACTION)
   using signal_handler_type = struct sigaction;
 #else
   using signal_handler_type = void (*)(int);
 #endif
-  // POSIX signal handler structure storage for the existing signal handler.
-  static SignalHandler::signal_handler_type old_signal_handler_;
 
-  /// Set the signal handler function.
-  static
-  SignalHandler::signal_handler_type
-  set_signal_handler(int signal_value, const SignalHandler::signal_handler_type & signal_handler);
+
+  SignalHandler() = default;
+
+  ~SignalHandler();
+
+  SignalHandler(const SignalHandler &) = delete;
+  SignalHandler(SignalHandler &&) = delete;
+  SignalHandler &
+  operator=(const SignalHandler &) = delete;
+  SignalHandler &&
+  operator=(SignalHandler &&) = delete;
 
   /// Common signal handler code between sigaction and non-sigaction versions.
-  static
   void
   signal_handler_common();
 
@@ -127,7 +139,6 @@ private:
    * This must be called before wait_for_signal() or notify_signal_handler().
    * This is not thread-safe.
    */
-  static
   void
   setup_wait_for_signal();
 
@@ -137,7 +148,6 @@ private:
    *
    * This is not thread-safe.
    */
-  static
   void
   teardown_wait_for_signal() noexcept;
 
@@ -147,7 +157,6 @@ private:
    *
    * This is not thread-safe.
    */
-  static
   void
   wait_for_signal();
 
@@ -158,29 +167,45 @@ private:
    *
    * This is thread-safe.
    */
-  static
   void
   notify_signal_handler() noexcept;
 
+  static
+  signal_handler_type
+  set_signal_handler(
+    int signal_value,
+    const signal_handler_type & signal_handler);
+
+  signal_handler_type
+  get_old_signal_handler(int signum);
+
+  rclcpp::SignalHandlerOptions signal_handlers_options_ = rclcpp::SignalHandlerOptions::None;
+
+  signal_handler_type old_sigint_handler_;
+  signal_handler_type old_sigterm_handler_;
+
+  // logger instance
+  rclcpp::Logger logger_ = rclcpp::get_logger("rclcpp");
+
   // Whether or not a signal has been received.
-  static std::atomic_bool signal_received_;
+  std::atomic_bool signal_received_ = false;
   // A thread to which singal handling tasks are deferred.
   std::thread signal_handler_thread_;
 
   // A mutex used to synchronize the install() and uninstall() methods.
   std::mutex install_mutex_;
   // Whether or not the signal handler has been installed.
-  std::atomic_bool installed_{false};
+  std::atomic_bool installed_ = false;
 
   // Whether or not the semaphore for wait_for_signal is setup.
-  static std::atomic_bool wait_for_signal_is_setup_;
+  std::atomic_bool wait_for_signal_is_setup_;
   // Storage for the wait_for_signal semaphore.
 #if defined(_WIN32)
-  static HANDLE signal_handler_sem_;
+  HANDLE signal_handler_sem_;
 #elif defined(__APPLE__)
-  static dispatch_semaphore_t signal_handler_sem_;
+  dispatch_semaphore_t signal_handler_sem_;
 #else  // posix
-  static sem_t signal_handler_sem_;
+  sem_t signal_handler_sem_;
 #endif
 };
 

rclcpp/src/rclcpp/subscription_base.cpp

@@ -143,6 +143,7 @@ SubscriptionBase::take_type_erased(void * message_out, rclcpp::MessageInfo & mes
     &message_info_out.get_rmw_message_info(),
     nullptr  // rmw_subscription_allocation_t is unused here
   );
+  TRACEPOINT(rclcpp_take, static_cast<const void *>(message_out));
   if (RCL_RET_SUBSCRIPTION_TAKE_FAILED == ret) {
     return false;
   } else if (RCL_RET_OK != ret) {

rclcpp/src/rclcpp/subscription_intra_process_base.cpp

@@ -13,16 +13,14 @@
 // limitations under the License.
 
 #include "rclcpp/experimental/subscription_intra_process_base.hpp"
+#include "rclcpp/detail/add_guard_condition_to_rcl_wait_set.hpp"
 
 using rclcpp::experimental::SubscriptionIntraProcessBase;
 
-bool
+void
 SubscriptionIntraProcessBase::add_to_wait_set(rcl_wait_set_t * wait_set)
 {
-  std::lock_guard<std::recursive_mutex> lock(reentrant_mutex_);
-
-  rcl_ret_t ret = rcl_wait_set_add_guard_condition(wait_set, &gc_, NULL);
-  return RCL_RET_OK == ret;
+  detail::add_guard_condition_to_rcl_wait_set(*wait_set, gc_);
 }
 
 const char *
@@ -31,7 +29,7 @@ SubscriptionIntraProcessBase::get_topic_name() const
   return topic_name_.c_str();
 }
 
-rmw_qos_profile_t
+rclcpp::QoS
 SubscriptionIntraProcessBase::get_actual_qos() const
 {
   return qos_profile_;

rclcpp/src/rclcpp/time_source.cpp

@@ -33,29 +33,499 @@
 namespace rclcpp
 {
 
+class TimeSource::ClocksState : public std::enable_shared_from_this<ClocksState>
+{
+public:
+  ClocksState()
+  : logger_(rclcpp::get_logger("rclcpp"))
+  {
+  }
+
+  // An internal method to use in the clock callback that iterates and enables all clocks
+  void enable_ros_time()
+  {
+    if (ros_time_active_) {
+      // already enabled no-op
+      return;
+    }
+
+    // Local storage
+    ros_time_active_ = true;
+
+    // Update all attached clocks to zero or last recorded time
+    std::lock_guard<std::mutex> guard(clock_list_lock_);
+    auto time_msg = std::make_shared<builtin_interfaces::msg::Time>();
+    if (last_msg_set_) {
+      time_msg = std::make_shared<builtin_interfaces::msg::Time>(last_msg_set_->clock);
+    }
+    for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
+      set_clock(time_msg, true, *it);
+    }
+  }
+
+  // An internal method to use in the clock callback that iterates and disables all clocks
+  void disable_ros_time()
+  {
+    if (!ros_time_active_) {
+      // already disabled no-op
+      return;
+    }
+
+    // Local storage
+    ros_time_active_ = false;
+
+    // Update all attached clocks
+    std::lock_guard<std::mutex> guard(clock_list_lock_);
+    for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
+      auto msg = std::make_shared<builtin_interfaces::msg::Time>();
+      set_clock(msg, false, *it);
+    }
+  }
+
+  // Check if ROS time is active
+  bool is_ros_time_active() const
+  {
+    return ros_time_active_;
+  }
+
+  // Attach a clock
+  void attachClock(rclcpp::Clock::SharedPtr clock)
+  {
+    if (clock->get_clock_type() != RCL_ROS_TIME) {
+      throw std::invalid_argument("Cannot attach clock to a time source that's not a ROS clock");
+    }
+
+    std::lock_guard<std::mutex> guard(clock_list_lock_);
+    associated_clocks_.push_back(clock);
+    // Set the clock to zero unless there's a recently received message
+    auto time_msg = std::make_shared<builtin_interfaces::msg::Time>();
+    if (last_msg_set_) {
+      time_msg = std::make_shared<builtin_interfaces::msg::Time>(last_msg_set_->clock);
+    }
+    set_clock(time_msg, ros_time_active_, clock);
+  }
+
+  // Detach a clock
+  void detachClock(rclcpp::Clock::SharedPtr clock)
+  {
+    std::lock_guard<std::mutex> guard(clock_list_lock_);
+    auto result = std::find(associated_clocks_.begin(), associated_clocks_.end(), clock);
+    if (result != associated_clocks_.end()) {
+      associated_clocks_.erase(result);
+    } else {
+      RCLCPP_ERROR(logger_, "failed to remove clock");
+    }
+  }
+
+  // Internal helper function used inside iterators
+  static void set_clock(
+    const builtin_interfaces::msg::Time::SharedPtr msg,
+    bool set_ros_time_enabled,
+    rclcpp::Clock::SharedPtr clock)
+  {
+    std::lock_guard<std::mutex> clock_guard(clock->get_clock_mutex());
+
+    // Do change
+    if (!set_ros_time_enabled && clock->ros_time_is_active()) {
+      auto ret = rcl_disable_ros_time_override(clock->get_clock_handle());
+      if (ret != RCL_RET_OK) {
+        rclcpp::exceptions::throw_from_rcl_error(
+          ret, "Failed to disable ros_time_override_status");
+      }
+    } else if (set_ros_time_enabled && !clock->ros_time_is_active()) {
+      auto ret = rcl_enable_ros_time_override(clock->get_clock_handle());
+      if (ret != RCL_RET_OK) {
+        rclcpp::exceptions::throw_from_rcl_error(
+          ret, "Failed to enable ros_time_override_status");
+      }
+    }
+
+    auto ret = rcl_set_ros_time_override(
+      clock->get_clock_handle(),
+      rclcpp::Time(*msg).nanoseconds());
+    if (ret != RCL_RET_OK) {
+      rclcpp::exceptions::throw_from_rcl_error(
+        ret, "Failed to set ros_time_override_status");
+    }
+  }
+
+  // Internal helper function
+  void set_all_clocks(
+    const builtin_interfaces::msg::Time::SharedPtr msg,
+    bool set_ros_time_enabled)
+  {
+    std::lock_guard<std::mutex> guard(clock_list_lock_);
+    for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
+      set_clock(msg, set_ros_time_enabled, *it);
+    }
+  }
+
+  // Cache the last clock message received
+  void cache_last_msg(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg)
+  {
+    last_msg_set_ = msg;
+  }
+
+private:
+  // Store (and update on node attach) logger for logging.
+  Logger logger_;
+
+  // A lock to protect iterating the associated_clocks_ field.
+  std::mutex clock_list_lock_;
+  // A vector to store references to associated clocks.
+  std::vector<rclcpp::Clock::SharedPtr> associated_clocks_;
+
+  // Local storage of validity of ROS time
+  // This is needed when new clocks are added.
+  bool ros_time_active_{false};
+  // Last set message to be passed to newly registered clocks
+  std::shared_ptr<const rosgraph_msgs::msg::Clock> last_msg_set_;
+};
+
+class TimeSource::NodeState : public std::enable_shared_from_this<NodeState>
+{
+public:
+  NodeState(std::weak_ptr<ClocksState> clocks_state, const rclcpp::QoS & qos, bool use_clock_thread)
+  : clocks_state_(std::move(clocks_state)),
+    use_clock_thread_(use_clock_thread),
+    logger_(rclcpp::get_logger("rclcpp")),
+    qos_(qos)
+  {
+  }
+
+  ~NodeState()
+  {
+    if (
+      node_base_ || node_topics_ || node_graph_ || node_services_ ||
+      node_logging_ || node_clock_ || node_parameters_)
+    {
+      detachNode();
+    }
+  }
+
+  // Check if a clock thread will be used
+  bool get_use_clock_thread()
+  {
+    return use_clock_thread_;
+  }
+
+  // Set whether a clock thread will be used
+  void set_use_clock_thread(bool use_clock_thread)
+  {
+    use_clock_thread_ = use_clock_thread;
+  }
+
+  // Check if the clock thread is joinable
+  bool clock_thread_is_joinable()
+  {
+    return clock_executor_thread_.joinable();
+  }
+
+  // Attach a node to this time source
+  void attachNode(
+    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface,
+    rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface,
+    rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
+    rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_interface,
+    rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging_interface,
+    rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock_interface,
+    rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters_interface)
+  {
+    node_base_ = node_base_interface;
+    node_topics_ = node_topics_interface;
+    node_graph_ = node_graph_interface;
+    node_services_ = node_services_interface;
+    node_logging_ = node_logging_interface;
+    node_clock_ = node_clock_interface;
+    node_parameters_ = node_parameters_interface;
+    // TODO(tfoote): Update QOS
+
+    logger_ = node_logging_->get_logger();
+
+    // Though this defaults to false, it can be overridden by initial parameter values for the
+    // node, which may be given by the user at the node's construction or even by command-line
+    // arguments.
+    rclcpp::ParameterValue use_sim_time_param;
+    const std::string use_sim_time_name = "use_sim_time";
+    if (!node_parameters_->has_parameter(use_sim_time_name)) {
+      use_sim_time_param = node_parameters_->declare_parameter(
+        use_sim_time_name,
+        rclcpp::ParameterValue(false),
+        rcl_interfaces::msg::ParameterDescriptor());
+    } else {
+      use_sim_time_param = node_parameters_->get_parameter(use_sim_time_name).get_parameter_value();
+    }
+    if (use_sim_time_param.get_type() == rclcpp::PARAMETER_BOOL) {
+      if (use_sim_time_param.get<bool>()) {
+        parameter_state_ = SET_TRUE;
+        // There should be no way to call this attachNode when the clocks_state_ pointer is not
+        // valid because it means the TimeSource is being destroyed
+        if (auto clocks_state_ptr = clocks_state_.lock()) {
+          clocks_state_ptr->enable_ros_time();
+          create_clock_sub();
+        }
+      }
+    } else {
+      RCLCPP_ERROR(
+        logger_, "Invalid type '%s' for parameter 'use_sim_time', should be 'bool'",
+        rclcpp::to_string(use_sim_time_param.get_type()).c_str());
+    }
+    sim_time_cb_handler_ = node_parameters_->add_on_set_parameters_callback(
+      [use_sim_time_name](const std::vector<rclcpp::Parameter> & parameters) {
+        rcl_interfaces::msg::SetParametersResult result;
+        result.successful = true;
+        for (const auto & parameter : parameters) {
+          if (
+            parameter.get_name() == use_sim_time_name &&
+            parameter.get_type() != rclcpp::PARAMETER_BOOL)
+          {
+            result.successful = false;
+            result.reason = "'" + use_sim_time_name + "' must be a bool";
+            break;
+          }
+        }
+        return result;
+      });
+
+    // TODO(tfoote) use parameters interface not subscribe to events via topic ticketed #609
+    parameter_subscription_ = rclcpp::AsyncParametersClient::on_parameter_event(
+      node_topics_,
+      [state = std::weak_ptr<NodeState>(this->shared_from_this())](
+        std::shared_ptr<const rcl_interfaces::msg::ParameterEvent> event) {
+        if (auto state_ptr = state.lock()) {
+          state_ptr->on_parameter_event(event);
+        }
+        // Do nothing if the pointer could not be locked because it means the TimeSource is now
+        // without an attached node
+      });
+  }
+
+  // Detach the attached node
+  void detachNode()
+  {
+    // There should be no way to call detachNode when the clocks_state_ pointer is not valid
+    // because it means the TimeSource is being destroyed
+    if (auto clocks_state_ptr = clocks_state_.lock()) {
+      clocks_state_ptr->disable_ros_time();
+    }
+    destroy_clock_sub();
+    parameter_subscription_.reset();
+    node_base_.reset();
+    node_topics_.reset();
+    node_graph_.reset();
+    node_services_.reset();
+    node_logging_.reset();
+    node_clock_.reset();
+    if (sim_time_cb_handler_ && node_parameters_) {
+      node_parameters_->remove_on_set_parameters_callback(sim_time_cb_handler_.get());
+    }
+    sim_time_cb_handler_.reset();
+    node_parameters_.reset();
+  }
+
+private:
+  std::weak_ptr<ClocksState> clocks_state_;
+
+  // Dedicated thread for clock subscription.
+  bool use_clock_thread_;
+  std::thread clock_executor_thread_;
+
+  // Preserve the node reference
+  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_;
+  rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_;
+  rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_;
+  rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_;
+  rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging_;
+  rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock_;
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters_;
+
+  // Store (and update on node attach) logger for logging.
+  Logger logger_;
+
+  // QoS of the clock subscription.
+  rclcpp::QoS qos_;
+
+  // The subscription for the clock callback
+  using MessageT = rosgraph_msgs::msg::Clock;
+  using Alloc = std::allocator<void>;
+  using SubscriptionT = rclcpp::Subscription<MessageT, Alloc>;
+  std::shared_ptr<SubscriptionT> clock_subscription_{nullptr};
+  std::mutex clock_sub_lock_;
+  rclcpp::CallbackGroup::SharedPtr clock_callback_group_;
+  rclcpp::executors::SingleThreadedExecutor::SharedPtr clock_executor_;
+  std::promise<void> cancel_clock_executor_promise_;
+
+  // The clock callback itself
+  void clock_cb(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg)
+  {
+    auto clocks_state_ptr = clocks_state_.lock();
+    if (!clocks_state_ptr) {
+      // The clock_state_ pointer is no longer valid, implying that the TimeSource object is being
+      // destroyed, so do nothing
+      return;
+    }
+    if (!clocks_state_ptr->is_ros_time_active() && SET_TRUE == this->parameter_state_) {
+      clocks_state_ptr->enable_ros_time();
+    }
+    // Cache the last message in case a new clock is attached.
+    clocks_state_ptr->cache_last_msg(msg);
+    auto time_msg = std::make_shared<builtin_interfaces::msg::Time>(msg->clock);
+
+    if (SET_TRUE == this->parameter_state_) {
+      clocks_state_ptr->set_all_clocks(time_msg, true);
+    }
+  }
+
+  // Create the subscription for the clock topic
+  void create_clock_sub()
+  {
+    std::lock_guard<std::mutex> guard(clock_sub_lock_);
+    if (clock_subscription_) {
+      // Subscription already created.
+      return;
+    }
+
+    rclcpp::SubscriptionOptions options;
+    options.qos_overriding_options = rclcpp::QosOverridingOptions(
+      {
+        rclcpp::QosPolicyKind::Depth,
+        rclcpp::QosPolicyKind::Durability,
+        rclcpp::QosPolicyKind::History,
+        rclcpp::QosPolicyKind::Reliability,
+      });
+
+    if (use_clock_thread_) {
+      clock_callback_group_ = node_base_->create_callback_group(
+        rclcpp::CallbackGroupType::MutuallyExclusive,
+        false
+      );
+      options.callback_group = clock_callback_group_;
+      rclcpp::ExecutorOptions exec_options;
+      exec_options.context = node_base_->get_context();
+      clock_executor_ =
+        std::make_shared<rclcpp::executors::SingleThreadedExecutor>(exec_options);
+      if (!clock_executor_thread_.joinable()) {
+        cancel_clock_executor_promise_ = std::promise<void>{};
+        clock_executor_thread_ = std::thread(
+          [this]() {
+            auto future = cancel_clock_executor_promise_.get_future();
+            clock_executor_->add_callback_group(clock_callback_group_, node_base_);
+            clock_executor_->spin_until_future_complete(future);
+          }
+        );
+      }
+    }
+
+    clock_subscription_ = rclcpp::create_subscription<rosgraph_msgs::msg::Clock>(
+      node_parameters_,
+      node_topics_,
+      "/clock",
+      qos_,
+      [state = std::weak_ptr<NodeState>(this->shared_from_this())](
+        std::shared_ptr<const rosgraph_msgs::msg::Clock> msg) {
+        if (auto state_ptr = state.lock()) {
+          state_ptr->clock_cb(msg);
+        }
+        // Do nothing if the pointer could not be locked because it means the TimeSource is now
+        // without an attached node
+      },
+      options
+    );
+  }
+
+  // Destroy the subscription for the clock topic
+  void destroy_clock_sub()
+  {
+    std::lock_guard<std::mutex> guard(clock_sub_lock_);
+    if (clock_executor_thread_.joinable()) {
+      cancel_clock_executor_promise_.set_value();
+      clock_executor_->cancel();
+      clock_executor_thread_.join();
+      clock_executor_->remove_callback_group(clock_callback_group_);
+    }
+    clock_subscription_.reset();
+  }
+
+  // Parameter Event subscription
+  using ParamMessageT = rcl_interfaces::msg::ParameterEvent;
+  using ParamSubscriptionT = rclcpp::Subscription<ParamMessageT, Alloc>;
+  std::shared_ptr<ParamSubscriptionT> parameter_subscription_;
+
+  // Callback for parameter updates
+  void on_parameter_event(std::shared_ptr<const rcl_interfaces::msg::ParameterEvent> event)
+  {
+    auto clocks_state_ptr = clocks_state_.lock();
+    if (!clocks_state_ptr) {
+      // The clock_state_ pointer is no longer valid, implying that the TimeSource object is being
+      // destroyed, so do nothing
+      return;
+    }
+    // Filter out events on 'use_sim_time' parameter instances in other nodes.
+    if (event->node != node_base_->get_fully_qualified_name()) {
+      return;
+    }
+    // Filter for only 'use_sim_time' being added or changed.
+    rclcpp::ParameterEventsFilter filter(event, {"use_sim_time"},
+      {rclcpp::ParameterEventsFilter::EventType::NEW,
+        rclcpp::ParameterEventsFilter::EventType::CHANGED});
+    for (auto & it : filter.get_events()) {
+      if (it.second->value.type != ParameterType::PARAMETER_BOOL) {
+        RCLCPP_ERROR(logger_, "use_sim_time parameter cannot be set to anything but a bool");
+        continue;
+      }
+      if (it.second->value.bool_value) {
+        parameter_state_ = SET_TRUE;
+        clocks_state_ptr->enable_ros_time();
+        create_clock_sub();
+      } else {
+        parameter_state_ = SET_FALSE;
+        clocks_state_ptr->disable_ros_time();
+        destroy_clock_sub();
+      }
+    }
+    // Handle the case that use_sim_time was deleted.
+    rclcpp::ParameterEventsFilter deleted(event, {"use_sim_time"},
+      {rclcpp::ParameterEventsFilter::EventType::DELETED});
+    for (auto & it : deleted.get_events()) {
+      (void) it;  // if there is a match it's already matched, don't bother reading it.
+      // If the parameter is deleted mark it as unset but dont' change state.
+      parameter_state_ = UNSET;
+    }
+  }
+
+  // An enum to hold the parameter state
+  enum UseSimTimeParameterState {UNSET, SET_TRUE, SET_FALSE};
+  UseSimTimeParameterState parameter_state_;
+
+  // A handler for the use_sim_time parameter callback.
+  rclcpp::node_interfaces::OnSetParametersCallbackHandle::SharedPtr sim_time_cb_handler_{nullptr};
+};
+
 TimeSource::TimeSource(
   std::shared_ptr<rclcpp::Node> node,
   const rclcpp::QoS & qos,
   bool use_clock_thread)
-: use_clock_thread_(use_clock_thread),
-  logger_(rclcpp::get_logger("rclcpp")),
-  qos_(qos)
+: constructed_use_clock_thread_(use_clock_thread),
+  constructed_qos_(qos)
 {
-  this->attachNode(node);
+  clocks_state_ = std::make_shared<ClocksState>();
+  node_state_ = std::make_shared<NodeState>(clocks_state_->weak_from_this(), qos, use_clock_thread);
+  attachNode(node);
 }
 
 TimeSource::TimeSource(
   const rclcpp::QoS & qos,
   bool use_clock_thread)
-: use_clock_thread_(use_clock_thread),
-  logger_(rclcpp::get_logger("rclcpp")),
-  qos_(qos)
+: constructed_use_clock_thread_(use_clock_thread),
+  constructed_qos_(qos)
 {
+  clocks_state_ = std::make_shared<ClocksState>();
+  node_state_ = std::make_shared<NodeState>(clocks_state_->weak_from_this(), qos, use_clock_thread);
 }
 
 void TimeSource::attachNode(rclcpp::Node::SharedPtr node)
 {
-  use_clock_thread_ = node->get_node_options().use_clock_thread();
+  node_state_->set_use_clock_thread(node->get_node_options().use_clock_thread());
   attachNode(
     node->get_node_base_interface(),
     node->get_node_topics_interface(),
@@ -75,298 +545,52 @@ void TimeSource::attachNode(
   rclcpp::node_interfaces::NodeClockInterface::SharedPtr node_clock_interface,
   rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters_interface)
 {
-  node_base_ = node_base_interface;
-  node_topics_ = node_topics_interface;
-  node_graph_ = node_graph_interface;
-  node_services_ = node_services_interface;
-  node_logging_ = node_logging_interface;
-  node_clock_ = node_clock_interface;
-  node_parameters_ = node_parameters_interface;
-  // TODO(tfoote): Update QOS
-
-  logger_ = node_logging_->get_logger();
-
-  // Though this defaults to false, it can be overridden by initial parameter values for the node,
-  // which may be given by the user at the node's construction or even by command-line arguments.
-  rclcpp::ParameterValue use_sim_time_param;
-  const std::string use_sim_time_name = "use_sim_time";
-  if (!node_parameters_->has_parameter(use_sim_time_name)) {
-    use_sim_time_param = node_parameters_->declare_parameter(
-      use_sim_time_name,
-      rclcpp::ParameterValue(false),
-      rcl_interfaces::msg::ParameterDescriptor());
-  } else {
-    use_sim_time_param = node_parameters_->get_parameter(use_sim_time_name).get_parameter_value();
-  }
-  if (use_sim_time_param.get_type() == rclcpp::PARAMETER_BOOL) {
-    if (use_sim_time_param.get<bool>()) {
-      parameter_state_ = SET_TRUE;
-      enable_ros_time();
-      create_clock_sub();
-    }
-  } else {
-    RCLCPP_ERROR(
-      logger_, "Invalid type '%s' for parameter 'use_sim_time', should be 'bool'",
-      rclcpp::to_string(use_sim_time_param.get_type()).c_str());
-  }
-  sim_time_cb_handler_ = node_parameters_->add_on_set_parameters_callback(
-    [use_sim_time_name](const std::vector<rclcpp::Parameter> & parameters) {
-      rcl_interfaces::msg::SetParametersResult result;
-      result.successful = true;
-      for (const auto & parameter : parameters) {
-        if (
-          parameter.get_name() == use_sim_time_name &&
-          parameter.get_type() != rclcpp::PARAMETER_BOOL)
-        {
-          result.successful = false;
-          result.reason = "'" + use_sim_time_name + "' must be a bool";
-          break;
-        }
-      }
-      return result;
-    });
-
-  // TODO(tfoote) use parameters interface not subscribe to events via topic ticketed #609
-  parameter_subscription_ = rclcpp::AsyncParametersClient::on_parameter_event(
-    node_topics_,
-    std::bind(&TimeSource::on_parameter_event, this, std::placeholders::_1));
+  node_state_->attachNode(
+    std::move(node_base_interface),
+    std::move(node_topics_interface),
+    std::move(node_graph_interface),
+    std::move(node_services_interface),
+    std::move(node_logging_interface),
+    std::move(node_clock_interface),
+    std::move(node_parameters_interface));
 }
 
 void TimeSource::detachNode()
 {
-  this->ros_time_active_ = false;
-  destroy_clock_sub();
-  parameter_subscription_.reset();
-  node_base_.reset();
-  node_topics_.reset();
-  node_graph_.reset();
-  node_services_.reset();
-  node_logging_.reset();
-  node_clock_.reset();
-  if (sim_time_cb_handler_ && node_parameters_) {
-    node_parameters_->remove_on_set_parameters_callback(sim_time_cb_handler_.get());
-  }
-  sim_time_cb_handler_.reset();
-  node_parameters_.reset();
-  disable_ros_time();
+  node_state_.reset();
+  node_state_ = std::make_shared<NodeState>(
+    clocks_state_->weak_from_this(),
+    constructed_qos_,
+    constructed_use_clock_thread_);
 }
 
 void TimeSource::attachClock(std::shared_ptr<rclcpp::Clock> clock)
 {
-  if (clock->get_clock_type() != RCL_ROS_TIME) {
-    throw std::invalid_argument("Cannot attach clock to a time source that's not a ROS clock");
-  }
-
-  std::lock_guard<std::mutex> guard(clock_list_lock_);
-  associated_clocks_.push_back(clock);
-  // Set the clock to zero unless there's a recently received message
-  auto time_msg = std::make_shared<builtin_interfaces::msg::Time>();
-  if (last_msg_set_) {
-    time_msg = std::make_shared<builtin_interfaces::msg::Time>(last_msg_set_->clock);
-  }
-  set_clock(time_msg, ros_time_active_, clock);
+  clocks_state_->attachClock(std::move(clock));
 }
 
 void TimeSource::detachClock(std::shared_ptr<rclcpp::Clock> clock)
 {
-  std::lock_guard<std::mutex> guard(clock_list_lock_);
-  auto result = std::find(associated_clocks_.begin(), associated_clocks_.end(), clock);
-  if (result != associated_clocks_.end()) {
-    associated_clocks_.erase(result);
-  } else {
-    RCLCPP_ERROR(logger_, "failed to remove clock");
-  }
+  clocks_state_->detachClock(std::move(clock));
+}
+
+bool TimeSource::get_use_clock_thread()
+{
+  return node_state_->get_use_clock_thread();
+}
+
+void TimeSource::set_use_clock_thread(bool use_clock_thread)
+{
+  node_state_->set_use_clock_thread(use_clock_thread);
+}
+
+bool TimeSource::clock_thread_is_joinable()
+{
+  return node_state_->clock_thread_is_joinable();
 }
 
 TimeSource::~TimeSource()
 {
-  if (
-    node_base_ || node_topics_ || node_graph_ || node_services_ ||
-    node_logging_ || node_clock_ || node_parameters_)
-  {
-    this->detachNode();
-  }
-}
-
-void TimeSource::set_clock(
-  const builtin_interfaces::msg::Time::SharedPtr msg, bool set_ros_time_enabled,
-  std::shared_ptr<rclcpp::Clock> clock)
-{
-  std::lock_guard<std::mutex> clock_guard(clock->get_clock_mutex());
-
-  // Do change
-  if (!set_ros_time_enabled && clock->ros_time_is_active()) {
-    auto ret = rcl_disable_ros_time_override(clock->get_clock_handle());
-    if (ret != RCL_RET_OK) {
-      rclcpp::exceptions::throw_from_rcl_error(
-        ret, "Failed to disable ros_time_override_status");
-    }
-  } else if (set_ros_time_enabled && !clock->ros_time_is_active()) {
-    auto ret = rcl_enable_ros_time_override(clock->get_clock_handle());
-    if (ret != RCL_RET_OK) {
-      rclcpp::exceptions::throw_from_rcl_error(
-        ret, "Failed to enable ros_time_override_status");
-    }
-  }
-
-  auto ret = rcl_set_ros_time_override(clock->get_clock_handle(), rclcpp::Time(*msg).nanoseconds());
-  if (ret != RCL_RET_OK) {
-    rclcpp::exceptions::throw_from_rcl_error(
-      ret, "Failed to set ros_time_override_status");
-  }
-}
-
-void TimeSource::clock_cb(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg)
-{
-  if (!this->ros_time_active_ && SET_TRUE == this->parameter_state_) {
-    enable_ros_time();
-  }
-  // Cache the last message in case a new clock is attached.
-  last_msg_set_ = msg;
-  auto time_msg = std::make_shared<builtin_interfaces::msg::Time>(msg->clock);
-
-  if (SET_TRUE == this->parameter_state_) {
-    std::lock_guard<std::mutex> guard(clock_list_lock_);
-    for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
-      set_clock(time_msg, true, *it);
-    }
-  }
-}
-
-void TimeSource::create_clock_sub()
-{
-  std::lock_guard<std::mutex> guard(clock_sub_lock_);
-  if (clock_subscription_) {
-    // Subscription already created.
-    return;
-  }
-
-  rclcpp::SubscriptionOptions options;
-  options.qos_overriding_options = rclcpp::QosOverridingOptions(
-    {
-      rclcpp::QosPolicyKind::Depth,
-      rclcpp::QosPolicyKind::Durability,
-      rclcpp::QosPolicyKind::History,
-      rclcpp::QosPolicyKind::Reliability,
-    });
-
-  if (use_clock_thread_) {
-    clock_callback_group_ = node_base_->create_callback_group(
-      rclcpp::CallbackGroupType::MutuallyExclusive,
-      false
-    );
-    options.callback_group = clock_callback_group_;
-    rclcpp::ExecutorOptions exec_options;
-    exec_options.context = node_base_->get_context();
-    clock_executor_ =
-      std::make_shared<rclcpp::executors::SingleThreadedExecutor>(exec_options);
-    if (!clock_executor_thread_.joinable()) {
-      cancel_clock_executor_promise_ = std::promise<void>{};
-      clock_executor_thread_ = std::thread(
-        [this]() {
-          auto future = cancel_clock_executor_promise_.get_future();
-          clock_executor_->add_callback_group(clock_callback_group_, node_base_);
-          clock_executor_->spin_until_future_complete(future);
-        }
-      );
-    }
-  }
-
-  clock_subscription_ = rclcpp::create_subscription<rosgraph_msgs::msg::Clock>(
-    node_parameters_,
-    node_topics_,
-    "/clock",
-    rclcpp::QoS(KeepLast(1)).best_effort(),
-    std::bind(&TimeSource::clock_cb, this, std::placeholders::_1),
-    options
-  );
-}
-
-void TimeSource::destroy_clock_sub()
-{
-  std::lock_guard<std::mutex> guard(clock_sub_lock_);
-  if (clock_executor_thread_.joinable()) {
-    cancel_clock_executor_promise_.set_value();
-    clock_executor_->cancel();
-    clock_executor_thread_.join();
-    clock_executor_->remove_callback_group(clock_callback_group_);
-  }
-  clock_subscription_.reset();
-}
-
-void TimeSource::on_parameter_event(
-  std::shared_ptr<const rcl_interfaces::msg::ParameterEvent> event)
-{
-  // Filter out events on 'use_sim_time' parameter instances in other nodes.
-  if (event->node != node_base_->get_fully_qualified_name()) {
-    return;
-  }
-  // Filter for only 'use_sim_time' being added or changed.
-  rclcpp::ParameterEventsFilter filter(event, {"use_sim_time"},
-    {rclcpp::ParameterEventsFilter::EventType::NEW,
-      rclcpp::ParameterEventsFilter::EventType::CHANGED});
-  for (auto & it : filter.get_events()) {
-    if (it.second->value.type != ParameterType::PARAMETER_BOOL) {
-      RCLCPP_ERROR(logger_, "use_sim_time parameter cannot be set to anything but a bool");
-      continue;
-    }
-    if (it.second->value.bool_value) {
-      parameter_state_ = SET_TRUE;
-      enable_ros_time();
-      create_clock_sub();
-    } else {
-      parameter_state_ = SET_FALSE;
-      disable_ros_time();
-      destroy_clock_sub();
-    }
-  }
-  // Handle the case that use_sim_time was deleted.
-  rclcpp::ParameterEventsFilter deleted(event, {"use_sim_time"},
-    {rclcpp::ParameterEventsFilter::EventType::DELETED});
-  for (auto & it : deleted.get_events()) {
-    (void) it;  // if there is a match it's already matched, don't bother reading it.
-    // If the parameter is deleted mark it as unset but dont' change state.
-    parameter_state_ = UNSET;
-  }
-}
-
-void TimeSource::enable_ros_time()
-{
-  if (ros_time_active_) {
-    // already enabled no-op
-    return;
-  }
-
-  // Local storage
-  ros_time_active_ = true;
-
-  // Update all attached clocks to zero or last recorded time
-  std::lock_guard<std::mutex> guard(clock_list_lock_);
-  auto time_msg = std::make_shared<builtin_interfaces::msg::Time>();
-  if (last_msg_set_) {
-    time_msg = std::make_shared<builtin_interfaces::msg::Time>(last_msg_set_->clock);
-  }
-  for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
-    set_clock(time_msg, true, *it);
-  }
-}
-
-void TimeSource::disable_ros_time()
-{
-  if (!ros_time_active_) {
-    // already disabled no-op
-    return;
-  }
-
-  // Local storage
-  ros_time_active_ = false;
-
-  // Update all attached clocks
-  std::lock_guard<std::mutex> guard(clock_list_lock_);
-  for (auto it = associated_clocks_.begin(); it != associated_clocks_.end(); ++it) {
-    auto msg = std::make_shared<builtin_interfaces::msg::Time>();
-    set_clock(msg, false, *it);
-  }
 }
 
 }  // namespace rclcpp

rclcpp/src/rclcpp/utilities.cpp

@@ -31,18 +31,22 @@ namespace rclcpp
 {
 
 void
-init(int argc, char const * const argv[], const InitOptions & init_options)
+init(
+  int argc,
+  char const * const argv[],
+  const InitOptions & init_options,
+  SignalHandlerOptions signal_handler_options)
 {
   using rclcpp::contexts::get_global_default_context;
   get_global_default_context()->init(argc, argv, init_options);
   // Install the signal handlers.
-  install_signal_handlers();
+  install_signal_handlers(signal_handler_options);
 }
 
 bool
-install_signal_handlers()
+install_signal_handlers(SignalHandlerOptions signal_handler_options)
 {
-  return SignalHandler::get_global_signal_handler().install();
+  return SignalHandler::get_global_signal_handler().install(signal_handler_options);
 }
 
 bool
@@ -51,6 +55,13 @@ signal_handlers_installed()
   return SignalHandler::get_global_signal_handler().is_installed();
 }
 
+SignalHandlerOptions
+get_current_signal_handler_options()
+{
+  return SignalHandler::get_global_signal_handler().get_current_signal_handler_options();
+}
+
+
 bool
 uninstall_signal_handlers()
 {
@@ -156,12 +167,6 @@ ok(Context::SharedPtr context)
   return context->is_valid();
 }
 
-bool
-is_initialized(Context::SharedPtr context)
-{
-  return ok(context);
-}
-
 bool
 shutdown(Context::SharedPtr context, const std::string & reason)
 {

rclcpp/test/benchmark/benchmark_client.cpp

@@ -62,6 +62,7 @@ BENCHMARK_F(ClientPerformanceTest, construct_client_no_service)(benchmark::State
 
   reset_heap_counters();
   for (auto _ : state) {
+    (void)_;
     auto client = node->create_client<test_msgs::srv::Empty>("not_an_existing_service");
     benchmark::DoNotOptimize(client);
     benchmark::ClobberMemory();
@@ -79,6 +80,7 @@ BENCHMARK_F(ClientPerformanceTest, construct_client_empty_srv)(benchmark::State
 
   reset_heap_counters();
   for (auto _ : state) {
+    (void)_;
     auto client = node->create_client<test_msgs::srv::Empty>(empty_service_name);
     benchmark::DoNotOptimize(client);
     benchmark::ClobberMemory();
@@ -96,6 +98,7 @@ BENCHMARK_F(ClientPerformanceTest, destroy_client_empty_srv)(benchmark::State &
 
   reset_heap_counters();
   for (auto _ : state) {
+    (void)_;
     state.PauseTiming();
     auto client = node->create_client<test_msgs::srv::Empty>(empty_service_name);
     state.ResumeTiming();
@@ -109,6 +112,7 @@ BENCHMARK_F(ClientPerformanceTest, destroy_client_empty_srv)(benchmark::State &
 BENCHMARK_F(ClientPerformanceTest, wait_for_service)(benchmark::State & state) {
   int count = 0;
   for (auto _ : state) {
+    (void)_;
     state.PauseTiming();
     const std::string service_name = std::string("service_") + std::to_string(count++);
     // Create client before service so it has to 'discover' the service after construction
@@ -132,6 +136,7 @@ BENCHMARK_F(ClientPerformanceTest, async_send_request_only)(benchmark::State & s
 
   reset_heap_counters();
   for (auto _ : state) {
+    (void)_;
     auto future = client->async_send_request(shared_request);
     benchmark::DoNotOptimize(future);
     benchmark::ClobberMemory();
@@ -144,6 +149,7 @@ BENCHMARK_F(ClientPerformanceTest, async_send_request_and_response)(benchmark::S
 
   reset_heap_counters();
   for (auto _ : state) {
+    (void)_;
     auto future = client->async_send_request(shared_request);
     rclcpp::spin_until_future_complete(
       node->get_node_base_interface(), future, std::chrono::seconds(1));

rclcpp/test/benchmark/benchmark_executor.cpp

@@ -20,7 +20,7 @@
 #include "performance_test_fixture/performance_test_fixture.hpp"
 
 #include "rclcpp/rclcpp.hpp"
-#include "rclcpp/scope_exit.hpp"
+#include "rcpputils/scope_exit.hpp"
 #include "test_msgs/msg/empty.hpp"
 
 using namespace std::chrono_literals;
@@ -78,6 +78,7 @@ BENCHMARK_F(PerformanceTestExecutor, single_thread_executor_spin_some)(benchmark
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     st.PauseTiming();
     for (unsigned int i = 0u; i < kNumberOfNodes; i++) {
       publishers[i]->publish(empty_msgs);
@@ -104,6 +105,7 @@ BENCHMARK_F(PerformanceTestExecutor, multi_thread_executor_spin_some)(benchmark:
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     st.PauseTiming();
     for (unsigned int i = 0u; i < kNumberOfNodes; i++) {
       publishers[i]->publish(empty_msgs);
@@ -142,6 +144,7 @@ BENCHMARK_F(PerformanceTestExecutorSimple, single_thread_executor_add_node)(benc
 {
   rclcpp::executors::SingleThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     executor.add_node(node);
     st.PauseTiming();
     executor.remove_node(node);
@@ -154,6 +157,7 @@ BENCHMARK_F(
 {
   rclcpp::executors::SingleThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     st.PauseTiming();
     executor.add_node(node);
     st.ResumeTiming();
@@ -165,6 +169,7 @@ BENCHMARK_F(PerformanceTestExecutorSimple, multi_thread_executor_add_node)(bench
 {
   rclcpp::executors::MultiThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     executor.add_node(node);
     st.PauseTiming();
     executor.remove_node(node);
@@ -176,6 +181,7 @@ BENCHMARK_F(PerformanceTestExecutorSimple, multi_thread_executor_remove_node)(be
 {
   rclcpp::executors::MultiThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     st.PauseTiming();
     executor.add_node(node);
     st.ResumeTiming();
@@ -189,6 +195,7 @@ BENCHMARK_F(
 {
   rclcpp::executors::StaticSingleThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     executor.add_node(node);
     st.PauseTiming();
     executor.remove_node(node);
@@ -202,6 +209,7 @@ BENCHMARK_F(
 {
   rclcpp::executors::StaticSingleThreadedExecutor executor;
   for (auto _ : st) {
+    (void)_;
     st.PauseTiming();
     executor.add_node(node);
     st.ResumeTiming();
@@ -228,6 +236,7 @@ BENCHMARK_F(
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     // static_single_thread_executor has a special design. We need to add/remove the node each
     // time you call spin
     st.PauseTiming();
@@ -265,6 +274,7 @@ BENCHMARK_F(
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     ret = rclcpp::executors::spin_node_until_future_complete(
       executor, node, shared_future, 1s);
     if (ret != rclcpp::FutureReturnCode::SUCCESS) {
@@ -294,6 +304,7 @@ BENCHMARK_F(
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     ret = rclcpp::executors::spin_node_until_future_complete(
       executor, node, shared_future, 1s);
     if (ret != rclcpp::FutureReturnCode::SUCCESS) {
@@ -317,6 +328,7 @@ BENCHMARK_F(
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     auto ret = rclcpp::executors::spin_node_until_future_complete(
       executor, node, shared_future, 1s);
     if (ret != rclcpp::FutureReturnCode::SUCCESS) {
@@ -342,6 +354,7 @@ BENCHMARK_F(PerformanceTestExecutorSimple, spin_until_future_complete)(benchmark
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     ret = rclcpp::spin_until_future_complete(node, shared_future, 1s);
     if (ret != rclcpp::FutureReturnCode::SUCCESS) {
       st.SkipWithError(rcutils_get_error_string().str);
@@ -366,7 +379,7 @@ BENCHMARK_F(
   if (ret != RCL_RET_OK) {
     st.SkipWithError(rcutils_get_error_string().str);
   }
-  RCLCPP_SCOPE_EXIT(
+  RCPPUTILS_SCOPE_EXIT(
   {
     rcl_ret_t ret = rcl_wait_set_fini(&wait_set);
     if (ret != RCL_RET_OK) {
@@ -376,14 +389,14 @@ BENCHMARK_F(
 
   auto memory_strategy = rclcpp::memory_strategies::create_default_strategy();
   rclcpp::GuardCondition guard_condition(shared_context);
-  rcl_guard_condition_t rcl_guard_condition = guard_condition.get_rcl_guard_condition();
 
-  entities_collector_->init(&wait_set, memory_strategy, &rcl_guard_condition);
-  RCLCPP_SCOPE_EXIT(entities_collector_->fini());
+  entities_collector_->init(&wait_set, memory_strategy);
+  RCPPUTILS_SCOPE_EXIT(entities_collector_->fini());
 
   reset_heap_counters();
 
   for (auto _ : st) {
+    (void)_;
     std::shared_ptr<void> data = entities_collector_->take_data();
     entities_collector_->execute(data);
   }