7.0.0

Signed-off-by: Scott K Logan <logans@cottsay.net>

rclcpp/CHANGELOG.rst

@@ -2,6 +2,89 @@
 Changelog for package rclcpp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+7.0.0 (2021-03-18)
+------------------
+* Document design decisions that were made for statically typed parameters (`#1568 <https://github.com/ros2/rclcpp/issues/1568>`_)
+* Fix doc typo in CallbackGroup constructor (`#1582 <https://github.com/ros2/rclcpp/issues/1582>`_)
+* Enable qos parameter overrides for the /parameter_events topic  (`#1532 <https://github.com/ros2/rclcpp/issues/1532>`_)
+* Add support for rmw_connextdds (`#1574 <https://github.com/ros2/rclcpp/issues/1574>`_)
+* Remove 'struct' from the rcl_time_jump_t. (`#1577 <https://github.com/ros2/rclcpp/issues/1577>`_)
+* Add tests for declaring statically typed parameters when undeclared parameters are allowed (`#1575 <https://github.com/ros2/rclcpp/issues/1575>`_)
+* Quiet clang memory leak warning on "DoNotOptimize". (`#1571 <https://github.com/ros2/rclcpp/issues/1571>`_)
+* Add ParameterEventsSubscriber class (`#829 <https://github.com/ros2/rclcpp/issues/829>`_)
+* When a parameter change is rejected, the parameters map shouldn't be updated. (`#1567 <https://github.com/ros2/rclcpp/pull/1567>`_)
+* Fix when to throw the NoParameterOverrideProvided exception. (`#1567 <https://github.com/ros2/rclcpp/pull/1567>`_)
+* Fix SEGV caused by order of destruction of Node sub-interfaces (`#1469 <https://github.com/ros2/rclcpp/issues/1469>`_)
+* Fix benchmark test failure introduced in `#1522 <https://github.com/ros2/rclcpp/issues/1522>`_ (`#1564 <https://github.com/ros2/rclcpp/issues/1564>`_)
+* Fix documented example in create_publisher (`#1558 <https://github.com/ros2/rclcpp/issues/1558>`_)
+* Enforce static parameter types (`#1522 <https://github.com/ros2/rclcpp/issues/1522>`_)
+* Allow timers to keep up the intended rate in MultiThreadedExecutor (`#1516 <https://github.com/ros2/rclcpp/issues/1516>`_)
+* Fix UBSAN warnings in any_subscription_callback. (`#1551 <https://github.com/ros2/rclcpp/issues/1551>`_)
+* Fix runtime error: reference binding to null pointer of type (`#1547 <https://github.com/ros2/rclcpp/issues/1547>`_)
+* Contributors: Andrea Sorbini, Chris Lalancette, Colin MacKenzie, Ivan Santiago Paunovic, Jacob Perron, Steven! Ragnarök, bpwilcox, tomoya
+
+6.3.1 (2021-02-08)
+------------------
+* Reference test resources directly from source tree (`#1543 <https://github.com/ros2/rclcpp/issues/1543>`_)
+* clear statistics after window reset (`#1531 <https://github.com/ros2/rclcpp/issues/1531>`_) (`#1535 <https://github.com/ros2/rclcpp/issues/1535>`_)
+* Fix a minor string error in the topic_statistics test. (`#1541 <https://github.com/ros2/rclcpp/issues/1541>`_)
+* Avoid `Resource deadlock avoided` if use intra_process_comms (`#1530 <https://github.com/ros2/rclcpp/issues/1530>`_)
+* Avoid an object copy in parameter_value.cpp. (`#1538 <https://github.com/ros2/rclcpp/issues/1538>`_)
+* Assert that the publisher_list size is 1. (`#1537 <https://github.com/ros2/rclcpp/issues/1537>`_)
+* Don't access objects after they have been std::move (`#1536 <https://github.com/ros2/rclcpp/issues/1536>`_)
+* Update for checking correct variable (`#1534 <https://github.com/ros2/rclcpp/issues/1534>`_)
+* Destroy msg extracted from LoanedMessage. (`#1305 <https://github.com/ros2/rclcpp/issues/1305>`_)
+* Contributors: Chen Lihui, Chris Lalancette, Ivan Santiago Paunovic, Miaofei Mei, Scott K Logan, William Woodall, hsgwa
+
+6.3.0 (2021-01-25)
+------------------
+* Add instrumentation for linking a timer to a node (`#1500 <https://github.com/ros2/rclcpp/issues/1500>`_)
+* Fix error when using IPC with StaticSingleThreadExecutor (`#1520 <https://github.com/ros2/rclcpp/issues/1520>`_)
+* Change to using unique_ptrs for DummyExecutor. (`#1517 <https://github.com/ros2/rclcpp/issues/1517>`_)
+* Allow reconfiguring 'clock' topic qos (`#1512 <https://github.com/ros2/rclcpp/issues/1512>`_)
+* Allow to add/remove nodes thread safely in rclcpp::Executor  (`#1505 <https://github.com/ros2/rclcpp/issues/1505>`_)
+* Call rclcpp::shutdown in test_node for clean shutdown on Windows (`#1515 <https://github.com/ros2/rclcpp/issues/1515>`_)
+* Reapply "Add get_logging_directory method to rclcpp::Logger (`#1509 <https://github.com/ros2/rclcpp/issues/1509>`_)" (`#1513 <https://github.com/ros2/rclcpp/issues/1513>`_)
+* use describe_parameters of parameter client for test (`#1499 <https://github.com/ros2/rclcpp/issues/1499>`_)
+* Revert "Add get_logging_directory method to rclcpp::Logger (`#1509 <https://github.com/ros2/rclcpp/issues/1509>`_)" (`#1511 <https://github.com/ros2/rclcpp/issues/1511>`_)
+* Add get_logging_directory method to rclcpp::Logger (`#1509 <https://github.com/ros2/rclcpp/issues/1509>`_)
+* Contributors: Chris Lalancette, Christophe Bedard, Ivan Santiago Paunovic, eboasson, mauropasse, tomoya
+
+6.2.0 (2021-01-08)
+------------------
+* Better documentation for the QoS class (`#1508 <https://github.com/ros2/rclcpp/issues/1508>`_)
+* Modify excluding callback duration from topic statistics (`#1492 <https://github.com/ros2/rclcpp/issues/1492>`_)
+* Make the test of graph users more robust. (`#1504 <https://github.com/ros2/rclcpp/issues/1504>`_)
+* Make sure to wait for graph change events in test_node_graph. (`#1503 <https://github.com/ros2/rclcpp/issues/1503>`_)
+* add timeout to SyncParametersClient methods (`#1493 <https://github.com/ros2/rclcpp/issues/1493>`_)
+* Fix wrong test expectations (`#1497 <https://github.com/ros2/rclcpp/issues/1497>`_)
+* Update create_publisher/subscription documentation, clarifying when a parameters interface is required (`#1494 <https://github.com/ros2/rclcpp/issues/1494>`_)
+* Fix string literal warnings (`#1442 <https://github.com/ros2/rclcpp/issues/1442>`_)
+* support describe_parameters methods to parameter client. (`#1453 <https://github.com/ros2/rclcpp/issues/1453>`_)
+* Contributors: Audrow Nash, Chris Lalancette, Ivan Santiago Paunovic, Nikolai Morin, hsgwa, tomoya
+
+6.1.0 (2020-12-10)
+------------------
+* Add getters to rclcpp::qos and rclcpp::Policy enum classes (`#1467 <https://github.com/ros2/rclcpp/issues/1467>`_)
+* Change nullptr checks to use ASSERT_TRUE. (`#1486 <https://github.com/ros2/rclcpp/issues/1486>`_)
+* Adjust logic around finding and erasing guard_condition (`#1474 <https://github.com/ros2/rclcpp/issues/1474>`_)
+* Update QDs to QL 1 (`#1477 <https://github.com/ros2/rclcpp/issues/1477>`_)
+* Add performance tests for parameter transport (`#1463 <https://github.com/ros2/rclcpp/issues/1463>`_)
+* Contributors: Chris Lalancette, Ivan Santiago Paunovic, Scott K Logan, Stephen Brawner
+
+6.0.0 (2020-11-18)
+------------------
+* Move ownership of shutdown_guard_condition to executors/graph_listener (`#1404 <https://github.com/ros2/rclcpp/issues/1404>`_)
+* Add options to automatically declare qos parameters when creating a publisher/subscription (`#1465 <https://github.com/ros2/rclcpp/issues/1465>`_)
+* Add `take_data` to `Waitable` and `data` to `AnyExecutable` (`#1241 <https://github.com/ros2/rclcpp/issues/1241>`_)
+* Add benchmarks for node parameters interface (`#1444 <https://github.com/ros2/rclcpp/issues/1444>`_)
+* Remove allocation from executor::remove_node() (`#1448 <https://github.com/ros2/rclcpp/issues/1448>`_)
+* Fix test crashes on CentOS 7 (`#1449 <https://github.com/ros2/rclcpp/issues/1449>`_)
+* Bump rclcpp packages to Quality Level 2 (`#1445 <https://github.com/ros2/rclcpp/issues/1445>`_)
+* Added executor benchmark tests (`#1413 <https://github.com/ros2/rclcpp/issues/1413>`_)
+* Add fully-qualified namespace to WeakCallbackGroupsToNodesMap (`#1435 <https://github.com/ros2/rclcpp/issues/1435>`_)
+* Contributors: Alejandro Hernández Cordero, Audrow Nash, Chris Lalancette, Ivan Santiago Paunovic, Louise Poubel, Scott K Logan, brawner
+
 5.1.0 (2020-11-02)
 ------------------
 * Deprecate Duration(rcl_duration_value_t) in favor of static Duration::from_nanoseconds(rcl_duration_value_t) (`#1432 <https://github.com/ros2/rclcpp/issues/1432>`_)

rclcpp/CMakeLists.txt

@@ -39,6 +39,8 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/clock.cpp
   src/rclcpp/context.cpp
   src/rclcpp/contexts/default_context.cpp
+  src/rclcpp/detail/mutex_two_priorities.cpp
+  src/rclcpp/detail/resolve_parameter_overrides.cpp
   src/rclcpp/detail/rmw_implementation_specific_payload.cpp
   src/rclcpp/detail/rmw_implementation_specific_publisher_payload.cpp
   src/rclcpp/detail/rmw_implementation_specific_subscription_payload.cpp
@@ -79,12 +81,14 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/parameter.cpp
   src/rclcpp/parameter_value.cpp
   src/rclcpp/parameter_client.cpp
+  src/rclcpp/parameter_event_handler.cpp
   src/rclcpp/parameter_events_filter.cpp
   src/rclcpp/parameter_map.cpp
   src/rclcpp/parameter_service.cpp
   src/rclcpp/publisher_base.cpp
   src/rclcpp/qos.cpp
   src/rclcpp/qos_event.cpp
+  src/rclcpp/qos_overriding_options.cpp
   src/rclcpp/serialization.cpp
   src/rclcpp/serialized_message.cpp
   src/rclcpp/service.cpp

rclcpp/QUALITY_DECLARATION.md

@@ -2,7 +2,7 @@ This document is a declaration of software quality for the `rclcpp` package, bas
 
 # rclcpp Quality Declaration
 
-The package `rclcpp` claims to be in the **Quality Level 2** category.
+The package `rclcpp` claims to be in the **Quality Level 1** category when it is used with a **Quality Level 1** middleware.
 
 Below are the rationales, notes, and caveats for this claim, organized by each requirement listed in the [Package Quality Categories in REP-2004](https://index.ros.org/doc/ros2/Contributing/Developer-Guide/#package-quality-categories) of the ROS2 developer guide.
 
@@ -82,13 +82,13 @@ The API is publicly available in its [ROS 2 API documentation](http://docs.ros2.
 
 The license for `rclcpp` is Apache 2.0, and a summary is in each source file, the type is declared in the [`package.xml`](./package.xml) manifest file, and a full copy of the license is in the [`LICENSE`](../LICENSE) file.
 
-There is an automated test which runs a linter that ensures each file has a license statement. [Here](http://build.ros2.org/view/Fpr/job/Fpr__rclcpp__ubuntu_focal_amd64/lastSuccessfulBuild/testReport/rclcpp/) can be found a list with the latest results of the various linters being run on the package.
+There is an automated test which runs a linter that ensures each file has a license statement. [Here](http://build.ros2.org/view/Rpr/job/Rpr__rclcpp__ubuntu_focal_amd64/lastCompletedBuild/testReport/rclcpp/) can be found a list with the latest results of the various linters being run on the package.
 
 ### Copyright Statements [3.iv]
 
 The copyright holders each provide a statement of copyright in each source code file in `rclcpp`.
 
-There is an automated test which runs a linter that ensures each file has at least one copyright statement. Latest linter result report can be seen [here](http://build.ros2.org/view/Fpr/job/Fpr__rclcpp__ubuntu_focal_amd64/lastSuccessfulBuild/testReport/rclcpp/copyright/).
+There is an automated test which runs a linter that ensures each file has at least one copyright statement. Latest linter result report can be seen [here](http://build.ros2.org/view/Rpr/job/Rpr__rclcpp__ubuntu_focal_amd64/lastCompletedBuild/testReport/rclcpp/copyright/).
 
 ## Testing [4]
 
@@ -121,13 +121,21 @@ This includes:
 
 Changes are required to make a best effort to keep or increase coverage before being accepted, but decreases are allowed if properly justified and accepted by reviewers.
 
-Current coverage statistics can be viewed [here](https://ci.ros2.org/job/nightly_linux_coverage/lastSuccessfulBuild/cobertura/src_ros2_rclcpp_rclcpp_src_rclcpp/). A description of how coverage statistics are calculated is summarized in this page ["ROS 2 Onboarding Guide"](https://index.ros.org/doc/ros2/Contributing/ROS-2-On-boarding-Guide/#note-on-coverage-runs).
+Current coverage statistics can be viewed [here](https://ci.ros2.org/job/nightly_linux_coverage/lastCompletedBuild/cobertura/src_ros2_rclcpp_rclcpp_src_rclcpp/). A description of how coverage statistics are calculated is summarized in this page ["ROS 2 Onboarding Guide"](https://index.ros.org/doc/ros2/Contributing/ROS-2-On-boarding-Guide/#note-on-coverage-runs).
 
 `rclcpp` has a line coverage `>= 95%`, which is calculated over all directories within `rclcpp` with the exception of the `experimental` directory.
 
 ### Performance [4.iv]
 
-It is not yet defined if this package requires performance testing and how addresses this topic.
+`rclcpp` follows the recommendations for performance testing of C/C++ code in the [ROS 2 Developer Guide](https://index.ros.org/doc/ros2/Contributing/Developer-Guide/#performance), and opts to do performance analysis on each release rather than each change.
+
+The performance tests of `rclcpp` are located in the [test/benchmark directory](https://github.com/ros2/rclcpp/tree/master/rclcpp/test/benchmark).
+
+System level performance benchmarks that cover features of `rclcpp` can be found at:
+* [Benchmarks](http://build.ros2.org/view/Rci/job/Rci__benchmark_ubuntu_focal_amd64/BenchmarkTable/)
+* [Performance](http://build.ros2.org/view/Rci/job/Rci__nightly-performance_ubuntu_focal_amd64/lastCompletedBuild/)
+
+Changes that introduce regressions in performance must be adequately justified in order to be accepted and merged.
 
 ### Linters and Static Analysis [4.v]
 
@@ -155,43 +163,43 @@ It also has several test dependencies, which do not affect the resulting quality
 
 The `libstatistics_collector` package provides lightweight aggregation utilities to collect statistics and measure message metrics.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros-tooling/libstatistics_collector/tree/master/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros-tooling/libstatistics_collector/tree/master/QUALITY_DECLARATION.md).
 
 #### `rcl`
 
 `rcl` a library to support implementation of language specific ROS 2 Client Libraries.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rcl/blob/master/rcl/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rcl/blob/master/rcl/QUALITY_DECLARATION.md).
 
 #### `rcl_yaml_param_parser`
 
 The `rcl_yaml_param_parser` package provides an API that is used to parse YAML configuration files which may be used to configure ROS and specific nodes.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rcl/tree/master/rcl_yaml_param_parser/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rcl/tree/master/rcl_yaml_param_parser/QUALITY_DECLARATION.md).
 
 #### `rcpputils`
 
 The `rcpputils` package provides an API which contains common utilities and data structures useful when programming in C++.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rcpputils/blob/master/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rcpputils/blob/master/QUALITY_DECLARATION.md).
 
 #### `rcutils`
 
 The `rcutils` package provides an API which contains common utilities and data structures useful when programming in C.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rcutils/blob/master/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rcutils/blob/master/QUALITY_DECLARATION.md).
 
 #### `rmw`
 
 `rmw` is the ROS 2 middleware library.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rmw/blob/master/rmw/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rmw/blob/master/rmw/QUALITY_DECLARATION.md).
 
 #### `statistics_msgs`
 
 The `statistics_msgs` package contains ROS 2 message definitions for reporting statistics for topics and system resources.
 
-It is **Quality Level 2**, see its [Quality Declaration document](https://github.com/ros2/rcl_interfaces/blob/master/statistics_msgs/QUALITY_DECLARATION.md).
+It is **Quality Level 1**, see its [Quality Declaration document](https://github.com/ros2/rcl_interfaces/blob/master/statistics_msgs/QUALITY_DECLARATION.md).
 
 #### `tracetools`
 

rclcpp/README.md

@@ -6,4 +6,4 @@ Visit the [rclcpp API documentation](http://docs.ros2.org/latest/api/rclcpp/) fo
 
 ## Quality Declaration
 
-This package claims to be in the **Quality Level 2** category, see the [Quality Declaration](QUALITY_DECLARATION.md) for more details.
+This package claims to be in the **Quality Level 1** category, see the [Quality Declaration](QUALITY_DECLARATION.md) for more details.

rclcpp/doc/notes_on_statically_typed_parameters.md

@@ -0,0 +1,141 @@
+# Notes on statically typed parameters
+
+## Introduction
+
+Until ROS 2 Foxy, all parameters could change type anytime, except if the user installed a parameter callback to reject a change.
+This could generate confusing errors, for example:
+
+```
+$ ros2 run demo_nodes_py listener &
+$ ros2 param set /listener use_sim_time not_a_boolean
+[ERROR] [1614712713.233733147] [listener]: use_sim_time parameter set to something besides a bool
+Set parameter successful
+$ ros2 param get /listener use_sim_time
+String value is: not_a_boolean
+```
+
+For most use cases, having static parameter types is enough.
+This article documents some of the decisions that were made when implementing static parameter types enforcement in:
+
+* https://github.com/ros2/rclcpp/pull/1522
+* https://github.com/ros2/rclpy/pull/683
+
+## Allowing dynamically typed parameters
+
+There might be some scenarios where dynamic typing is desired, so a `dynamic_typing` field was added to the [parameter descriptor](https://github.com/ros2/rcl_interfaces/blob/09b5ed93a733adb9deddc47f9a4a8c6e9f584667/rcl_interfaces/msg/ParameterDescriptor.msg#L25).
+It defaults to `false`.
+
+For example:
+
+```cpp
+rcl_interfaces::msg::ParameterDescriptor descriptor;
+descriptor.dynamic_typing = true;
+
+node->declare_parameter("dynamically_typed_parameter", rclcpp::ParameterValue{}, descriptor);
+```
+
+```py
+rcl_interfaces.msg.ParameterDescriptor descriptor;
+descriptor.dynamic_typing = True;
+
+node.declare_parameter("dynamically_typed_parameter", None, descriptor);
+```
+
+## How is the parameter type specified?
+
+The parameter type will be inferred from the default value provided when declaring it.
+
+## Statically typed parameters when allowing undeclared parameters
+
+When undeclared parameters are allowed and a parameter is set without a previous declaration, the parameter will be dynamically typed.
+This is consistent with other allowed behaviors when undeclared parameters are allowed, e.g. trying to get an undeclared parameter returns "NOT_SET".
+Parameter declarations will remain special and dynamic or static typing will be used based on the parameter descriptor (default to static).
+
+## Declaring a parameter without a default value
+
+There might be cases were a default value does not make sense and the user must always provide an override.
+In those cases, the parameter type can be specified explicitly:
+
+```cpp
+// method signature
+template<typename T>
+Node::declare_parameter<T>(std::string name, rcl_interfaces::msg::ParameterDescriptor = rcl_interfaces::msg::ParameterDescriptor{});
+// or alternatively
+Node::declare_parameter(std::string name, rclcpp::ParameterType type, rcl_interfaces::msg::ParameterDescriptor = rcl_interfaces::msg::ParameterDescriptor{});
+
+// examples
+node->declare_parameter<int64_t>("my_integer_parameter");  // declare an integer parameter
+node->declare_parameter("another_integer_parameter", rclcpp::ParameterType::PARAMETER_INTEGER);  // another way to do the same
+```
+
+```py
+# method signature
+Node.declare_parameter(name: str, param_type: rclpy.Parameter.Type, descriptor: rcl_interfaces.msg.ParameterDescriptor = rcl_interfaces.msg.ParameterDescriptor())
+
+# example
+node.declare_parameter('my_integer_parameter', rclpy.Parameter.Type.INTEGER);  # declare an integer parameter
+```
+
+If the parameter may be unused, but when used requires a parameter override, then you could conditionally declare it:
+
+```cpp
+auto mode = node->declare_parameter("mode", "modeA");  // "mode" parameter is an string
+if (mode == "modeB") {
+    node->declare_parameter<int64_t>("param_needed_when_mode_b");  // when "modeB", the user must provide "param_needed_when_mode_b"
+}
+```
+
+## Other migration notes
+
+Declaring a parameter with only a name is deprecated:
+
+```cpp
+node->declare_parameter("my_param");  // this generates a build warning
+```
+
+```py
+node.declare_parameter("my_param");  # this generates a python user warning
+```
+
+Before, you could initialize a parameter with the "NOT SET" value (in cpp `rclcpp::ParameterValue{}`, in python `None`).
+Now this will throw an exception in both cases:
+
+```cpp
+node->declare_parameter("my_param", rclcpp::ParameterValue{});  // not valid, will throw exception
+```
+
+```py
+node.declare_parameter("my_param", None);  # not valid, will raise error
+```
+
+## Possible improvements
+
+### Easier way to declare dynamically typed parameters
+
+Declaring a dynamically typed parameter in `rclcpp` could be considered to be a bit verbose:
+
+```cpp
+rcl_interfaces::msg::ParameterDescriptor descriptor;
+descriptor.dynamic_typing = true;
+
+node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
+```
+
+the following ways could be supported to make it simpler:
+
+```cpp
+node->declare_parameter(name, rclcpp::PARAMETER_DYNAMIC);
+node->declare_parameter(name, default_value, rclcpp::PARAMETER_DYNAMIC);
+```
+
+or alternatively:
+
+```cpp
+node->declare_parameter(name, default_value, rclcpp::ParameterDescriptor{}.dynamic_typing());
+```
+
+For `rclpy`, there's already a short way to do it:
+
+```py
+node.declare_parameter(name, default_value, rclpy.ParameterDescriptor(dynamic_typing=true));
+```

rclcpp/include/rclcpp/any_executable.hpp

@@ -47,6 +47,7 @@ struct AnyExecutable
   // These are used to keep the scope on the containing items
   rclcpp::CallbackGroup::SharedPtr callback_group;
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base;
+  std::shared_ptr<void> data;
 };
 
 namespace executor

rclcpp/include/rclcpp/any_subscription_callback.hpp

@@ -65,6 +65,9 @@ public:
     const_shared_ptr_callback_(nullptr), const_shared_ptr_with_info_callback_(nullptr),
     unique_ptr_callback_(nullptr), unique_ptr_with_info_callback_(nullptr)
   {
+    if (allocator == nullptr) {
+      throw std::runtime_error("invalid allocator");
+    }
     message_allocator_ = std::make_shared<MessageAlloc>(*allocator.get());
     allocator::set_allocator_for_deleter(&message_deleter_, message_allocator_.get());
   }

rclcpp/include/rclcpp/callback_group.hpp

@@ -85,8 +85,8 @@ public:
    * group, or after, is irrelevant; the callback group will be automatically
    * added to the executor in either case.
    *
-   * \param[in] group_type They type of the callback group.
-   * \param[in] automatically_add_to_executor_with_node a boolean which
+   * \param[in] group_type The type of the callback group.
+   * \param[in] automatically_add_to_executor_with_node A boolean that
    *   determines whether a callback group is automatically added to an executor
    *   with the node with which it is associated.
    */

rclcpp/include/rclcpp/clock.hpp

@@ -136,7 +136,7 @@ private:
   RCLCPP_PUBLIC
   static void
   on_time_jump(
-    const struct rcl_time_jump_t * time_jump,
+    const rcl_time_jump_t * time_jump,
     bool before_jump,
     void * user_data);
 

rclcpp/include/rclcpp/context.hpp

@@ -248,67 +248,6 @@ public:
   void
   interrupt_all_sleep_for();
 
-  /// Get a handle to the guard condition which is triggered when interrupted.
-  /**
-   * This guard condition is triggered any time interrupt_all_wait_sets() is
-   * called, which may be called by the user, or shutdown().
-   * And in turn, shutdown() may be called by the user, the destructor of this
-   * context, or the signal handler if installed and shutdown_on_sigint is true
-   * for this context.
-   *
-   * The first time that this function is called for a given wait set a new guard
-   * condition will be created and returned; thereafter the same guard condition
-   * will be returned for the same wait set.
-   * This mechanism is designed to ensure that the same guard condition is not
-   * reused across wait sets (e.g., when using multiple executors in the same
-   * process).
-   * This method will throw an exception if initialization of the guard
-   * condition fails.
-   *
-   * The returned guard condition needs to be released with the
-   * release_interrupt_guard_condition() method in order to reclaim resources.
-   *
-   * \param[in] wait_set Pointer to the rcl_wait_set_t that will be using the
-   *   resulting guard condition.
-   * \return Pointer to the guard condition.
-   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
-   */
-  RCLCPP_PUBLIC
-  rcl_guard_condition_t *
-  get_interrupt_guard_condition(rcl_wait_set_t * wait_set);
-
-  /// Release the previously allocated guard condition which is triggered when interrupted.
-  /**
-   * If you previously called get_interrupt_guard_condition() for a given wait
-   * set to get a interrupt guard condition, then you should call
-   * release_interrupt_guard_condition() when you're done, to free that
-   * condition.
-   * Will throw an exception if get_interrupt_guard_condition() wasn't
-   * previously called for the given wait set.
-   *
-   * After calling this, the pointer returned by get_interrupt_guard_condition()
-   * for the given wait_set is invalid.
-   *
-   * \param[in] wait_set Pointer to the rcl_wait_set_t that was using the
-   *   resulting guard condition.
-   * \throws anything rclcpp::exceptions::throw_from_rcl_error can throw.
-   * \throws std::runtime_error if a nonexistent wait set is trying to release sigint guard condition.
-   */
-  RCLCPP_PUBLIC
-  void
-  release_interrupt_guard_condition(rcl_wait_set_t * wait_set);
-
-  /// Nothrow version of release_interrupt_guard_condition(), logs to RCLCPP_ERROR instead.
-  RCLCPP_PUBLIC
-  void
-  release_interrupt_guard_condition(rcl_wait_set_t * wait_set, const std::nothrow_t &) noexcept;
-
-  /// Interrupt any blocking executors, or wait sets associated with this context.
-  RCLCPP_PUBLIC
-  virtual
-  void
-  interrupt_all_wait_sets();
-
   /// Return a singleton instance for the SubContext type, constructing one if necessary.
   template<typename SubContext, typename ... Args>
   std::shared_ptr<SubContext>
@@ -368,11 +307,6 @@ private:
   /// Mutex for protecting the global condition variable.
   std::mutex interrupt_mutex_;
 
-  /// Mutex to protect sigint_guard_cond_handles_.
-  std::mutex interrupt_guard_cond_handles_mutex_;
-  /// Guard conditions for interrupting of associated wait sets on interrupt_all_wait_sets().
-  std::unordered_map<rcl_wait_set_t *, rcl_guard_condition_t> interrupt_guard_cond_handles_;
-
   /// Keep shared ownership of global vector of weak contexts
   std::shared_ptr<WeakContextsWrapper> weak_contexts_;
 };

rclcpp/include/rclcpp/create_publisher.hpp

@@ -17,6 +17,7 @@
 
 #include <memory>
 #include <string>
+#include <utility>
 
 #include "rclcpp/node_interfaces/get_node_topics_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
@@ -24,15 +25,65 @@
 #include "rclcpp/publisher_factory.hpp"
 #include "rclcpp/publisher_options.hpp"
 #include "rclcpp/qos.hpp"
+#include "rclcpp/qos_overriding_options.hpp"
+#include "rclcpp/detail/qos_parameters.hpp"
+
 #include "rmw/qos_profiles.h"
 
 namespace rclcpp
 {
 
+namespace detail
+{
+/// Create and return a publisher of the given MessageT type.
+template<
+  typename MessageT,
+  typename AllocatorT = std::allocator<void>,
+  typename PublisherT = rclcpp::Publisher<MessageT, AllocatorT>,
+  typename NodeParametersT,
+  typename NodeTopicsT>
+std::shared_ptr<PublisherT>
+create_publisher(
+  NodeParametersT & node_parameters,
+  NodeTopicsT & node_topics,
+  const std::string & topic_name,
+  const rclcpp::QoS & qos,
+  const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::PublisherOptionsWithAllocator<AllocatorT>()
+  )
+)
+{
+  auto node_topics_interface = rclcpp::node_interfaces::get_node_topics_interface(node_topics);
+  const rclcpp::QoS & actual_qos = options.qos_overriding_options.get_policy_kinds().size() ?
+    rclcpp::detail::declare_qos_parameters(
+    options.qos_overriding_options, node_parameters,
+    node_topics_interface->resolve_topic_name(topic_name),
+    qos, rclcpp::detail::PublisherQosParametersTraits{}) :
+    qos;
+
+  // Create the publisher.
+  auto pub = node_topics_interface->create_publisher(
+    topic_name,
+    rclcpp::create_publisher_factory<MessageT, AllocatorT, PublisherT>(options),
+    actual_qos
+  );
+
+  // Add the publisher to the node topics interface.
+  node_topics_interface->add_publisher(pub, options.callback_group);
+
+  return std::dynamic_pointer_cast<PublisherT>(pub);
+}
+}  // namespace detail
+
+
 /// Create and return a publisher of the given MessageT type.
 /**
  * The NodeT type only needs to have a method called get_node_topics_interface()
  * which returns a shared_ptr to a NodeTopicsInterface.
+ *
+ * In case `options.qos_overriding_options` is enabling qos parameter overrides,
+ * NodeT must also have a method called get_node_parameters_interface()
+ * which returns a shared_ptr to a NodeParametersInterface.
  */
 template<
   typename MessageT,
@@ -49,21 +100,28 @@ create_publisher(
   )
 )
 {
-  // Extract the NodeTopicsInterface from the NodeT.
-  using rclcpp::node_interfaces::get_node_topics_interface;
-  auto node_topics = get_node_topics_interface(node);
+  return detail::create_publisher<MessageT, AllocatorT, PublisherT>(
+    node, node, topic_name, qos, options);
+}
 
-  // Create the publisher.
-  auto pub = node_topics->create_publisher(
-    topic_name,
-    rclcpp::create_publisher_factory<MessageT, AllocatorT, PublisherT>(options),
-    qos
-  );
-
-  // Add the publisher to the node topics interface.
-  node_topics->add_publisher(pub, options.callback_group);
-
-  return std::dynamic_pointer_cast<PublisherT>(pub);
+/// Create and return a publisher of the given MessageT type.
+template<
+  typename MessageT,
+  typename AllocatorT = std::allocator<void>,
+  typename PublisherT = rclcpp::Publisher<MessageT, AllocatorT>>
+std::shared_ptr<PublisherT>
+create_publisher(
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & node_parameters,
+  rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr & node_topics,
+  const std::string & topic_name,
+  const rclcpp::QoS & qos,
+  const rclcpp::PublisherOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::PublisherOptionsWithAllocator<AllocatorT>()
+  )
+)
+{
+  return detail::create_publisher<MessageT, AllocatorT, PublisherT>(
+    node_parameters, node_topics, topic_name, qos, options);
 }
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/create_subscription.hpp

@@ -41,12 +41,115 @@
 namespace rclcpp
 {
 
+namespace detail
+{
+template<
+  typename MessageT,
+  typename CallbackT,
+  typename AllocatorT,
+  typename CallbackMessageT,
+  typename SubscriptionT,
+  typename MessageMemoryStrategyT,
+  typename NodeParametersT,
+  typename NodeTopicsT>
+typename std::shared_ptr<SubscriptionT>
+create_subscription(
+  NodeParametersT & node_parameters,
+  NodeTopicsT & node_topics,
+  const std::string & topic_name,
+  const rclcpp::QoS & qos,
+  CallbackT && callback,
+  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>()
+  ),
+  typename MessageMemoryStrategyT::SharedPtr msg_mem_strat = (
+    MessageMemoryStrategyT::create_default()
+  )
+)
+{
+  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>>
+  subscription_topic_stats = nullptr;
+
+  if (rclcpp::detail::resolve_enable_topic_statistics(
+      options,
+      *node_topics_interface->get_node_base_interface()))
+  {
+    if (options.topic_stats_options.publish_period <= std::chrono::milliseconds(0)) {
+      throw std::invalid_argument(
+              "topic_stats_options.publish_period must be greater than 0, specified value of " +
+              std::to_string(options.topic_stats_options.publish_period.count()) +
+              " ms");
+    }
+
+    std::shared_ptr<Publisher<statistics_msgs::msg::MetricsMessage>>
+    publisher = rclcpp::detail::create_publisher<statistics_msgs::msg::MetricsMessage>(
+      node_parameters,
+      node_topics_interface,
+      options.topic_stats_options.publish_topic,
+      qos);
+
+    subscription_topic_stats = std::make_shared<
+      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
+      >(node_topics_interface->get_node_base_interface()->get_name(), publisher);
+
+    std::weak_ptr<
+      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
+    > weak_subscription_topic_stats(subscription_topic_stats);
+    auto sub_call_back = [weak_subscription_topic_stats]() {
+        auto subscription_topic_stats = weak_subscription_topic_stats.lock();
+        if (subscription_topic_stats) {
+          subscription_topic_stats->publish_message_and_reset_measurements();
+        }
+      };
+
+    auto node_timer_interface = node_topics_interface->get_node_timers_interface();
+
+    auto timer = create_wall_timer(
+      std::chrono::duration_cast<std::chrono::nanoseconds>(
+        options.topic_stats_options.publish_period),
+      sub_call_back,
+      options.callback_group,
+      node_topics_interface->get_node_base_interface(),
+      node_timer_interface
+    );
+
+    subscription_topic_stats->set_publisher_timer(timer);
+  }
+
+  auto factory = rclcpp::create_subscription_factory<MessageT>(
+    std::forward<CallbackT>(callback),
+    options,
+    msg_mem_strat,
+    subscription_topic_stats
+  );
+
+  const rclcpp::QoS & actual_qos = options.qos_overriding_options.get_policy_kinds().size() ?
+    rclcpp::detail::declare_qos_parameters(
+    options.qos_overriding_options, node_parameters,
+    node_topics_interface->resolve_topic_name(topic_name),
+    qos, rclcpp::detail::SubscriptionQosParametersTraits{}) :
+    qos;
+
+  auto sub = node_topics_interface->create_subscription(topic_name, factory, actual_qos);
+  node_topics_interface->add_subscription(sub, options.callback_group);
+
+  return std::dynamic_pointer_cast<SubscriptionT>(sub);
+}
+}  // namespace detail
+
 /// Create and return a subscription of the given MessageT type.
 /**
  * The NodeT type only needs to have a method called get_node_topics_interface()
  * which returns a shared_ptr to a NodeTopicsInterface, or be a
  * NodeTopicsInterface pointer itself.
  *
+ * In case `options.qos_overriding_options` is enabling qos parameter overrides,
+ * NodeT must also have a method called get_node_parameters_interface()
+ * which returns a shared_ptr to a NodeParametersInterface.
+ *
  * \tparam MessageT
  * \tparam CallbackT
  * \tparam AllocatorT
@@ -78,7 +181,7 @@ template<
   typename NodeT>
 typename std::shared_ptr<SubscriptionT>
 create_subscription(
-  NodeT && node,
+  NodeT & node,
   const std::string & topic_name,
   const rclcpp::QoS & qos,
   CallbackT && callback,
@@ -90,68 +193,45 @@ create_subscription(
   )
 )
 {
-  using rclcpp::node_interfaces::get_node_topics_interface;
-  auto node_topics = get_node_topics_interface(std::forward<NodeT>(node));
+  return rclcpp::detail::create_subscription<
+    MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT, MessageMemoryStrategyT>(
+    node, node, topic_name, qos, std::forward<CallbackT>(callback), options, msg_mem_strat);
+}
 
-  std::shared_ptr<rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>>
-  subscription_topic_stats = nullptr;
-
-  if (rclcpp::detail::resolve_enable_topic_statistics(
-      options,
-      *node_topics->get_node_base_interface()))
-  {
-    if (options.topic_stats_options.publish_period <= std::chrono::milliseconds(0)) {
-      throw std::invalid_argument(
-              "topic_stats_options.publish_period must be greater than 0, specified value of " +
-              std::to_string(options.topic_stats_options.publish_period.count()) +
-              " ms");
-    }
-
-    std::shared_ptr<Publisher<statistics_msgs::msg::MetricsMessage>> publisher =
-      create_publisher<statistics_msgs::msg::MetricsMessage>(
-      node,
-      options.topic_stats_options.publish_topic,
-      qos);
-
-    subscription_topic_stats = std::make_shared<
-      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
-      >(node_topics->get_node_base_interface()->get_name(), publisher);
-
-    std::weak_ptr<
-      rclcpp::topic_statistics::SubscriptionTopicStatistics<CallbackMessageT>
-    > weak_subscription_topic_stats(subscription_topic_stats);
-    auto sub_call_back = [weak_subscription_topic_stats]() {
-        auto subscription_topic_stats = weak_subscription_topic_stats.lock();
-        if (subscription_topic_stats) {
-          subscription_topic_stats->publish_message();
-        }
-      };
-
-    auto node_timer_interface = node_topics->get_node_timers_interface();
-
-    auto timer = create_wall_timer(
-      std::chrono::duration_cast<std::chrono::nanoseconds>(
-        options.topic_stats_options.publish_period),
-      sub_call_back,
-      options.callback_group,
-      node_topics->get_node_base_interface(),
-      node_timer_interface
-    );
-
-    subscription_topic_stats->set_publisher_timer(timer);
-  }
-
-  auto factory = rclcpp::create_subscription_factory<MessageT>(
-    std::forward<CallbackT>(callback),
-    options,
-    msg_mem_strat,
-    subscription_topic_stats
-  );
-
-  auto sub = node_topics->create_subscription(topic_name, factory, qos);
-  node_topics->add_subscription(sub, options.callback_group);
-
-  return std::dynamic_pointer_cast<SubscriptionT>(sub);
+/// Create and return a subscription of the given MessageT type.
+/**
+ * See \ref create_subscription().
+ */
+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 std::shared_ptr<SubscriptionT>
+create_subscription(
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & node_parameters,
+  rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr & node_topics,
+  const std::string & topic_name,
+  const rclcpp::QoS & qos,
+  CallbackT && callback,
+  const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options = (
+    rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>()
+  ),
+  typename MessageMemoryStrategyT::SharedPtr msg_mem_strat = (
+    MessageMemoryStrategyT::create_default()
+  )
+)
+{
+  return rclcpp::detail::create_subscription<
+    MessageT, CallbackT, AllocatorT, CallbackMessageT, SubscriptionT, MessageMemoryStrategyT>(
+    node_parameters, node_topics, topic_name, qos,
+    std::forward<CallbackT>(callback), options, msg_mem_strat);
 }
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/detail/mutex_two_priorities.hpp

@@ -0,0 +1,75 @@
+// 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 <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:
+  // Implementation detail: the idea here is that only one low priority thread can be
+  // trying to take the data_ mutex while the others are excluded by the barrier_ mutex.
+  // All high priority threads are already waiting for the data_ mutex.
+  std::mutex barrier_;
+  std::mutex data_;
+};
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__MUTEX_TWO_PRIORITIES_HPP_

rclcpp/include/rclcpp/detail/qos_parameters.hpp

@@ -0,0 +1,326 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__DETAIL__QOS_PARAMETERS_HPP_
+#define RCLCPP__DETAIL__QOS_PARAMETERS_HPP_
+
+#include <algorithm>
+#include <array>
+#include <functional>
+#include <initializer_list>
+#include <map>
+#include <string>
+#include <type_traits>
+#include <vector>
+
+#include "rcl_interfaces/msg/parameter_descriptor.hpp"
+#include "rcpputils/pointer_traits.hpp"
+#include "rmw/qos_string_conversions.h"
+
+#include "rclcpp/duration.hpp"
+#include "rclcpp/node_interfaces/get_node_parameters_interface.hpp"
+#include "rclcpp/node_interfaces/node_parameters_interface.hpp"
+#include "rclcpp/qos_overriding_options.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+
+/// \internal Trait used to specialize `declare_qos_parameters()` for publishers.
+struct PublisherQosParametersTraits
+{
+  static constexpr const char * entity_type() {return "publisher";}
+  static constexpr auto allowed_policies()
+  {
+    return std::array<::rclcpp::QosPolicyKind, 9> {
+      QosPolicyKind::AvoidRosNamespaceConventions,
+      QosPolicyKind::Deadline,
+      QosPolicyKind::Durability,
+      QosPolicyKind::History,
+      QosPolicyKind::Depth,
+      QosPolicyKind::Lifespan,
+      QosPolicyKind::Liveliness,
+      QosPolicyKind::LivelinessLeaseDuration,
+      QosPolicyKind::Reliability,
+    };
+  }
+};
+
+/// \internal Trait used to specialize `declare_qos_parameters()` for subscriptions.
+struct SubscriptionQosParametersTraits
+{
+  static constexpr const char * entity_type() {return "subscription";}
+  static constexpr auto allowed_policies()
+  {
+    return std::array<::rclcpp::QosPolicyKind, 8> {
+      QosPolicyKind::AvoidRosNamespaceConventions,
+      QosPolicyKind::Deadline,
+      QosPolicyKind::Durability,
+      QosPolicyKind::History,
+      QosPolicyKind::Depth,
+      QosPolicyKind::Liveliness,
+      QosPolicyKind::LivelinessLeaseDuration,
+      QosPolicyKind::Reliability,
+    };
+  }
+};
+
+/// \internal Returns the given `policy` of the profile `qos` converted to a parameter value.
+inline
+::rclcpp::ParameterValue
+get_default_qos_param_value(rclcpp::QosPolicyKind policy, const rclcpp::QoS & qos);
+
+/// \internal Modify the given `policy` in `qos` to be `value`.
+inline
+void
+apply_qos_override(
+  rclcpp::QosPolicyKind policy, rclcpp::ParameterValue value, rclcpp::QoS & qos);
+
+inline
+rclcpp::ParameterValue
+declare_parameter_or_get(
+  rclcpp::node_interfaces::NodeParametersInterface & parameters_interface,
+  const std::string & param_name,
+  rclcpp::ParameterValue param_value,
+  rcl_interfaces::msg::ParameterDescriptor descriptor)
+{
+  try {
+    return parameters_interface.declare_parameter(
+      param_name, param_value, descriptor);
+  } catch (const rclcpp::exceptions::ParameterAlreadyDeclaredException &) {
+    return parameters_interface.get_parameter(param_name).get_parameter_value();
+  }
+}
+
+/// \internal Declare QoS parameters for the given entity.
+/**
+ * \tparam NodeT Node pointer or reference type.
+ * \tparam EntityQosParametersTraits A class with two static methods: `entity_type()` and
+ *  `allowed_policies()`. See `PublisherQosParametersTraits` and `SubscriptionQosParametersTraits`.
+ * \param options User provided options that indicate if QoS parameter overrides should be
+ *  declared or not, which policy can have overrides, and optionally a callback to validate the profile.
+ * \param node Parameters will be declared using this node.
+ * \param topic_name Name of the topic of the entity.
+ * \param default_qos User provided qos. It will be used as a default for the parameters declared.
+ * \return qos profile based on the user provided parameter overrides.
+ */
+template<typename NodeT, typename EntityQosParametersTraits>
+std::enable_if_t<
+  rclcpp::node_interfaces::has_node_parameters_interface<
+    decltype(std::declval<typename rcpputils::remove_pointer<NodeT>::type>())>::value ||
+  std::is_same<typename std::decay_t<NodeT>,
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr>::value,
+  rclcpp::QoS>
+declare_qos_parameters(
+  const ::rclcpp::QosOverridingOptions & options,
+  NodeT & node,
+  const std::string & topic_name,
+  const ::rclcpp::QoS & default_qos,
+  EntityQosParametersTraits)
+{
+  auto & parameters_interface = *rclcpp::node_interfaces::get_node_parameters_interface(node);
+  std::string param_prefix;
+  const auto & id = options.get_id();
+  {
+    std::ostringstream oss{"qos_overrides.", std::ios::ate};
+    oss << topic_name << "." << EntityQosParametersTraits::entity_type();
+    if (!id.empty()) {
+      oss << "_" << id;
+    }
+    oss << ".";
+    param_prefix = oss.str();
+  }
+  std::string param_description_suffix;
+  {
+    std::ostringstream oss{"} for ", std::ios::ate};
+    oss << EntityQosParametersTraits::entity_type() << " {" << topic_name << "}";
+    if (!id.empty()) {
+      oss << " with id {" << id << "}";
+    }
+    param_description_suffix = oss.str();
+  }
+  rclcpp::QoS qos = default_qos;
+  for (auto policy : EntityQosParametersTraits::allowed_policies()) {
+    if (
+      std::count(options.get_policy_kinds().begin(), options.get_policy_kinds().end(), policy))
+    {
+      std::ostringstream param_name{param_prefix, std::ios::ate};
+      param_name << qos_policy_kind_to_cstr(policy);
+      std::ostringstream param_desciption{"qos policy {", std::ios::ate};
+      param_desciption << qos_policy_kind_to_cstr(policy) << param_description_suffix;
+      rcl_interfaces::msg::ParameterDescriptor descriptor{};
+      descriptor.description = param_desciption.str();
+      descriptor.read_only = true;
+      auto value = declare_parameter_or_get(
+        parameters_interface, param_name.str(),
+        get_default_qos_param_value(policy, qos), descriptor);
+      ::rclcpp::detail::apply_qos_override(policy, value, qos);
+    }
+  }
+  const auto & validation_callback = options.get_validation_callback();
+  if (validation_callback) {
+    auto result = validation_callback(qos);
+    if (!result.successful) {
+      throw rclcpp::exceptions::InvalidQosOverridesException{
+              "validation callback failed: " + result.reason};
+    }
+  }
+  return qos;
+}
+
+// TODO(ivanpauno): This overload cannot declare the QoS parameters, as a node parameters interface
+// was not provided.
+template<typename NodeT, typename EntityQosParametersTraits>
+std::enable_if_t<
+  !(rclcpp::node_interfaces::has_node_parameters_interface<
+    decltype(std::declval<typename rcpputils::remove_pointer<NodeT>::type>())>::value ||
+  std::is_same<typename std::decay_t<NodeT>,
+  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr>::value),
+  rclcpp::QoS>
+declare_qos_parameters(
+  const ::rclcpp::QosOverridingOptions & options,
+  NodeT &,
+  const std::string &,
+  const ::rclcpp::QoS & default_qos,
+  EntityQosParametersTraits)
+{
+  if (options.get_policy_kinds().size()) {
+    std::runtime_error exc{
+      "passed non-default qos overriding options without providing a parameters interface"};
+    throw exc;
+  }
+  return default_qos;
+}
+
+/// \internal Helper function to get a rmw qos policy value from a string.
+#define RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING( \
+    kind_lower, kind_upper, parameter_value, rclcpp_qos) \
+  do { \
+    auto policy_string = (parameter_value).get<std::string>(); \
+    auto policy_value = rmw_qos_ ## kind_lower ## _policy_from_str(policy_string.c_str()); \
+    if (RMW_QOS_POLICY_ ## kind_upper ## _UNKNOWN == policy_value) { \
+      throw std::invalid_argument{"unknown QoS policy " #kind_lower " value: " + policy_string}; \
+    } \
+    ((rclcpp_qos).kind_lower)(policy_value); \
+  } while (0)
+
+inline
+void
+apply_qos_override(
+  rclcpp::QosPolicyKind policy, rclcpp::ParameterValue value, rclcpp::QoS & qos)
+{
+  switch (policy) {
+    case QosPolicyKind::AvoidRosNamespaceConventions:
+      qos.avoid_ros_namespace_conventions(value.get<bool>());
+      break;
+    case QosPolicyKind::Deadline:
+      qos.deadline(::rclcpp::Duration::from_nanoseconds(value.get<int64_t>()));
+      break;
+    case QosPolicyKind::Durability:
+      RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING(
+        durability, DURABILITY, value, qos);
+      break;
+    case QosPolicyKind::History:
+      RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING(
+        history, HISTORY, value, qos);
+      break;
+    case QosPolicyKind::Depth:
+      qos.get_rmw_qos_profile().depth = static_cast<size_t>(value.get<int64_t>());
+      break;
+    case QosPolicyKind::Lifespan:
+      qos.lifespan(::rclcpp::Duration::from_nanoseconds(value.get<int64_t>()));
+      break;
+    case QosPolicyKind::Liveliness:
+      RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING(
+        liveliness, LIVELINESS, value, qos);
+      break;
+    case QosPolicyKind::LivelinessLeaseDuration:
+      qos.liveliness_lease_duration(::rclcpp::Duration::from_nanoseconds(value.get<int64_t>()));
+      break;
+    case QosPolicyKind::Reliability:
+      RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING(
+        reliability, RELIABILITY, value, qos);
+      break;
+    default:
+      throw std::invalid_argument{"unknown QosPolicyKind"};
+  }
+}
+
+/// Convert `rmw_time_t` to `int64_t` that can be used as a parameter value.
+inline
+int64_t
+rmw_duration_to_int64_t(rmw_time_t rmw_duration)
+{
+  return ::rclcpp::Duration(
+    static_cast<int32_t>(rmw_duration.sec),
+    static_cast<uint32_t>(rmw_duration.nsec)
+  ).nanoseconds();
+}
+
+/// \internal Throw an exception if `policy_value_stringified` is NULL.
+inline
+const char *
+check_if_stringified_policy_is_null(const char * policy_value_stringified, QosPolicyKind kind)
+{
+  if (!policy_value_stringified) {
+    std::ostringstream oss{"unknown value for policy kind {", std::ios::ate};
+    oss << kind << "}";
+    throw std::invalid_argument{oss.str()};
+  }
+  return policy_value_stringified;
+}
+
+inline
+::rclcpp::ParameterValue
+get_default_qos_param_value(rclcpp::QosPolicyKind kind, const rclcpp::QoS & qos)
+{
+  using ParameterValue = ::rclcpp::ParameterValue;
+  const auto & rmw_qos = qos.get_rmw_qos_profile();
+  switch (kind) {
+    case QosPolicyKind::AvoidRosNamespaceConventions:
+      return ParameterValue(rmw_qos.avoid_ros_namespace_conventions);
+    case QosPolicyKind::Deadline:
+      return ParameterValue(rmw_duration_to_int64_t(rmw_qos.deadline));
+    case QosPolicyKind::Durability:
+      return ParameterValue(
+        check_if_stringified_policy_is_null(
+          rmw_qos_durability_policy_to_str(rmw_qos.durability), kind));
+    case QosPolicyKind::History:
+      return ParameterValue(
+        check_if_stringified_policy_is_null(
+          rmw_qos_history_policy_to_str(rmw_qos.history), kind));
+    case QosPolicyKind::Depth:
+      return ParameterValue(static_cast<int64_t>(rmw_qos.depth));
+    case QosPolicyKind::Lifespan:
+      return ParameterValue(rmw_duration_to_int64_t(rmw_qos.lifespan));
+    case QosPolicyKind::Liveliness:
+      return ParameterValue(
+        check_if_stringified_policy_is_null(
+          rmw_qos_liveliness_policy_to_str(rmw_qos.liveliness), kind));
+    case QosPolicyKind::LivelinessLeaseDuration:
+      return ParameterValue(rmw_duration_to_int64_t(rmw_qos.liveliness_lease_duration));
+    case QosPolicyKind::Reliability:
+      return ParameterValue(
+        check_if_stringified_policy_is_null(
+          rmw_qos_reliability_policy_to_str(rmw_qos.reliability), kind));
+    default:
+      throw std::invalid_argument{"unknown QoS policy kind"};
+  }
+}
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__QOS_PARAMETERS_HPP_

rclcpp/include/rclcpp/duration.hpp

@@ -137,6 +137,9 @@ public:
   static Duration
   from_nanoseconds(rcl_duration_value_t nanoseconds);
 
+  static Duration
+  from_rmw_time(rmw_time_t duration);
+
   /// Convert Duration into a std::chrono::Duration.
   template<class DurationT>
   DurationT

rclcpp/include/rclcpp/exceptions/exceptions.hpp

@@ -282,6 +282,27 @@ 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
+{
+public:
+  /// Construct an instance.
+  /**
+   * \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")
+  {}
+};
+
+/// Thrown if the QoS overrides provided aren't valid.
+class InvalidQosOverridesException : public std::runtime_error
+{
+  // Inherit constructors from runtime_error.
+  using std::runtime_error::runtime_error;
+};
+
 }  // namespace exceptions
 }  // namespace rclcpp
 

rclcpp/include/rclcpp/executor.hpp

@@ -31,6 +31,7 @@
 #include "rcl/wait.h"
 
 #include "rclcpp/contexts/default_context.hpp"
+#include "rclcpp/guard_condition.hpp"
 #include "rclcpp/executor_options.hpp"
 #include "rclcpp/future_return_code.hpp"
 #include "rclcpp/memory_strategies.hpp"
@@ -447,7 +448,7 @@ protected:
   RCLCPP_PUBLIC
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr
   get_node_by_group(
-    WeakCallbackGroupsToNodesMap weak_groups_to_nodes,
+    const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes,
     rclcpp::CallbackGroup::SharedPtr group);
 
   /// Return true if the node has been added to this executor.
@@ -459,7 +460,7 @@ protected:
   bool
   has_node(
     const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
-    WeakCallbackGroupsToNodesMap weak_groups_to_nodes) const;
+    const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes) const;
 
   RCLCPP_PUBLIC
   rclcpp::CallbackGroup::SharedPtr
@@ -475,7 +476,7 @@ protected:
     rclcpp::CallbackGroup::SharedPtr group_ptr,
     rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
     WeakCallbackGroupsToNodesMap & weak_groups_to_nodes,
-    bool notify = true);
+    bool notify = true) RCPPUTILS_TSA_REQUIRES(mutex_);
 
   /// Remove a callback group from the executor.
   /**
@@ -486,7 +487,7 @@ protected:
   remove_callback_group_from_map(
     rclcpp::CallbackGroup::SharedPtr group_ptr,
     WeakCallbackGroupsToNodesMap & weak_groups_to_nodes,
-    bool notify = true);
+    bool notify = true) RCPPUTILS_TSA_REQUIRES(mutex_);
 
   RCLCPP_PUBLIC
   bool
@@ -496,7 +497,7 @@ protected:
   bool
   get_next_ready_executable_from_map(
     AnyExecutable & any_executable,
-    WeakCallbackGroupsToNodesMap weak_groups_to_nodes);
+    const WeakCallbackGroupsToNodesMap & weak_groups_to_nodes);
 
   RCLCPP_PUBLIC
   bool
@@ -517,7 +518,7 @@ protected:
    */
   RCLCPP_PUBLIC
   virtual void
-  add_callback_groups_from_nodes_associated_to_executor();
+  add_callback_groups_from_nodes_associated_to_executor() RCPPUTILS_TSA_REQUIRES(mutex_);
 
   /// Spinning state, used to prevent multi threaded calls to spin and to cancel blocking spins.
   std::atomic_bool spinning;
@@ -525,14 +526,17 @@ protected:
   /// 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();
 
+  std::shared_ptr<rclcpp::GuardCondition> shutdown_guard_condition_;
+
   /// Wait set for managing entities that the rmw layer waits on.
   rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
 
   // Mutex to protect the subsequent memory_strategy_.
-  std::mutex memory_strategy_mutex_;
+  mutable std::mutex mutex_;
 
   /// The memory strategy: an interface for handling user-defined memory allocation strategies.
-  memory_strategy::MemoryStrategy::SharedPtr memory_strategy_;
+  memory_strategy::MemoryStrategy::SharedPtr
+  memory_strategy_ RCPPUTILS_TSA_PT_GUARDED_BY(mutex_);
 
   /// The context associated with this executor.
   std::shared_ptr<rclcpp::Context> context_;
@@ -549,19 +553,24 @@ protected:
     WeakNodesToGuardConditionsMap;
 
   /// maps nodes to guard conditions
-  WeakNodesToGuardConditionsMap weak_nodes_to_guard_conditions_;
+  WeakNodesToGuardConditionsMap
+  weak_nodes_to_guard_conditions_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
 
   /// maps callback groups associated to nodes
-  WeakCallbackGroupsToNodesMap weak_groups_associated_with_executor_to_nodes_;
+  WeakCallbackGroupsToNodesMap
+  weak_groups_associated_with_executor_to_nodes_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
 
   /// maps callback groups to nodes associated with executor
-  WeakCallbackGroupsToNodesMap weak_groups_to_nodes_associated_with_executor_;
+  WeakCallbackGroupsToNodesMap
+  weak_groups_to_nodes_associated_with_executor_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
 
   /// maps all callback groups to nodes
-  WeakCallbackGroupsToNodesMap weak_groups_to_nodes_;
+  WeakCallbackGroupsToNodesMap
+  weak_groups_to_nodes_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
 
   /// nodes that are associated with the executor
-  std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
+  std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr>
+  weak_nodes_ RCPPUTILS_TSA_GUARDED_BY(mutex_);
 };
 
 namespace executor

rclcpp/include/rclcpp/executors/multi_threaded_executor.hpp

@@ -22,6 +22,7 @@
 #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"
@@ -81,7 +82,7 @@ protected:
 private:
   RCLCPP_DISABLE_COPY(MultiThreadedExecutor)
 
-  std::mutex wait_mutex_;
+  detail::MutexTwoPriorities wait_mutex_;
   size_t number_of_threads_;
   bool yield_before_execute_;
   std::chrono::nanoseconds next_exec_timeout_;

rclcpp/include/rclcpp/executors/static_executor_entities_collector.hpp

@@ -72,9 +72,19 @@ public:
   void
   fini();
 
+  /// Execute the waitable.
   RCLCPP_PUBLIC
   void
-  execute() override;
+  execute(std::shared_ptr<void> & data) override;
+
+  /// Take the data so that it can be consumed with `execute`.
+  /**
+   * For `StaticExecutorEntitiesCollector`, this always return `nullptr`.
+   * \sa rclcpp::Waitable::take_data()
+   */
+  RCLCPP_PUBLIC
+  std::shared_ptr<void>
+  take_data() override;
 
   /// Function to add_handles_to_wait_set and wait for work and
   /**

rclcpp/include/rclcpp/experimental/intra_process_manager.hpp

@@ -307,7 +307,7 @@ private:
   {
     SubscriptionInfo() = default;
 
-    rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr subscription;
+    rclcpp::experimental::SubscriptionIntraProcessBase::WeakPtr subscription;
     rmw_qos_profile_t qos;
     const char * topic_name;
     bool use_take_shared_method;
@@ -361,13 +361,16 @@ private:
       if (subscription_it == subscriptions_.end()) {
         throw std::runtime_error("subscription has unexpectedly gone out of scope");
       }
-      auto subscription_base = subscription_it->second.subscription;
+      auto subscription_base = subscription_it->second.subscription.lock();
+      if (subscription_base) {
+        auto subscription = std::static_pointer_cast<
+          rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+          >(subscription_base);
 
-      auto subscription = std::static_pointer_cast<
-        rclcpp::experimental::SubscriptionIntraProcess<MessageT>
-        >(subscription_base);
-
-      subscription->provide_intra_process_message(message);
+        subscription->provide_intra_process_message(message);
+      } else {
+        subscriptions_.erase(id);
+      }
     }
   }
 
@@ -389,24 +392,27 @@ private:
       if (subscription_it == subscriptions_.end()) {
         throw std::runtime_error("subscription has unexpectedly gone out of scope");
       }
-      auto subscription_base = subscription_it->second.subscription;
+      auto subscription_base = subscription_it->second.subscription.lock();
+      if (subscription_base) {
+        auto subscription = std::static_pointer_cast<
+          rclcpp::experimental::SubscriptionIntraProcess<MessageT>
+          >(subscription_base);
 
-      auto subscription = std::static_pointer_cast<
-        rclcpp::experimental::SubscriptionIntraProcess<MessageT>
-        >(subscription_base);
+        if (std::next(it) == subscription_ids.end()) {
+          // If this is the last subscription, give up ownership
+          subscription->provide_intra_process_message(std::move(message));
+        } else {
+          // Copy the message since we have additional subscriptions to serve
+          MessageUniquePtr copy_message;
+          Deleter deleter = message.get_deleter();
+          auto ptr = MessageAllocTraits::allocate(*allocator.get(), 1);
+          MessageAllocTraits::construct(*allocator.get(), ptr, *message);
+          copy_message = MessageUniquePtr(ptr, deleter);
 
-      if (std::next(it) == subscription_ids.end()) {
-        // If this is the last subscription, give up ownership
-        subscription->provide_intra_process_message(std::move(message));
+          subscription->provide_intra_process_message(std::move(copy_message));
+        }
       } else {
-        // Copy the message since we have additional subscriptions to serve
-        MessageUniquePtr copy_message;
-        Deleter deleter = message.get_deleter();
-        auto ptr = MessageAllocTraits::allocate(*allocator.get(), 1);
-        MessageAllocTraits::construct(*allocator.get(), ptr, *message);
-        copy_message = MessageUniquePtr(ptr, deleter);
-
-        subscription->provide_intra_process_message(std::move(copy_message));
+        subscriptions_.erase(subscription_it);
       }
     }
   }

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -18,7 +18,9 @@
 #include <rmw/rmw.h>
 
 #include <functional>
+#include <map>
 #include <memory>
+#include <stdexcept>
 #include <string>
 #include <utility>
 
@@ -115,13 +117,31 @@ public:
   bool
   is_ready(rcl_wait_set_t * wait_set)
   {
-    (void)wait_set;
+    (void) wait_set;
     return buffer_->has_data();
   }
 
-  void execute()
+  std::shared_ptr<void>
+  take_data()
   {
-    execute_impl<CallbackMessageT>();
+    ConstMessageSharedPtr shared_msg;
+    MessageUniquePtr unique_msg;
+
+    if (any_callback_.use_take_shared_method()) {
+      shared_msg = buffer_->consume_shared();
+    } else {
+      unique_msg = buffer_->consume_unique();
+    }
+    return std::static_pointer_cast<void>(
+      std::make_shared<std::pair<ConstMessageSharedPtr, MessageUniquePtr>>(
+        std::pair<ConstMessageSharedPtr, MessageUniquePtr>(
+          shared_msg, std::move(unique_msg)))
+    );
+  }
+
+  void execute(std::shared_ptr<void> & data)
+  {
+    execute_impl<CallbackMessageT>(data);
   }
 
   void
@@ -154,26 +174,35 @@ private:
 
   template<typename T>
   typename std::enable_if<std::is_same<T, rcl_serialized_message_t>::value, void>::type
-  execute_impl()
+  execute_impl(std::shared_ptr<void> & data)
   {
+    (void)data;
     throw std::runtime_error("Subscription intra-process can't handle serialized messages");
   }
 
   template<class T>
   typename std::enable_if<!std::is_same<T, rcl_serialized_message_t>::value, void>::type
-  execute_impl()
+  execute_impl(std::shared_ptr<void> & data)
   {
+    if (!data) {
+      throw std::runtime_error("'data' is empty");
+    }
+
     rmw_message_info_t msg_info;
     msg_info.publisher_gid = {0, {0}};
     msg_info.from_intra_process = true;
 
+    auto shared_ptr = std::static_pointer_cast<std::pair<ConstMessageSharedPtr, MessageUniquePtr>>(
+      data);
+
     if (any_callback_.use_take_shared_method()) {
-      ConstMessageSharedPtr msg = buffer_->consume_shared();
-      any_callback_.dispatch_intra_process(msg, msg_info);
+      ConstMessageSharedPtr shared_msg = shared_ptr->first;
+      any_callback_.dispatch_intra_process(shared_msg, msg_info);
     } else {
-      MessageUniquePtr msg = buffer_->consume_unique();
-      any_callback_.dispatch_intra_process(std::move(msg), msg_info);
+      MessageUniquePtr unique_msg = std::move(shared_ptr->second);
+      any_callback_.dispatch_intra_process(std::move(unique_msg), msg_info);
     }
+    shared_ptr.reset();
   }
 
   AnySubscriptionCallback<CallbackMessageT, Alloc> any_callback_;

rclcpp/include/rclcpp/experimental/subscription_intra_process_base.hpp

@@ -56,8 +56,12 @@ public:
   virtual bool
   is_ready(rcl_wait_set_t * wait_set) = 0;
 
+  virtual
+  std::shared_ptr<void>
+  take_data() = 0;
+
   virtual void
-  execute() = 0;
+  execute(std::shared_ptr<void> & data) = 0;
 
   virtual bool
   use_take_shared_method() const = 0;

rclcpp/include/rclcpp/graph_listener.hpp

@@ -63,7 +63,7 @@ class GraphListener : public std::enable_shared_from_this<GraphListener>
 {
 public:
   RCLCPP_PUBLIC
-  explicit GraphListener(std::shared_ptr<rclcpp::Context> parent_context);
+  explicit GraphListener(const rclcpp::Context::SharedPtr & parent_context);
 
   RCLCPP_PUBLIC
   virtual ~GraphListener();
@@ -161,19 +161,22 @@ protected:
   run_loop();
 
   RCLCPP_PUBLIC
-  void init_wait_set();
+  void
+  init_wait_set();
 
   RCLCPP_PUBLIC
-  void cleanup_wait_set();
+  void
+  cleanup_wait_set();
 
 private:
   RCLCPP_DISABLE_COPY(GraphListener)
 
   /** \internal */
   void
-  __shutdown(bool);
+  __shutdown();
 
-  rclcpp::Context::WeakPtr parent_context_;
+  std::weak_ptr<rclcpp::Context> weak_parent_context_;
+  std::shared_ptr<rcl_context_t> rcl_parent_context_;
 
   std::thread listener_thread_;
   bool is_started_;
@@ -185,7 +188,6 @@ private:
   std::vector<rclcpp::node_interfaces::NodeGraphInterface *> node_graph_interfaces_;
 
   rcl_guard_condition_t interrupt_guard_condition_ = rcl_get_zero_initialized_guard_condition();
-  rcl_guard_condition_t * shutdown_guard_condition_;
   rcl_wait_set_t wait_set_ = rcl_get_zero_initialized_wait_set();
 };
 

rclcpp/include/rclcpp/loaned_message.hpp

@@ -183,14 +183,30 @@ public:
   /**
    * A call to `release()` will unmanage the memory for the ROS message.
    * That means that the destructor of this class will not free the memory on scope exit.
+   * If the message is loaned from the middleware but not be published, the user needs to call
+   * `rcl_return_loaned_message_from_publisher` manually.
+   * If the memory is from the local allocator, the memory is freed when the unique pointer
+   * goes out instead.
    *
-   * \return Raw pointer to the message instance.
+   * \return std::unique_ptr to the message instance.
    */
-  MessageT * release()
+  std::unique_ptr<MessageT, std::function<void(MessageT *)>>
+  release()
   {
     auto msg = message_;
     message_ = nullptr;
-    return msg;
+
+    if (pub_.can_loan_messages()) {
+      return std::unique_ptr<MessageT, std::function<void(MessageT *)>>(msg, [](MessageT *) {});
+    }
+
+    return std::unique_ptr<MessageT, std::function<void(MessageT *)>>(
+      msg,
+      [allocator = message_allocator_](MessageT * msg_ptr) mutable {
+        // call destructor before deallocating
+        msg_ptr->~MessageT();
+        allocator.deallocate(msg_ptr, 1);
+      });
   }
 
 protected:

rclcpp/include/rclcpp/logger.hpp

@@ -22,6 +22,7 @@
 
 #include "rcl/node.h"
 #include "rcutils/logging.h"
+#include "rcpputils/filesystem_helper.hpp"
 
 /**
  * \def RCLCPP_LOGGING_ENABLED
@@ -75,6 +76,18 @@ RCLCPP_PUBLIC
 Logger
 get_node_logger(const rcl_node_t * node);
 
+/// Get the current logging directory.
+/**
+ * For more details of how the logging directory is determined,
+ * see \ref rcl_logging_get_logging_directory.
+ *
+ * \returns the logging directory being used.
+ * \throws rclcpp::exceptions::RCLError if an unexpected error occurs.
+ */
+RCLCPP_PUBLIC
+rcpputils::fs::path
+get_logging_directory();
+
 class Logger
 {
 public:

rclcpp/include/rclcpp/node.hpp

@@ -163,7 +163,7 @@ public:
    * pub = node->create_publisher<MsgT>("chatter", QoS(10));  // implicitly KeepLast
    * pub = node->create_publisher<MsgT>("chatter", QoS(KeepLast(10)));
    * pub = node->create_publisher<MsgT>("chatter", QoS(KeepAll()));
-   * pub = node->create_publisher<MsgT>("chatter", QoS(1).best_effort().volatile());
+   * pub = node->create_publisher<MsgT>("chatter", QoS(1).best_effort().durability_volatile());
    * {
    *   rclcpp::QoS custom_qos(KeepLast(10), rmw_qos_profile_sensor_data);
    *   pub = node->create_publisher<MsgT>("chatter", custom_qos);
@@ -305,16 +305,59 @@ public:
    *   name is invalid.
    * \throws rclcpp::exceptions::InvalidParameterValueException if initial
    *   value fails to be set.
+   * \throws rclcpp::exceptions::InvalidParameterTypeException
+   *   if the type of the default value or override is wrong.
    */
   RCLCPP_PUBLIC
   const rclcpp::ParameterValue &
   declare_parameter(
     const std::string & name,
-    const rclcpp::ParameterValue & default_value = rclcpp::ParameterValue(),
+    const rclcpp::ParameterValue & default_value,
     const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
     rcl_interfaces::msg::ParameterDescriptor(),
     bool ignore_override = false);
 
+  /// Declare and initialize a parameter, return the effective value.
+  /**
+   * Same as the previous one, but a default value is not provided and the user
+   * must provide a parameter override of the correct type.
+   *
+   * \param[in] name The name of the parameter.
+   * \param[in] type Desired type of the parameter, which will enforced at runtime.
+   * \param[in] parameter_descriptor An optional, custom description for
+   *   the parameter.
+   * \param[in] ignore_override When `true`, the parameter override is ignored.
+   *    Default to `false`.
+   * \return A const reference to the value of the parameter.
+   * \throws Same as the previous overload taking a default value.
+   * \throws rclcpp::exceptions::InvalidParameterTypeException
+   *   if an override is not provided or the provided override is of the wrong type.
+   */
+  RCLCPP_PUBLIC
+  const rclcpp::ParameterValue &
+  declare_parameter(
+    const std::string & name,
+    rclcpp::ParameterType type,
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor{},
+    bool ignore_override = false);
+
+  /// Declare a parameter
+  [[deprecated(
+    "declare_parameter() with only a name is deprecated and will be deleted in the future.\n" \
+    "If you want to declare a parameter that won't change type without a default value use:\n" \
+    "`node->declare_parameter<ParameterT>(name)`, where e.g. ParameterT=int64_t.\n\n" \
+    "If you want to declare a parameter that can dynamically change type use:\n" \
+    "```\n" \
+    "rcl_interfaces::msg::ParameterDescriptor descriptor;\n" \
+    "descriptor.dynamic_typing = true;\n" \
+    "node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);\n" \
+    "```"
+  )]]
+  RCLCPP_PUBLIC
+  const rclcpp::ParameterValue &
+  declare_parameter(const std::string & name);
+
   /// Declare and initialize a parameter with a type.
   /**
    * See the non-templated declare_parameter() on this class for details.
@@ -345,6 +388,18 @@ public:
     rcl_interfaces::msg::ParameterDescriptor(),
     bool ignore_override = false);
 
+  /// Declare and initialize a parameter with a type.
+  /**
+   * See the non-templated declare_parameter() on this class for details.
+   */
+  template<typename ParameterT>
+  auto
+  declare_parameter(
+    const std::string & name,
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor(),
+    bool ignore_override = false);
+
   /// Declare and initialize several parameters with the same namespace and type.
   /**
    * For each key in the map, a parameter with a name of "namespace.key"

rclcpp/include/rclcpp/node_impl.hpp

@@ -172,6 +172,24 @@ Node::declare_parameter(
   }
 }
 
+template<typename ParameterT>
+auto
+Node::declare_parameter(
+  const std::string & name,
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
+{
+  // 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>();
+}
+
 template<typename ParameterT>
 std::vector<ParameterT>
 Node::declare_parameters(

rclcpp/include/rclcpp/node_interfaces/node_parameters.hpp

@@ -103,13 +103,42 @@ public:
   virtual
   ~NodeParameters();
 
+// This is overriding a deprecated method, so we need to ignore the deprecation warning here.
+// Users of the method will still get a warning!
+#ifndef _WIN32
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#else
+# pragma warning(push)
+# pragma warning(disable: 4996)
+#endif
+  [[deprecated(RCLCPP_INTERNAL_NODE_PARAMETERS_INTERFACE_DEPRECATE_DECLARE)]]
+  RCLCPP_PUBLIC
+  const rclcpp::ParameterValue &
+  declare_parameter(const std::string & name) override;
+#ifndef _WIN32
+# pragma GCC diagnostic pop
+#else
+# pragma warning(pop)
+#endif
+
   RCLCPP_PUBLIC
   const rclcpp::ParameterValue &
   declare_parameter(
     const std::string & name,
     const rclcpp::ParameterValue & default_value,
-    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
-    bool ignore_override) override;
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor{},
+    bool ignore_override = false) override;
+
+  RCLCPP_PUBLIC
+  const rclcpp::ParameterValue &
+  declare_parameter(
+    const std::string & name,
+    rclcpp::ParameterType type,
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor(),
+    bool ignore_override = false) override;
 
   RCLCPP_PUBLIC
   void

rclcpp/include/rclcpp/node_interfaces/node_parameters_interface.hpp

@@ -45,6 +45,17 @@ struct OnSetParametersCallbackHandle
   OnParametersSetCallbackType callback;
 };
 
+#define RCLCPP_INTERNAL_NODE_PARAMETERS_INTERFACE_DEPRECATE_DECLARE \
+  "declare_parameter() with only a name is deprecated and will be deleted in the future.\n" \
+  "If you want to declare a parameter that won't change type without a default value use:\n" \
+  "`node_params->declare_parameter(name, type)`, with e.g. type=rclcpp::PARAMETER_INTEGER.\n\n" \
+  "If you want to declare a parameter that can dynamically change type use:\n" \
+  "```\n" \
+  "rcl_interfaces::msg::ParameterDescriptor descriptor;\n" \
+  "descriptor.dynamic_typing = true;\n" \
+  "node_params->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);\n" \
+  "```"
+
 /// Pure virtual interface class for the NodeParameters part of the Node API.
 class NodeParametersInterface
 {
@@ -55,6 +66,15 @@ public:
   virtual
   ~NodeParametersInterface() = default;
 
+  /// Declare a parameter.
+  /**
+   * \sa rclcpp::Node::declare_parameter
+   */
+  [[deprecated(RCLCPP_INTERNAL_NODE_PARAMETERS_INTERFACE_DEPRECATE_DECLARE)]]
+  virtual
+  const rclcpp::ParameterValue &
+  declare_parameter(const std::string & name) = 0;
+
   /// Declare and initialize a parameter.
   /**
    * \sa rclcpp::Node::declare_parameter
@@ -64,7 +84,21 @@ public:
   const rclcpp::ParameterValue &
   declare_parameter(
     const std::string & name,
-    const rclcpp::ParameterValue & default_value = rclcpp::ParameterValue(),
+    const rclcpp::ParameterValue & default_value,
+    const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
+    rcl_interfaces::msg::ParameterDescriptor(),
+    bool ignore_override = false) = 0;
+
+  /// Declare a parameter.
+  /**
+   * \sa rclcpp::Node::declare_parameter
+   */
+  RCLCPP_PUBLIC
+  virtual
+  const rclcpp::ParameterValue &
+  declare_parameter(
+    const std::string & name,
+    rclcpp::ParameterType type,
     const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
     rcl_interfaces::msg::ParameterDescriptor(),
     bool ignore_override = false) = 0;

rclcpp/include/rclcpp/parameter_client.hpp

@@ -15,6 +15,8 @@
 #ifndef RCLCPP__PARAMETER_CLIENT_HPP_
 #define RCLCPP__PARAMETER_CLIENT_HPP_
 
+#include <functional>
+#include <future>
 #include <memory>
 #include <string>
 #include <utility>
@@ -120,6 +122,14 @@ public:
       void(std::shared_future<std::vector<rclcpp::Parameter>>)
     > callback = nullptr);
 
+  RCLCPP_PUBLIC
+  std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>
+  describe_parameters(
+    const std::vector<std::string> & names,
+    std::function<
+      void(std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>)
+    > callback = nullptr);
+
   RCLCPP_PUBLIC
   std::shared_future<std::vector<rclcpp::ParameterType>>
   get_parameter_types(
@@ -332,9 +342,17 @@ public:
       qos_profile);
   }
 
-  RCLCPP_PUBLIC
+  template<typename RepT = int64_t, typename RatioT = std::milli>
   std::vector<rclcpp::Parameter>
-  get_parameters(const std::vector<std::string> & parameter_names);
+  get_parameters(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return get_parameters(
+      parameter_names,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
 
   RCLCPP_PUBLIC
   bool
@@ -378,23 +396,67 @@ public:
     );
   }
 
-  RCLCPP_PUBLIC
+  template<typename RepT = int64_t, typename RatioT = std::milli>
+  std::vector<rcl_interfaces::msg::ParameterDescriptor>
+  describe_parameters(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return describe_parameters(
+      parameter_names,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
+
+  template<typename RepT = int64_t, typename RatioT = std::milli>
   std::vector<rclcpp::ParameterType>
-  get_parameter_types(const std::vector<std::string> & parameter_names);
+  get_parameter_types(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return get_parameter_types(
+      parameter_names,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
 
-  RCLCPP_PUBLIC
+  template<typename RepT = int64_t, typename RatioT = std::milli>
   std::vector<rcl_interfaces::msg::SetParametersResult>
-  set_parameters(const std::vector<rclcpp::Parameter> & parameters);
+  set_parameters(
+    const std::vector<rclcpp::Parameter> & parameters,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return set_parameters(
+      parameters,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
 
-  RCLCPP_PUBLIC
+  template<typename RepT = int64_t, typename RatioT = std::milli>
   rcl_interfaces::msg::SetParametersResult
-  set_parameters_atomically(const std::vector<rclcpp::Parameter> & parameters);
+  set_parameters_atomically(
+    const std::vector<rclcpp::Parameter> & parameters,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return set_parameters_atomically(
+      parameters,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
 
-  RCLCPP_PUBLIC
+  template<typename RepT = int64_t, typename RatioT = std::milli>
   rcl_interfaces::msg::ListParametersResult
   list_parameters(
     const std::vector<std::string> & parameter_prefixes,
-    uint64_t depth);
+    uint64_t depth,
+    std::chrono::duration<RepT, RatioT> timeout = std::chrono::duration<RepT, RatioT>(-1))
+  {
+    return list_parameters(
+      parameter_prefixes,
+      depth,
+      std::chrono::duration_cast<std::chrono::nanoseconds>(timeout)
+    );
+  }
 
   template<typename CallbackT>
   typename rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr
@@ -437,6 +499,44 @@ public:
     return async_parameters_client_->wait_for_service(timeout);
   }
 
+protected:
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::Parameter>
+  get_parameters(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::nanoseconds timeout);
+
+  RCLCPP_PUBLIC
+  std::vector<rcl_interfaces::msg::ParameterDescriptor>
+  describe_parameters(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::nanoseconds timeout);
+
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::ParameterType>
+  get_parameter_types(
+    const std::vector<std::string> & parameter_names,
+    std::chrono::nanoseconds timeout);
+
+  RCLCPP_PUBLIC
+  std::vector<rcl_interfaces::msg::SetParametersResult>
+  set_parameters(
+    const std::vector<rclcpp::Parameter> & parameters,
+    std::chrono::nanoseconds timeout);
+
+  RCLCPP_PUBLIC
+  rcl_interfaces::msg::SetParametersResult
+  set_parameters_atomically(
+    const std::vector<rclcpp::Parameter> & parameters,
+    std::chrono::nanoseconds timeout);
+
+  RCLCPP_PUBLIC
+  rcl_interfaces::msg::ListParametersResult
+  list_parameters(
+    const std::vector<std::string> & parameter_prefixes,
+    uint64_t depth,
+    std::chrono::nanoseconds timeout);
+
 private:
   rclcpp::Executor::SharedPtr executor_;
   const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface_;

rclcpp/include/rclcpp/parameter_event_handler.hpp

@@ -0,0 +1,338 @@
+// Copyright 2019 Intel Corporation
+//
+// 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__PARAMETER_EVENT_HANDLER_HPP_
+#define RCLCPP__PARAMETER_EVENT_HANDLER_HPP_
+
+#include <list>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "rclcpp/create_subscription.hpp"
+#include "rclcpp/node_interfaces/get_node_base_interface.hpp"
+#include "rclcpp/node_interfaces/get_node_topics_interface.hpp"
+#include "rclcpp/node_interfaces/node_base_interface.hpp"
+#include "rclcpp/node_interfaces/node_topics_interface.hpp"
+#include "rclcpp/parameter.hpp"
+#include "rclcpp/qos.hpp"
+#include "rclcpp/subscription.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "rcl_interfaces/msg/parameter_event.hpp"
+
+namespace rclcpp
+{
+
+struct ParameterCallbackHandle
+{
+  RCLCPP_SMART_PTR_DEFINITIONS(ParameterCallbackHandle)
+
+  using ParameterCallbackType = std::function<void (const rclcpp::Parameter &)>;
+
+  std::string parameter_name;
+  std::string node_name;
+  ParameterCallbackType callback;
+};
+
+struct ParameterEventCallbackHandle
+{
+  RCLCPP_SMART_PTR_DEFINITIONS(ParameterEventCallbackHandle)
+
+  using ParameterEventCallbackType =
+    std::function<void (const rcl_interfaces::msg::ParameterEvent::SharedPtr &)>;
+
+  ParameterEventCallbackType callback;
+};
+
+/// A class used to "handle" (monitor and respond to) changes to parameters.
+/**
+ * The ParameterEventHandler class allows for the monitoring of changes to node parameters,
+ * either a node's own parameters or parameters owned by other nodes in the system.
+ * Multiple parameter callbacks can be set and will be invoked when the specified parameter
+ * changes.
+ *
+ * The first step is to instantiate a ParameterEventHandler, providing a ROS node to use
+ * to create any required subscriptions:
+ *
+ *   auto param_handler = std::make_shared<rclcpp::ParameterEventHandler>(node);
+ *
+ * Next, you can supply a callback to the add_parameter_callback method, as follows:
+ *
+ *   auto cb1 = [&node](const rclcpp::Parameter & p) {
+ *      RCLCPP_INFO(
+ *        node->get_logger(),
+ *        "cb1: Received an update to parameter \"%s\" of type %s: \"%ld\"",
+ *        p.get_name().c_str(),
+ *        p.get_type_name().c_str(),
+ *        p.as_int());
+ *   };
+ *   auto handle1 = param_handler->add_parameter_callback("an_int_param", cb1);
+ *
+ * In this case, we didn't supply a node name (the third, optional, parameter) so the
+ * default will be to monitor for changes to the "an_int_param" parameter associated with
+ * the ROS node supplied in the ParameterEventHandler constructor.
+ * The callback, a lambda function in this case, simply prints out the value of the parameter.
+ *
+ * You may also monitor for changes to parameters in other nodes by supplying the node
+ * name to add_parameter_callback:
+ *
+ *   auto cb2 = [&node](const rclcpp::Parameter & p) {
+ *       RCLCPP_INFO(
+ *         node->get_logger(),
+ *         "cb2: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *         p.get_name().c_str(),
+ *         p.get_type_name().c_str(),
+ *         p.as_string().c_str());
+ *     };
+ *   auto handle2 = param_handler->add_parameter_callback(
+ *     "some_remote_param_name", cb2, "some_remote_node_name");
+ *
+ * In this case, the callback will be invoked whenever "some_remote_param_name" changes
+ * on remote node "some_remote_node_name".
+ *
+ * To remove a parameter callback, call remove_parameter_callback, passing the handle returned
+ * from add_parameter_callback:
+ *
+ *   param_handler->remove_parameter_callback(handle2);
+ *
+ * You can also monitor for *all* parameter changes, using add_parameter_event_callback.
+ * In this case, the callback will be invoked whenever any parameter changes in the system.
+ * You are likely interested in a subset of these parameter changes, so in the callback it
+ * is convenient to use a regular expression on the node names or namespaces of interest.
+ * For example:
+ *
+ *   auto cb3 =
+ *     [fqn, remote_param_name, &node](const rcl_interfaces::msg::ParameterEvent::SharedPtr & event) {
+ *       // Look for any updates to parameters in "/a_namespace" as well as any parameter changes
+ *       // to our own node ("this_node")
+ *       std::regex re("(/a_namespace/.*)|(/this_node)");
+ *       if (regex_match(event->node, re)) {
+ *         // Now that we know the event matches the regular expression we scanned for, we can
+ *         // use 'get_parameter_from_event' to get a specific parameter name that we're looking for
+ *         rclcpp::Parameter p;
+ *         if (rclcpp::ParameterEventsSubscriber::get_parameter_from_event(
+ *             *event, p, remote_param_name, fqn))
+ *         {
+ *           RCLCPP_INFO(
+ *             node->get_logger(),
+ *             "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *             p.get_name().c_str(),
+ *             p.get_type_name().c_str(),
+ *             p.as_string().c_str());
+ *         }
+ *
+ *         // You can also use 'get_parameter*s*_from_event' to enumerate all changes that came
+ *         // in on this event
+ *         auto params = rclcpp::ParameterEventsSubscriber::get_parameters_from_event(*event);
+ *         for (auto & p : params) {
+ *           RCLCPP_INFO(
+ *             node->get_logger(),
+ *             "cb3: Received an update to parameter \"%s\" of type: %s: \"%s\"",
+ *             p.get_name().c_str(),
+ *             p.get_type_name().c_str(),
+ *             p.value_to_string().c_str());
+ *         }
+ *       }
+ *     };
+ *   auto handle3 = param_handler->add_parameter_event_callback(cb3);
+ *
+ * For both parameter callbacks and parameter event callbacks, when multiple callbacks are added,
+ * the callbacks are invoked last-in, first-called order (LIFO).
+ *
+ * To remove a parameter event callback, use:
+ *
+ *   param_handler->remove_event_parameter_callback(handle);
+ */
+class ParameterEventHandler
+{
+public:
+  /// Construct a parameter events monitor.
+  /**
+   * \param[in] node The node to use to create any required subscribers.
+   * \param[in] qos The QoS settings to use for any subscriptions.
+   */
+  template<typename NodeT>
+  ParameterEventHandler(
+    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);
+    auto node_topics = rclcpp::node_interfaces::get_node_topics_interface(node);
+
+    event_subscription_ = rclcpp::create_subscription<rcl_interfaces::msg::ParameterEvent>(
+      node_topics, "/parameter_events", qos,
+      std::bind(&ParameterEventHandler::event_callback, this, std::placeholders::_1));
+  }
+
+  using ParameterEventCallbackType =
+    ParameterEventCallbackHandle::ParameterEventCallbackType;
+
+  /// Set a callback for all parameter events.
+  /**
+   * This function may be called multiple times to set multiple parameter event callbacks.
+   *
+   * \param[in] callback Function callback to be invoked on parameter updates.
+   * \returns A handle used to refer to the callback.
+   */
+  RCLCPP_PUBLIC
+  ParameterEventCallbackHandle::SharedPtr
+  add_parameter_event_callback(
+    ParameterEventCallbackType callback);
+
+  /// Remove parameter event callback registered with add_parameter_event_callback.
+  /**
+   * \param[in] callback_handle Handle of the callback to remove.
+   */
+  RCLCPP_PUBLIC
+  void
+  remove_parameter_event_callback(
+    ParameterEventCallbackHandle::SharedPtr callback_handle);
+
+  using ParameterCallbackType = ParameterCallbackHandle::ParameterCallbackType;
+
+  /// Add a callback for a specified parameter.
+  /**
+   * If a node_name is not provided, defaults to the current node.
+   *
+   * \param[in] parameter_name Name of parameter to monitor.
+   * \param[in] callback Function callback to be invoked upon parameter update.
+   * \param[in] node_name Name of node which hosts the parameter.
+   * \returns A handle used to refer to the callback.
+   */
+  RCLCPP_PUBLIC
+  ParameterCallbackHandle::SharedPtr
+  add_parameter_callback(
+    const std::string & parameter_name,
+    ParameterCallbackType callback,
+    const std::string & node_name = "");
+
+  /// Remove a parameter callback registered with add_parameter_callback.
+  /**
+   * The parameter name and node name are inspected from the callback handle. The callback handle
+   * is erased from the list of callback handles on the {parameter_name, node_name} in the map.
+   * An error is thrown if the handle does not exist and/or was already removed.
+   *
+   * \param[in] callback_handle Handle of the callback to remove.
+   */
+  RCLCPP_PUBLIC
+  void
+  remove_parameter_callback(
+    ParameterCallbackHandle::SharedPtr callback_handle);
+
+  /// Get an rclcpp::Parameter from a parameter event.
+  /**
+   * If a node_name is not provided, defaults to the current node.
+   *
+   * \param[in] event Event msg to be inspected.
+   * \param[out] parameter Reference to rclcpp::Parameter to be assigned.
+   * \param[in] parameter_name Name of parameter.
+   * \param[in] node_name Name of node which hosts the parameter.
+   * \returns Output parameter is set with requested parameter info and returns true if
+   * requested parameter name and node is in event. Otherwise, returns false.
+   */
+  RCLCPP_PUBLIC
+  static bool
+  get_parameter_from_event(
+    const rcl_interfaces::msg::ParameterEvent & event,
+    rclcpp::Parameter & parameter,
+    const std::string parameter_name,
+    const std::string node_name = "");
+
+  /// Get an rclcpp::Parameter from parameter event
+  /**
+   * If a node_name is not provided, defaults to the current node.
+   *
+   * The user is responsible to check if the returned parameter has been properly assigned.
+   * By default, if the requested parameter is not found in the event, the returned parameter
+   * has parameter value of type rclcpp::PARAMETER_NOT_SET.
+   *
+   * \param[in] event Event msg to be inspected.
+   * \param[in] parameter_name Name of parameter.
+   * \param[in] node_name Name of node which hosts the parameter.
+   * \returns The resultant rclcpp::Parameter from the event.
+   */
+  RCLCPP_PUBLIC
+  static rclcpp::Parameter
+  get_parameter_from_event(
+    const rcl_interfaces::msg::ParameterEvent & event,
+    const std::string parameter_name,
+    const std::string node_name = "");
+
+  /// Get all rclcpp::Parameter values from a parameter event
+  /**
+   * \param[in] event Event msg to be inspected.
+   * \returns A vector rclcpp::Parameter values from the event.
+   */
+  RCLCPP_PUBLIC
+  static std::vector<rclcpp::Parameter>
+  get_parameters_from_event(
+    const rcl_interfaces::msg::ParameterEvent & event);
+
+  using CallbacksContainerType = std::list<ParameterCallbackHandle::WeakPtr>;
+
+protected:
+  /// Callback for parameter events subscriptions.
+  RCLCPP_PUBLIC
+  void
+  event_callback(const rcl_interfaces::msg::ParameterEvent::SharedPtr 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
+  class StringPairHash
+  {
+  public:
+    template<typename T>
+    inline void hash_combine(std::size_t & seed, const T & v) const
+    {
+      std::hash<T> hasher;
+      seed ^= hasher(v) + 0x9e3779b9 + (seed << 6) + (seed >> 2);
+    }
+
+    inline size_t operator()(const std::pair<std::string, std::string> & s) const
+    {
+      size_t seed = 0;
+      hash_combine(seed, s.first);
+      hash_combine(seed, s.second);
+      return seed;
+    }
+  };
+  // *INDENT-ON*
+
+  // Map container for registered parameters
+  std::unordered_map<
+    std::pair<std::string, std::string>,
+    CallbacksContainerType,
+    StringPairHash
+  > parameter_callbacks_;
+
+  rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr event_subscription_;
+
+  std::list<ParameterEventCallbackHandle::WeakPtr> event_callbacks_;
+
+  std::recursive_mutex mutex_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__PARAMETER_EVENT_HANDLER_HPP_

rclcpp/include/rclcpp/publisher.hpp

@@ -261,7 +261,7 @@ public:
     if (this->can_loan_messages()) {
       // we release the ownership from the rclpp::LoanedMessage instance
       // and let the middleware clean up the memory.
-      this->do_loaned_message_publish(loaned_msg.release());
+      this->do_loaned_message_publish(std::move(loaned_msg.release()));
     } else {
       // we don't release the ownership, let the middleware copy the ros message
       // and thus the destructor of rclcpp::LoanedMessage cleans up the memory.
@@ -310,9 +310,9 @@ protected:
   }
 
   void
-  do_loaned_message_publish(MessageT * msg)
+  do_loaned_message_publish(std::unique_ptr<MessageT, std::function<void(MessageT *)>> msg)
   {
-    auto status = rcl_publish_loaned_message(publisher_handle_.get(), msg, nullptr);
+    auto status = rcl_publish_loaned_message(publisher_handle_.get(), msg.get(), nullptr);
 
     if (RCL_RET_PUBLISHER_INVALID == status) {
       rcl_reset_error();  // next call will reset error message if not context

rclcpp/include/rclcpp/publisher_options.hpp

@@ -26,6 +26,7 @@
 #include "rclcpp/intra_process_setting.hpp"
 #include "rclcpp/qos.hpp"
 #include "rclcpp/qos_event.hpp"
+#include "rclcpp/qos_overriding_options.hpp"
 
 namespace rclcpp
 {
@@ -50,6 +51,8 @@ struct PublisherOptionsBase
   /// Optional RMW implementation specific payload to be used during creation of the publisher.
   std::shared_ptr<rclcpp::detail::RMWImplementationSpecificPublisherPayload>
   rmw_implementation_payload = nullptr;
+
+  QosOverridingOptions qos_overriding_options;
 };
 
 /// Structure containing optional configuration for Publishers.
@@ -92,12 +95,7 @@ struct PublisherOptionsWithAllocator : public PublisherOptionsBase
   get_allocator() const
   {
     if (!this->allocator) {
-      // TODO(wjwwood): I would like to use the commented line instead, but
-      //   cppcheck 1.89 fails with:
-      //     Syntax Error: AST broken, binary operator '>' doesn't have two operands.
-      // return std::make_shared<Allocator>();
-      std::shared_ptr<Allocator> tmp(new Allocator());
-      return tmp;
+      return std::make_shared<Allocator>();
     }
     return this->allocator;
   }

rclcpp/include/rclcpp/qos.hpp

@@ -30,6 +30,38 @@ namespace rclcpp
 RCLCPP_PUBLIC
 std::string qos_policy_name_from_kind(rmw_qos_policy_kind_t policy_kind);
 
+enum class HistoryPolicy
+{
+  KeepLast = RMW_QOS_POLICY_HISTORY_KEEP_LAST,
+  KeepAll = RMW_QOS_POLICY_HISTORY_KEEP_ALL,
+  SystemDefault = RMW_QOS_POLICY_HISTORY_SYSTEM_DEFAULT,
+  Unknown = RMW_QOS_POLICY_HISTORY_UNKNOWN,
+};
+
+enum class ReliabilityPolicy
+{
+  BestEffort = RMW_QOS_POLICY_RELIABILITY_BEST_EFFORT,
+  Reliable = RMW_QOS_POLICY_RELIABILITY_RELIABLE,
+  SystemDefault = RMW_QOS_POLICY_RELIABILITY_SYSTEM_DEFAULT,
+  Unknown = RMW_QOS_POLICY_RELIABILITY_UNKNOWN,
+};
+
+enum class DurabilityPolicy
+{
+  Volatile = RMW_QOS_POLICY_DURABILITY_VOLATILE,
+  TransientLocal = RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL,
+  SystemDefault = RMW_QOS_POLICY_DURABILITY_SYSTEM_DEFAULT,
+  Unknown = RMW_QOS_POLICY_DURABILITY_UNKNOWN,
+};
+
+enum class LivelinessPolicy
+{
+  Automatic = RMW_QOS_POLICY_LIVELINESS_AUTOMATIC,
+  ManualByTopic = RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC,
+  SystemDefault = RMW_QOS_POLICY_LIVELINESS_SYSTEM_DEFAULT,
+  Unknown = RMW_QOS_POLICY_LIVELINESS_UNKNOWN,
+};
+
 /// QoS initialization values, cannot be created directly, use KeepAll or KeepLast instead.
 struct RCLCPP_PUBLIC QoSInitialization
 {
@@ -58,10 +90,32 @@ struct RCLCPP_PUBLIC KeepLast : public rclcpp::QoSInitialization
 };
 
 /// Encapsulation of Quality of Service settings.
+/**
+ * Quality of Service settings control the behavior of publishers, subscriptions,
+ * and other entities, and includes things like how data is sent or resent,
+ * how data is buffered on the publishing and subscribing side, and other things.
+ * See:
+ *   <a href="https://index.ros.org/doc/ros2/Concepts/About-Quality-of-Service-Settings">
+ *     https://index.ros.org/doc/ros2/Concepts/About-Quality-of-Service-Settings
+ *   </a>
+ */
 class RCLCPP_PUBLIC QoS
 {
 public:
-  /// Constructor which allows you to construct a QoS by giving the only required settings.
+  /// Create a QoS by specifying only the history policy and history depth.
+  /**
+   * When using the default initial profile, the defaults will include:
+   *
+   *   - \link rclcpp::ReliabilityPolicy::Reliable ReliabilityPolicy::Reliable\endlink
+   *   - \link rclcpp::DurabilityPolicy::Volatile DurabilityPolicy::Volatile\endlink
+   *
+   * See rmw_qos_profile_default for a full list of default settings.
+   * If some other rmw_qos_profile_t is passed to initial_profile, then the defaults will derive from
+   * that profile instead.
+   *
+   * \param[in] qos_initialization Specifies history policy and history depth.
+   * \param[in] initial_profile The rmw_qos_profile_t instance on which to base the default settings.
+   */
   explicit
   QoS(
     const QoSInitialization & qos_initialization,
@@ -69,7 +123,11 @@ public:
 
   /// Conversion constructor to ease construction in the common case of just specifying depth.
   /**
-   * Convenience constructor, equivalent to QoS(KeepLast(history_depth)).
+   * This is a convenience constructor that calls QoS(KeepLast(history_depth)).
+   *
+   * \param[in] history_depth How many messages can be queued when publishing
+   *   with a Publisher, or how many messages can be queued before being replaced
+   *   by a Subscription.
    */
   // cppcheck-suppress noExplicitConstructor
   QoS(size_t history_depth);  // NOLINT(runtime/explicit): conversion constructor
@@ -82,6 +140,10 @@ public:
   const rmw_qos_profile_t &
   get_rmw_qos_profile() const;
 
+  /// Set the history policy.
+  QoS &
+  history(HistoryPolicy history);
+
   /// Set the history policy.
   QoS &
   history(rmw_qos_history_policy_t history);
@@ -98,6 +160,10 @@ public:
   QoS &
   reliability(rmw_qos_reliability_policy_t reliability);
 
+  /// Set the reliability setting.
+  QoS &
+  reliability(ReliabilityPolicy reliability);
+
   /// Set the reliability setting to reliable.
   QoS &
   reliable();
@@ -110,6 +176,10 @@ public:
   QoS &
   durability(rmw_qos_durability_policy_t durability);
 
+  /// Set the durability setting.
+  QoS &
+  durability(DurabilityPolicy durability);
+
   /// Set the durability setting to volatile.
   /**
     * Note that this cannot be named `volatile` because it is a C++ keyword.
@@ -141,6 +211,10 @@ public:
   QoS &
   liveliness(rmw_qos_liveliness_policy_t liveliness);
 
+  /// Set the liveliness setting.
+  QoS &
+  liveliness(LivelinessPolicy liveliness);
+
   /// Set the liveliness_lease_duration setting.
   QoS &
   liveliness_lease_duration(rmw_time_t liveliness_lease_duration);
@@ -153,6 +227,42 @@ public:
   QoS &
   avoid_ros_namespace_conventions(bool avoid_ros_namespace_conventions);
 
+  /// Get the history qos policy.
+  HistoryPolicy
+  history() const;
+
+  /// Get the history depth.
+  size_t
+  depth() const;
+
+  /// Get the reliability policy.
+  ReliabilityPolicy
+  reliability() const;
+
+  /// Get the durability policy.
+  DurabilityPolicy
+  durability() const;
+
+  /// Get the deadline duration setting.
+  rclcpp::Duration
+  deadline() const;
+
+  /// Get the lifespan duration setting.
+  rclcpp::Duration
+  lifespan() const;
+
+  /// Get the liveliness policy.
+  LivelinessPolicy
+  liveliness() const;
+
+  /// Get the liveliness lease duration setting.
+  rclcpp::Duration
+  liveliness_lease_duration() const;
+
+  /// Get the `avoid ros namespace convention` setting.
+  bool
+  avoid_ros_namespace_conventions() const;
+
 private:
   rmw_qos_profile_t rmw_qos_profile_;
 };

rclcpp/include/rclcpp/qos_event.hpp

@@ -16,6 +16,8 @@
 #define RCLCPP__QOS_EVENT_HPP_
 
 #include <functional>
+#include <memory>
+#include <stdexcept>
 #include <string>
 
 #include "rcl/error_handling.h"
@@ -131,21 +133,31 @@ public:
     }
   }
 
-  /// Execute any entities of the Waitable that are ready.
-  void
-  execute() override
+  /// Take data so that the callback cannot be scheduled again
+  std::shared_ptr<void>
+  take_data() override
   {
     EventCallbackInfoT callback_info;
-
     rcl_ret_t ret = rcl_take_event(&event_handle_, &callback_info);
     if (ret != RCL_RET_OK) {
       RCUTILS_LOG_ERROR_NAMED(
         "rclcpp",
         "Couldn't take event info: %s", rcl_get_error_string().str);
-      return;
+      return nullptr;
     }
+    return std::static_pointer_cast<void>(std::make_shared<EventCallbackInfoT>(callback_info));
+  }
 
-    event_callback_(callback_info);
+  /// Execute any entities of the Waitable that are ready.
+  void
+  execute(std::shared_ptr<void> & data) override
+  {
+    if (!data) {
+      throw std::runtime_error("'data' is empty");
+    }
+    auto callback_ptr = std::static_pointer_cast<EventCallbackInfoT>(data);
+    event_callback_(*callback_ptr);
+    callback_ptr.reset();
   }
 
 private:

rclcpp/include/rclcpp/qos_overriding_options.hpp

@@ -0,0 +1,154 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#ifndef RCLCPP__QOS_OVERRIDING_OPTIONS_HPP_
+#define RCLCPP__QOS_OVERRIDING_OPTIONS_HPP_
+
+#include <functional>
+#include <initializer_list>
+#include <ostream>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "rclcpp/qos.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+#include "rcl_interfaces/msg/set_parameters_result.hpp"
+#include "rmw/qos_policy_kind.h"
+
+namespace rclcpp
+{
+
+enum class RCLCPP_PUBLIC_TYPE QosPolicyKind
+{
+  AvoidRosNamespaceConventions = RMW_QOS_POLICY_AVOID_ROS_NAMESPACE_CONVENTIONS,
+  Deadline = RMW_QOS_POLICY_DEADLINE,
+  Depth = RMW_QOS_POLICY_DEPTH,
+  Durability = RMW_QOS_POLICY_DURABILITY,
+  History = RMW_QOS_POLICY_HISTORY,
+  Lifespan = RMW_QOS_POLICY_LIFESPAN,
+  Liveliness = RMW_QOS_POLICY_LIVELINESS,
+  LivelinessLeaseDuration = RMW_QOS_POLICY_LIVELINESS_LEASE_DURATION,
+  Reliability = RMW_QOS_POLICY_RELIABILITY,
+  Invalid = RMW_QOS_POLICY_INVALID,
+};
+
+RCLCPP_PUBLIC
+const char *
+qos_policy_kind_to_cstr(const QosPolicyKind & qpk);
+
+RCLCPP_PUBLIC
+std::ostream &
+operator<<(std::ostream & os, const QosPolicyKind & qpk);
+
+using QosCallbackResult = rcl_interfaces::msg::SetParametersResult;
+using QosCallback = std::function<QosCallbackResult(const rclcpp::QoS &)>;
+
+namespace detail
+{
+// forward declare
+template<typename T>
+class QosParameters;
+}
+
+/// Options that are passed in subscription/publisher constructor to specify QoSConfigurability.
+/**
+ * This options struct allows configuring:
+ * - Which policy kinds will have declared parameters.
+ * - An optional callback, that will be called to validate the final qos profile.
+ * - An optional id. In the case that different qos are desired for two publishers/subscriptions in
+ *   the same topic, this id will allow disambiguating them.
+ *
+ * Example parameter file:
+ *
+ * ```yaml
+ * my_node_name:
+ *  ros__parameters:
+ *    qos_overrides:
+ *      /my/topic/name:
+ *        publisher:  # publisher without provided id
+ *          reliability: reliable
+ *          depth: 100
+ *        publisher_my_id:  # publisher with `id="my_id"
+ *          reliability: reliable
+ *          depth: 10
+ * ```
+ */
+class QosOverridingOptions
+{
+public:
+  /// Default constructor, no overrides allowed.
+  RCLCPP_PUBLIC
+  QosOverridingOptions() = default;
+
+  /// Construct passing a list of QoS policies and a verification callback.
+  /**
+   * This constructor is implicit, e.g.:
+   * ```cpp
+   * node->create_publisher(
+   *   "topic_name",
+   *   default_qos_profile,
+   *   {
+   *     {QosPolicyKind::Reliability},
+   *     [] (auto && qos) {return check_qos_validity(qos)},
+   *     "my_id"
+   *   });
+   * ```
+   * \param policy_kinds list of policy kinds that will be reconfigurable.
+   * \param validation_callback callbak that will be called to validate the validity of
+   *   the qos profile set by the user.
+   * \param id id of the entity.
+   */
+  RCLCPP_PUBLIC
+  QosOverridingOptions(
+    std::initializer_list<QosPolicyKind> policy_kinds,
+    QosCallback validation_callback = nullptr,
+    std::string id = {});
+
+  RCLCPP_PUBLIC
+  const std::string &
+  get_id() const;
+
+  RCLCPP_PUBLIC
+  const std::vector<QosPolicyKind> &
+  get_policy_kinds() const;
+
+  RCLCPP_PUBLIC
+  const QosCallback &
+  get_validation_callback() const;
+
+  /// Construct passing a list of QoS policies and a verification callback.
+  /**
+   * Same as `QosOverridingOptions` constructor, but only declares the default policies:
+   *
+   * History, Depth, Reliability.
+   */
+  RCLCPP_PUBLIC
+  static
+  QosOverridingOptions
+  with_default_policies(QosCallback validation_callback = nullptr, std::string id = {});
+
+private:
+  /// \internal Id of the entity requesting to create parameters.
+  std::string id_;
+  /// \internal Policy kinds that are allowed to be reconfigured.
+  std::vector<QosPolicyKind> policy_kinds_;
+  /// \internal Validation callback that will be called to verify the profile.
+  QosCallback validation_callback_;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__QOS_OVERRIDING_OPTIONS_HPP_

rclcpp/include/rclcpp/rclcpp.hpp

@@ -147,14 +147,15 @@
 #include "rclcpp/guard_condition.hpp"
 #include "rclcpp/logging.hpp"
 #include "rclcpp/node.hpp"
-#include "rclcpp/parameter.hpp"
 #include "rclcpp/parameter_client.hpp"
+#include "rclcpp/parameter_event_handler.hpp"
+#include "rclcpp/parameter.hpp"
 #include "rclcpp/parameter_service.hpp"
 #include "rclcpp/rate.hpp"
 #include "rclcpp/time.hpp"
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/visibility_control.hpp"
-#include "rclcpp/wait_set.hpp"
 #include "rclcpp/waitable.hpp"
+#include "rclcpp/wait_set.hpp"
 
 #endif  // RCLCPP__RCLCPP_HPP_

rclcpp/include/rclcpp/service.hpp

@@ -180,7 +180,7 @@ public:
     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](rcl_service_t * service)
+      new rcl_service_t, [weak_node_handle, service_name](rcl_service_t * service)
       {
         auto handle = weak_node_handle.lock();
         if (handle) {
@@ -192,10 +192,10 @@ public:
             rcl_reset_error();
           }
         } else {
-          RCLCPP_ERROR(
+          RCLCPP_ERROR_STREAM(
             rclcpp::get_logger("rclcpp"),
-            "Error in destruction of rcl service handle: "
-            "the Node Handle was destructed too early. You will leak memory");
+            "Error in destruction of rcl service handle " << service_name <<
+              ": the Node Handle was destructed too early. You will leak memory");
         }
         delete service;
       });

rclcpp/include/rclcpp/subscription.hpp

@@ -171,11 +171,7 @@ public:
 
       // First create a SubscriptionIntraProcess which will be given to the intra-process manager.
       auto context = node_base->get_context();
-      using SubscriptionIntraProcessT = rclcpp::experimental::SubscriptionIntraProcess<
-        CallbackMessageT,
-        AllocatorT,
-        typename MessageUniquePtr::deleter_type>;
-      auto subscription_intra_process = std::make_shared<SubscriptionIntraProcessT>(
+      subscription_intra_process_ = std::make_shared<SubscriptionIntraProcessT>(
         callback,
         options.get_allocator(),
         context,
@@ -185,12 +181,12 @@ public:
       TRACEPOINT(
         rclcpp_subscription_init,
         static_cast<const void *>(get_subscription_handle().get()),
-        static_cast<const void *>(subscription_intra_process.get()));
+        static_cast<const void *>(subscription_intra_process_.get()));
 
       // Add it to the intra process manager.
       using rclcpp::experimental::IntraProcessManager;
       auto ipm = context->get_sub_context<IntraProcessManager>();
-      uint64_t intra_process_subscription_id = ipm->add_subscription(subscription_intra_process);
+      uint64_t intra_process_subscription_id = ipm->add_subscription(subscription_intra_process_);
       this->setup_intra_process(intra_process_subscription_id, ipm);
     }
 
@@ -277,11 +273,18 @@ public:
       return;
     }
     auto typed_message = std::static_pointer_cast<CallbackMessageT>(message);
+
+    std::chrono::time_point<std::chrono::system_clock> now;
+    if (subscription_topic_statistics_) {
+      // get current time before executing callback to
+      // exclude callback duration from topic statistics result.
+      now = std::chrono::system_clock::now();
+    }
+
     any_callback_.dispatch(typed_message, message_info);
 
     if (subscription_topic_statistics_) {
-      const auto nanos = std::chrono::time_point_cast<std::chrono::nanoseconds>(
-        std::chrono::system_clock::now());
+      const auto nanos = std::chrono::time_point_cast<std::chrono::nanoseconds>(now);
       const auto time = rclcpp::Time(nanos.time_since_epoch().count());
       subscription_topic_statistics_->handle_message(*typed_message, time);
     }
@@ -340,6 +343,11 @@ private:
     message_memory_strategy_;
   /// Component which computes and publishes topic statistics for this subscriber
   SubscriptionTopicStatisticsSharedPtr subscription_topic_statistics_{nullptr};
+  using SubscriptionIntraProcessT = rclcpp::experimental::SubscriptionIntraProcess<
+    CallbackMessageT,
+    AllocatorT,
+    typename MessageUniquePtr::deleter_type>;
+  std::shared_ptr<SubscriptionIntraProcessT> subscription_intra_process_;
 };
 
 }  // namespace rclcpp

rclcpp/include/rclcpp/subscription_options.hpp

@@ -26,6 +26,7 @@
 #include "rclcpp/intra_process_setting.hpp"
 #include "rclcpp/qos.hpp"
 #include "rclcpp/qos_event.hpp"
+#include "rclcpp/qos_overriding_options.hpp"
 #include "rclcpp/topic_statistics_state.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -72,6 +73,8 @@ struct SubscriptionOptionsBase
   };
 
   TopicStatisticsOptions topic_stats_options;
+
+  QosOverridingOptions qos_overriding_options;
 };
 
 /// Structure containing optional configuration for Subscriptions.
@@ -101,7 +104,7 @@ struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
     rcl_subscription_options_t result = rcl_subscription_get_default_options();
     using AllocatorTraits = std::allocator_traits<Allocator>;
     using MessageAllocatorT = typename AllocatorTraits::template rebind_alloc<MessageT>;
-    auto message_alloc = std::make_shared<MessageAllocatorT>(*allocator.get());
+    auto message_alloc = std::make_shared<MessageAllocatorT>(*this->get_allocator().get());
     result.allocator = allocator::get_rcl_allocator<MessageT>(*message_alloc);
     result.qos = qos.get_rmw_qos_profile();
     result.rmw_subscription_options.ignore_local_publications = this->ignore_local_publications;

rclcpp/include/rclcpp/time_source.hpp

@@ -32,6 +32,20 @@ namespace rclcpp
 {
 class Clock;
 
+/**
+ * Time source that will drive the attached clocks.
+ *
+ * If the attached node `use_sim_time` parameter is `true`, the attached clocks will
+ * be updated based on messages received.
+ *
+ * The subscription to the clock topic created by the time source can have it's qos reconfigured
+ * using parameter overrides, particularly the following ones are accepted:
+ *
+ * - qos_overrides./clock.depth
+ * - qos_overrides./clock.durability
+ * - qos_overrides./clock.history
+ * - qos_overrides./clock.reliability
+ */
 class TimeSource
 {
 public:

rclcpp/include/rclcpp/topic_statistics/subscription_topic_statistics.hpp

@@ -127,7 +127,7 @@ public:
   /**
    * This method acquires a lock to prevent race conditions to collectors list.
    */
-  virtual void publish_message()
+  virtual void publish_message_and_reset_measurements()
   {
     std::vector<MetricsMessage> msgs;
     rclcpp::Time window_end{get_current_nanoseconds_since_epoch()};
@@ -136,6 +136,7 @@ public:
       std::lock_guard<std::mutex> lock(mutex_);
       for (auto & collector : subscriber_statistics_collectors_) {
         const auto collected_stats = collector->GetStatisticsResults();
+        collector->ClearCurrentMeasurements();
 
         auto message = libstatistics_collector::collector::GenerateStatisticMessage(
           node_name_,

rclcpp/include/rclcpp/waitable.hpp

@@ -16,6 +16,7 @@
 #define RCLCPP__WAITABLE_HPP_
 
 #include <atomic>
+#include <memory>
 
 #include "rclcpp/macros.hpp"
 #include "rclcpp/visibility_control.hpp"
@@ -125,8 +126,17 @@ public:
   bool
   is_ready(rcl_wait_set_t * wait_set) = 0;
 
-  /// Execute any entities of the Waitable that are ready.
+  /// Take the data so that it can be consumed with `execute`.
   /**
+   * NOTE: take_data is a partial fix to a larger design issue with the
+   * multithreaded executor. This method is likely to be removed when
+   * a more permanent fix is implemented. A longterm fix is currently
+   * being discussed here: https://github.com/ros2/rclcpp/pull/1276
+   *
+   * This method takes the data from the underlying data structure and
+   * writes it to the void shared pointer `data` that is passed into the
+   * method. The `data` can then be executed with the `execute` method.
+   *
    * Before calling this method, the Waitable should be added to a wait set,
    * waited on, and then updated.
    *
@@ -143,13 +153,41 @@ public:
    * // Update the Waitable
    * waitable.update(wait_set);
    * // Execute any entities of the Waitable that may be ready
-   * waitable.execute();
+   * std::shared_ptr<void> data = waitable.take_data();
+   * ```
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::shared_ptr<void>
+  take_data() = 0;
+
+  /// Execute data that is passed in.
+  /**
+   * Before calling this method, the Waitable should be added to a wait set,
+   * waited on, and then updated - and the `take_data` method should be
+   * called.
+   *
+   * Example usage:
+   *
+   * ```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
+   * // Wait
+   * rcl_ret_t wait_ret = rcl_wait(wait_set);
+   * // ... error handling
+   * // Update the Waitable
+   * waitable.update(wait_set);
+   * // Execute any entities of the Waitable that may be ready
+   * std::shared_ptr<void> data = waitable.take_data();
+   * waitable.execute(data);
    * ```
    */
   RCLCPP_PUBLIC
   virtual
   void
-  execute() = 0;
+  execute(std::shared_ptr<void> & data) = 0;
 
   /// Exchange the "in use by wait set" state for this timer.
   /**

rclcpp/package.xml

@@ -2,7 +2,7 @@
 <?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>5.1.0</version>
+  <version>7.0.0</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>

rclcpp/resource/logging.hpp.em

@@ -151,10 +151,9 @@ def get_rclcpp_suffix_from_features(features):
 @[ end if]@
       logger.get_name(), \
 @[ if 'stream' not in feature_combination]@
-      rclcpp::get_c_string(RCLCPP_FIRST_ARG(__VA_ARGS__, "")), \
-        RCLCPP_ALL_BUT_FIRST_ARGS(__VA_ARGS__,"")); \
+      __VA_ARGS__); \
 @[ else]@
-      "%s", rclcpp::get_c_string(ss.str())); \
+      "%s", ss.str().c_str()); \
 @[ end if]@
   } while (0)
 

rclcpp/src/rclcpp/clock.cpp

@@ -113,7 +113,7 @@ Clock::get_clock_mutex() noexcept
 
 void
 Clock::on_time_jump(
-  const struct rcl_time_jump_t * time_jump,
+  const rcl_time_jump_t * time_jump,
   bool before_jump,
   void * user_data)
 {

rclcpp/src/rclcpp/context.cpp

@@ -320,7 +320,6 @@ Context::shutdown(const std::string & reason)
   }
   // interrupt all blocking sleep_for() and all blocking executors or wait sets
   this->interrupt_all_sleep_for();
-  this->interrupt_all_wait_sets();
   // remove self from the global contexts
   weak_contexts_->remove_context(this);
   // shutdown logger
@@ -391,75 +390,6 @@ Context::interrupt_all_sleep_for()
   interrupt_condition_variable_.notify_all();
 }
 
-rcl_guard_condition_t *
-Context::get_interrupt_guard_condition(rcl_wait_set_t * wait_set)
-{
-  std::lock_guard<std::mutex> lock(interrupt_guard_cond_handles_mutex_);
-  auto kv = interrupt_guard_cond_handles_.find(wait_set);
-  if (kv != interrupt_guard_cond_handles_.end()) {
-    return &kv->second;
-  } else {
-    rcl_guard_condition_t handle = rcl_get_zero_initialized_guard_condition();
-    rcl_guard_condition_options_t options = rcl_guard_condition_get_default_options();
-    auto ret = rcl_guard_condition_init(&handle, this->get_rcl_context().get(), options);
-    if (RCL_RET_OK != ret) {
-      rclcpp::exceptions::throw_from_rcl_error(ret, "Couldn't initialize guard condition");
-    }
-    interrupt_guard_cond_handles_.emplace(wait_set, handle);
-    return &interrupt_guard_cond_handles_[wait_set];
-  }
-}
-
-void
-Context::release_interrupt_guard_condition(rcl_wait_set_t * wait_set)
-{
-  std::lock_guard<std::mutex> lock(interrupt_guard_cond_handles_mutex_);
-  auto kv = interrupt_guard_cond_handles_.find(wait_set);
-  if (kv != interrupt_guard_cond_handles_.end()) {
-    rcl_ret_t ret = rcl_guard_condition_fini(&kv->second);
-    if (RCL_RET_OK != ret) {
-      rclcpp::exceptions::throw_from_rcl_error(ret, "Failed to destroy sigint guard condition");
-    }
-    interrupt_guard_cond_handles_.erase(kv);
-  } else {
-    throw std::runtime_error("Tried to release sigint guard condition for nonexistent wait set");
-  }
-}
-
-void
-Context::release_interrupt_guard_condition(
-  rcl_wait_set_t * wait_set,
-  const std::nothrow_t &) noexcept
-{
-  try {
-    this->release_interrupt_guard_condition(wait_set);
-  } catch (const std::exception & exc) {
-    RCLCPP_ERROR(
-      rclcpp::get_logger("rclcpp"),
-      "caught %s exception when releasing interrupt guard condition: %s",
-      rmw::impl::cpp::demangle(exc).c_str(), exc.what());
-  } catch (...) {
-    RCLCPP_ERROR(
-      rclcpp::get_logger("rclcpp"),
-      "caught unknown exception when releasing interrupt guard condition");
-  }
-}
-
-void
-Context::interrupt_all_wait_sets()
-{
-  std::lock_guard<std::mutex> lock(interrupt_guard_cond_handles_mutex_);
-  for (auto & kv : interrupt_guard_cond_handles_) {
-    rcl_ret_t status = rcl_trigger_guard_condition(&(kv.second));
-    if (status != RCL_RET_OK) {
-      RCUTILS_LOG_ERROR_NAMED(
-        "rclcpp",
-        "failed to trigger guard condition in Context::interrupt_all_wait_sets(): %s",
-        rcl_get_error_string().str);
-    }
-  }
-}
-
 void
 Context::clean_up()
 {

rclcpp/src/rclcpp/detail/mutex_two_priorities.cpp

@@ -0,0 +1,75 @@
+// 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()
+{
+  parent_.data_.lock();
+}
+
+void
+HighPriorityLockable::unlock()
+{
+  parent_.data_.unlock();
+}
+
+LowPriorityLockable::LowPriorityLockable(MutexTwoPriorities & parent)
+: parent_(parent)
+{}
+
+void
+LowPriorityLockable::lock()
+{
+  std::unique_lock<std::mutex> barrier_guard{parent_.barrier_};
+  parent_.data_.lock();
+  barrier_guard.release();
+}
+
+void
+LowPriorityLockable::unlock()
+{
+  std::lock_guard<std::mutex> barrier_guard{parent_.barrier_, std::adopt_lock};
+  parent_.data_.unlock();
+}
+
+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

@@ -0,0 +1,77 @@
+// 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 "./resolve_parameter_overrides.hpp"
+
+#include <string>
+#include <map>
+#include <vector>
+
+#include "rcl_yaml_param_parser/parser.h"
+
+#include "rclcpp/scope_exit.hpp"
+#include "rclcpp/parameter_map.hpp"
+
+std::map<std::string, rclcpp::ParameterValue>
+rclcpp::detail::resolve_parameter_overrides(
+  const std::string & node_fqn,
+  const std::vector<rclcpp::Parameter> & parameter_overrides,
+  const rcl_arguments_t * local_args,
+  const rcl_arguments_t * global_args)
+{
+  std::map<std::string, rclcpp::ParameterValue> result;
+
+  // global before local so that local overwrites global
+  std::array<const rcl_arguments_t *, 2> argument_sources = {global_args, local_args};
+
+  // Get fully qualified node name post-remapping to use to find node's params in yaml files
+
+  for (const rcl_arguments_t * source : argument_sources) {
+    if (!source) {
+      continue;
+    }
+    rcl_params_t * params = NULL;
+    rcl_ret_t ret = rcl_arguments_get_param_overrides(source, &params);
+    if (RCL_RET_OK != ret) {
+      rclcpp::exceptions::throw_from_rcl_error(ret);
+    }
+    if (params) {
+      auto cleanup_params = make_scope_exit(
+        [params]() {
+          rcl_yaml_node_struct_fini(params);
+        });
+      rclcpp::ParameterMap initial_map = rclcpp::parameter_map_from(params);
+
+      // Enforce wildcard matching precedence
+      // TODO(cottsay) implement further wildcard matching
+      const std::array<std::string, 2> node_matching_names{"/**", node_fqn};
+      for (const auto & node_name : node_matching_names) {
+        if (initial_map.count(node_name) > 0) {
+          // Combine parameter yaml files, overwriting values in older ones
+          for (const rclcpp::Parameter & param : initial_map.at(node_name)) {
+            result[param.get_name()] =
+              rclcpp::ParameterValue(param.get_value_message());
+          }
+        }
+      }
+    }
+  }
+
+  // parameter overrides passed to constructor will overwrite overrides from yaml file sources
+  for (auto & param : parameter_overrides) {
+    result[param.get_name()] =
+      rclcpp::ParameterValue(param.get_value_message());
+  }
+  return result;
+}

rclcpp/src/rclcpp/detail/resolve_parameter_overrides.hpp

@@ -0,0 +1,44 @@
+// 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__RESOLVE_PARAMETER_OVERRIDES_HPP_
+#define RCLCPP__DETAIL__RESOLVE_PARAMETER_OVERRIDES_HPP_
+
+#include <string>
+#include <map>
+#include <vector>
+
+#include "rcl/arguments.h"
+
+#include "rclcpp/parameter.hpp"
+#include "rclcpp/parameter_value.hpp"
+#include "rclcpp/visibility_control.hpp"
+
+namespace rclcpp
+{
+namespace detail
+{
+/// \internal Get the parameter overrides from the arguments.
+RCLCPP_LOCAL
+std::map<std::string, rclcpp::ParameterValue>
+resolve_parameter_overrides(
+  const std::string & node_name,
+  const std::vector<rclcpp::Parameter> & parameter_overrides,
+  const rcl_arguments_t * local_args,
+  const rcl_arguments_t * global_args);
+
+}  // namespace detail
+}  // namespace rclcpp
+
+#endif  // RCLCPP__DETAIL__RESOLVE_PARAMETER_OVERRIDES_HPP_

rclcpp/src/rclcpp/duration.cpp

@@ -246,6 +246,27 @@ Duration::to_rmw_time() const
   return result;
 }
 
+Duration
+Duration::from_rmw_time(rmw_time_t duration)
+{
+  Duration ret;
+  constexpr rcl_duration_value_t limit_ns = std::numeric_limits<rcl_duration_value_t>::max();
+  constexpr rcl_duration_value_t limit_sec = RCL_NS_TO_S(limit_ns);
+  if (duration.sec > limit_sec || duration.nsec > limit_ns) {
+    // saturate if will overflow
+    ret.rcl_duration_.nanoseconds = limit_ns;
+    return ret;
+  }
+  uint64_t total_ns = RCL_S_TO_NS(duration.sec) + duration.nsec;
+  if (total_ns > limit_ns) {
+    // saturate if will overflow
+    ret.rcl_duration_.nanoseconds = limit_ns;
+    return ret;
+  }
+  ret.rcl_duration_.nanoseconds = static_cast<rcl_duration_value_t>(total_ns);
+  return ret;
+}
+
 Duration
 Duration::from_seconds(double seconds)
 {

rclcpp/src/rclcpp/executor.cpp

@@ -25,6 +25,7 @@
 
 #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"
@@ -42,28 +43,35 @@ using rclcpp::FutureReturnCode;
 
 Executor::Executor(const rclcpp::ExecutorOptions & options)
 : spinning(false),
+  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_, options.context->get_rcl_context().get(), guard_condition_options);
+    &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(
+    [weak_gc = std::weak_ptr<rclcpp::GuardCondition>{shutdown_guard_condition_}]() {
+      auto strong_gc = weak_gc.lock();
+      if (strong_gc) {
+        strong_gc->trigger();
+      }
+    });
+
   // 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_)
-
-  // Put the global ctrl-c guard condition in
-  memory_strategy_->add_guard_condition(options.context->get_interrupt_guard_condition(&wait_set_));
+  memory_strategy_->add_guard_condition(&shutdown_guard_condition_->get_rcl_guard_condition());
 
   // Put the executor's guard condition in
   memory_strategy_->add_guard_condition(&interrupt_guard_condition_);
   rcl_allocator_t allocator = memory_strategy_->get_allocator();
 
-  // Store the context for later use.
-  context_ = options.context;
-
   ret = rcl_wait_set_init(
     &wait_set_,
     0, 2, 0, 0, 0, 0,
@@ -129,14 +137,14 @@ Executor::~Executor()
     rcl_reset_error();
   }
   // Remove and release the sigint guard condition
-  memory_strategy_->remove_guard_condition(context_->get_interrupt_guard_condition(&wait_set_));
-  context_->release_interrupt_guard_condition(&wait_set_, std::nothrow);
+  memory_strategy_->remove_guard_condition(&shutdown_guard_condition_->get_rcl_guard_condition());
 }
 
 std::vector<rclcpp::CallbackGroup::WeakPtr>
 Executor::get_all_callback_groups()
 {
   std::vector<rclcpp::CallbackGroup::WeakPtr> groups;
+  std::lock_guard<std::mutex> guard{mutex_};
   for (const auto & group_node_ptr : weak_groups_associated_with_executor_to_nodes_) {
     groups.push_back(group_node_ptr.first);
   }
@@ -150,6 +158,7 @@ std::vector<rclcpp::CallbackGroup::WeakPtr>
 Executor::get_manually_added_callback_groups()
 {
   std::vector<rclcpp::CallbackGroup::WeakPtr> groups;
+  std::lock_guard<std::mutex> guard{mutex_};
   for (auto const & group_node_ptr : weak_groups_associated_with_executor_to_nodes_) {
     groups.push_back(group_node_ptr.first);
   }
@@ -160,6 +169,7 @@ std::vector<rclcpp::CallbackGroup::WeakPtr>
 Executor::get_automatically_added_callback_groups_from_nodes()
 {
   std::vector<rclcpp::CallbackGroup::WeakPtr> groups;
+  std::lock_guard<std::mutex> guard{mutex_};
   for (auto const & group_node_ptr : weak_groups_to_nodes_associated_with_executor_) {
     groups.push_back(group_node_ptr.first);
   }
@@ -226,7 +236,6 @@ Executor::add_callback_group_to_map(
       }
     }
     // Add the node's notify condition to the guard condition handles
-    std::unique_lock<std::mutex> lock(memory_strategy_mutex_);
     memory_strategy_->add_guard_condition(node_ptr->get_notify_guard_condition());
   }
 }
@@ -237,6 +246,7 @@ Executor::add_callback_group(
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
   bool notify)
 {
+  std::lock_guard<std::mutex> guard{mutex_};
   this->add_callback_group_to_map(
     group_ptr,
     node_ptr,
@@ -252,6 +262,7 @@ Executor::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_pt
   if (has_executor.exchange(true)) {
     throw std::runtime_error("Node 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() &&
@@ -300,7 +311,6 @@ Executor::remove_callback_group_from_map(
         throw_from_rcl_error(ret, "Failed to trigger guard condition on callback group remove");
       }
     }
-    std::unique_lock<std::mutex> lock(memory_strategy_mutex_);
     memory_strategy_->remove_guard_condition(node_ptr->get_notify_guard_condition());
   }
 }
@@ -310,6 +320,7 @@ Executor::remove_callback_group(
   rclcpp::CallbackGroup::SharedPtr group_ptr,
   bool notify)
 {
+  std::lock_guard<std::mutex> guard{mutex_};
   this->remove_callback_group_from_map(
     group_ptr,
     weak_groups_associated_with_executor_to_nodes_,
@@ -329,6 +340,7 @@ Executor::remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node
     throw std::runtime_error("Node needs to be associated with an executor.");
   }
 
+  std::lock_guard<std::mutex> guard{mutex_};
   bool found_node = false;
   auto node_it = weak_nodes_.begin();
   while (node_it != weak_nodes_.end()) {
@@ -482,6 +494,7 @@ Executor::set_memory_strategy(rclcpp::memory_strategy::MemoryStrategy::SharedPtr
   if (memory_strategy == nullptr) {
     throw std::runtime_error("Received NULL memory strategy in executor.");
   }
+  std::lock_guard<std::mutex> guard{mutex_};
   memory_strategy_ = memory_strategy;
 }
 
@@ -504,7 +517,7 @@ Executor::execute_any_executable(AnyExecutable & any_exec)
     execute_client(any_exec.client);
   }
   if (any_exec.waitable) {
-    any_exec.waitable->execute();
+    any_exec.waitable->execute(any_exec.data);
   }
   // Reset the callback_group, regardless of type
   any_exec.callback_group->can_be_taken_from().store(true);
@@ -655,7 +668,7 @@ void
 Executor::wait_for_work(std::chrono::nanoseconds timeout)
 {
   {
-    std::unique_lock<std::mutex> lock(memory_strategy_mutex_);
+    std::lock_guard<std::mutex> guard(mutex_);
 
     // Check weak_nodes_ to find any callback group that is not owned
     // by an executor and add it to the list of callbackgroups for
@@ -676,8 +689,11 @@ Executor::wait_for_work(std::chrono::nanoseconds timeout)
         if (weak_group_ptr.expired() || weak_node_ptr.expired()) {
           invalid_group_ptrs.push_back(weak_group_ptr);
           auto node_guard_pair = weak_nodes_to_guard_conditions_.find(weak_node_ptr);
-          weak_nodes_to_guard_conditions_.erase(weak_node_ptr);
-          memory_strategy_->remove_guard_condition(node_guard_pair->second);
+          if (node_guard_pair != weak_nodes_to_guard_conditions_.end()) {
+            auto guard_condition = node_guard_pair->second;
+            weak_nodes_to_guard_conditions_.erase(weak_node_ptr);
+            memory_strategy_->remove_guard_condition(guard_condition);
+          }
         }
       }
       std::for_each(
@@ -731,12 +747,14 @@ Executor::wait_for_work(std::chrono::nanoseconds timeout)
 
   // check the null handles in the wait set and remove them from the handles in memory strategy
   // for callback-based entities
+  std::lock_guard<std::mutex> guard(mutex_);
   memory_strategy_->remove_null_handles(&wait_set_);
 }
 
 rclcpp::node_interfaces::NodeBaseInterface::SharedPtr
 Executor::get_node_by_group(
-  rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap weak_groups_to_nodes,
+  const rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap &
+  weak_groups_to_nodes,
   rclcpp::CallbackGroup::SharedPtr group)
 {
   if (!group) {
@@ -754,6 +772,7 @@ Executor::get_node_by_group(
 rclcpp::CallbackGroup::SharedPtr
 Executor::get_group_by_timer(rclcpp::TimerBase::SharedPtr timer)
 {
+  std::lock_guard<std::mutex> guard{mutex_};
   for (const auto & pair : weak_groups_associated_with_executor_to_nodes_) {
     auto group = pair.first.lock();
     if (!group) {
@@ -794,9 +813,11 @@ Executor::get_next_ready_executable(AnyExecutable & any_executable)
 bool
 Executor::get_next_ready_executable_from_map(
   AnyExecutable & any_executable,
-  rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap weak_groups_to_nodes)
+  const rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap &
+  weak_groups_to_nodes)
 {
   bool success = false;
+  std::lock_guard<std::mutex> guard{mutex_};
   // Check the timers to see if there are any that are ready
   memory_strategy_->get_next_timer(any_executable, weak_groups_to_nodes);
   if (any_executable.timer) {
@@ -827,6 +848,7 @@ Executor::get_next_ready_executable_from_map(
     // Check the waitables to see if there are any that are ready
     memory_strategy_->get_next_waitable(any_executable, weak_groups_to_nodes);
     if (any_executable.waitable) {
+      any_executable.data = any_executable.waitable->take_data();
       success = true;
     }
   }
@@ -882,7 +904,8 @@ Executor::get_next_executable(AnyExecutable & any_executable, std::chrono::nanos
 bool
 Executor::has_node(
   const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
-  rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap weak_groups_to_nodes) const
+  const rclcpp::memory_strategy::MemoryStrategy::WeakCallbackGroupsToNodesMap &
+  weak_groups_to_nodes) const
 {
   return std::find_if(
     weak_groups_to_nodes.begin(),

rclcpp/src/rclcpp/executors/multi_threaded_executor.cpp

@@ -22,6 +22,7 @@
 #include "rclcpp/utilities.hpp"
 #include "rclcpp/scope_exit.hpp"
 
+using rclcpp::detail::MutexTwoPriorities;
 using rclcpp::executors::MultiThreadedExecutor;
 
 MultiThreadedExecutor::MultiThreadedExecutor(
@@ -51,7 +52,8 @@ MultiThreadedExecutor::spin()
   std::vector<std::thread> threads;
   size_t thread_id = 0;
   {
-    std::lock_guard<std::mutex> wait_lock(wait_mutex_);
+    auto low_priority_wait_mutex = wait_mutex_.get_low_priority_lockable();
+    std::lock_guard<MutexTwoPriorities::LowPriorityLockable> wait_lock(low_priority_wait_mutex);
     for (; thread_id < number_of_threads_ - 1; ++thread_id) {
       auto func = std::bind(&MultiThreadedExecutor::run, this, thread_id);
       threads.emplace_back(func);
@@ -76,7 +78,8 @@ MultiThreadedExecutor::run(size_t)
   while (rclcpp::ok(this->context_) && spinning.load()) {
     rclcpp::AnyExecutable any_exec;
     {
-      std::lock_guard<std::mutex> wait_lock(wait_mutex_);
+      auto low_priority_wait_mutex = wait_mutex_.get_low_priority_lockable();
+      std::lock_guard<MutexTwoPriorities::LowPriorityLockable> wait_lock(low_priority_wait_mutex);
       if (!rclcpp::ok(this->context_) || !spinning.load()) {
         return;
       }
@@ -103,7 +106,8 @@ MultiThreadedExecutor::run(size_t)
     execute_any_executable(any_exec);
 
     if (any_exec.timer) {
-      std::lock_guard<std::mutex> wait_lock(wait_mutex_);
+      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);

rclcpp/src/rclcpp/executors/static_executor_entities_collector.cpp

@@ -77,7 +77,8 @@ StaticExecutorEntitiesCollector::init(
   // Add executor's guard condition
   memory_strategy_->add_guard_condition(executor_guard_condition);
   // Get memory strategy and executable list. Prepare wait_set_
-  execute();
+  std::shared_ptr<void> shared_ptr;
+  execute(shared_ptr);
 }
 
 void
@@ -87,9 +88,16 @@ StaticExecutorEntitiesCollector::fini()
   exec_list_.clear();
 }
 
-void
-StaticExecutorEntitiesCollector::execute()
+std::shared_ptr<void>
+StaticExecutorEntitiesCollector::take_data()
 {
+  return nullptr;
+}
+
+void
+StaticExecutorEntitiesCollector::execute(std::shared_ptr<void> & data)
+{
+  (void) data;
   // Fill memory strategy with entities coming from weak_nodes_
   fill_memory_strategy();
   // Fill exec_list_ with entities coming from weak_nodes_ (same as memory strategy)
@@ -315,8 +323,7 @@ StaticExecutorEntitiesCollector::add_callback_group(
     throw std::runtime_error("Callback group was already added to executor.");
   }
   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();
+    weak_nodes_to_guard_conditions_[node_ptr] = node_ptr->get_notify_guard_condition();
     return true;
   }
   return false;

rclcpp/src/rclcpp/executors/static_single_threaded_executor.cpp

@@ -175,8 +175,10 @@ StaticSingleThreadedExecutor::execute_ready_executables()
   }
   // Execute all the ready waitables
   for (size_t i = 0; i < entities_collector_->get_number_of_waitables(); ++i) {
-    if (entities_collector_->get_waitable(i)->is_ready(&wait_set_)) {
-      entities_collector_->get_waitable(i)->execute();
+    auto waitable = entities_collector_->get_waitable(i);
+    if (waitable->is_ready(&wait_set_)) {
+      auto data = waitable->take_data();
+      waitable->execute(data);
     }
   }
 }

rclcpp/src/rclcpp/graph_listener.cpp

@@ -36,11 +36,11 @@ namespace rclcpp
 namespace graph_listener
 {
 
-GraphListener::GraphListener(std::shared_ptr<rclcpp::Context> parent_context)
-: parent_context_(parent_context),
+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),
-  shutdown_guard_condition_(nullptr)
+  is_shutdown_(false)
 {
   // TODO(wjwwood): make a guard condition class in rclcpp so this can be tracked
   //   automatically with the rcl guard condition
@@ -48,13 +48,11 @@ GraphListener::GraphListener(std::shared_ptr<rclcpp::Context> parent_context)
   // guard condition is using it.
   rcl_ret_t ret = rcl_guard_condition_init(
     &interrupt_guard_condition_,
-    parent_context->get_rcl_context().get(),
+    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");
   }
-
-  shutdown_guard_condition_ = parent_context->get_interrupt_guard_condition(&wait_set_);
 }
 
 GraphListener::~GraphListener()
@@ -64,10 +62,6 @@ GraphListener::~GraphListener()
 
 void GraphListener::init_wait_set()
 {
-  auto parent_context = parent_context_.lock();
-  if (!parent_context) {
-    throw std::runtime_error("parent context was destroyed");
-  }
   rcl_ret_t ret = rcl_wait_set_init(
     &wait_set_,
     0,  // number_of_subscriptions
@@ -76,7 +70,7 @@ void GraphListener::init_wait_set()
     0,  // number_of_clients
     0,  // number_of_services
     0,  // number_of_events
-    parent_context->get_rcl_context().get(),
+    rcl_parent_context_.get(),
     rcl_get_default_allocator());
   if (RCL_RET_OK != ret) {
     throw_from_rcl_error(ret, "failed to initialize wait set");
@@ -90,14 +84,13 @@ GraphListener::start_if_not_started()
   if (is_shutdown_.load()) {
     throw GraphListenerShutdownError();
   }
-  if (!is_started_) {
-    // Initialize the wait set before starting.
-    init_wait_set();
-    // Register an on_shutdown hook to shutdown the graph listener.
+  auto parent_context = weak_parent_context_.lock();
+  if (!is_started_ && parent_context) {
+    // Register an on_shutdown hook to shtudown the graph listener.
     // This is important to ensure that the wait set is finalized before
     // destruction of static objects occurs.
     std::weak_ptr<GraphListener> weak_this = shared_from_this();
-    rclcpp::on_shutdown(
+    parent_context->on_shutdown(
       [weak_this]() {
         auto shared_this = weak_this.lock();
         if (shared_this) {
@@ -105,6 +98,8 @@ GraphListener::start_if_not_started()
           shared_this->shutdown(std::nothrow);
         }
       });
+    // Initialize the wait set before starting.
+    init_wait_set();
     // Start the listener thread.
     listener_thread_ = std::thread(&GraphListener::run, this);
     is_started_ = true;
@@ -149,14 +144,6 @@ GraphListener::run_loop()
     }
     // This lock is released when the loop continues or exits.
     std::lock_guard<std::mutex> nodes_lock(node_graph_interfaces_mutex_, std::adopt_lock);
-    // Ensure that the context doesn't go out of scope.
-    auto parent_context = parent_context_.lock();
-    if (!parent_context) {
-      // The parent context may be destroyed before this loop is stopped.
-      // In that case, the loop is broken and the function just returns silently.
-      return;
-    }
-
     // Resize the wait set if necessary.
     const size_t node_graph_interfaces_size = node_graph_interfaces_.size();
     // Add 2 for the interrupt and shutdown guard conditions
@@ -176,13 +163,7 @@ GraphListener::run_loop()
     if (RCL_RET_OK != ret) {
       throw_from_rcl_error(ret, "failed to add interrupt guard condition to wait set");
     }
-    // Put the shutdown guard condition in the wait set.
-    size_t shutdown_guard_condition_index = 0u;
-    ret = rcl_wait_set_add_guard_condition(
-      &wait_set_, shutdown_guard_condition_, &shutdown_guard_condition_index);
-    if (RCL_RET_OK != ret) {
-      throw_from_rcl_error(ret, "failed to add shutdown guard condition to wait set");
-    }
+
     // Put graph guard conditions for each node into the wait set.
     std::vector<size_t> graph_gc_indexes(node_graph_interfaces_size, 0u);
     for (size_t i = 0u; i < node_graph_interfaces_size; ++i) {
@@ -211,9 +192,6 @@ GraphListener::run_loop()
       throw_from_rcl_error(ret, "failed to wait on wait set");
     }
 
-    // Check to see if the shutdown guard condition has been triggered.
-    bool shutdown_guard_condition_triggered =
-      (shutdown_guard_condition_ == wait_set_.guard_conditions[shutdown_guard_condition_index]);
     // Notify nodes who's guard conditions are set (triggered).
     for (size_t i = 0u; i < node_graph_interfaces_size; ++i) {
       const auto node_ptr = node_graph_interfaces_[i];
@@ -224,7 +202,7 @@ GraphListener::run_loop()
       if (graph_gc == wait_set_.guard_conditions[graph_gc_indexes[i]]) {
         node_ptr->notify_graph_change();
       }
-      if (shutdown_guard_condition_triggered) {
+      if (is_shutdown_) {
         // If shutdown, then notify the node of this as well.
         node_ptr->notify_shutdown();
       }
@@ -365,7 +343,7 @@ GraphListener::cleanup_wait_set()
 }
 
 void
-GraphListener::__shutdown(bool should_throw)
+GraphListener::__shutdown()
 {
   std::lock_guard<std::mutex> shutdown_lock(shutdown_mutex_);
   if (!is_shutdown_.exchange(true)) {
@@ -377,28 +355,6 @@ GraphListener::__shutdown(bool should_throw)
     if (RCL_RET_OK != ret) {
       throw_from_rcl_error(ret, "failed to finalize interrupt guard condition");
     }
-    if (shutdown_guard_condition_) {
-      auto parent_context_ptr = parent_context_.lock();
-      if (parent_context_ptr) {
-        if (should_throw) {
-          parent_context_ptr->release_interrupt_guard_condition(&wait_set_);
-        } else {
-          parent_context_ptr->release_interrupt_guard_condition(&wait_set_, std::nothrow);
-        }
-      } else {
-        ret = rcl_guard_condition_fini(shutdown_guard_condition_);
-        if (RCL_RET_OK != ret) {
-          if (should_throw) {
-            throw_from_rcl_error(ret, "failed to finalize shutdown guard condition");
-          } else {
-            RCLCPP_ERROR(
-              rclcpp::get_logger("rclcpp"),
-              "failed to finalize shutdown guard condition");
-          }
-        }
-      }
-      shutdown_guard_condition_ = nullptr;
-    }
     if (is_started_) {
       cleanup_wait_set();
     }
@@ -408,14 +364,14 @@ GraphListener::__shutdown(bool should_throw)
 void
 GraphListener::shutdown()
 {
-  this->__shutdown(true);
+  this->__shutdown();
 }
 
 void
 GraphListener::shutdown(const std::nothrow_t &) noexcept
 {
   try {
-    this->__shutdown(false);
+    this->__shutdown();
   } catch (const std::exception & exc) {
     RCLCPP_ERROR(
       rclcpp::get_logger("rclcpp"),

rclcpp/src/rclcpp/intra_process_manager.cpp

@@ -157,7 +157,13 @@ IntraProcessManager::get_subscription_intra_process(uint64_t intra_process_subsc
   if (subscription_it == subscriptions_.end()) {
     return nullptr;
   } else {
-    return subscription_it->second.subscription;
+    auto subscription = subscription_it->second.subscription.lock();
+    if (subscription) {
+      return subscription;
+    } else {
+      subscriptions_.erase(subscription_it);
+      return nullptr;
+    }
   }
 }
 

rclcpp/src/rclcpp/logger.cpp

@@ -14,6 +14,8 @@
 
 #include <string>
 
+#include "rcl_logging_interface/rcl_logging_interface.h"
+
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/logger.hpp"
 #include "rclcpp/logging.hpp"
@@ -38,12 +40,28 @@ get_node_logger(const rcl_node_t * node)
   const char * logger_name = rcl_node_get_logger_name(node);
   if (nullptr == logger_name) {
     auto logger = rclcpp::get_logger("rclcpp");
-    RCLCPP_ERROR(logger, "failed to get logger name from node at address %p", node);
+    RCLCPP_ERROR(
+      logger, "failed to get logger name from node at address %p",
+      static_cast<void *>(const_cast<rcl_node_t *>(node)));
     return logger;
   }
   return rclcpp::get_logger(logger_name);
 }
 
+rcpputils::fs::path
+get_logging_directory()
+{
+  char * log_dir = NULL;
+  auto allocator = rcutils_get_default_allocator();
+  rcl_logging_ret_t ret = rcl_logging_get_logging_directory(allocator, &log_dir);
+  if (RCL_LOGGING_RET_OK != ret) {
+    rclcpp::exceptions::throw_from_rcl_error(ret);
+  }
+  std::string path{log_dir};
+  allocator.deallocate(log_dir, allocator.state);
+  return path;
+}
+
 void
 Logger::set_level(Level level)
 {

rclcpp/src/rclcpp/node.cpp

@@ -13,6 +13,7 @@
 // limitations under the License.
 
 #include <algorithm>
+#include <array>
 #include <limits>
 #include <map>
 #include <memory>
@@ -20,6 +21,9 @@
 #include <utility>
 #include <vector>
 
+#include "rcl/arguments.h"
+
+#include "rclcpp/detail/qos_parameters.hpp"
 #include "rclcpp/exceptions.hpp"
 #include "rclcpp/graph_listener.hpp"
 #include "rclcpp/node.hpp"
@@ -33,9 +37,12 @@
 #include "rclcpp/node_interfaces/node_timers.hpp"
 #include "rclcpp/node_interfaces/node_topics.hpp"
 #include "rclcpp/node_interfaces/node_waitables.hpp"
+#include "rclcpp/qos_overriding_options.hpp"
 
 #include "rmw/validate_namespace.h"
 
+#include "./detail/resolve_parameter_overrides.hpp"
+
 using rclcpp::Node;
 using rclcpp::NodeOptions;
 using rclcpp::exceptions::throw_from_rcl_error;
@@ -94,6 +101,45 @@ Node::Node(
 {
 }
 
+static
+rclcpp::QoS
+get_parameter_events_qos(
+  rclcpp::node_interfaces::NodeBaseInterface & node_base,
+  const rclcpp::NodeOptions & options)
+{
+  auto final_qos = options.parameter_event_qos();
+  const rcl_arguments_t * global_args = nullptr;
+  auto * rcl_options = options.get_rcl_node_options();
+  if (rcl_options->use_global_arguments) {
+    auto context_ptr = node_base.get_context()->get_rcl_context();
+    global_args = &(context_ptr->global_arguments);
+  }
+
+  auto parameter_overrides = rclcpp::detail::resolve_parameter_overrides(
+    node_base.get_fully_qualified_name(),
+    options.parameter_overrides(),
+    &rcl_options->arguments,
+    global_args);
+
+  auto final_topic_name = node_base.resolve_topic_or_service_name("/parameter_events", false);
+  auto prefix = "qos_overrides." + final_topic_name + ".";
+  std::array<rclcpp::QosPolicyKind, 4> policies = {
+    rclcpp::QosPolicyKind::Depth,
+    rclcpp::QosPolicyKind::Durability,
+    rclcpp::QosPolicyKind::History,
+    rclcpp::QosPolicyKind::Reliability,
+  };
+  for (const auto & policy : policies) {
+    auto param_name = prefix + rclcpp::qos_policy_kind_to_cstr(policy);
+    auto it = parameter_overrides.find(param_name);
+    auto value = it != parameter_overrides.end() ?
+      it->second :
+      rclcpp::detail::get_default_qos_param_value(policy, options.parameter_event_qos());
+    rclcpp::detail::apply_qos_override(policy, value, final_qos);
+  }
+  return final_qos;
+}
+
 Node::Node(
   const std::string & node_name,
   const std::string & namespace_,
@@ -126,7 +172,9 @@ Node::Node(
       options.parameter_overrides(),
       options.start_parameter_services(),
       options.start_parameter_event_publisher(),
-      options.parameter_event_qos(),
+      // This is needed in order to apply parameter overrides to the qos profile provided in
+      // options.
+      get_parameter_events_qos(*node_base_, options),
       options.parameter_event_publisher_options(),
       options.allow_undeclared_parameters(),
       options.automatically_declare_parameters_from_overrides()
@@ -146,6 +194,20 @@ Node::Node(
   sub_namespace_(""),
   effective_namespace_(create_effective_namespace(this->get_namespace(), sub_namespace_))
 {
+  // we have got what we wanted directly from the overrides,
+  // but declare the parameters anyway so they are visible.
+  rclcpp::detail::declare_qos_parameters(
+    rclcpp::QosOverridingOptions
+  {
+    QosPolicyKind::Depth,
+    QosPolicyKind::Durability,
+    QosPolicyKind::History,
+    QosPolicyKind::Reliability,
+  },
+    node_parameters_,
+    node_topics_->resolve_topic_name("/parameter_events"),
+    options.parameter_event_qos(),
+    rclcpp::detail::PublisherQosParametersTraits{});
 }
 
 Node::Node(
@@ -185,7 +247,18 @@ Node::Node(
 }
 
 Node::~Node()
-{}
+{
+  // release sub-interfaces in an order that allows them to consult with node_base during tear-down
+  node_waitables_.reset();
+  node_time_source_.reset();
+  node_parameters_.reset();
+  node_clock_.reset();
+  node_services_.reset();
+  node_topics_.reset();
+  node_timers_.reset();
+  node_logging_.reset();
+  node_graph_.reset();
+}
 
 const char *
 Node::get_name() const
@@ -219,6 +292,24 @@ Node::create_callback_group(
   return node_base_->create_callback_group(group_type, automatically_add_to_executor_with_node);
 }
 
+const rclcpp::ParameterValue &
+Node::declare_parameter(const std::string & name)
+{
+#ifndef _WIN32
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#else
+# pragma warning(push)
+# pragma warning(disable: 4996)
+#endif
+  return this->node_parameters_->declare_parameter(name);
+#ifndef _WIN32
+# pragma GCC diagnostic pop
+#else
+# pragma warning(pop)
+#endif
+}
+
 const rclcpp::ParameterValue &
 Node::declare_parameter(
   const std::string & name,
@@ -233,6 +324,20 @@ Node::declare_parameter(
     ignore_override);
 }
 
+const rclcpp::ParameterValue &
+Node::declare_parameter(
+  const std::string & name,
+  rclcpp::ParameterType type,
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
+{
+  return this->node_parameters_->declare_parameter(
+    name,
+    type,
+    parameter_descriptor,
+    ignore_override);
+}
+
 void
 Node::undeclare_parameter(const std::string & name)
 {

rclcpp/src/rclcpp/node_interfaces/node_base.cpp

@@ -70,6 +70,7 @@ NodeBase::NodeBase(
   std::shared_ptr<std::recursive_mutex> logging_mutex = get_global_logging_mutex();
   {
     std::lock_guard<std::recursive_mutex> guard(*logging_mutex);
+    // TODO(ivanpauno): /rosout Qos should be reconfigurable.
     // TODO(ivanpauno): Instead of mutually excluding rcl_node_init with the global logger mutex,
     // rcl_logging_rosout_init_publisher_for_node could be decoupled from there and be called
     // here directly.

rclcpp/src/rclcpp/node_interfaces/node_parameters.cpp

@@ -16,8 +16,10 @@
 
 #include <rcl_yaml_param_parser/parser.h>
 
+#include <array>
 #include <cmath>
 #include <cstdlib>
+#include <cstring>
 #include <functional>
 #include <limits>
 #include <map>
@@ -34,6 +36,8 @@
 #include "rcutils/logging_macros.h"
 #include "rmw/qos_profiles.h"
 
+#include "../detail/resolve_parameter_overrides.hpp"
+
 using rclcpp::node_interfaces::NodeParameters;
 
 NodeParameters::NodeParameters(
@@ -67,6 +71,7 @@ NodeParameters::NodeParameters(
   }
 
   if (start_parameter_event_publisher) {
+    // TODO(ivanpauno): Qos of the `/parameters_event` topic should be somehow overridable.
     events_publisher_ = rclcpp::create_publisher<MessageT, AllocatorT, PublisherT>(
       node_topics,
       "/parameter_events",
@@ -84,60 +89,27 @@ NodeParameters::NodeParameters(
     throw std::runtime_error("Need valid node options in NodeParameters");
   }
 
-  std::vector<const rcl_arguments_t *> argument_sources;
-  // global before local so that local overwrites global
+  const rcl_arguments_t * global_args = nullptr;
   if (options->use_global_arguments) {
     auto context_ptr = node_base->get_context()->get_rcl_context();
-    argument_sources.push_back(&(context_ptr->global_arguments));
+    global_args = &(context_ptr->global_arguments);
   }
-  argument_sources.push_back(&options->arguments);
-
-  // Get fully qualified node name post-remapping to use to find node's params in yaml files
   combined_name_ = node_base->get_fully_qualified_name();
 
-  for (const rcl_arguments_t * source : argument_sources) {
-    rcl_params_t * params = NULL;
-    rcl_ret_t ret = rcl_arguments_get_param_overrides(source, &params);
-    if (RCL_RET_OK != ret) {
-      rclcpp::exceptions::throw_from_rcl_error(ret);
-    }
-    if (params) {
-      auto cleanup_params = make_scope_exit(
-        [params]() {
-          rcl_yaml_node_struct_fini(params);
-        });
-      rclcpp::ParameterMap initial_map = rclcpp::parameter_map_from(params);
-
-      // Enforce wildcard matching precedence
-      // TODO(cottsay) implement further wildcard matching
-      const std::vector<std::string> node_matching_names{"/**", combined_name_};
-      for (const auto & node_name : node_matching_names) {
-        if (initial_map.count(node_name) > 0) {
-          // Combine parameter yaml files, overwriting values in older ones
-          for (const rclcpp::Parameter & param : initial_map.at(node_name)) {
-            parameter_overrides_[param.get_name()] =
-              rclcpp::ParameterValue(param.get_value_message());
-          }
-        }
-      }
-    }
-  }
-
-  // parameter overrides passed to constructor will overwrite overrides from yaml file sources
-  for (auto & param : parameter_overrides) {
-    parameter_overrides_[param.get_name()] =
-      rclcpp::ParameterValue(param.get_value_message());
-  }
+  parameter_overrides_ = rclcpp::detail::resolve_parameter_overrides(
+    combined_name_, parameter_overrides, &options->arguments, global_args);
 
   // If asked, initialize any parameters that ended up in the initial parameter values,
   // but did not get declared explcitily by this point.
   if (automatically_declare_parameters_from_overrides) {
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
     for (const auto & pair : this->get_parameter_overrides()) {
       if (!this->has_parameter(pair.first)) {
         this->declare_parameter(
           pair.first,
           pair.second,
-          rcl_interfaces::msg::ParameterDescriptor(),
+          descriptor,
           true);
       }
     }
@@ -164,14 +136,13 @@ __are_doubles_equal(double x, double y, double ulp = 100.0)
   return std::abs(x - y) <= std::numeric_limits<double>::epsilon() * std::abs(x + y) * ulp;
 }
 
-RCLCPP_LOCAL
-inline
-void
-format_reason(std::string & reason, const std::string & name, const char * range_type)
+static
+std::string
+format_range_reason(const std::string & name, const char * range_type)
 {
   std::ostringstream ss;
   ss << "Parameter {" << name << "} doesn't comply with " << range_type << " range.";
-  reason = ss.str();
+  return ss.str();
 }
 
 RCLCPP_LOCAL
@@ -190,7 +161,7 @@ __check_parameter_value_in_range(
     }
     if ((v < integer_range.from_value) || (v > integer_range.to_value)) {
       result.successful = false;
-      format_reason(result.reason, descriptor.name, "integer");
+      result.reason = format_range_reason(descriptor.name, "integer");
       return result;
     }
     if (integer_range.step == 0) {
@@ -200,7 +171,7 @@ __check_parameter_value_in_range(
       return result;
     }
     result.successful = false;
-    format_reason(result.reason, descriptor.name, "integer");
+    result.reason = format_range_reason(descriptor.name, "integer");
     return result;
   }
 
@@ -212,7 +183,7 @@ __check_parameter_value_in_range(
     }
     if ((v < fp_range.from_value) || (v > fp_range.to_value)) {
       result.successful = false;
-      format_reason(result.reason, descriptor.name, "floating point");
+      result.reason = format_range_reason(descriptor.name, "floating point");
       return result;
     }
     if (fp_range.step == 0.0) {
@@ -223,29 +194,62 @@ __check_parameter_value_in_range(
       return result;
     }
     result.successful = false;
-    format_reason(result.reason, descriptor.name, "floating point");
+    result.reason = format_range_reason(descriptor.name, "floating point");
     return result;
   }
   return result;
 }
 
+static
+std::string
+format_type_reason(
+  const std::string & name, const std::string & old_type, const std::string & new_type)
+{
+  std::ostringstream ss;
+  // WARN: A condition later depends on this message starting with "Wrong parameter type",
+  // check `declare_parameter` if you modify this!
+  ss << "Wrong parameter type, parameter {" << name << "} is of type {" << old_type <<
+    "}, setting it to {" << new_type << "} is not allowed.";
+  return ss.str();
+}
+
 // Return true if parameter values comply with the descriptors in parameter_infos.
 RCLCPP_LOCAL
 rcl_interfaces::msg::SetParametersResult
 __check_parameters(
   std::map<std::string, rclcpp::node_interfaces::ParameterInfo> & parameter_infos,
-  const std::vector<rclcpp::Parameter> & parameters)
+  const std::vector<rclcpp::Parameter> & parameters,
+  bool allow_undeclared)
 {
   rcl_interfaces::msg::SetParametersResult result;
   result.successful = true;
   for (const rclcpp::Parameter & parameter : parameters) {
-    const rcl_interfaces::msg::ParameterDescriptor & descriptor =
-      parameter_infos[parameter.get_name()].descriptor;
+    std::string name = parameter.get_name();
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    if (allow_undeclared) {
+      auto it = parameter_infos.find(name);
+      if (it != parameter_infos.cend()) {
+        descriptor = it->second.descriptor;
+      } else {
+        // implicitly declared parameters are dinamically typed!
+        descriptor.dynamic_typing = true;
+      }
+    } else {
+      descriptor = parameter_infos[name].descriptor;
+    }
+    const auto new_type = parameter.get_type();
+    const auto specified_type = static_cast<rclcpp::ParameterType>(descriptor.type);
+    result.successful = descriptor.dynamic_typing || specified_type == new_type;
+    if (!result.successful) {
+      result.reason = format_type_reason(
+        name, rclcpp::to_string(specified_type), rclcpp::to_string(new_type));
+      return result;
+    }
     result = __check_parameter_value_in_range(
       descriptor,
       parameter.get_parameter_value());
     if (!result.successful) {
-      break;
+      return result;
     }
   }
   return result;
@@ -292,7 +296,8 @@ __set_parameters_atomically_common(
   const std::vector<rclcpp::Parameter> & parameters,
   std::map<std::string, rclcpp::node_interfaces::ParameterInfo> & parameter_infos,
   CallbacksContainerType & callback_container,
-  const OnParametersSetCallbackType & callback)
+  const OnParametersSetCallbackType & callback,
+  bool allow_undeclared = false)
 {
   // Call the user callback to see if the new value(s) are allowed.
   rcl_interfaces::msg::SetParametersResult result =
@@ -301,7 +306,7 @@ __set_parameters_atomically_common(
     return result;
   }
   // Check if the value being set complies with the descriptor.
-  result = __check_parameters(parameter_infos, parameters);
+  result = __check_parameters(parameter_infos, parameters, allow_undeclared);
   if (!result.successful) {
     return result;
   }
@@ -352,6 +357,10 @@ __declare_parameter_common(
     callback_container,
     callback);
 
+  if (!result.successful) {
+    return result;
+  }
+
   // Add declared parameters to storage.
   parameters_out[name] = parameter_infos.at(name);
 
@@ -363,6 +372,99 @@ __declare_parameter_common(
   return result;
 }
 
+static
+const rclcpp::ParameterValue &
+declare_parameter_helper(
+  const std::string & name,
+  rclcpp::ParameterType type,
+  const rclcpp::ParameterValue & default_value,
+  rcl_interfaces::msg::ParameterDescriptor parameter_descriptor,
+  bool ignore_override,
+  std::map<std::string, rclcpp::node_interfaces::ParameterInfo> & parameters,
+  const std::map<std::string, rclcpp::ParameterValue> & overrides,
+  CallbacksContainerType & callback_container,
+  const OnParametersSetCallbackType & callback,
+  rclcpp::Publisher<rcl_interfaces::msg::ParameterEvent> * events_publisher,
+  const std::string & combined_name,
+  rclcpp::node_interfaces::NodeClockInterface & node_clock)
+{
+  // TODO(sloretz) parameter name validation
+  if (name.empty()) {
+    throw rclcpp::exceptions::InvalidParametersException("parameter name must not be empty");
+  }
+
+  // Error if this parameter has already been declared and is different
+  if (__lockless_has_parameter(parameters, name)) {
+    throw rclcpp::exceptions::ParameterAlreadyDeclaredException(
+            "parameter '" + name + "' has already been declared");
+  }
+
+  if (!parameter_descriptor.dynamic_typing) {
+    if (rclcpp::PARAMETER_NOT_SET == type) {
+      type = default_value.get_type();
+    }
+    if (rclcpp::PARAMETER_NOT_SET == type) {
+      throw rclcpp::exceptions::InvalidParameterTypeException{
+              name,
+              "cannot declare a statically typed parameter with an uninitialized value"
+      };
+    }
+    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,
+    default_value,
+    parameter_descriptor,
+    parameters,
+    overrides,
+    callback_container,
+    callback,
+    &parameter_event,
+    ignore_override);
+
+  // If it failed to be set, then throw an exception.
+  if (!result.successful) {
+    constexpr const char type_error_msg_start[] = "Wrong parameter type";
+    if (
+      0u == std::strncmp(
+        result.reason.c_str(), type_error_msg_start, sizeof(type_error_msg_start) - 1))
+    {
+      // TODO(ivanpauno): Refactor the logic so we don't need the above `strncmp` and we can
+      // detect between both exceptions more elegantly.
+      throw rclcpp::exceptions::InvalidParameterTypeException(name, result.reason);
+    }
+    throw rclcpp::exceptions::InvalidParameterValueException(
+            "parameter '" + name + "' could not be set: " + result.reason);
+  }
+
+  // Publish if events_publisher_ is not nullptr, which may be if disabled in the constructor.
+  if (nullptr != events_publisher) {
+    parameter_event.node = combined_name;
+    parameter_event.stamp = node_clock.get_clock()->now();
+    events_publisher->publish(parameter_event);
+  }
+
+  return parameters.at(name).value;
+}
+
+const rclcpp::ParameterValue &
+NodeParameters::declare_parameter(const std::string & name)
+{
+  rcl_interfaces::msg::ParameterDescriptor descriptor;
+  descriptor.dynamic_typing = true;
+  return this->declare_parameter(name, rclcpp::ParameterValue{}, descriptor, false);
+}
+
 const rclcpp::ParameterValue &
 NodeParameters::declare_parameter(
   const std::string & name,
@@ -371,46 +473,57 @@ NodeParameters::declare_parameter(
   bool ignore_override)
 {
   std::lock_guard<std::recursive_mutex> lock(mutex_);
-
   ParameterMutationRecursionGuard guard(parameter_modification_enabled_);
 
-  // TODO(sloretz) parameter name validation
-  if (name.empty()) {
-    throw rclcpp::exceptions::InvalidParametersException("parameter name must not be empty");
-  }
-
-  // Error if this parameter has already been declared and is different
-  if (__lockless_has_parameter(parameters_, name)) {
-    throw rclcpp::exceptions::ParameterAlreadyDeclaredException(
-            "parameter '" + name + "' has already been declared");
-  }
-
-  rcl_interfaces::msg::ParameterEvent parameter_event;
-  auto result = __declare_parameter_common(
+  return declare_parameter_helper(
     name,
+    rclcpp::PARAMETER_NOT_SET,
     default_value,
     parameter_descriptor,
+    ignore_override,
     parameters_,
     parameter_overrides_,
     on_parameters_set_callback_container_,
     on_parameters_set_callback_,
-    &parameter_event,
-    ignore_override);
+    events_publisher_.get(),
+    combined_name_,
+    *node_clock_);
+}
 
-  // If it failed to be set, then throw an exception.
-  if (!result.successful) {
-    throw rclcpp::exceptions::InvalidParameterValueException(
-            "parameter '" + name + "' could not be set: " + result.reason);
+const rclcpp::ParameterValue &
+NodeParameters::declare_parameter(
+  const std::string & name,
+  rclcpp::ParameterType type,
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  ParameterMutationRecursionGuard guard(parameter_modification_enabled_);
+
+  if (rclcpp::PARAMETER_NOT_SET == type) {
+    throw std::invalid_argument{
+            "declare_parameter(): the provided parameter type cannot be rclcpp::PARAMETER_NOT_SET"};
   }
 
-  // Publish if events_publisher_ is not nullptr, which may be if disabled in the constructor.
-  if (nullptr != events_publisher_) {
-    parameter_event.node = combined_name_;
-    parameter_event.stamp = node_clock_->get_clock()->now();
-    events_publisher_->publish(parameter_event);
+  if (parameter_descriptor.dynamic_typing == true) {
+    throw std::invalid_argument{
+            "declare_parameter(): cannot declare parameter of specific type and pass descriptor"
+            "with `dynamic_typing=true`"};
   }
 
-  return parameters_.at(name).value;
+  return declare_parameter_helper(
+    name,
+    type,
+    rclcpp::ParameterValue{},
+    parameter_descriptor,
+    ignore_override,
+    parameters_,
+    parameter_overrides_,
+    on_parameters_set_callback_container_,
+    on_parameters_set_callback_,
+    events_publisher_.get(),
+    combined_name_,
+    *node_clock_);
 }
 
 void
@@ -430,6 +543,10 @@ NodeParameters::undeclare_parameter(const std::string & name)
     throw rclcpp::exceptions::ParameterImmutableException(
             "cannot undeclare parameter '" + name + "' because it is read-only");
   }
+  if (!parameter_info->second.descriptor.dynamic_typing) {
+    throw rclcpp::exceptions::InvalidParameterTypeException{
+            name, "cannot undeclare an statically typed parameter"};
+  }
 
   parameters_.erase(parameter_info);
 }
@@ -523,13 +640,17 @@ NodeParameters::set_parameters_atomically(const std::vector<rclcpp::Parameter> &
   rcl_interfaces::msg::ParameterEvent parameter_event_msg;
   parameter_event_msg.node = combined_name_;
   CallbacksContainerType empty_callback_container;
+
+  // Implicit declare uses dynamic type descriptor.
+  rcl_interfaces::msg::ParameterDescriptor descriptor;
+  descriptor.dynamic_typing = true;
   for (auto parameter_to_be_declared : parameters_to_be_declared) {
     // This should not throw, because we validated the name and checked that
     // the parameter was not already declared.
     result = __declare_parameter_common(
       parameter_to_be_declared->get_name(),
       parameter_to_be_declared->get_parameter_value(),
-      rcl_interfaces::msg::ParameterDescriptor(),  // Implicit declare uses default descriptor.
+      descriptor,
       staged_parameter_changes,
       parameter_overrides_,
       // Only call callbacks once below
@@ -578,6 +699,11 @@ NodeParameters::set_parameters_atomically(const std::vector<rclcpp::Parameter> &
     if (rclcpp::PARAMETER_NOT_SET == parameter.get_type()) {
       auto it = parameters_.find(parameter.get_name());
       if (it != parameters_.end() && rclcpp::PARAMETER_NOT_SET != it->second.value.get_type()) {
+        if (!it->second.descriptor.dynamic_typing) {
+          result.reason = "cannot undeclare an statically typed parameter";
+          result.successful = false;
+          return result;
+        }
         parameters_to_be_undeclared.push_back(&parameter);
       }
     }
@@ -593,7 +719,8 @@ NodeParameters::set_parameters_atomically(const std::vector<rclcpp::Parameter> &
     on_parameters_set_callback_container_,
     // These callbacks are called once. When a callback returns an unsuccessful result,
     // the remaining aren't called.
-    on_parameters_set_callback_);
+    on_parameters_set_callback_,
+    allow_undeclared_);  // allow undeclared
 
   // If not successful, then stop here.
   if (!result.successful) {

rclcpp/src/rclcpp/node_interfaces/node_timers.cpp

@@ -16,6 +16,8 @@
 
 #include <string>
 
+#include "tracetools/tracetools.h"
+
 using rclcpp::node_interfaces::NodeTimers;
 
 NodeTimers::NodeTimers(rclcpp::node_interfaces::NodeBaseInterface * node_base)
@@ -44,4 +46,8 @@ NodeTimers::add_timer(
             std::string("Failed to notify wait set on timer creation: ") +
             rmw_get_error_string().str);
   }
+  TRACEPOINT(
+    rclcpp_timer_link_node,
+    static_cast<const void *>(timer->get_timer_handle().get()),
+    static_cast<const void *>(node_base_->get_rcl_node_handle()));
 }

rclcpp/src/rclcpp/parameter_client.cpp

@@ -144,6 +144,35 @@ AsyncParametersClient::get_parameters(
   return future_result;
 }
 
+std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>
+AsyncParametersClient::describe_parameters(
+  const std::vector<std::string> & names,
+  std::function<
+    void(std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>)
+  > callback)
+{
+  auto promise_result =
+    std::make_shared<std::promise<std::vector<rcl_interfaces::msg::ParameterDescriptor>>>();
+  auto future_result = promise_result->get_future().share();
+
+  auto request = std::make_shared<rcl_interfaces::srv::DescribeParameters::Request>();
+  request->names = names;
+
+  describe_parameters_client_->async_send_request(
+    request,
+    [promise_result, future_result, callback](
+      rclcpp::Client<rcl_interfaces::srv::DescribeParameters>::SharedFuture cb_f)
+    {
+      promise_result->set_value(cb_f.get()->descriptors);
+      if (callback != nullptr) {
+        callback(future_result);
+      }
+    }
+  );
+
+  return future_result;
+}
+
 std::shared_future<std::vector<rclcpp::ParameterType>>
 AsyncParametersClient::get_parameter_types(
   const std::vector<std::string> & names,
@@ -313,14 +342,16 @@ AsyncParametersClient::wait_for_service_nanoseconds(std::chrono::nanoseconds tim
 }
 
 std::vector<rclcpp::Parameter>
-SyncParametersClient::get_parameters(const std::vector<std::string> & parameter_names)
+SyncParametersClient::get_parameters(
+  const std::vector<std::string> & parameter_names,
+  std::chrono::nanoseconds timeout)
 {
   auto f = async_parameters_client_->get_parameters(parameter_names);
   using rclcpp::executors::spin_node_until_future_complete;
   if (
     spin_node_until_future_complete(
-      *executor_, node_base_interface_,
-      f) == rclcpp::FutureReturnCode::SUCCESS)
+      *executor_, node_base_interface_, f,
+      timeout) == rclcpp::FutureReturnCode::SUCCESS)
   {
     return f.get();
   }
@@ -337,16 +368,34 @@ SyncParametersClient::has_parameter(const std::string & parameter_name)
   return vars.names.size() > 0;
 }
 
+std::vector<rcl_interfaces::msg::ParameterDescriptor>
+SyncParametersClient::describe_parameters(
+  const std::vector<std::string> & parameter_names,
+  std::chrono::nanoseconds timeout)
+{
+  auto f = async_parameters_client_->describe_parameters(parameter_names);
+
+  using rclcpp::executors::spin_node_until_future_complete;
+  rclcpp::FutureReturnCode future =
+    spin_node_until_future_complete(*executor_, node_base_interface_, f, timeout);
+  if (future == rclcpp::FutureReturnCode::SUCCESS) {
+    return f.get();
+  }
+  return std::vector<rcl_interfaces::msg::ParameterDescriptor>();
+}
+
 std::vector<rclcpp::ParameterType>
-SyncParametersClient::get_parameter_types(const std::vector<std::string> & parameter_names)
+SyncParametersClient::get_parameter_types(
+  const std::vector<std::string> & parameter_names,
+  std::chrono::nanoseconds timeout)
 {
   auto f = async_parameters_client_->get_parameter_types(parameter_names);
 
   using rclcpp::executors::spin_node_until_future_complete;
   if (
     spin_node_until_future_complete(
-      *executor_, node_base_interface_,
-      f) == rclcpp::FutureReturnCode::SUCCESS)
+      *executor_, node_base_interface_, f,
+      timeout) == rclcpp::FutureReturnCode::SUCCESS)
   {
     return f.get();
   }
@@ -355,15 +404,16 @@ SyncParametersClient::get_parameter_types(const std::vector<std::string> & param
 
 std::vector<rcl_interfaces::msg::SetParametersResult>
 SyncParametersClient::set_parameters(
-  const std::vector<rclcpp::Parameter> & parameters)
+  const std::vector<rclcpp::Parameter> & parameters,
+  std::chrono::nanoseconds timeout)
 {
   auto f = async_parameters_client_->set_parameters(parameters);
 
   using rclcpp::executors::spin_node_until_future_complete;
   if (
     spin_node_until_future_complete(
-      *executor_, node_base_interface_,
-      f) == rclcpp::FutureReturnCode::SUCCESS)
+      *executor_, node_base_interface_, f,
+      timeout) == rclcpp::FutureReturnCode::SUCCESS)
   {
     return f.get();
   }
@@ -372,15 +422,16 @@ SyncParametersClient::set_parameters(
 
 rcl_interfaces::msg::SetParametersResult
 SyncParametersClient::set_parameters_atomically(
-  const std::vector<rclcpp::Parameter> & parameters)
+  const std::vector<rclcpp::Parameter> & parameters,
+  std::chrono::nanoseconds timeout)
 {
   auto f = async_parameters_client_->set_parameters_atomically(parameters);
 
   using rclcpp::executors::spin_node_until_future_complete;
   if (
     spin_node_until_future_complete(
-      *executor_, node_base_interface_,
-      f) == rclcpp::FutureReturnCode::SUCCESS)
+      *executor_, node_base_interface_, f,
+      timeout) == rclcpp::FutureReturnCode::SUCCESS)
   {
     return f.get();
   }
@@ -391,15 +442,16 @@ SyncParametersClient::set_parameters_atomically(
 rcl_interfaces::msg::ListParametersResult
 SyncParametersClient::list_parameters(
   const std::vector<std::string> & parameter_prefixes,
-  uint64_t depth)
+  uint64_t depth,
+  std::chrono::nanoseconds timeout)
 {
   auto f = async_parameters_client_->list_parameters(parameter_prefixes, depth);
 
   using rclcpp::executors::spin_node_until_future_complete;
   if (
     spin_node_until_future_complete(
-      *executor_, node_base_interface_,
-      f) == rclcpp::FutureReturnCode::SUCCESS)
+      *executor_, node_base_interface_, f,
+      timeout) == rclcpp::FutureReturnCode::SUCCESS)
   {
     return f.get();
   }

rclcpp/src/rclcpp/parameter_event_handler.cpp

@@ -0,0 +1,222 @@
+// Copyright 2019 Intel Corporation
+//
+// 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 <functional>
+#include <memory>
+#include <string>
+#include <unordered_map>
+#include <utility>
+#include <vector>
+
+#include "rclcpp/parameter_event_handler.hpp"
+#include "rcpputils/join.hpp"
+
+namespace rclcpp
+{
+
+ParameterEventCallbackHandle::SharedPtr
+ParameterEventHandler::add_parameter_event_callback(
+  ParameterEventCallbackType callback)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  auto handle = std::make_shared<ParameterEventCallbackHandle>();
+  handle->callback = callback;
+  event_callbacks_.emplace_front(handle);
+
+  return handle;
+}
+
+template<typename CallbackHandleT>
+struct HandleCompare
+  : public std::unary_function<typename CallbackHandleT::WeakPtr, bool>
+{
+  explicit HandleCompare(const CallbackHandleT * const base)
+  : base_(base) {}
+  bool operator()(const typename CallbackHandleT::WeakPtr & handle)
+  {
+    auto shared_handle = handle.lock();
+    if (base_ == shared_handle.get()) {
+      return true;
+    }
+    return false;
+  }
+  const CallbackHandleT * const base_;
+};
+
+void
+ParameterEventHandler::remove_parameter_event_callback(
+  ParameterEventCallbackHandle::SharedPtr callback_handle)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  auto it = std::find_if(
+    event_callbacks_.begin(),
+    event_callbacks_.end(),
+    HandleCompare<ParameterEventCallbackHandle>(callback_handle.get()));
+  if (it != event_callbacks_.end()) {
+    event_callbacks_.erase(it);
+  } else {
+    throw std::runtime_error("Callback doesn't exist");
+  }
+}
+
+ParameterCallbackHandle::SharedPtr
+ParameterEventHandler::add_parameter_callback(
+  const std::string & parameter_name,
+  ParameterCallbackType callback,
+  const std::string & node_name)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  auto full_node_name = resolve_path(node_name);
+
+  auto handle = std::make_shared<ParameterCallbackHandle>();
+  handle->callback = 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);
+
+  return handle;
+}
+
+void
+ParameterEventHandler::remove_parameter_callback(
+  ParameterCallbackHandle::SharedPtr callback_handle)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+  auto handle = callback_handle.get();
+  auto & container = parameter_callbacks_[{handle->parameter_name, handle->node_name}];
+  auto it = std::find_if(
+    container.begin(),
+    container.end(),
+    HandleCompare<ParameterCallbackHandle>(handle));
+  if (it != container.end()) {
+    container.erase(it);
+    if (container.empty()) {
+      parameter_callbacks_.erase({handle->parameter_name, handle->node_name});
+    }
+  } else {
+    throw std::runtime_error("Callback doesn't exist");
+  }
+}
+
+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)
+{
+  if (event.node != node_name) {
+    return false;
+  }
+
+  for (auto & new_parameter : event.new_parameters) {
+    if (new_parameter.name == parameter_name) {
+      parameter = rclcpp::Parameter::from_parameter_msg(new_parameter);
+      return true;
+    }
+  }
+
+  for (auto & changed_parameter : event.changed_parameters) {
+    if (changed_parameter.name == parameter_name) {
+      parameter = rclcpp::Parameter::from_parameter_msg(changed_parameter);
+      return true;
+    }
+  }
+
+  return false;
+}
+
+rclcpp::Parameter
+ParameterEventHandler::get_parameter_from_event(
+  const rcl_interfaces::msg::ParameterEvent & event,
+  const std::string parameter_name,
+  const std::string node_name)
+{
+  rclcpp::Parameter p;
+  if (!get_parameter_from_event(event, p, parameter_name, node_name)) {
+    throw std::runtime_error(
+            "Parameter '" + parameter_name + "' of node '" + node_name +
+            "' is not part of parameter event");
+  }
+  return p;
+}
+
+std::vector<rclcpp::Parameter>
+ParameterEventHandler::get_parameters_from_event(
+  const rcl_interfaces::msg::ParameterEvent & event)
+{
+  std::vector<rclcpp::Parameter> params;
+
+  for (auto & new_parameter : event.new_parameters) {
+    params.push_back(rclcpp::Parameter::from_parameter_msg(new_parameter));
+  }
+
+  for (auto & changed_parameter : event.changed_parameters) {
+    params.push_back(rclcpp::Parameter::from_parameter_msg(changed_parameter));
+  }
+
+  return params;
+}
+
+void
+ParameterEventHandler::event_callback(
+  const rcl_interfaces::msg::ParameterEvent::SharedPtr event)
+{
+  std::lock_guard<std::recursive_mutex> lock(mutex_);
+
+  for (auto it = parameter_callbacks_.begin(); it != parameter_callbacks_.end(); ++it) {
+    rclcpp::Parameter p;
+    if (get_parameter_from_event(*event, p, it->first.first, it->first.second)) {
+      for (auto cb = it->second.begin(); cb != it->second.end(); ++cb) {
+        auto shared_handle = cb->lock();
+        if (nullptr != shared_handle) {
+          shared_handle->callback(p);
+        } else {
+          cb = it->second.erase(cb);
+        }
+      }
+    }
+  }
+
+  for (auto event_cb = event_callbacks_.begin(); event_cb != event_callbacks_.end(); ++event_cb) {
+    auto shared_event_handle = event_cb->lock();
+    if (nullptr != shared_event_handle) {
+      shared_event_handle->callback(event);
+    } else {
+      event_cb = event_callbacks_.erase(event_cb);
+    }
+  }
+}
+
+std::string
+ParameterEventHandler::resolve_path(const std::string & path)
+{
+  std::string full_path;
+
+  if (path == "") {
+    full_path = node_base_->get_fully_qualified_name();
+  } else {
+    full_path = path;
+    if (*path.begin() != '/') {
+      auto ns = node_base_->get_namespace();
+      const std::vector<std::string> paths{ns, path};
+      full_path = (ns == std::string("/")) ? ns + path : rcpputils::join(paths, "/");
+    }
+  }
+
+  return full_path;
+}
+
+}  // namespace rclcpp

rclcpp/src/rclcpp/parameter_value.cpp

@@ -67,7 +67,7 @@ array_to_string(
   type_array << "[";
   type_array.setf(format_flags, std::ios_base::basefield | std::ios::boolalpha);
   type_array << std::showbase;
-  for (const ValType value : array) {
+  for (const ValType & value : array) {
     if (!first_item) {
       type_array << ", ";
     } else {

rclcpp/src/rclcpp/qos.cpp

@@ -99,6 +99,13 @@ QoS::history(rmw_qos_history_policy_t history)
   return *this;
 }
 
+QoS &
+QoS::history(HistoryPolicy history)
+{
+  rmw_qos_profile_.history = static_cast<rmw_qos_history_policy_t>(history);
+  return *this;
+}
+
 QoS &
 QoS::keep_last(size_t depth)
 {
@@ -122,6 +129,13 @@ QoS::reliability(rmw_qos_reliability_policy_t reliability)
   return *this;
 }
 
+QoS &
+QoS::reliability(ReliabilityPolicy reliability)
+{
+  rmw_qos_profile_.reliability = static_cast<rmw_qos_reliability_policy_t>(reliability);
+  return *this;
+}
+
 QoS &
 QoS::reliable()
 {
@@ -141,6 +155,13 @@ QoS::durability(rmw_qos_durability_policy_t durability)
   return *this;
 }
 
+QoS &
+QoS::durability(DurabilityPolicy durability)
+{
+  rmw_qos_profile_.durability = static_cast<rmw_qos_durability_policy_t>(durability);
+  return *this;
+}
+
 QoS &
 QoS::durability_volatile()
 {
@@ -186,6 +207,14 @@ QoS::liveliness(rmw_qos_liveliness_policy_t liveliness)
   return *this;
 }
 
+QoS &
+QoS::liveliness(LivelinessPolicy liveliness)
+{
+  rmw_qos_profile_.liveliness = static_cast<rmw_qos_liveliness_policy_t>(liveliness);
+  return *this;
+}
+
+
 QoS &
 QoS::liveliness_lease_duration(rmw_time_t liveliness_lease_duration)
 {
@@ -206,6 +235,51 @@ QoS::avoid_ros_namespace_conventions(bool avoid_ros_namespace_conventions)
   return *this;
 }
 
+HistoryPolicy
+QoS::history() const
+{
+  return static_cast<HistoryPolicy>(rmw_qos_profile_.history);
+}
+
+size_t
+QoS::depth() const {return rmw_qos_profile_.depth;}
+
+ReliabilityPolicy
+QoS::reliability() const
+{
+  return static_cast<ReliabilityPolicy>(rmw_qos_profile_.reliability);
+}
+
+DurabilityPolicy
+QoS::durability() const
+{
+  return static_cast<DurabilityPolicy>(rmw_qos_profile_.durability);
+}
+
+Duration
+QoS::deadline() const {return Duration::from_rmw_time(rmw_qos_profile_.deadline);}
+
+Duration
+QoS::lifespan() const {return Duration::from_rmw_time(rmw_qos_profile_.lifespan);}
+
+LivelinessPolicy
+QoS::liveliness() const
+{
+  return static_cast<LivelinessPolicy>(rmw_qos_profile_.liveliness);
+}
+
+Duration
+QoS::liveliness_lease_duration() const
+{
+  return Duration::from_rmw_time(rmw_qos_profile_.liveliness_lease_duration);
+}
+
+bool
+QoS::avoid_ros_namespace_conventions() const
+{
+  return rmw_qos_profile_.avoid_ros_namespace_conventions;
+}
+
 namespace
 {
 /// Check if two rmw_time_t have the same values.

rclcpp/src/rclcpp/qos_overriding_options.cpp

@@ -0,0 +1,84 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "rclcpp/qos_overriding_options.hpp"
+
+#include <initializer_list>
+#include <ostream>
+#include <stdexcept>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "rmw/qos_policy_kind.h"
+#include "rmw/qos_string_conversions.h"
+
+namespace rclcpp
+{
+
+const char *
+qos_policy_kind_to_cstr(const QosPolicyKind & qpk)
+{
+  const char * ret = rmw_qos_policy_kind_to_str(static_cast<rmw_qos_policy_kind_t>(qpk));
+  if (!ret) {
+    throw std::invalid_argument{"unknown QoS policy kind"};
+  }
+  return ret;
+}
+
+std::ostream &
+operator<<(std::ostream & oss, const QosPolicyKind & qpk)
+{
+  return oss << qos_policy_kind_to_cstr(qpk);
+}
+
+static std::initializer_list<QosPolicyKind> kDefaultPolicies =
+{QosPolicyKind::History, QosPolicyKind::Depth, QosPolicyKind::Reliability};
+
+QosOverridingOptions::QosOverridingOptions(
+  std::initializer_list<QosPolicyKind> policy_kinds,
+  QosCallback validation_callback,
+  std::string id)
+: id_{std::move(id)},
+  policy_kinds_{policy_kinds},
+  validation_callback_{std::move(validation_callback)}
+{}
+
+QosOverridingOptions
+QosOverridingOptions::with_default_policies(
+  QosCallback validation_callback,
+  std::string id)
+{
+  return QosOverridingOptions{kDefaultPolicies, validation_callback, id};
+}
+
+const std::string &
+QosOverridingOptions::get_id() const
+{
+  return id_;
+}
+
+const std::vector<QosPolicyKind> &
+QosOverridingOptions::get_policy_kinds() const
+{
+  return policy_kinds_;
+}
+
+const QosCallback &
+QosOverridingOptions::get_validation_callback() const
+{
+  return validation_callback_;
+}
+
+}  // namespace rclcpp

rclcpp/src/rclcpp/signal_handler.cpp

@@ -243,7 +243,7 @@ SignalHandler::deferred_signal_handler()
             get_logger(),
             "deferred_signal_handler(): "
             "shutting down rclcpp::Context @ %p, because it had shutdown_on_sigint == true",
-            context_ptr.get());
+            static_cast<void *>(context_ptr.get()));
           context_ptr->shutdown("signal handler");
         }
       }

rclcpp/src/rclcpp/time_source.cpp

@@ -233,11 +233,22 @@ void TimeSource::create_clock_sub()
     return;
   }
 
+  rclcpp::SubscriptionOptions options;
+  options.qos_overriding_options = rclcpp::QosOverridingOptions(
+    {
+      rclcpp::QosPolicyKind::Depth,
+      rclcpp::QosPolicyKind::Durability,
+      rclcpp::QosPolicyKind::History,
+      rclcpp::QosPolicyKind::Reliability,
+    });
+
   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)
+    std::bind(&TimeSource::clock_cb, this, std::placeholders::_1),
+    options
   );
 }
 

rclcpp/test/CMakeLists.txt

@@ -4,6 +4,8 @@ find_package(test_msgs REQUIRED)
 
 include(cmake/rclcpp_add_build_failure_test.cmake)
 
+set(TEST_RESOURCES_DIRECTORY "${CMAKE_CURRENT_SOURCE_DIR}/resources")
+
 add_subdirectory(benchmark)
 add_subdirectory(rclcpp)
 
@@ -11,8 +13,3 @@ ament_add_gtest(test_rclcpp_gtest_macros utils/test_rclcpp_gtest_macros.cpp)
 if(TARGET test_rclcpp_gtest_macros)
   target_link_libraries(test_rclcpp_gtest_macros ${PROJECT_NAME})
 endif()
-
-# Install test resources
-install(
-  DIRECTORY resources
-  DESTINATION ${CMAKE_CURRENT_BINARY_DIR})

rclcpp/test/benchmark/CMakeLists.txt

@@ -1,3 +1,4 @@
+find_package(ament_cmake_google_benchmark REQUIRED)
 find_package(performance_test_fixture REQUIRED)
 
 # These benchmarks are only being created and run for the default RMW
@@ -31,6 +32,11 @@ if(TARGET benchmark_node_parameters_interface)
   target_link_libraries(benchmark_node_parameters_interface ${PROJECT_NAME})
 endif()
 
+ament_add_google_benchmark(benchmark_parameter_client benchmark_parameter_client.cpp)
+if(TARGET benchmark_parameter_client)
+  target_link_libraries(benchmark_parameter_client ${PROJECT_NAME})
+endif()
+
 add_performance_test(benchmark_service benchmark_service.cpp)
 if(TARGET benchmark_service)
   target_link_libraries(benchmark_service ${PROJECT_NAME})

rclcpp/test/benchmark/benchmark_executor.cpp

@@ -384,6 +384,7 @@ BENCHMARK_F(
   reset_heap_counters();
 
   for (auto _ : st) {
-    entities_collector_->execute();
+    std::shared_ptr<void> data = entities_collector_->take_data();
+    entities_collector_->execute(data);
   }
 }

rclcpp/test/benchmark/benchmark_node.cpp

@@ -46,7 +46,9 @@ BENCHMARK_F(NodePerformanceTest, create_node)(benchmark::State & state)
   for (auto _ : state) {
     // Using pointer to separate construction and destruction in timing
     auto node = std::make_shared<rclcpp::Node>("node");
+#ifndef __clang_analyzer__
     benchmark::DoNotOptimize(node);
+#endif
     benchmark::ClobberMemory();
 
     // Ensure destruction of node is not counted toward timing
@@ -69,7 +71,9 @@ BENCHMARK_F(NodePerformanceTest, destroy_node)(benchmark::State & state)
     auto node = std::make_shared<rclcpp::Node>("node");
     state.ResumeTiming();
 
+#ifndef __clang_analyzer__
     benchmark::DoNotOptimize(node);
+#endif
     benchmark::ClobberMemory();
 
     node.reset();

rclcpp/test/benchmark/benchmark_node_parameters_interface.cpp

@@ -30,6 +30,7 @@ public:
     param2_name(param_prefix + ".my_param_2"),
     param3_name(param_prefix + ".my_param_3")
   {
+    dynamically_typed_descriptor.dynamic_typing = true;
   }
 
   void SetUp(benchmark::State & state)
@@ -37,9 +38,12 @@ public:
     rclcpp::init(0, nullptr);
     node = std::make_shared<rclcpp::Node>(node_name);
 
-    node->declare_parameter(param1_name);
-    node->declare_parameter(param2_name);
-    node->declare_parameter(param3_name);
+    node->declare_parameter(
+      param1_name, rclcpp::ParameterValue{}, dynamically_typed_descriptor);
+    node->declare_parameter(
+      param2_name, rclcpp::ParameterValue{}, dynamically_typed_descriptor);
+    node->declare_parameter(
+      param3_name, rclcpp::ParameterValue{}, dynamically_typed_descriptor);
     node->undeclare_parameter(param3_name);
 
     performance_test_fixture::PerformanceTest::SetUp(state);
@@ -58,6 +62,7 @@ public:
   const std::string param1_name;
   const std::string param2_name;
   const std::string param3_name;
+  rcl_interfaces::msg::ParameterDescriptor dynamically_typed_descriptor;
 
 protected:
   rclcpp::Node::SharedPtr node;
@@ -66,7 +71,7 @@ protected:
 BENCHMARK_F(NodeParametersInterfaceTest, declare_undeclare)(benchmark::State & state)
 {
   for (auto _ : state) {
-    node->declare_parameter(param3_name);
+    node->declare_parameter(param3_name, rclcpp::ParameterValue{}, dynamically_typed_descriptor);
     node->undeclare_parameter(param3_name);
   }
 }

rclcpp/test/benchmark/benchmark_parameter_client.cpp

@@ -0,0 +1,327 @@
+// Copyright 2020 Open Source Robotics Foundation, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include <memory>
+#include <vector>
+#include <string>
+
+#include "benchmark/benchmark.h"
+
+#include "rclcpp/rclcpp.hpp"
+
+class RemoteNodeTest : public benchmark::Fixture
+{
+public:
+  RemoteNodeTest()
+  : remote_node_name("my_remote_node")
+  {
+  }
+
+#ifdef __GNUC__
+#pragma GCC diagnostic push
+#pragma GCC diagnostic ignored "-Woverloaded-virtual"
+#endif
+  void SetUp(benchmark::State &)
+  {
+    remote_context = std::make_shared<rclcpp::Context>();
+    remote_context->init(0, nullptr, rclcpp::InitOptions().auto_initialize_logging(false));
+
+    rclcpp::ExecutorOptions exec_options;
+    exec_options.context = remote_context;
+
+    remote_executor = std::make_shared<rclcpp::executors::SingleThreadedExecutor>(exec_options);
+
+    remote_node = std::make_shared<rclcpp::Node>(
+      remote_node_name, rclcpp::NodeOptions().context(remote_context));
+    remote_executor->add_node(remote_node);
+
+    remote_thread = std::thread(&rclcpp::executors::SingleThreadedExecutor::spin, remote_executor);
+  }
+
+  void TearDown(benchmark::State &)
+  {
+    remote_executor->cancel();
+    remote_context->shutdown("Test is complete");
+    remote_thread.join();
+
+    remote_node.reset();
+    remote_executor.reset();
+    remote_context.reset();
+  }
+#ifdef __GNUC__
+#pragma GCC diagnostic pop
+#endif
+
+  const std::string remote_node_name;
+
+protected:
+  rclcpp::Context::SharedPtr remote_context;
+  rclcpp::executors::SingleThreadedExecutor::SharedPtr remote_executor;
+  rclcpp::Node::SharedPtr remote_node;
+  std::thread remote_thread;
+};
+
+class ParameterClientTest : public RemoteNodeTest
+{
+public:
+  ParameterClientTest()
+  : node_name("my_node"),
+    param_prefix("my_prefix"),
+    param1_name(param_prefix + ".my_param_1"),
+    param2_name(param_prefix + ".my_param_2"),
+    param3_name(param_prefix + ".my_param_3")
+  {
+  }
+
+  void SetUp(benchmark::State & state)
+  {
+    RemoteNodeTest::SetUp(state);
+
+    rclcpp::init(0, nullptr);
+    node = std::make_shared<rclcpp::Node>(node_name);
+
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+
+    remote_node->declare_parameter(
+      param1_name, rclcpp::ParameterValue("param1_value"), descriptor);
+    remote_node->declare_parameter(
+      param2_name, rclcpp::ParameterValue(std::vector<int> {1, 2, 3}), descriptor);
+    remote_node->declare_parameter(param3_name, rclcpp::ParameterValue{}, descriptor);
+    remote_node->undeclare_parameter(param3_name);
+
+    params_client = std::make_shared<rclcpp::SyncParametersClient>(node, remote_node_name);
+
+    if (!params_client->wait_for_service()) {
+      state.SkipWithError("Client failed to become ready");
+    }
+  }
+
+  void TearDown(benchmark::State & state)
+  {
+    RemoteNodeTest::TearDown(state);
+
+    rclcpp::shutdown();
+    node.reset();
+    params_client.reset();
+  }
+
+  const std::string node_name;
+  const std::string param_prefix;
+  const std::string param1_name;
+  const std::string param2_name;
+  const std::string param3_name;
+
+protected:
+  rclcpp::Node::SharedPtr node;
+  rclcpp::SyncParametersClient::SharedPtr params_client;
+};
+
+static bool result_is_successful(rcl_interfaces::msg::SetParametersResult result)
+{
+  return result.successful;
+}
+
+BENCHMARK_F(ParameterClientTest, create_destroy_client)(benchmark::State & state)
+{
+  for (auto _ : state) {
+    params_client.reset();
+    params_client = std::make_shared<rclcpp::SyncParametersClient>(node, remote_node_name);
+    if (!params_client->wait_for_service()) {
+      state.SkipWithError("Client failed to become ready");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, has_parameter_hit)(benchmark::State & state)
+{
+  for (auto _ : state) {
+    if (!params_client->has_parameter(param1_name)) {
+      state.SkipWithError("Parameter was expected");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, has_parameter_miss)(benchmark::State & state)
+{
+  for (auto _ : state) {
+    if (params_client->has_parameter(param3_name)) {
+      state.SkipWithError("Parameter was not expected");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, set_parameters_bool)(benchmark::State & state)
+{
+  const std::vector<rclcpp::Parameter> param_values1
+  {
+    rclcpp::Parameter(param1_name, true),
+    rclcpp::Parameter(param2_name, false),
+  };
+  const std::vector<rclcpp::Parameter> param_values2
+  {
+    rclcpp::Parameter(param1_name, false),
+    rclcpp::Parameter(param2_name, true),
+  };
+
+  for (auto _ : state) {
+    std::vector<rcl_interfaces::msg::SetParametersResult> results =
+      params_client->set_parameters(param_values2);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+
+    results = params_client->set_parameters(param_values1);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, set_parameters_atomically_bool)(benchmark::State & state)
+{
+  const std::vector<rclcpp::Parameter> param_values1
+  {
+    rclcpp::Parameter(param1_name, true),
+    rclcpp::Parameter(param2_name, false),
+  };
+  const std::vector<rclcpp::Parameter> param_values2
+  {
+    rclcpp::Parameter(param1_name, false),
+    rclcpp::Parameter(param2_name, true),
+  };
+
+  for (auto _ : state) {
+    rcl_interfaces::msg::SetParametersResult result =
+      params_client->set_parameters_atomically(param_values2);
+    if (!result.successful) {
+      state.SkipWithError(("Failed to set parameters: " + result.reason).c_str());
+      break;
+    }
+
+    result = params_client->set_parameters_atomically(param_values1);
+    if (!result.successful) {
+      state.SkipWithError(("Failed to set parameters: " + result.reason).c_str());
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, set_parameters_string)(benchmark::State & state)
+{
+  const std::vector<rclcpp::Parameter> param_values1
+  {
+    rclcpp::Parameter(param1_name, "param 1 value A"),
+    rclcpp::Parameter(param2_name, "param 2 value B"),
+  };
+  const std::vector<rclcpp::Parameter> param_values2
+  {
+    rclcpp::Parameter(param1_name, "param 1 value B"),
+    rclcpp::Parameter(param2_name, "param 2 value A"),
+  };
+
+  for (auto _ : state) {
+    std::vector<rcl_interfaces::msg::SetParametersResult> results =
+      params_client->set_parameters(param_values2);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+
+    results = params_client->set_parameters(param_values1);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, set_parameters_array)(benchmark::State & state)
+{
+  const std::vector<rclcpp::Parameter> param_values1
+  {
+    rclcpp::Parameter(param1_name, std::vector<int> {0, 1, 2}),
+    rclcpp::Parameter(param2_name, std::vector<int> {3, 4, 5}),
+  };
+  const std::vector<rclcpp::Parameter> param_values2
+  {
+    rclcpp::Parameter(param1_name, std::vector<int> {4, 5, 6}),
+    rclcpp::Parameter(param2_name, std::vector<int> {7, 8, 9}),
+  };
+
+  for (auto _ : state) {
+    std::vector<rcl_interfaces::msg::SetParametersResult> results =
+      params_client->set_parameters(param_values2);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+
+    results = params_client->set_parameters(param_values1);
+    if (!std::all_of(results.begin(), results.end(), result_is_successful)) {
+      state.SkipWithError("Failed to set one or more parameters");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, get_parameters)(benchmark::State & state)
+{
+  for (auto _ : state) {
+    std::vector<rclcpp::Parameter> results = params_client->get_parameters({param1_name});
+    if (results.size() != 1 || results[0].get_name() != param1_name) {
+      state.SkipWithError("Got the wrong parameter(s)");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, list_parameters_hit)(benchmark::State & state)
+{
+  const std::vector<std::string> prefixes
+  {
+    param_prefix,
+  };
+
+  for (auto _ : state) {
+    rcl_interfaces::msg::ListParametersResult param_list =
+      params_client->list_parameters(prefixes, 10);
+    if (param_list.names.size() != 2) {
+      state.SkipWithError("Expected parameters");
+      break;
+    }
+  }
+}
+
+BENCHMARK_F(ParameterClientTest, list_parameters_miss)(benchmark::State & state)
+{
+  const std::vector<std::string> prefixes
+  {
+    "your_prefix",
+  };
+
+  for (auto _ : state) {
+    rcl_interfaces::msg::ListParametersResult param_list =
+      params_client->list_parameters(prefixes, 10);
+    if (param_list.names.size() != 0) {
+      state.SkipWithError("Expected no parameters");
+      break;
+    }
+  }
+}

rclcpp/test/rclcpp/CMakeLists.txt

@@ -2,7 +2,7 @@ find_package(ament_cmake_gtest REQUIRED)
 
 find_package(rmw_implementation_cmake REQUIRED)
 
-add_definitions(-DTEST_RESOURCES_DIRECTORY="${CMAKE_CURRENT_BINARY_DIR}/../resources")
+add_definitions(-DTEST_RESOURCES_DIRECTORY="${TEST_RESOURCES_DIRECTORY}")
 
 rosidl_generate_interfaces(${PROJECT_NAME}_test_msgs
   ../msg/Header.msg
@@ -323,6 +323,16 @@ if(TARGET test_parameter)
   )
   target_link_libraries(test_parameter ${PROJECT_NAME})
 endif()
+ament_add_gtest(test_parameter_event_handler test_parameter_event_handler.cpp)
+if(TARGET test_parameter_event_handler)
+  ament_target_dependencies(test_parameter_event_handler
+    "rcl_interfaces"
+    "rmw"
+    "rosidl_generator_cpp"
+    "rosidl_typesupport_cpp"
+  )
+  target_link_libraries(test_parameter_event_handler ${PROJECT_NAME})
+endif()
 ament_add_gtest(test_parameter_map test_parameter_map.cpp)
 if(TARGET test_parameter_map)
   target_link_libraries(test_parameter_map ${PROJECT_NAME})
@@ -369,6 +379,18 @@ if(TARGET test_qos_event)
     mimick
   )
 endif()
+ament_add_gmock(test_qos_overriding_options test_qos_overriding_options.cpp)
+if(TARGET test_qos_overriding_options)
+  target_link_libraries(test_qos_overriding_options
+    ${PROJECT_NAME}
+  )
+endif()
+ament_add_gmock(test_qos_parameters test_qos_parameters.cpp)
+if(TARGET test_qos_parameters)
+  target_link_libraries(test_qos_parameters
+    ${PROJECT_NAME}
+  )
+endif()
 ament_add_gtest(test_rate test_rate.cpp)
 if(TARGET test_rate)
   ament_target_dependencies(test_rate

rclcpp/test/rclcpp/allocator/test_allocator_common.cpp

@@ -23,7 +23,9 @@ TEST(TestAllocatorCommon, retyped_allocate) {
   void * untyped_allocator = &allocator;
   void * allocated_mem =
     rclcpp::allocator::retyped_allocate<std::allocator<char>>(1u, untyped_allocator);
-  ASSERT_NE(nullptr, allocated_mem);
+  // The more natural check here is ASSERT_NE(nullptr, ptr), but clang static
+  // analysis throws a false-positive memory leak warning.  Use ASSERT_TRUE instead.
+  ASSERT_TRUE(nullptr != allocated_mem);
 
   auto code = [&untyped_allocator, allocated_mem]() {
       rclcpp::allocator::retyped_deallocate<int, std::allocator<int>>(
@@ -32,11 +34,15 @@ TEST(TestAllocatorCommon, retyped_allocate) {
   EXPECT_NO_THROW(code());
 
   allocated_mem = allocator.allocate(1);
-  ASSERT_NE(nullptr, allocated_mem);
+  // The more natural check here is ASSERT_NE(nullptr, ptr), but clang static
+  // analysis throws a false-positive memory leak warning.  Use ASSERT_TRUE instead.
+  ASSERT_TRUE(nullptr != allocated_mem);
   void * reallocated_mem =
     rclcpp::allocator::retyped_reallocate<int, std::allocator<int>>(
     allocated_mem, 2u, untyped_allocator);
-  ASSERT_NE(nullptr, reallocated_mem);
+  // The more natural check here is ASSERT_NE(nullptr, ptr), but clang static
+  // analysis throws a false-positive memory leak warning.  Use ASSERT_TRUE instead.
+  ASSERT_TRUE(nullptr != reallocated_mem);
 
   auto code2 = [&untyped_allocator, reallocated_mem]() {
       rclcpp::allocator::retyped_deallocate<int, std::allocator<int>>(

rclcpp/test/rclcpp/allocator/test_allocator_deleter.cpp

@@ -38,7 +38,9 @@ TEST(TestAllocatorDeleter, construct_destruct) {
 TEST(TestAllocatorDeleter, delete) {
   std::allocator<int> allocator;
   int * some_mem = allocator.allocate(1u);
-  ASSERT_NE(nullptr, some_mem);
+  // The more natural check here is ASSERT_NE(nullptr, ptr), but clang static
+  // analysis throws a false-positive memory leak warning.  Use ASSERT_TRUE instead.
+  ASSERT_TRUE(nullptr != some_mem);
 
   rclcpp::allocator::AllocatorDeleter<std::allocator<int>> deleter(&allocator);
   EXPECT_NO_THROW(deleter(some_mem));

rclcpp/test/rclcpp/executors/test_executors.cpp

@@ -436,9 +436,16 @@ public:
     return true;
   }
 
-  void
-  execute() override
+  std::shared_ptr<void>
+  take_data() override
   {
+    return nullptr;
+  }
+
+  void
+  execute(std::shared_ptr<void> & data) override
+  {
+    (void) data;
     count_++;
     std::this_thread::sleep_for(1ms);
   }

rclcpp/test/rclcpp/executors/test_static_executor_entities_collector.cpp

@@ -235,7 +235,16 @@ public:
 
   bool is_ready(rcl_wait_set_t *) override {return true;}
 
-  void execute() override {}
+  std::shared_ptr<void>
+  take_data() override
+  {
+    return nullptr;
+  }
+  void
+  execute(std::shared_ptr<void> & data) override
+  {
+    (void) data;
+  }
 };
 
 TEST_F(TestStaticExecutorEntitiesCollector, add_remove_node_with_entities) {
@@ -363,8 +372,9 @@ TEST_F(TestStaticExecutorEntitiesCollector, prepare_wait_set_rcl_wait_set_clear_
 
   {
     auto mock = mocking_utils::patch_and_return("lib:rclcpp", rcl_wait_set_clear, RCL_RET_ERROR);
+    std::shared_ptr<void> data = entities_collector_->take_data();
     RCLCPP_EXPECT_THROW_EQ(
-      entities_collector_->execute(),
+      entities_collector_->execute(data),
       std::runtime_error("Couldn't clear wait set"));
   }
 
@@ -393,8 +403,9 @@ TEST_F(TestStaticExecutorEntitiesCollector, prepare_wait_set_rcl_wait_set_resize
 
   {
     auto mock = mocking_utils::patch_and_return("lib:rclcpp", rcl_wait_set_resize, RCL_RET_ERROR);
+    std::shared_ptr<void> data = entities_collector_->take_data();
     RCLCPP_EXPECT_THROW_EQ(
-      entities_collector_->execute(),
+      entities_collector_->execute(data),
       std::runtime_error("Couldn't resize the wait set: error not set"));
   }
 
@@ -616,7 +627,8 @@ TEST_F(
   RCLCPP_SCOPE_EXIT(entities_collector_->fini());
 
   cb_group->get_associated_with_executor_atomic().exchange(false);
-  entities_collector_->execute();
+  std::shared_ptr<void> data = entities_collector_->take_data();
+  entities_collector_->execute(data);
 
   EXPECT_TRUE(entities_collector_->remove_node(node->get_node_base_interface()));
 }

rclcpp/test/rclcpp/node_interfaces/test_node_graph.cpp

@@ -14,9 +14,11 @@
 
 #include <gtest/gtest.h>
 
+#include <functional>
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "rcl/graph.h"
 #include "rcl/node_options.h"
@@ -66,6 +68,43 @@ protected:
 
   const rclcpp::node_interfaces::NodeGraph * node_graph() const {return node_graph_;}
 
+  size_t get_num_graph_things(std::function<size_t()> predicate)
+  {
+    constexpr std::chrono::milliseconds timeout(100);
+
+    size_t tries = 0;
+    size_t num_things = 0;
+    while (tries++ < 5) {
+      num_things = predicate();
+      if (num_things >= 1) {
+        break;
+      }
+
+      auto event = node()->get_graph_event();
+      EXPECT_NO_THROW(node()->wait_for_graph_change(event, timeout));
+    }
+
+    return num_things;
+  }
+
+  size_t get_num_topics()
+  {
+    return get_num_graph_things(
+      [this]() -> size_t {
+        auto topic_names_and_types = node_graph()->get_topic_names_and_types();
+        return topic_names_and_types.size();
+      });
+  }
+
+  size_t get_num_services()
+  {
+    return get_num_graph_things(
+      [this]() -> size_t {
+        auto service_names_and_types = node_graph()->get_service_names_and_types();
+        return service_names_and_types.size();
+      });
+  }
+
 private:
   std::shared_ptr<rclcpp::Node> node_;
   rclcpp::node_interfaces::NodeGraph * node_graph_;
@@ -73,11 +112,9 @@ private:
 
 TEST_F(TestNodeGraph, construct_from_node)
 {
-  auto topic_names_and_types = node_graph()->get_topic_names_and_types(false);
-  EXPECT_LT(0u, topic_names_and_types.size());
+  EXPECT_LT(0u, get_num_topics());
 
-  auto service_names_and_types = node_graph()->get_service_names_and_types();
-  EXPECT_LT(0u, service_names_and_types.size());
+  EXPECT_LT(0u, get_num_services());
 
   auto names = node_graph()->get_node_names();
   EXPECT_EQ(1u, names.size());
@@ -91,13 +128,12 @@ TEST_F(TestNodeGraph, construct_from_node)
 
   // get_graph_event is non-const
   EXPECT_NE(nullptr, node()->get_node_graph_interface()->get_graph_event());
-  EXPECT_EQ(1u, node_graph()->count_graph_users());
+  EXPECT_LE(1u, node_graph()->count_graph_users());
 }
 
 TEST_F(TestNodeGraph, get_topic_names_and_types)
 {
-  auto topic_names_and_types = node_graph()->get_topic_names_and_types();
-  EXPECT_LT(0u, topic_names_and_types.size());
+  ASSERT_LT(0u, get_num_topics());
 }
 
 TEST_F(TestNodeGraph, get_topic_names_and_types_rcl_error)
@@ -126,8 +162,7 @@ TEST_F(TestNodeGraph, get_topic_names_and_types_rcl_names_and_types_fini_error)
 
 TEST_F(TestNodeGraph, get_service_names_and_types)
 {
-  auto service_names_and_types = node_graph()->get_service_names_and_types();
-  EXPECT_LT(0u, service_names_and_types.size());
+  ASSERT_LT(0u, get_num_services());
 }
 
 TEST_F(TestNodeGraph, get_service_names_and_types_rcl_error)
@@ -309,8 +344,13 @@ TEST_F(TestNodeGraph, get_info_by_topic)
 
   EXPECT_EQ(0u, node_graph()->get_publishers_info_by_topic("topic", true).size());
 
-  auto publishers = node_graph()->get_publishers_info_by_topic("topic", false);
-  ASSERT_EQ(1u, publishers.size());
+  std::vector<rclcpp::TopicEndpointInfo> publishers;
+  size_t num_publishers = get_num_graph_things(
+    [this, &publishers]() {
+      publishers = node_graph()->get_publishers_info_by_topic("topic", false);
+      return publishers.size();
+    });
+  ASSERT_EQ(1u, num_publishers);
 
   auto publisher_endpoint_info = publishers[0];
   const auto const_publisher_endpoint_info = publisher_endpoint_info;

rclcpp/test/rclcpp/node_interfaces/test_node_parameters.cpp

@@ -125,7 +125,7 @@ TEST_F(TestNodeParameters, parameter_overrides)
   auto * node_parameters_interface =
     dynamic_cast<rclcpp::node_interfaces::NodeParameters *>(
     node2->get_node_parameters_interface().get());
-  ASSERT_NE(nullptr, node_parameters);
+  ASSERT_NE(nullptr, node_parameters_interface);
 
   const auto & parameter_overrides = node_parameters_interface->get_parameter_overrides();
   EXPECT_EQ(2u, parameter_overrides.size());

rclcpp/test/rclcpp/node_interfaces/test_node_waitables.cpp

@@ -30,7 +30,17 @@ class TestWaitable : public rclcpp::Waitable
 public:
   bool add_to_wait_set(rcl_wait_set_t *) override {return false;}
   bool is_ready(rcl_wait_set_t *) override {return false;}
-  void execute() override {}
+
+  std::shared_ptr<void>
+  take_data() override
+  {
+    return nullptr;
+  }
+
+  void execute(std::shared_ptr<void> & data) override
+  {
+    (void) data;
+  }
 };
 
 class TestNodeWaitables : public ::testing::Test

rclcpp/test/rclcpp/strategies/test_allocator_memory_strategy.cpp

@@ -49,7 +49,16 @@ public:
     return test_waitable_result;
   }
 
-  void execute() override {}
+  std::shared_ptr<void>
+  take_data() override
+  {
+    return nullptr;
+  }
+
+  void execute(std::shared_ptr<void> & data) override
+  {
+    (void) data;
+  }
 };
 
 struct RclWaitSetSizes
@@ -502,10 +511,11 @@ TEST_F(TestAllocatorMemoryStrategy, number_of_entities_with_subscription) {
   RclWaitSetSizes expected_sizes = {};
   expected_sizes.size_of_subscriptions = 1;
   const std::string implementation_identifier = rmw_get_implementation_identifier();
+  // TODO(asorbini): Remove Connext exception once ros2/rmw_connext is deprecated.
   if (implementation_identifier == "rmw_connext_cpp" ||
     implementation_identifier == "rmw_cyclonedds_cpp")
   {
-    // For connext, a subscription will also add an event and waitable
+    // For cyclonedds, a subscription will also add an event and waitable
     expected_sizes.size_of_events += 1;
     expected_sizes.size_of_waitables += 1;
   }

rclcpp/test/rclcpp/test_add_callback_groups_to_executor.cpp

@@ -30,10 +30,6 @@
 #include "rclcpp/executor.hpp"
 #include "rclcpp/rclcpp.hpp"
 
-// Note: This is a long running test with rmw_connext_cpp, if you change this file, please check
-// that this test can complete fully, or adjust the timeout as necessary.
-// See https://github.com/ros2/rmw_connext/issues/325 for resolution]
-
 using namespace std::chrono_literals;
 
 template<typename T>

rclcpp/test/rclcpp/test_any_subscription_callback.cpp

@@ -26,7 +26,8 @@ class TestAnySubscriptionCallback : public ::testing::Test
 {
 public:
   TestAnySubscriptionCallback()
-  : any_subscription_callback_(allocator_) {}
+  : allocator_(std::make_shared<std::allocator<void>>()),
+    any_subscription_callback_(allocator_) {}
   void SetUp()
   {
     msg_shared_ptr_ = std::make_shared<test_msgs::msg::Empty>();
@@ -45,6 +46,20 @@ protected:
   rclcpp::MessageInfo message_info_;
 };
 
+void construct_with_null_allocator()
+{
+  // We need to wrap this in a function because `EXPECT_THROW` is a macro, and thinks
+  // that the comma in here splits macro arguments, not the template arguments.
+  rclcpp::AnySubscriptionCallback<
+    test_msgs::msg::Empty, std::allocator<void>> any_subscription_callback_(nullptr);
+}
+
+TEST(AnySubscription, null_allocator) {
+  EXPECT_THROW(
+    construct_with_null_allocator(),
+    std::runtime_error);
+}
+
 TEST_F(TestAnySubscriptionCallback, construct_destruct) {
 }
 

rclcpp/test/rclcpp/test_create_subscription.cpp

@@ -50,6 +50,34 @@ TEST_F(TestCreateSubscription, create) {
   EXPECT_STREQ("/ns/topic_name", subscription->get_topic_name());
 }
 
+TEST_F(TestCreateSubscription, create_with_overriding_options) {
+  auto node = std::make_shared<rclcpp::Node>("my_node", "/ns");
+  const rclcpp::QoS qos(10);
+  auto options = rclcpp::SubscriptionOptions();
+  options.qos_overriding_options = rclcpp::QosOverridingOptions::with_default_policies();
+  auto callback = [](const test_msgs::msg::Empty::SharedPtr) {};
+  auto subscription =
+    rclcpp::create_subscription<test_msgs::msg::Empty>(node, "topic_name", qos, callback, options);
+
+  ASSERT_NE(nullptr, subscription);
+  EXPECT_STREQ("/ns/topic_name", subscription->get_topic_name());
+}
+
+TEST_F(TestCreateSubscription, create_separated_node_topics_and_parameters) {
+  auto node = std::make_shared<rclcpp::Node>("my_node", "/ns");
+  const rclcpp::QoS qos(10);
+  auto options = rclcpp::SubscriptionOptions();
+  auto callback = [](const test_msgs::msg::Empty::SharedPtr) {};
+
+  auto node_parameters = node->get_node_parameters_interface();
+  auto node_topics = node->get_node_topics_interface();
+  auto subscription = rclcpp::create_subscription<test_msgs::msg::Empty>(
+    node_parameters, node_topics, "topic_name", qos, callback, options);
+
+  ASSERT_NE(nullptr, subscription);
+  EXPECT_STREQ("/ns/topic_name", subscription->get_topic_name());
+}
+
 TEST_F(TestCreateSubscription, create_with_statistics) {
   auto node = std::make_shared<rclcpp::Node>("my_node", "/ns");
   const rclcpp::QoS qos(10);

rclcpp/test/rclcpp/test_duration.cpp

@@ -148,6 +148,34 @@ TEST_F(TestDuration, from_seconds) {
     rclcpp::Duration::from_seconds(-1.5));
 }
 
+TEST_F(TestDuration, from_rmw_time) {
+  constexpr auto max_rcl_duration = std::numeric_limits<rcl_duration_value_t>::max();
+  {
+    rmw_time_t rmw_duration{};
+    rmw_duration.sec = RCL_NS_TO_S(max_rcl_duration) + 1uLL;
+    EXPECT_EQ(rclcpp::Duration::from_rmw_time(rmw_duration).nanoseconds(), max_rcl_duration);
+  }
+  {
+    rmw_time_t rmw_duration{};
+    rmw_duration.nsec = max_rcl_duration + 1uLL;
+    EXPECT_EQ(rclcpp::Duration::from_rmw_time(rmw_duration).nanoseconds(), max_rcl_duration);
+  }
+  {
+    rmw_time_t rmw_duration{};
+    rmw_duration.nsec = max_rcl_duration;
+    rmw_duration.sec = RCL_NS_TO_S(max_rcl_duration);
+    EXPECT_EQ(rclcpp::Duration::from_rmw_time(rmw_duration).nanoseconds(), max_rcl_duration);
+  }
+  {
+    rmw_time_t rmw_duration{};
+    rmw_duration.sec = 1u;
+    rmw_duration.nsec = 1000u;
+    EXPECT_EQ(
+      rclcpp::Duration::from_rmw_time(rmw_duration).nanoseconds(),
+      static_cast<rcl_duration_value_t>(RCL_S_TO_NS(rmw_duration.sec) + rmw_duration.nsec));
+  }
+}
+
 TEST_F(TestDuration, std_chrono_constructors) {
   EXPECT_EQ(rclcpp::Duration(0ns), rclcpp::Duration(0.0s));
   EXPECT_EQ(rclcpp::Duration(0ns), rclcpp::Duration(0s));

rclcpp/test/rclcpp/test_executor.cpp

@@ -21,6 +21,7 @@
 
 #include "rclcpp/executor.hpp"
 #include "rclcpp/memory_strategy.hpp"
+#include "rclcpp/executors/single_threaded_executor.hpp"
 #include "rclcpp/strategies/allocator_memory_strategy.hpp"
 
 #include "../mocking_utils/patch.hpp"
@@ -54,6 +55,7 @@ public:
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr local_get_node_by_group(
     rclcpp::CallbackGroup::SharedPtr group)
   {
+    std::lock_guard<std::mutex> guard_{mutex_};  // only to make the TSA happy
     return get_node_by_group(weak_groups_to_nodes_, group);
   }
 
@@ -87,19 +89,47 @@ MOCKING_UTILS_BOOL_OPERATOR_RETURNS_FALSE(rcutils_allocator_t, !=)
 MOCKING_UTILS_BOOL_OPERATOR_RETURNS_FALSE(rcutils_allocator_t, <)
 MOCKING_UTILS_BOOL_OPERATOR_RETURNS_FALSE(rcutils_allocator_t, >)
 
+TEST_F(TestExecutor, add_remove_node_thread_safe) {
+  using namespace std::chrono_literals;
+
+  // Create an Executor
+  rclcpp::executors::SingleThreadedExecutor executor;
+
+  auto future = std::async(std::launch::async, [&executor] {executor.spin();});
+
+  // Add and remove nodes repeatedly
+  // Test that this does not cause a segfault
+  size_t num_nodes = 100;
+  for (size_t i = 0; i < num_nodes; ++i) {
+    std::ostringstream name;
+    name << "node_" << i;
+    auto node = std::make_shared<rclcpp::Node>(name.str());
+    executor.add_node(node);
+    // Sleeping here helps exaggerate the issue
+    std::this_thread::sleep_for(std::chrono::milliseconds(1));
+    executor.remove_node(node);
+  }
+  std::future_status future_status = std::future_status::timeout;
+  do {
+    executor.cancel();
+    future_status = future.wait_for(1s);
+  } while (future_status == std::future_status::timeout);
+  EXPECT_EQ(future_status, std::future_status::ready);
+  future.get();
+}
+
 TEST_F(TestExecutor, constructor_bad_guard_condition_init) {
   auto mock = mocking_utils::patch_and_return(
     "lib:rclcpp", rcl_guard_condition_init, RCL_RET_ERROR);
-  RCLCPP_EXPECT_THROW_EQ(
-    new DummyExecutor(),
-    std::runtime_error(
-      "Failed to create interrupt guard condition in Executor constructor: error not set"));
+  EXPECT_THROW(
+    static_cast<void>(std::make_unique<DummyExecutor>()),
+    rclcpp::exceptions::RCLError);
 }
 
 TEST_F(TestExecutor, constructor_bad_wait_set_init) {
   auto mock = mocking_utils::patch_and_return("lib:rclcpp", rcl_wait_set_init, RCL_RET_ERROR);
   RCLCPP_EXPECT_THROW_EQ(
-    new DummyExecutor(),
+    static_cast<void>(std::make_unique<DummyExecutor>()),
     std::runtime_error("Failed to create wait set in Executor constructor: error not set"));
 }
 

rclcpp/test/rclcpp/test_graph_listener.cpp

@@ -143,7 +143,9 @@ TEST_F(TestGraphListener, error_run_graph_listener_destroy_context) {
   auto graph_listener_error =
     std::make_shared<TestGraphListenerProtectedMethods>(context_to_destroy);
   context_to_destroy.reset();
-  EXPECT_NO_THROW(graph_listener_error->run_protected());
+  EXPECT_THROW(
+    graph_listener_error->run_protected(),
+    rclcpp::exceptions::RCLError);
 }
 
 TEST_F(TestGraphListener, error_run_graph_listener_mock_wait_set_clear) {
@@ -170,26 +172,6 @@ TEST_F(TestGraphListener, error_run_graph_listener_mock_wait_set_add_guard_condi
     std::runtime_error("failed to add interrupt guard condition to wait set: error not set"));
 }
 
-TEST_F(TestGraphListener, error_run_graph_listener_mock_wait_set_add_guard_condition_twice) {
-  auto global_context = rclcpp::contexts::get_global_default_context();
-  auto graph_listener_test =
-    std::make_shared<TestGraphListenerProtectedMethods>(global_context);
-  graph_listener_test->mock_init_wait_set();
-  auto mock = mocking_utils::patch(
-    "lib:rclcpp", rcl_wait_set_add_guard_condition, [](auto, ...) {
-      static int counter = 1;
-      if (counter == 1) {
-        counter++;
-        return RCL_RET_OK;
-      } else {
-        return RCL_RET_ERROR;
-      }
-    });
-  RCLCPP_EXPECT_THROW_EQ(
-    graph_listener_test->run_protected(),
-    std::runtime_error("failed to add shutdown guard condition to wait set: error not set"));
-}
-
 TEST_F(TestGraphListener, error_run_graph_listener_mock_wait_error) {
   auto global_context = rclcpp::contexts::get_global_default_context();
   auto graph_listener_test =

rclcpp/test/rclcpp/test_loaned_message.cpp

@@ -67,7 +67,7 @@ TEST_F(TestLoanedMessage, release) {
   auto node = std::make_shared<rclcpp::Node>("loaned_message_test_node");
   auto pub = node->create_publisher<MessageT>("loaned_message_test_topic", 1);
 
-  MessageT * msg = nullptr;
+  std::unique_ptr<MessageT, std::function<void(MessageT *)>> msg;
   {
     auto loaned_msg = pub->borrow_loaned_message();
     ASSERT_TRUE(loaned_msg.is_valid());
@@ -81,6 +81,15 @@ TEST_F(TestLoanedMessage, release) {
 
   ASSERT_EQ(42.0f, msg->float64_value);
 
+  // Generally, the memory released from `LoanedMessage::release()` will be freed
+  // in deleter of unique_ptr or is managed in the middleware after calling
+  // `Publisher::do_loaned_message_publish` inside Publisher::publish().
+  if (pub->can_loan_messages()) {
+    ASSERT_EQ(
+      RCL_RET_OK,
+      rcl_return_loaned_message_from_publisher(pub->get_publisher_handle().get(), msg.get()));
+  }
+
   SUCCEED();
 }
 

rclcpp/test/rclcpp/test_logger.cpp

@@ -17,6 +17,8 @@
 #include <memory>
 #include <string>
 
+#include "rcutils/env.h"
+
 #include "rclcpp/logger.hpp"
 #include "rclcpp/logging.hpp"
 #include "rclcpp/node.hpp"
@@ -80,78 +82,99 @@ TEST(TestLogger, set_level) {
   rcutils_logging_set_output_handler(rcutils_logging_console_output_handler);
 
   // default
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message info", g_last_log_event.message);
 
   // unset
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Unset);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message info", g_last_log_event.message);
 
   // debug
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Debug);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message debug", g_last_log_event.message);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_EQ("message info", g_last_log_event.message);
 
   // info
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Info);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message info", g_last_log_event.message);
 
   // warn
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Warn);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_WARN(logger, std::string("message %s"), "warn");
+  RCLCPP_WARN(logger, "message %s", "warn");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message warn", g_last_log_event.message);
 
   // error
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Error);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_WARN(logger, std::string("message %s"), "warn");
+  RCLCPP_WARN(logger, "message %s", "warn");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_ERROR(logger, std::string("message %s"), "error");
+  RCLCPP_ERROR(logger, "message %s", "error");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message error", g_last_log_event.message);
 
   // fatal
   g_last_log_event.console_output_handler_called = false;
   logger.set_level(rclcpp::Logger::Level::Fatal);
-  RCLCPP_DEBUG(logger, std::string("message %s"), "debug");
+  RCLCPP_DEBUG(logger, "message %s", "debug");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_INFO(logger, std::string("message %s"), "info");
+  RCLCPP_INFO(logger, "message %s", "info");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_WARN(logger, std::string("message %s"), "warn");
+  RCLCPP_WARN(logger, "message %s", "warn");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_ERROR(logger, std::string("message %s"), "error");
+  RCLCPP_ERROR(logger, "message %s", "error");
   EXPECT_FALSE(g_last_log_event.console_output_handler_called);
-  RCLCPP_FATAL(logger, std::string("message %s"), "fatal");
+  RCLCPP_FATAL(logger, "message %s", "fatal");
   EXPECT_TRUE(g_last_log_event.console_output_handler_called);
   EXPECT_EQ("message fatal", g_last_log_event.message);
 
   rcutils_logging_set_output_handler(previous_output_handler);
   EXPECT_EQ(RCUTILS_RET_OK, rcutils_logging_shutdown());
 }
+
+TEST(TestLogger, get_logging_directory) {
+  ASSERT_EQ(true, rcutils_set_env("HOME", "/fake_home_dir"));
+  ASSERT_EQ(true, rcutils_set_env("USERPROFILE", nullptr));
+  ASSERT_EQ(true, rcutils_set_env("ROS_LOG_DIR", nullptr));
+  ASSERT_EQ(true, rcutils_set_env("ROS_HOME", nullptr));
+
+  auto path = rclcpp::get_logging_directory();
+  auto expected_path = rcpputils::fs::path{"/fake_home_dir"} / ".ros" / "log";
+
+  // TODO(ivanpauno): Add operator== to rcpputils::fs::path
+  auto it = path.cbegin();
+  auto eit = expected_path.cbegin();
+  for (; it != path.cend() && eit != expected_path.cend(); ++it, ++eit) {
+    EXPECT_EQ(*eit, *it);
+  }
+  EXPECT_EQ(it, path.cend());
+  EXPECT_EQ(eit, expected_path.cend());
+}

rclcpp/test/rclcpp/test_logging.cpp

@@ -110,26 +110,6 @@ TEST_F(TestLoggingMacros, test_logging_named) {
   EXPECT_EQ("message 3", g_last_log_event.message);
 }
 
-TEST_F(TestLoggingMacros, test_logging_string) {
-  for (std::string i : {"one", "two", "three"}) {
-    RCLCPP_DEBUG(g_logger, "message " + i);
-  }
-  EXPECT_EQ(3u, g_log_calls);
-  EXPECT_EQ("message three", g_last_log_event.message);
-
-  RCLCPP_DEBUG(g_logger, "message " "four");
-  EXPECT_EQ("message four", g_last_log_event.message);
-
-  RCLCPP_DEBUG(g_logger, std::string("message " "five"));
-  EXPECT_EQ("message five", g_last_log_event.message);
-
-  RCLCPP_DEBUG(g_logger, std::string("message %s"), "six");
-  EXPECT_EQ("message six", g_last_log_event.message);
-
-  RCLCPP_DEBUG(g_logger, "message seven");
-  EXPECT_EQ("message seven", g_last_log_event.message);
-}
-
 TEST_F(TestLoggingMacros, test_logging_stream) {
   for (std::string i : {"one", "two", "three"}) {
     RCLCPP_DEBUG_STREAM(g_logger, "message " << i);

rclcpp/test/rclcpp/test_memory_strategy.cpp

@@ -37,7 +37,8 @@ class TestWaitable : public rclcpp::Waitable
 public:
   bool add_to_wait_set(rcl_wait_set_t *) override {return true;}
   bool is_ready(rcl_wait_set_t *) override {return true;}
-  void execute() override {}
+  std::shared_ptr<void> take_data() override {return nullptr;}
+  void execute(std::shared_ptr<void> & data) override {(void)data;}
 };
 
 class TestMemoryStrategy : public ::testing::Test

rclcpp/test/rclcpp/test_node.cpp

@@ -43,6 +43,11 @@ protected:
     rclcpp::init(0, nullptr);
   }
 
+  static void TearDownTestCase()
+  {
+    rclcpp::shutdown();
+  }
+
   void SetUp() override
   {
     test_resources_path /= "test_node";
@@ -325,8 +330,11 @@ TEST_F(TestNode, declare_parameter_with_no_initial_values) {
   // test cases without initial values
   auto node = std::make_shared<rclcpp::Node>("test_declare_parameter_node"_unq);
   {
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
     // no default, no initial
-    rclcpp::ParameterValue value = node->declare_parameter("parameter"_unq);
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter"_unq, rclcpp::ParameterValue{}, descriptor);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
   }
   {
@@ -358,15 +366,21 @@ TEST_F(TestNode, declare_parameter_with_no_initial_values) {
   {
     // parameter already declared throws
     auto name = "parameter"_unq;
-    node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_THROW(
-      {node->declare_parameter(name);},
+    {
+      rcl_interfaces::msg::ParameterDescriptor descriptor;
+      descriptor.dynamic_typing = true;
+      node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
+    },
       rclcpp::exceptions::ParameterAlreadyDeclaredException);
   }
   {
     // parameter name invalid throws
     EXPECT_THROW(
-      {node->declare_parameter("");},
+      {node->declare_parameter("", 5);},
       rclcpp::exceptions::InvalidParametersException);
   }
   {
@@ -395,6 +409,46 @@ TEST_F(TestNode, declare_parameter_with_no_initial_values) {
   }
 }
 
+TEST_F(TestNode, declare_parameter_with_allow_undeclared_parameters) {
+  // test cases without initial values
+  auto node = std::make_shared<rclcpp::Node>(
+    "test_declare_parameter_node"_unq, "/",
+    rclcpp::NodeOptions{}.allow_undeclared_parameters(true));
+  {
+    // declared parameters static typing is still enforced
+    auto param_name = "parameter"_unq;
+    auto value = node->declare_parameter(param_name, 5);
+    EXPECT_EQ(value, 5);
+    EXPECT_FALSE(node->set_parameter({param_name, "asd"}).successful);
+    auto param = node->get_parameter(param_name);
+    EXPECT_EQ(param.get_type(), rclcpp::PARAMETER_INTEGER);
+    EXPECT_EQ(param.get_value<int64_t>(), 5);
+  }
+  {
+    // not for automatically declared parameters
+    auto param_name = "parameter"_unq;
+    EXPECT_TRUE(node->set_parameter({param_name, 5}).successful);
+    auto param = node->get_parameter(param_name);
+    EXPECT_EQ(param.get_type(), rclcpp::PARAMETER_INTEGER);
+    EXPECT_EQ(param.get_value<int64_t>(), 5);
+    EXPECT_TRUE(node->set_parameter({param_name, "asd"}).successful);
+    param = node->get_parameter(param_name);
+    EXPECT_EQ(param.get_type(), rclcpp::PARAMETER_STRING);
+    EXPECT_EQ(param.get_value<std::string>(), "asd");
+  }
+  {
+    // declare after set is invalid
+    auto param_name = "parameter"_unq;
+    EXPECT_TRUE(node->set_parameter({param_name, 5}).successful);
+    auto param = node->get_parameter(param_name);
+    EXPECT_EQ(param.get_type(), rclcpp::PARAMETER_INTEGER);
+    EXPECT_EQ(param.get_value<int64_t>(), 5);
+    EXPECT_THROW(
+      node->declare_parameter(param_name, 5),
+      rclcpp::exceptions::ParameterAlreadyDeclaredException);
+  }
+}
+
 auto get_fixed_on_parameter_set_callback(const std::string & name, bool successful)
 {
   return
@@ -492,13 +546,15 @@ TEST_F(TestNode, declare_parameter_with_overrides) {
   auto node = std::make_shared<rclcpp::Node>("test_declare_parameter_node"_unq, no);
   {
     // no default, with override
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_no_default");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_no_default", rclcpp::ParameterType::PARAMETER_INTEGER);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
     EXPECT_EQ(value.get<int>(), 42);
   }
   {
     // no default, with override, and set after
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_no_default_set");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_no_default_set", rclcpp::ParameterType::PARAMETER_INTEGER);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
     EXPECT_EQ(value.get<int>(), 42);
     // check that the value is changed after a set
@@ -507,8 +563,8 @@ TEST_F(TestNode, declare_parameter_with_overrides) {
   }
   {
     // no default, with override
-    const rclcpp::ParameterValue & value =
-      node->declare_parameter("parameter_no_default_set_cvref");
+    const rclcpp::ParameterValue & value = node->declare_parameter(
+      "parameter_no_default_set_cvref", rclcpp::ParameterType::PARAMETER_INTEGER);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
     EXPECT_EQ(value.get<int>(), 42);
     // check that the value is changed after a set
@@ -555,15 +611,21 @@ TEST_F(TestNode, declare_parameter_with_overrides) {
   {
     // parameter already declared throws
     auto name = "parameter_already_declared";
-    node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_THROW(
-      {node->declare_parameter(name);},
+    {
+      rcl_interfaces::msg::ParameterDescriptor descriptor;
+      descriptor.dynamic_typing = true;
+      node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
+    },
       rclcpp::exceptions::ParameterAlreadyDeclaredException);
   }
   {
     // parameter name invalid throws
     EXPECT_THROW(
-      {node->declare_parameter("");},
+      {node->declare_parameter("", 5);},
       rclcpp::exceptions::InvalidParametersException);
   }
   {
@@ -598,6 +660,22 @@ TEST_F(TestNode, declare_parameter_with_overrides) {
       {node->declare_parameter("parameter_type_mismatch", 42);},
       rclcpp::exceptions::InvalidParameterTypeException);
   }
+  {
+    // default type and expected type do not match
+    EXPECT_THROW(
+      {node->declare_parameter(
+          "parameter_type_mismatch", rclcpp::ParameterType::PARAMETER_INTEGER);},
+      rclcpp::exceptions::InvalidParameterTypeException);
+  }
+  {
+    // cannot pass an expected type and a descriptor with dynamic_typing=True
+    rcl_interfaces::msg::ParameterDescriptor descriptor{};
+    descriptor.dynamic_typing = true;
+    EXPECT_THROW(
+      {node->declare_parameter(
+          "invalid_argument", rclcpp::ParameterType::PARAMETER_INTEGER, descriptor);},
+      std::invalid_argument);
+  }
 }
 
 TEST_F(TestNode, declare_parameters_with_no_initial_values) {
@@ -668,7 +746,7 @@ TEST_F(TestNode, declare_parameters_with_no_initial_values) {
   {
     // parameter already declared throws, even with not_set type
     auto name = "parameter"_unq;
-    node->declare_parameter(name);
+    node->declare_parameter(name, 42);
     EXPECT_THROW(
       {node->declare_parameters<int64_t>("", {{name, 42}});},
       rclcpp::exceptions::ParameterAlreadyDeclaredException);
@@ -727,45 +805,53 @@ TEST_F(TestNode, declare_parameter_with_cli_overrides) {
   // To match parameters YAML file content, use a well-known node name for this test only.
   auto node = std::make_shared<rclcpp::Node>("test_declare_parameter_node", no);
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_bool");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_bool", rclcpp::ParameterType::PARAMETER_BOOL);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_BOOL);
     EXPECT_EQ(value.get<bool>(), true);
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_int");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_int", rclcpp::ParameterType::PARAMETER_INTEGER);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
     EXPECT_EQ(value.get<int64_t>(), 21);  // set to 42 in CLI, overriden by file
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_double");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_double", rclcpp::ParameterType::PARAMETER_DOUBLE);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_DOUBLE);
     EXPECT_EQ(value.get<double>(), 0.42);
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_string");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_string", rclcpp::ParameterType::PARAMETER_STRING);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_STRING);
     EXPECT_EQ(value.get<std::string>(), "foo");
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_bool_array");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_bool_array", rclcpp::ParameterType::PARAMETER_BOOL_ARRAY);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_BOOL_ARRAY);
     std::vector<bool> expected_value{false, true};
     EXPECT_EQ(value.get<std::vector<bool>>(), expected_value);
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_int_array");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_int_array", rclcpp::ParameterType::PARAMETER_INTEGER_ARRAY);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER_ARRAY);
     std::vector<int64_t> expected_value{-21, 42};
     EXPECT_EQ(value.get<std::vector<int64_t>>(), expected_value);
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_double_array");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_double_array", rclcpp::ParameterType::PARAMETER_DOUBLE_ARRAY);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_DOUBLE_ARRAY);
     std::vector<double> expected_value{-1.0, 0.42};
     EXPECT_EQ(value.get<std::vector<double>>(), expected_value);
   }
   {
-    rclcpp::ParameterValue value = node->declare_parameter("parameter_string_array");
+    rclcpp::ParameterValue value = node->declare_parameter(
+      "parameter_string_array", rclcpp::ParameterType::PARAMETER_STRING_ARRAY);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_STRING_ARRAY);
     std::vector<std::string> expected_value{"foo", "bar"};
     // set to [baz, baz, baz] in file, overriden by CLI
@@ -778,7 +864,9 @@ TEST_F(TestNode, undeclare_parameter) {
   {
     // normal use
     auto name = "parameter"_unq;
-    node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_TRUE(node->has_parameter(name));
     node->undeclare_parameter(name);
     EXPECT_FALSE(node->has_parameter(name));
@@ -791,6 +879,16 @@ TEST_F(TestNode, undeclare_parameter) {
       {node->undeclare_parameter(name);},
       rclcpp::exceptions::ParameterNotDeclaredException);
   }
+  {
+    // statically typed parameter throws
+    auto name = "parameter"_unq;
+    node->declare_parameter(name, 42);
+    EXPECT_TRUE(node->has_parameter(name));
+    EXPECT_THROW(
+      {node->undeclare_parameter(name);},
+      rclcpp::exceptions::InvalidParameterTypeException);
+    EXPECT_TRUE(node->has_parameter(name));
+  }
   {
     // read only parameter throws
     auto name = "parameter"_unq;
@@ -810,7 +908,9 @@ TEST_F(TestNode, has_parameter) {
   // normal use
   auto name = "parameter"_unq;
   EXPECT_FALSE(node->has_parameter(name));
-  node->declare_parameter(name);
+  rcl_interfaces::msg::ParameterDescriptor descriptor;
+  descriptor.dynamic_typing = true;
+  node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
   EXPECT_TRUE(node->has_parameter(name));
   node->undeclare_parameter(name);
   EXPECT_FALSE(node->has_parameter(name));
@@ -821,7 +921,9 @@ TEST_F(TestNode, list_parameters) {
   // normal use
   auto name = "parameter"_unq;
   const size_t before_size = node->list_parameters({}, 1u).names.size();
-  node->declare_parameter(name);
+  rcl_interfaces::msg::ParameterDescriptor descriptor;
+  descriptor.dynamic_typing = true;
+  node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
   EXPECT_EQ(1u + before_size, node->list_parameters({}, 1u).names.size());
   node->undeclare_parameter(name);
   EXPECT_EQ(before_size, node->list_parameters({}, 1u).names.size());
@@ -842,12 +944,23 @@ TEST_F(TestNode, set_parameter_undeclared_parameters_not_allowed) {
     EXPECT_EQ(node->get_parameter(name).get_value<int>(), 43);
   }
   {
-    // normal use, change type
+    // normal use, change type not allowed
     auto name = "parameter"_unq;
     EXPECT_FALSE(node->has_parameter(name));
     node->declare_parameter(name, 42);
     EXPECT_TRUE(node->has_parameter(name));
     EXPECT_EQ(node->get_parameter(name).get_value<int>(), 42);
+    EXPECT_FALSE(node->set_parameter(rclcpp::Parameter(name, "not an integer")).successful);
+  }
+  {
+    // normal use, change type
+    auto name = "parameter"_unq;
+    EXPECT_FALSE(node->has_parameter(name));
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, 42, descriptor);
+    EXPECT_TRUE(node->has_parameter(name));
+    EXPECT_EQ(node->get_parameter(name).get_value<int>(), 42);
     EXPECT_TRUE(node->set_parameter(rclcpp::Parameter(name, "not an integer")).successful);
     EXPECT_EQ(node->get_parameter(name).get_value<std::string>(), std::string("not an integer"));
   }
@@ -864,8 +977,6 @@ TEST_F(TestNode, set_parameter_undeclared_parameters_not_allowed) {
     EXPECT_TRUE(node->has_parameter(name3));
 
     EXPECT_EQ(node->get_parameter(name1).get_value<int>(), 42);
-    EXPECT_TRUE(node->set_parameter(rclcpp::Parameter(name1, "not an integer")).successful);
-    EXPECT_EQ(node->get_parameter(name1).get_value<std::string>(), std::string("not an integer"));
 
     EXPECT_EQ(node->get_parameter(name2).get_value<bool>(), true);
     EXPECT_TRUE(node->set_parameter(rclcpp::Parameter(name2, false)).successful);
@@ -900,7 +1011,9 @@ TEST_F(TestNode, set_parameter_undeclared_parameters_not_allowed) {
   {
     // setting type of rclcpp::PARAMETER_NOT_SET, when already not set, does not undeclare
     auto name = "parameter"_unq;
-    auto value = node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    auto value = node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_TRUE(node->has_parameter(name));
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
 
@@ -910,13 +1023,26 @@ TEST_F(TestNode, set_parameter_undeclared_parameters_not_allowed) {
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
   }
   {
-    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will undeclare
+    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will fail
     auto name = "parameter"_unq;
     node->declare_parameter(name, 42);
     EXPECT_TRUE(node->has_parameter(name));
     auto value = node->get_parameter(name);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
 
+    EXPECT_FALSE(node->set_parameter(rclcpp::Parameter(name)).successful);
+  }
+  {
+    // setting type of rclcpp::PARAMETER_NOT_SET,
+    // when dynamic typing is allowing and already set to another type, will undeclare
+    auto name = "parameter"_unq;
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, 42, descriptor);
+    EXPECT_TRUE(node->has_parameter(name));
+    auto value = node->get_parameter(name);
+    EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
+
     EXPECT_TRUE(node->set_parameter(rclcpp::Parameter(name)).successful);
 
     EXPECT_FALSE(node->has_parameter(name));
@@ -1256,15 +1382,9 @@ TEST_F(TestNode, set_parameter_undeclared_parameters_not_allowed) {
     auto name = "parameter"_unq;
     rcl_interfaces::msg::ParameterDescriptor descriptor;
     descriptor.type = rclcpp::PARAMETER_INTEGER;
-    node->declare_parameter(name, 42, descriptor);
+    node->declare_parameter(name, "asd", descriptor);
     EXPECT_TRUE(node->has_parameter(name));
     auto value = node->get_parameter(name);
-    EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
-    EXPECT_EQ(value.get_value<int64_t>(), 42);
-
-    EXPECT_TRUE(node->set_parameter(rclcpp::Parameter(name, "asd")).successful);
-    EXPECT_TRUE(node->has_parameter(name));
-    value = node->get_parameter(name);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_STRING);
     EXPECT_EQ(value.get_value<std::string>(), "asd");
   }
@@ -1412,7 +1532,9 @@ TEST_F(TestNode, set_parameters_undeclared_parameters_not_allowed) {
   {
     // setting type of rclcpp::PARAMETER_NOT_SET, when already not set, does not undeclare
     auto name = "parameter"_unq;
-    auto value = node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    auto value = node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_TRUE(node->has_parameter(name));
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
 
@@ -1422,13 +1544,26 @@ TEST_F(TestNode, set_parameters_undeclared_parameters_not_allowed) {
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
   }
   {
-    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will undeclare
+    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will fail
     auto name = "parameter"_unq;
     node->declare_parameter(name, 42);
     EXPECT_TRUE(node->has_parameter(name));
     auto value = node->get_parameter(name);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
 
+    EXPECT_FALSE(node->set_parameters({rclcpp::Parameter(name)})[0].successful);
+  }
+  {
+    // setting type of rclcpp::PARAMETER_NOT_SET,
+    // when already to another type and dynamic typic allowed, will undeclare
+    auto name = "parameter"_unq;
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, 42, descriptor);
+    EXPECT_TRUE(node->has_parameter(name));
+    auto value = node->get_parameter(name);
+    EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
+
     EXPECT_TRUE(node->set_parameters({rclcpp::Parameter(name)})[0].successful);
 
     EXPECT_FALSE(node->has_parameter(name));
@@ -1586,7 +1721,9 @@ TEST_F(TestNode, set_parameters_atomically_undeclared_parameters_not_allowed) {
   {
     // setting type of rclcpp::PARAMETER_NOT_SET, when already not set, does not undeclare
     auto name = "parameter"_unq;
-    auto value = node->declare_parameter(name);
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    auto value = node->declare_parameter(name, rclcpp::ParameterValue{}, descriptor);
     EXPECT_TRUE(node->has_parameter(name));
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
 
@@ -1596,13 +1733,26 @@ TEST_F(TestNode, set_parameters_atomically_undeclared_parameters_not_allowed) {
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_NOT_SET);
   }
   {
-    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will undeclare
+    // setting type of rclcpp::PARAMETER_NOT_SET, when already to another type, will fail
     auto name = "parameter"_unq;
     node->declare_parameter(name, 42);
     EXPECT_TRUE(node->has_parameter(name));
     auto value = node->get_parameter(name);
     EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
 
+    EXPECT_FALSE(node->set_parameters_atomically({rclcpp::Parameter(name)}).successful);
+  }
+  {
+    // setting type of rclcpp::PARAMETER_NOT_SET,
+    // when dynamic typing is allowed and already declared to another type, will undeclare
+    auto name = "parameter"_unq;
+    rcl_interfaces::msg::ParameterDescriptor descriptor;
+    descriptor.dynamic_typing = true;
+    node->declare_parameter(name, 42, descriptor);
+    EXPECT_TRUE(node->has_parameter(name));
+    auto value = node->get_parameter(name);
+    EXPECT_EQ(value.get_type(), rclcpp::PARAMETER_INTEGER);
+
     EXPECT_TRUE(node->set_parameters_atomically({rclcpp::Parameter(name)}).successful);
 
     EXPECT_FALSE(node->has_parameter(name));
@@ -1958,30 +2108,28 @@ TEST_F(TestNode, get_parameters_undeclared_parameters_not_allowed) {
   {
     // templated version with empty prefix will get all parameters
     auto node_local = std::make_shared<rclcpp::Node>("test_get_parameters_node"_unq);
-    auto name1 = "prefix1.parameter"_unq;
-    auto name2 = "prefix2.parameter"_unq;
+    auto name1 = "parameter"_unq;
+    auto name2 = "parameter"_unq;
 
-    node_local->declare_parameter(name1, 42);
-    node_local->declare_parameter(name2, 100);
-    // undeclare so that it doesn't interfere with the test
-    node_local->undeclare_parameter("use_sim_time");
+    node_local->declare_parameter("prefix." + name1, 42);
+    node_local->declare_parameter("prefix." + name2, 100);
 
     {
       std::map<std::string, int64_t> actual;
-      EXPECT_TRUE(node_local->get_parameters("", actual));
+      EXPECT_TRUE(node_local->get_parameters("prefix", actual));
       EXPECT_NE(actual.find(name1), actual.end());
       EXPECT_NE(actual.find(name2), actual.end());
     }
 
     // will throw if set of parameters is non-homogeneous
-    auto name3 = "prefix2.parameter"_unq;
-    node_local->declare_parameter<std::string>(name3, "not an int");
+    auto name3 = "prefix1.parameter"_unq;
+    node_local->declare_parameter<std::string>("prefix." + name3, "not an int");
 
     {
       std::map<std::string, int64_t> actual;
       EXPECT_THROW(
       {
-        node_local->get_parameters("", actual);
+        node_local->get_parameters("prefix", actual);
       },
         rclcpp::exceptions::InvalidParameterTypeException);
     }
@@ -2410,7 +2558,7 @@ TEST_F(TestNode, get_publishers_subscriptions_info_by_topic) {
   auto publisher = node->create_publisher<test_msgs::msg::BasicTypes>(topic_name, qos);
   // List should have one item
   auto publisher_list = node->get_publishers_info_by_topic(fq_topic_name);
-  EXPECT_EQ(publisher_list.size(), (size_t)1);
+  ASSERT_EQ(publisher_list.size(), (size_t)1);
   // Subscription list should be empty
   EXPECT_TRUE(node->get_subscriptions_info_by_topic(fq_topic_name).empty());
   // Verify publisher list has the right data.
@@ -2572,3 +2720,76 @@ TEST_F(TestNode, create_sub_node_rmw_validate_namespace_error) {
       rclcpp::exceptions::RCLError);
   }
 }
+
+TEST_F(TestNode, static_and_dynamic_typing) {
+  rclcpp::NodeOptions no;
+  no.parameter_overrides(
+  {
+    {"integer_parameter_override_ok", 43},
+    {"string_parameter_override_should_throw", 43},
+    {"integer_must_provide_override", 43},
+    {"cool_way_of_declaring_a_string_without_a_default", "hello!"}
+  });
+  auto node = std::make_shared<rclcpp::Node>("node", "ns", no);
+  {
+    auto param = node->declare_parameter("an_int", 42);
+    EXPECT_EQ(42, param);
+    auto result = node->set_parameter({"an_int", "string value"});
+    EXPECT_FALSE(result.successful);
+    result = node->set_parameter({"an_int", 43});
+    EXPECT_TRUE(result.successful);
+    EXPECT_TRUE(node->get_parameter("an_int", param));
+    EXPECT_EQ(43, param);
+  }
+  {
+    auto param = node->declare_parameter("integer_parameter_override_ok", 42);
+    EXPECT_EQ(43, param);
+  }
+  {
+    EXPECT_THROW(
+      node->declare_parameter("string_parameter_override_should_throw", "a string"),
+      rclcpp::exceptions::InvalidParameterTypeException);
+  }
+  {
+    auto param = node->declare_parameter(
+      "integer_must_provide_override", rclcpp::PARAMETER_INTEGER);
+    EXPECT_EQ(43, param.get<int64_t>());
+  }
+  {
+    auto param = node->declare_parameter<std::string>(
+      "cool_way_of_declaring_a_string_without_a_default");
+    EXPECT_EQ("hello!", param);
+  }
+  {
+    EXPECT_THROW(
+      node->declare_parameter("integer_override_not_given", rclcpp::PARAMETER_INTEGER),
+      rclcpp::exceptions::NoParameterOverrideProvided);
+  }
+  {
+    EXPECT_THROW(
+      node->declare_parameter("parameter_not_set_is_not_a_valid_type", rclcpp::PARAMETER_NOT_SET),
+      std::invalid_argument);
+  }
+  {
+    EXPECT_THROW(
+      node->declare_parameter(
+        "uninitialized_not_valid_except_dynamic_typing", rclcpp::ParameterValue{}),
+      rclcpp::exceptions::InvalidParameterTypeException);
+  }
+  {
+#ifndef _WIN32
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wdeprecated-declarations"
+#else
+# pragma warning(push)
+# pragma warning(disable: 4996)
+#endif
+    auto param = node->declare_parameter("deprecated_way_dynamic_typing");
+    EXPECT_EQ(param, rclcpp::ParameterValue{});
+#ifndef _WIN32
+# pragma GCC diagnostic pop
+#else
+# pragma warning(pop)
+#endif
+  }
+}

rclcpp/test/rclcpp/test_parameter_client.cpp

@@ -28,6 +28,8 @@
 
 #include "rcl_interfaces/msg/parameter_event.hpp"
 
+using namespace std::chrono_literals;
+
 class TestParameterClient : public ::testing::Test
 {
 public:
@@ -45,14 +47,20 @@ protected:
   void SetUp()
   {
     node = std::make_shared<rclcpp::Node>("test_parameter_client", "/ns");
+    node_with_option =
+      std::make_shared<rclcpp::Node>(
+      "test_parameter_client_allow_undeclare", "/ns",
+      rclcpp::NodeOptions().allow_undeclared_parameters(true));
   }
 
   void TearDown()
   {
     node.reset();
+    node_with_option.reset();
   }
 
   rclcpp::Node::SharedPtr node;
+  rclcpp::Node::SharedPtr node_with_option;
 };
 
 /*
@@ -287,7 +295,337 @@ TEST_F(TestParameterClient, sync_parameter_get_parameter_types) {
   auto synchronous_client = std::make_shared<rclcpp::SyncParametersClient>(node);
   std::vector<std::string> names{"foo"};
   std::vector<rclcpp::ParameterType> parameter_types =
-    synchronous_client->get_parameter_types(names);
+    synchronous_client->get_parameter_types(names, 10s);
   ASSERT_EQ(1u, parameter_types.size());
   ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
 }
+
+/*
+  Coverage for async describe_parameters
+ */
+TEST_F(TestParameterClient, async_parameter_describe_parameters) {
+  node->declare_parameter("foo", 4);
+  node->declare_parameter("bar", "this is bar");
+  auto asynchronous_client = std::make_shared<rclcpp::AsyncParametersClient>(node);
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        // We expect the result to be empty since we tried to get a parameter that didn't exist.
+        if (result.valid() && result.get().size() == 0) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"none"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        if (result.valid() && result.get().size() == 1) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"foo"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs = future.get();
+    ASSERT_EQ(1u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        // We expect the result to be empty since we tried to get a parameter that didn't exist.
+        if (result.valid() && result.get().size() == 0) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"foo", "baz"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        // We expect the result to be empty since we tried to get a parameter that didn't exist.
+        if (result.valid() && result.get().size() == 0) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"baz", "foo"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        if (result.valid() && result.get().size() == 2) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"foo", "bar"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs = future.get();
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("bar", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+    ASSERT_TRUE(callback_called);
+  }
+}
+/*
+  Coverage for sync describe_parameters
+ */
+TEST_F(TestParameterClient, sync_parameter_describe_parameters) {
+  node->declare_parameter("foo", 4);
+  node->declare_parameter("bar", "this is bar");
+  auto synchronous_client = std::make_shared<rclcpp::SyncParametersClient>(node);
+
+  {
+    std::vector<std::string> names{"none"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(0u, parameter_descs.size());
+  }
+
+  {
+    std::vector<std::string> names{"foo"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(1u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+  }
+
+  {
+    std::vector<std::string> names{"foo", "baz"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(0u, parameter_descs.size());
+  }
+
+  {
+    std::vector<std::string> names{"baz", "foo"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(0u, parameter_descs.size());
+  }
+
+  {
+    std::vector<std::string> names{"foo", "bar"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("bar", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+  }
+}
+
+/*
+  Coverage for async describe_parameters with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, async_parameter_describe_parameters_allow_undeclared) {
+  node_with_option->declare_parameter("foo", 4);
+  node_with_option->declare_parameter("bar", "this is bar");
+  auto asynchronous_client =
+    std::make_shared<rclcpp::AsyncParametersClient>(node_with_option);
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        // We expect the result to be defaut since we tried to get a parameter that didn't exist.
+        if (result.valid() && result.get().size() == 1) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"none"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node_with_option, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs = future.get();
+    ASSERT_EQ(1u, parameter_descs.size());
+    ASSERT_EQ("none", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        if (result.valid() && result.get().size() == 2) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"foo", "baz"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node_with_option, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs = future.get();
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("baz", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+    ASSERT_TRUE(callback_called);
+  }
+
+  {
+    bool callback_called = false;
+    auto callback = [&callback_called](
+      std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> result)
+      {
+        if (result.valid() && result.get().size() == 2) {
+          callback_called = true;
+        }
+      };
+    std::vector<std::string> names{"baz", "foo"};
+    std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>> future =
+      asynchronous_client->describe_parameters(names, callback);
+    auto return_code = rclcpp::spin_until_future_complete(
+      node_with_option, future, std::chrono::milliseconds(100));
+    ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs = future.get();
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("baz", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("foo", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+    ASSERT_TRUE(callback_called);
+  }
+}
+/*
+  Coverage for sync describe_parameters with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, sync_parameter_describe_parameters_allow_undeclared) {
+  node_with_option->declare_parameter("foo", 4);
+  node_with_option->declare_parameter("bar", "this is bar");
+  auto synchronous_client =
+    std::make_shared<rclcpp::SyncParametersClient>(node_with_option);
+
+  {
+    std::vector<std::string> names{"none"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(1u, parameter_descs.size());
+    ASSERT_EQ("none", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+  }
+
+  {
+    std::vector<std::string> names{"foo", "baz"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("foo", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("baz", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+  }
+
+  {
+    std::vector<std::string> names{"baz", "foo"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      synchronous_client->describe_parameters(names, 10s);
+    ASSERT_EQ(2u, parameter_descs.size());
+    ASSERT_EQ("baz", parameter_descs[0].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_descs[0].type);
+    ASSERT_EQ("", parameter_descs[0].description);
+    ASSERT_EQ("", parameter_descs[0].additional_constraints);
+    ASSERT_FALSE(parameter_descs[0].read_only);
+    ASSERT_EQ("foo", parameter_descs[1].name);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[1].type);
+    ASSERT_EQ("", parameter_descs[1].description);
+    ASSERT_EQ("", parameter_descs[1].additional_constraints);
+    ASSERT_FALSE(parameter_descs[1].read_only);
+  }
+}

rclcpp/test/rclcpp/test_parameter_event_handler.cpp

@@ -0,0 +1,432 @@
+// Copyright 2019 Intel Corporation
+//
+// 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 <chrono>
+#include <memory>
+#include <string>
+#include <thread>
+
+#include "gtest/gtest.h"
+#include "rclcpp/rclcpp.hpp"
+
+class TestParameterEventHandler : public rclcpp::ParameterEventHandler
+{
+public:
+  explicit TestParameterEventHandler(rclcpp::Node::SharedPtr node)
+  : ParameterEventHandler(node)
+  {}
+
+  void test_event(const rcl_interfaces::msg::ParameterEvent::SharedPtr event)
+  {
+    event_callback(event);
+  }
+
+  size_t num_event_callbacks()
+  {
+    return event_callbacks_.size();
+  }
+
+  size_t num_parameter_callbacks()
+  {
+    return parameter_callbacks_.size();
+  }
+};
+
+class TestNode : public ::testing::Test
+{
+protected:
+  static void SetUpTestCase()
+  {
+    rclcpp::init(0, nullptr);
+  }
+
+  void SetUp()
+  {
+    rclcpp::NodeOptions options;
+    node = std::make_shared<rclcpp::Node>(
+      "test_parameter_events_subscriber", options);
+
+    remote_node_name = "/remote_node";
+    diff_ns_name = "/ns/remote_node";
+
+    param_handler = std::make_shared<TestParameterEventHandler>(node);
+
+    same_node_int = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+    same_node_double = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+    multiple = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+    remote_node_string = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+    diff_ns_bool = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+    diff_node_int = std::make_shared<rcl_interfaces::msg::ParameterEvent>();
+
+    same_node_int->node = node->get_fully_qualified_name();
+    same_node_double->node = node->get_fully_qualified_name();
+    multiple->node = node->get_fully_qualified_name();
+    remote_node_string->node = remote_node_name;
+    diff_ns_bool->node = diff_ns_name;
+    diff_node_int->node = remote_node_name;
+
+    rcl_interfaces::msg::Parameter p;
+    p.name = "my_int";
+    p.value.type = rcl_interfaces::msg::ParameterType::PARAMETER_INTEGER;
+    p.value.integer_value = 1;
+    same_node_int->changed_parameters.push_back(p);
+    diff_node_int->changed_parameters.push_back(p);
+    multiple->changed_parameters.push_back(p);
+
+    p.name = "my_double";
+    p.value.type = rcl_interfaces::msg::ParameterType::PARAMETER_DOUBLE;
+    p.value.double_value = 1.0;
+    same_node_double->changed_parameters.push_back(p);
+    multiple->changed_parameters.push_back(p);
+
+    p.name = "my_string";
+    p.value.type = rcl_interfaces::msg::ParameterType::PARAMETER_STRING;
+    p.value.string_value = "test";
+    remote_node_string->changed_parameters.push_back(p);
+
+    p.name = "my_bool";
+    p.value.type = rcl_interfaces::msg::ParameterType::PARAMETER_BOOL;
+    p.value.bool_value = true;
+    diff_ns_bool->changed_parameters.push_back(p);
+  }
+
+  void TearDown()
+  {
+    node.reset();
+    param_handler.reset();
+  }
+
+  rcl_interfaces::msg::ParameterEvent::SharedPtr same_node_int;
+  rcl_interfaces::msg::ParameterEvent::SharedPtr same_node_double;
+  rcl_interfaces::msg::ParameterEvent::SharedPtr diff_node_int;
+  rcl_interfaces::msg::ParameterEvent::SharedPtr remote_node_string;
+  rcl_interfaces::msg::ParameterEvent::SharedPtr multiple;
+  rcl_interfaces::msg::ParameterEvent::SharedPtr diff_ns_bool;
+
+  rclcpp::Node::SharedPtr node;
+  std::string remote_node_name;
+  std::string diff_ns_name;
+  std::shared_ptr<TestParameterEventHandler> param_handler;
+};
+
+TEST_F(TestNode, RegisterParameterCallback)
+{
+  bool received;
+  auto cb = [&received](const rclcpp::Parameter &) {received = true;};
+
+  auto h1 = param_handler->add_parameter_callback("my_double", cb);
+  auto h2 = param_handler->add_parameter_callback("my_int", cb);
+  auto h3 = param_handler->add_parameter_callback("my_string", cb, remote_node_name);
+  auto h4 = param_handler->add_parameter_callback("my_bool", cb, diff_ns_name);
+
+  received = false;
+  param_handler->test_event(same_node_double);
+  EXPECT_EQ(received, true);
+
+  received = false;
+  param_handler->test_event(same_node_int);
+  EXPECT_EQ(received, true);
+
+  received = false;
+  param_handler->test_event(remote_node_string);
+  EXPECT_EQ(received, true);
+
+  received = false;
+  param_handler->test_event(diff_ns_bool);
+  EXPECT_EQ(received, true);
+}
+
+TEST_F(TestNode, SameParameterDifferentNode)
+{
+  int64_t int_param_node1;
+  int64_t int_param_node2;
+
+  auto cb1 = [&int_param_node1](const rclcpp::Parameter & p) {
+      int_param_node1 = p.get_value<int64_t>();
+    };
+  auto cb2 = [&int_param_node2](const rclcpp::Parameter & p) {
+      int_param_node2 = p.get_value<int64_t>();
+    };
+
+  // Set individual parameters
+  auto h1 = param_handler->add_parameter_callback("my_int", cb1);
+  auto h2 = param_handler->add_parameter_callback("my_int", cb2, remote_node_name);
+
+  param_handler->test_event(same_node_int);
+  EXPECT_EQ(int_param_node1, 1);
+  EXPECT_NE(int_param_node2, 1);
+
+  int_param_node1 = 0;
+  int_param_node2 = 0;
+
+  param_handler->test_event(diff_node_int);
+  EXPECT_NE(int_param_node1, 1);
+  EXPECT_EQ(int_param_node2, 1);
+
+  param_handler->remove_parameter_callback(h1);
+  param_handler->remove_parameter_callback(h2);
+  EXPECT_EQ(param_handler->num_parameter_callbacks(), 0UL);
+}
+
+TEST_F(TestNode, GetParameterFromEvent)
+{
+  using rclcpp::ParameterEventHandler;
+  std::string node_name = node->get_fully_qualified_name();
+  std::string wrong_name = "/wrong_node_name";
+
+  rclcpp::Parameter p;
+  EXPECT_TRUE(
+    ParameterEventHandler::get_parameter_from_event(*multiple, p, "my_int", node_name));
+  EXPECT_EQ(p.get_value<int>(), 1);
+  // False if parameter not with correct node name
+  EXPECT_FALSE(
+    ParameterEventHandler::get_parameter_from_event(*multiple, p, "my_int", wrong_name));
+  // False if parameter not part of event
+  EXPECT_FALSE(
+    ParameterEventHandler::get_parameter_from_event(*diff_ns_bool, p, "my_int", node_name));
+
+  EXPECT_NO_THROW(
+    ParameterEventHandler::get_parameter_from_event(*multiple, "my_int", node_name));
+  // Throws if parameter not with correct node name
+  EXPECT_THROW(
+    ParameterEventHandler::get_parameter_from_event(*multiple, "my_int", wrong_name),
+    std::runtime_error);
+  // Throws if parameter not part of event
+  EXPECT_THROW(
+    ParameterEventHandler::get_parameter_from_event(*diff_ns_bool, "my_int", node_name),
+    std::runtime_error);
+}
+
+TEST_F(TestNode, GetParametersFromEvent)
+{
+  using rclcpp::ParameterEventHandler;
+  std::string node_name = node->get_fully_qualified_name();
+
+  auto params = ParameterEventHandler::get_parameters_from_event(*multiple);
+  EXPECT_EQ(params.size(), 2u);
+  bool found_int = false;
+  bool found_double = false;
+  for (auto & p : params) {
+    if (p.get_name() == std::string("my_int")) {
+      found_int = true;
+      EXPECT_EQ(p.get_value<int>(), 1);
+    } else if (p.get_name() == std::string("my_double")) {
+      found_double = true;
+      EXPECT_EQ(p.get_value<double>(), 1.0);
+    }
+  }
+  EXPECT_EQ(found_int, true);
+  EXPECT_EQ(found_double, true);
+
+  params = ParameterEventHandler::get_parameters_from_event(*remote_node_string);
+  EXPECT_EQ(params.size(), 1u);
+  bool found_string = false;
+  for (auto & p : params) {
+    if (p.get_name() == std::string("my_string")) {
+      found_string = true;
+      EXPECT_EQ(p.get_value<std::string>(), std::string("test"));
+    }
+  }
+  EXPECT_EQ(found_string, true);
+
+  params = ParameterEventHandler::get_parameters_from_event(*diff_ns_bool);
+  EXPECT_EQ(params.size(), 1u);
+  bool found_bool = false;
+  for (auto & p : params) {
+    if (p.get_name() == std::string("my_bool")) {
+      found_bool = true;
+      EXPECT_EQ(p.get_value<bool>(), true);
+    }
+  }
+  EXPECT_EQ(found_bool, true);
+}
+
+TEST_F(TestNode, EventCallback)
+{
+  using rclcpp::ParameterEventHandler;
+
+  double double_param = 0.0;
+  int64_t int_param = 0;
+  bool bool_param{false};
+  bool received{false};
+
+  double product;
+  auto cb =
+    [&int_param, &double_param, &product, &received,
+      this](const rcl_interfaces::msg::ParameterEvent::SharedPtr & event)
+    {
+      auto node_name = node->get_fully_qualified_name();
+
+      if (event->node == node_name) {
+        received = true;
+      }
+
+      rclcpp::Parameter p;
+      if (ParameterEventHandler::get_parameter_from_event(*event, p, "my_int", node_name)) {
+        int_param = p.get_value<int64_t>();
+      }
+      try {
+        p = ParameterEventHandler::get_parameter_from_event(*event, "my_double", node_name);
+        double_param = p.get_value<double>();
+      } catch (...) {
+      }
+
+      product = static_cast<double>(int_param) * double_param;
+    };
+
+  auto cb2 =
+    [&bool_param, this](const rcl_interfaces::msg::ParameterEvent::SharedPtr & event)
+    {
+      rclcpp::Parameter p;
+      if (event->node == diff_ns_name) {
+        if (ParameterEventHandler::get_parameter_from_event(
+            *event, p, "my_bool", diff_ns_name))
+        {
+          bool_param = p.get_value<bool>();
+        }
+      }
+    };
+
+  auto event_handle1 = param_handler->add_parameter_event_callback(cb);
+  auto event_handle2 = param_handler->add_parameter_event_callback(cb2);
+
+  bool_param = false;
+  param_handler->test_event(multiple);
+  EXPECT_EQ(received, true);
+  EXPECT_EQ(product, 1.0);
+  EXPECT_EQ(bool_param, false);
+
+  param_handler->test_event(diff_ns_bool);
+  EXPECT_EQ(bool_param, true);
+
+  // Test removal of event callback
+  received = false;
+  bool_param = false;
+  param_handler->remove_parameter_event_callback(event_handle1);
+  param_handler->test_event(multiple);
+  param_handler->test_event(diff_ns_bool);
+  EXPECT_EQ(received, false);
+  EXPECT_EQ(bool_param, true);
+
+  // Should throw if callback handle no longer exists or already removed
+  EXPECT_THROW(
+    param_handler->remove_parameter_event_callback(event_handle1), std::runtime_error);
+}
+
+TEST_F(TestNode, MultipleParameterCallbacks)
+{
+  bool received_1{false};
+  bool received_2{false};
+
+  auto cb1 = [&received_1](const rclcpp::Parameter &) {received_1 = true;};
+  auto cb2 = [&received_2](const rclcpp::Parameter &) {received_2 = true;};
+  auto cb3 = [](const rclcpp::Parameter &) { /*do nothing*/};
+
+  auto h1 = param_handler->add_parameter_callback("my_int", cb1);
+  auto h2 = param_handler->add_parameter_callback("my_int", cb2);
+  auto h3 = param_handler->add_parameter_callback("my_double", cb3);
+
+  // Test multiple callbacks per parameter
+  param_handler->test_event(same_node_int);
+  EXPECT_EQ(received_1, true);
+  EXPECT_EQ(received_2, true);
+
+  // Test removal of parameter callback by callback handle
+  received_1 = false;
+  received_2 = false;
+  param_handler->remove_parameter_callback(h1);
+  param_handler->test_event(same_node_int);
+  EXPECT_EQ(received_1, false);
+  EXPECT_EQ(received_2, true);
+
+  // Test removal of parameter callback by name
+  received_2 = false;
+  param_handler->remove_parameter_callback(h2);
+  param_handler->test_event(same_node_int);
+  EXPECT_EQ(received_2, false);
+
+  // Should throw if callback handle no longer exists or already removed
+  EXPECT_THROW(param_handler->remove_parameter_callback(h1), std::runtime_error);
+  EXPECT_THROW(param_handler->remove_parameter_callback(h2), std::runtime_error);
+
+  param_handler->remove_parameter_callback(h3);
+
+  // All callbacks should have been removed
+  EXPECT_EQ(received_2, 0);
+  EXPECT_EQ(param_handler->num_event_callbacks(), 0UL);
+}
+
+TEST_F(TestNode, LastInFirstCallForParameterCallbacks)
+{
+  rclcpp::Time time_1;
+  rclcpp::Time time_2;
+
+  // The callbacks will log the current time for comparison purposes. Add a bit of a stall
+  // to ensure that the time noted in the back-to-back calls isn't the same
+  auto cb1 = [this, &time_1](const rclcpp::Parameter &) {
+      time_1 = node->now();
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    };
+  auto cb2 = [this, &time_2](const rclcpp::Parameter &) {
+      time_2 = node->now();
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    };
+
+  auto h1 = param_handler->add_parameter_callback("my_int", cb1);
+  auto h2 = param_handler->add_parameter_callback("my_int", cb2);
+
+  // Test multiple callbacks per parameter
+  param_handler->test_event(same_node_int);
+
+  // The most-recently install handler should be called first
+  EXPECT_EQ(time_2 < time_1, true);
+
+  param_handler->remove_parameter_callback(h1);
+  param_handler->remove_parameter_callback(h2);
+  EXPECT_EQ(param_handler->num_parameter_callbacks(), 0UL);
+}
+
+TEST_F(TestNode, LastInFirstCallForParameterEventCallbacks)
+{
+  rclcpp::Time time_1;
+  rclcpp::Time time_2;
+
+  // The callbacks will log the current time for comparison purposes. Add a bit of a stall
+  // to ensure that the time noted in the back-to-back calls isn't the same
+  auto cb1 =
+    [this, &time_1](const rcl_interfaces::msg::ParameterEvent::SharedPtr &)
+    {
+      time_1 = node->now();
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    };
+  auto cb2 =
+    [this, &time_2](const rcl_interfaces::msg::ParameterEvent::SharedPtr &)
+    {
+      time_2 = node->now();
+      std::this_thread::sleep_for(std::chrono::milliseconds(10));
+    };
+
+  auto h1 = param_handler->add_parameter_event_callback(cb1);
+  auto h2 = param_handler->add_parameter_event_callback(cb2);
+
+  // Test multiple callbacks per parameter
+  param_handler->test_event(same_node_int);
+
+  // The most-recently install handler should be called first
+  EXPECT_EQ(time_2 < time_1, true);
+
+  param_handler->remove_parameter_event_callback(h1);
+  param_handler->remove_parameter_event_callback(h2);
+  EXPECT_EQ(param_handler->num_event_callbacks(), 0UL);
+}

rclcpp/test/rclcpp/test_parameter_service.cpp

@@ -22,6 +22,8 @@
 #include "rclcpp/rclcpp.hpp"
 #include "../../src/rclcpp/parameter_service_names.hpp"
 
+using namespace std::chrono_literals;
+
 // This tests the ParameterService as it is included in an rclcpp::Node. Creating a separate
 // ParameterService would interfere with the built-in one
 class TestParameterService : public ::testing::Test
@@ -59,12 +61,12 @@ TEST_F(TestParameterService, get_parameter_types) {
   node->declare_parameter("parameter1", rclcpp::ParameterValue(42));
 
   const std::vector<std::string> declared_parameters = {"parameter1"};
-  const auto parameter_types = client->get_parameter_types(declared_parameters);
+  const auto parameter_types = client->get_parameter_types(declared_parameters, 10s);
   ASSERT_EQ(1u, parameter_types.size());
   EXPECT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
 
   const std::vector<std::string> undeclared_parameters = {"parameter2"};
-  const auto undeclared_parameter_types = client->get_parameter_types(undeclared_parameters);
+  const auto undeclared_parameter_types = client->get_parameter_types(undeclared_parameters, 10s);
   EXPECT_EQ(0u, undeclared_parameter_types.size());
 }
 
@@ -75,7 +77,7 @@ TEST_F(TestParameterService, set_parameters) {
   const std::vector<rclcpp::Parameter> parameters = {
     rclcpp::Parameter("parameter1", 0),
   };
-  client->set_parameters(parameters);
+  client->set_parameters(parameters, 10s);
   EXPECT_EQ(0, client->get_parameter("parameter1", 100));
 }
 
@@ -86,54 +88,34 @@ TEST_F(TestParameterService, set_parameters_atomically) {
   const std::vector<rclcpp::Parameter> parameters = {
     rclcpp::Parameter("parameter1", 0),
   };
-  client->set_parameters_atomically(parameters);
+  client->set_parameters_atomically(parameters, 10s);
   EXPECT_EQ(0, client->get_parameter("parameter1", 100));
 }
 
 TEST_F(TestParameterService, list_parameters) {
-  const size_t number_parameters_in_basic_node = client->list_parameters({}, 1).names.size();
+  const size_t number_parameters_in_basic_node = client->list_parameters({}, 1, 10s).names.size();
   node->declare_parameter("parameter1", rclcpp::ParameterValue(42));
 
-  const auto list_result = client->list_parameters({}, 1);
+  const auto list_result = client->list_parameters({}, 1, 10s);
   EXPECT_EQ(1u + number_parameters_in_basic_node, list_result.names.size());
 }
 
 TEST_F(TestParameterService, describe_parameters) {
-  // There is no current API in ParameterClient for calling the describe_parameters service
-  // Update this test when https://github.com/ros2/rclcpp/issues/1354 is resolved
-
-  const std::string describe_parameters_service_name =
-    node->get_fully_qualified_name() + std::string("/") +
-    rclcpp::parameter_service_names::describe_parameters;
-  using ServiceT = rcl_interfaces::srv::DescribeParameters;
-  auto client =
-    node->create_client<ServiceT>(describe_parameters_service_name);
-
-  ASSERT_TRUE(client->wait_for_service(std::chrono::seconds(1)));
   node->declare_parameter("parameter1", rclcpp::ParameterValue(42));
 
   {
-    auto request = std::make_shared<rcl_interfaces::srv::DescribeParameters::Request>();
-    request->names.push_back("parameter1");
-    auto future = client->async_send_request(request);
-
-    rclcpp::spin_until_future_complete(node, future, std::chrono::seconds(1));
-    auto response = future.get();
-    ASSERT_NE(nullptr, response);
-    EXPECT_EQ(1u, response->descriptors.size());
-
-    auto descriptor = response->descriptors[0];
-    EXPECT_EQ("parameter1", descriptor.name);
-    EXPECT_EQ(rcl_interfaces::msg::ParameterType::PARAMETER_INTEGER, descriptor.type);
+    const std::vector<std::string> names{"parameter1"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      client->describe_parameters(names, 10s);
+    ASSERT_EQ(1u, parameter_descs.size());
+    EXPECT_EQ("parameter1", parameter_descs[0].name);
+    EXPECT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_descs[0].type);
   }
-  {
-    auto request = std::make_shared<rcl_interfaces::srv::DescribeParameters::Request>();
-    request->names.push_back("undeclared_parameter");
-    auto future = client->async_send_request(request);
 
-    rclcpp::spin_until_future_complete(node, future, std::chrono::seconds(1));
-    auto response = future.get();
-    ASSERT_NE(nullptr, response);
-    EXPECT_EQ(0u, response->descriptors.size());
+  {
+    const std::vector<std::string> names{"undeclared_parameter"};
+    std::vector<rcl_interfaces::msg::ParameterDescriptor> parameter_descs =
+      client->describe_parameters(names, 10s);
+    EXPECT_EQ(0u, parameter_descs.size());
   }
 }

rclcpp/test/rclcpp/test_publisher.cpp

@@ -29,10 +29,6 @@
 
 #include "test_msgs/msg/empty.hpp"
 
-// Note: This is a long running test with rmw_connext_cpp, if you change this file, please check
-// that this test can complete fully, or adjust the timeout as necessary.
-// See https://github.com/ros2/rmw_connext/issues/325 for resolution
-
 class TestPublisher : public ::testing::Test
 {
 public:
@@ -151,6 +147,20 @@ TEST_F(TestPublisher, various_creation_signatures) {
       rclcpp::create_publisher<Empty>(node, "topic", 42, rclcpp::PublisherOptions());
     (void)publisher;
   }
+  {
+    rclcpp::PublisherOptions options;
+    options.qos_overriding_options = rclcpp::QosOverridingOptions::with_default_policies();
+    auto publisher =
+      rclcpp::create_publisher<Empty>(node, "topic", 42, options);
+    (void)publisher;
+  }
+  {
+    auto node_parameters = node->get_node_parameters_interface();
+    auto node_topics = node->get_node_topics_interface();
+    auto publisher = rclcpp::create_publisher<Empty>(
+      node_parameters, node_topics, "topic", 42, rclcpp::PublisherOptions());
+    (void)publisher;
+  }
 }
 
 /*
@@ -448,9 +458,9 @@ class TestPublisherProtectedMethods : public rclcpp::Publisher<MessageT, Allocat
 public:
   using rclcpp::Publisher<MessageT, AllocatorT>::Publisher;
 
-  void publish_loaned_message(MessageT * msg)
+  void publish_loaned_message(rclcpp::LoanedMessage<MessageT, AllocatorT> && loaned_msg)
   {
-    this->do_loaned_message_publish(msg);
+    this->do_loaned_message_publish(std::move(loaned_msg.release()));
   }
 
   void call_default_incompatible_qos_callback(rclcpp::QOSOfferedIncompatibleQoSInfo & event) const
@@ -465,13 +475,14 @@ TEST_F(TestPublisher, do_loaned_message_publish_error) {
   auto publisher =
     node->create_publisher<test_msgs::msg::Empty, std::allocator<void>, PublisherT>("topic", 10);
 
-  auto msg = std::make_shared<test_msgs::msg::Empty>();
+  auto msg = publisher->borrow_loaned_message();
+
   {
     // Using 'self' instead of 'lib:rclcpp' because `rcl_publish_loaned_message` is entirely
     // defined in a header
     auto mock = mocking_utils::patch_and_return(
       "self", rcl_publish_loaned_message, RCL_RET_PUBLISHER_INVALID);
-    EXPECT_THROW(publisher->publish_loaned_message(msg.get()), rclcpp::exceptions::RCLError);
+    EXPECT_THROW(publisher->publish_loaned_message(std::move(msg)), rclcpp::exceptions::RCLError);
   }
 }
 
@@ -489,7 +500,9 @@ TEST_F(TestPublisher, default_incompatible_qos_callback) {
 TEST_F(TestPublisher, run_event_handlers) {
   initialize();
   auto publisher = node->create_publisher<test_msgs::msg::Empty>("topic", 10);
+
   for (const auto & handler : publisher->get_event_handlers()) {
-    EXPECT_NO_THROW(handler->execute());
+    std::shared_ptr<void> data = handler->take_data();
+    handler->execute(data);
   }
 }

rclcpp/test/rclcpp/test_qos.cpp

@@ -78,33 +78,41 @@ TEST(TestQoS, equality_namespace) {
   EXPECT_NE(a, b);
 }
 
-TEST(TestQoS, setters) {
+TEST(TestQoS, setters_and_getters) {
   rclcpp::QoS qos(10);
 
   qos.keep_all();
-  EXPECT_EQ(RMW_QOS_POLICY_HISTORY_KEEP_ALL, qos.get_rmw_qos_profile().history);
+  EXPECT_EQ(rclcpp::HistoryPolicy::KeepAll, qos.history());
 
   qos.keep_last(20);
-  EXPECT_EQ(RMW_QOS_POLICY_HISTORY_KEEP_LAST, qos.get_rmw_qos_profile().history);
-  EXPECT_EQ(20u, qos.get_rmw_qos_profile().depth);
+  EXPECT_EQ(rclcpp::HistoryPolicy::KeepLast, qos.history());
+  EXPECT_EQ(20u, qos.depth());
 
   qos.reliable();
-  EXPECT_EQ(RMW_QOS_POLICY_RELIABILITY_RELIABLE, qos.get_rmw_qos_profile().reliability);
+  EXPECT_EQ(rclcpp::ReliabilityPolicy::Reliable, qos.reliability());
+
+  qos.reliability(rclcpp::ReliabilityPolicy::BestEffort);
+  EXPECT_EQ(rclcpp::ReliabilityPolicy::BestEffort, qos.reliability());
 
   qos.durability_volatile();
-  EXPECT_EQ(RMW_QOS_POLICY_DURABILITY_VOLATILE, qos.get_rmw_qos_profile().durability);
+  EXPECT_EQ(rclcpp::DurabilityPolicy::Volatile, qos.durability());
 
   qos.transient_local();
-  EXPECT_EQ(RMW_QOS_POLICY_DURABILITY_TRANSIENT_LOCAL, qos.get_rmw_qos_profile().durability);
+  EXPECT_EQ(rclcpp::DurabilityPolicy::TransientLocal, qos.durability());
+
+  qos.durability(rclcpp::DurabilityPolicy::Volatile);
+  EXPECT_EQ(rclcpp::DurabilityPolicy::Volatile, qos.durability());
 
   qos.history(RMW_QOS_POLICY_HISTORY_KEEP_ALL);
-  EXPECT_EQ(RMW_QOS_POLICY_HISTORY_KEEP_ALL, qos.get_rmw_qos_profile().history);
+  EXPECT_EQ(rclcpp::HistoryPolicy::KeepAll, qos.history());
 
-  constexpr size_t duration_ns = 12345;
+  qos.history(rclcpp::HistoryPolicy::KeepLast);
+  EXPECT_EQ(rclcpp::HistoryPolicy::KeepLast, qos.history());
+
+  constexpr rcl_duration_value_t duration_ns = 12345;
   constexpr std::chrono::nanoseconds duration(duration_ns);
   qos.deadline(duration);
-  EXPECT_EQ(0u, qos.get_rmw_qos_profile().deadline.sec);
-  EXPECT_EQ(duration_ns, qos.get_rmw_qos_profile().deadline.nsec);
+  EXPECT_EQ(duration_ns, qos.deadline().nanoseconds());
 
   const rmw_time_t rmw_time {0, 54321};
   qos.deadline(rmw_time);
@@ -112,28 +120,29 @@ TEST(TestQoS, setters) {
   EXPECT_EQ(rmw_time.nsec, qos.get_rmw_qos_profile().deadline.nsec);
 
   qos.lifespan(duration);
-  EXPECT_EQ(0u, qos.get_rmw_qos_profile().lifespan.sec);
-  EXPECT_EQ(duration_ns, qos.get_rmw_qos_profile().lifespan.nsec);
+  EXPECT_EQ(duration_ns, qos.lifespan().nanoseconds());
 
   qos.lifespan(rmw_time);
   EXPECT_EQ(rmw_time.sec, qos.get_rmw_qos_profile().lifespan.sec);
   EXPECT_EQ(rmw_time.nsec, qos.get_rmw_qos_profile().lifespan.nsec);
 
   qos.liveliness(RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC);
-  EXPECT_EQ(RMW_QOS_POLICY_LIVELINESS_MANUAL_BY_TOPIC, qos.get_rmw_qos_profile().liveliness);
+  EXPECT_EQ(rclcpp::LivelinessPolicy::ManualByTopic, qos.liveliness());
+
+  qos.liveliness(rclcpp::LivelinessPolicy::Automatic);
+  EXPECT_EQ(rclcpp::LivelinessPolicy::Automatic, qos.liveliness());
 
   qos.liveliness_lease_duration(duration);
-  EXPECT_EQ(0u, qos.get_rmw_qos_profile().liveliness_lease_duration.sec);
-  EXPECT_EQ(duration_ns, qos.get_rmw_qos_profile().liveliness_lease_duration.nsec);
+  EXPECT_EQ(duration_ns, qos.liveliness_lease_duration().nanoseconds());
 
   qos.liveliness_lease_duration(rmw_time);
   EXPECT_EQ(rmw_time.sec, qos.get_rmw_qos_profile().liveliness_lease_duration.sec);
   EXPECT_EQ(rmw_time.nsec, qos.get_rmw_qos_profile().liveliness_lease_duration.nsec);
 
   qos.avoid_ros_namespace_conventions(true);
-  EXPECT_TRUE(qos.get_rmw_qos_profile().avoid_ros_namespace_conventions);
+  EXPECT_TRUE(qos.avoid_ros_namespace_conventions());
   qos.avoid_ros_namespace_conventions(false);
-  EXPECT_FALSE(qos.get_rmw_qos_profile().avoid_ros_namespace_conventions);
+  EXPECT_FALSE(qos.avoid_ros_namespace_conventions());
 }
 
 bool operator==(const rmw_qos_profile_t & lhs, const rmw_qos_profile_t & rhs)