7.0.1

Signed-off-by: Ivan Santiago Paunovic <ivanpauno@ekumenlabs.com>

rclcpp/CHANGELOG.rst

@@ -2,6 +2,33 @@
 Changelog for package rclcpp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+7.0.1 (2021-03-22)
+------------------
+* get_parameters service should return empty if undeclared parameters are allowed (`#1514 <https://github.com/ros2/rclcpp/issues/1514>`_)
+* Made 'Context::shutdown_reason' function a const function (`#1578 <https://github.com/ros2/rclcpp/issues/1578>`_)
+* Contributors: Tomoya Fujita, suab321321
+
+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>`_)

rclcpp/CMakeLists.txt

@@ -39,6 +39,8 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/clock.cpp
   src/rclcpp/context.cpp
   src/rclcpp/contexts/default_context.cpp
+  src/rclcpp/detail/mutex_two_priorities.cpp
+  src/rclcpp/detail/resolve_parameter_overrides.cpp
   src/rclcpp/detail/rmw_implementation_specific_payload.cpp
   src/rclcpp/detail/rmw_implementation_specific_publisher_payload.cpp
   src/rclcpp/detail/rmw_implementation_specific_subscription_payload.cpp
@@ -79,6 +81,7 @@ set(${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

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_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

@@ -150,7 +150,7 @@ public:
    */
   RCLCPP_PUBLIC
   std::string
-  shutdown_reason();
+  shutdown_reason() const;
 
   /// Shutdown the context, making it uninitialized and therefore invalid for derived entities.
   /**
@@ -286,7 +286,7 @@ private:
 
   // This mutex is recursive so that the destructor can ensure atomicity
   // between is_initialized and shutdown.
-  std::recursive_mutex init_mutex_;
+  mutable std::recursive_mutex init_mutex_;
   std::shared_ptr<rcl_context_t> rcl_context_;
   rclcpp::InitOptions init_options_;
   std::string shutdown_reason_;

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/exceptions/exceptions.hpp

@@ -282,6 +282,20 @@ 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
 {

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/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_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_options.hpp

@@ -95,12 +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/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_options.hpp

@@ -104,7 +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/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>6.3.1</version>
+  <version>7.0.1</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/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

@@ -291,7 +291,7 @@ Context::get_domain_id() const
 }
 
 std::string
-Context::shutdown_reason()
+Context::shutdown_reason() const
 {
   std::lock_guard<std::recursive_mutex> lock(init_mutex_);
   return shutdown_reason_;

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/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/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_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(
@@ -85,60 +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);
       }
     }
@@ -165,14 +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
@@ -191,7 +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) {
@@ -201,7 +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;
   }
 
@@ -213,7 +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) {
@@ -224,29 +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;
@@ -293,7 +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 =
@@ -302,7 +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;
   }
@@ -353,6 +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);
 
@@ -364,6 +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,
@@ -372,46 +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
@@ -431,6 +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);
 }
@@ -524,13 +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
@@ -579,6 +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);
       }
     }
@@ -594,7 +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/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_service.cpp

@@ -41,12 +41,13 @@ ParameterService::ParameterService(
       const std::shared_ptr<rcl_interfaces::srv::GetParameters::Request> request,
       std::shared_ptr<rcl_interfaces::srv::GetParameters::Response> response)
     {
-      for (const auto & name : request->names) {
-        // Default construct param to NOT_SET
-        rclcpp::Parameter param;
-        node_params->get_parameter(name, param);
-        // push back NOT_SET when get_parameter() call fails
-        response->values.push_back(param.get_value_message());
+      try {
+        auto parameters = node_params->get_parameters(request->names);
+        for (const auto param : parameters) {
+          response->values.push_back(param.get_value_message());
+        }
+      } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
+        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to get parameters: %s", ex.what());
       }
     },
     qos_profile, nullptr);
@@ -67,7 +68,7 @@ ParameterService::ParameterService(
             return static_cast<rclcpp::ParameterType>(type);
           });
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to get parameter types: %s", ex.what());
+        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to get parameter types: %s", ex.what());
       }
     },
     qos_profile, nullptr);
@@ -88,7 +89,7 @@ ParameterService::ParameterService(
           result = node_params->set_parameters_atomically(
             {rclcpp::Parameter::from_parameter_msg(p)});
         } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-          RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to set parameter: %s", ex.what());
+          RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to set parameter: %s", ex.what());
           result.successful = false;
           result.reason = ex.what();
         }
@@ -116,7 +117,7 @@ ParameterService::ParameterService(
         auto result = node_params->set_parameters_atomically(pvariants);
         response->result = result;
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_WARN(
+        RCLCPP_DEBUG(
           rclcpp::get_logger("rclcpp"), "Failed to set parameters atomically: %s", ex.what());
         response->result.successful = false;
         response->result.reason = "One or more parameters were not declared before setting";
@@ -136,7 +137,7 @@ ParameterService::ParameterService(
         auto descriptors = node_params->describe_parameters(request->names);
         response->descriptors = descriptors;
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to describe parameters: %s", ex.what());
+        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to describe parameters: %s", ex.what());
       }
     },
     qos_profile, nullptr);

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

@@ -91,11 +91,14 @@ public:
     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"));
+      param1_name, rclcpp::ParameterValue("param1_value"), descriptor);
     remote_node->declare_parameter(
-      param2_name, rclcpp::ParameterValue(std::vector<int> {1, 2, 3}));
-    remote_node->declare_parameter(param3_name);
+      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);

rclcpp/test/rclcpp/CMakeLists.txt

@@ -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})

rclcpp/test/rclcpp/strategies/test_allocator_memory_strategy.cpp

@@ -511,10 +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_node.cpp

@@ -330,8 +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);
   }
   {
@@ -363,15 +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);
   }
   {
@@ -400,6 +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
@@ -497,13 +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
@@ -512,8 +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
@@ -560,15 +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);
   }
   {
@@ -603,6 +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) {
@@ -673,7 +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);
@@ -732,45 +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
@@ -783,7 +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));
@@ -796,6 +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;
@@ -815,7 +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));
@@ -826,7 +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());
@@ -847,12 +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"));
   }
@@ -869,8 +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);
@@ -905,7 +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);
 
@@ -915,13 +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));
@@ -1261,15 +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");
   }
@@ -1417,7 +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);
 
@@ -1427,13 +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));
@@ -1591,7 +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);
 
@@ -1601,13 +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));
@@ -1963,30 +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);
     }
@@ -2577,3 +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

@@ -218,12 +218,59 @@ TEST_F(TestParameterClient, async_parameter_get_parameter_types) {
   ASSERT_TRUE(callback_called);
 }
 
+/*
+  Coverage for async get_parameter_types with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, async_parameter_get_parameter_types_allow_undeclared) {
+  auto asynchronous_client =
+    std::make_shared<rclcpp::AsyncParametersClient>(node_with_option);
+  bool callback_called = false;
+  auto callback = [&callback_called](std::shared_future<std::vector<rclcpp::ParameterType>> result)
+    {
+      if (result.valid() && result.get().size() == 1 &&
+        result.get()[0] == rclcpp::PARAMETER_NOT_SET)
+      {
+        callback_called = true;
+      }
+    };
+  std::vector<std::string> names{"foo"};
+  std::shared_future<std::vector<rclcpp::ParameterType>> future =
+    asynchronous_client->get_parameter_types(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);
+  ASSERT_TRUE(callback_called);
+}
+
 /*
   Coverage for async get_parameters
  */
 TEST_F(TestParameterClient, async_parameter_get_parameters) {
   auto asynchronous_client = std::make_shared<rclcpp::AsyncParametersClient>(node);
   bool callback_called = false;
+  auto callback = [&callback_called](std::shared_future<std::vector<rclcpp::Parameter>> 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"};
+  std::shared_future<std::vector<rclcpp::Parameter>> future = asynchronous_client->get_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);
+}
+
+/*
+  Coverage for async get_parameters with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, async_parameter_get_parameters_allow_undeclared) {
+  auto asynchronous_client =
+    std::make_shared<rclcpp::AsyncParametersClient>(node_with_option);
+  bool callback_called = false;
   auto callback = [&callback_called](std::shared_future<std::vector<rclcpp::Parameter>> result)
     {
       if (result.valid() && result.get().size() == 1 && result.get()[0].get_name() == "foo") {
@@ -234,7 +281,7 @@ TEST_F(TestParameterClient, async_parameter_get_parameters) {
   std::shared_future<std::vector<rclcpp::Parameter>> future = asynchronous_client->get_parameters(
     names, callback);
   auto return_code = rclcpp::spin_until_future_complete(
-    node, future, std::chrono::milliseconds(100));
+    node_with_option, future, std::chrono::milliseconds(100));
   ASSERT_EQ(rclcpp::FutureReturnCode::SUCCESS, return_code);
   ASSERT_TRUE(callback_called);
 }
@@ -292,12 +339,197 @@ TEST_F(TestParameterClient, async_parameter_list_parameters) {
  */
 TEST_F(TestParameterClient, sync_parameter_get_parameter_types) {
   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{"foo"};
-  std::vector<rclcpp::ParameterType> parameter_types =
-    synchronous_client->get_parameter_types(names, 10s);
-  ASSERT_EQ(1u, parameter_types.size());
-  ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
+
+  {
+    std::vector<std::string> names{"none"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(0u, parameter_types.size());
+  }
+
+  {
+    std::vector<std::string> names{"none", "foo", "bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(0u, parameter_types.size());
+  }
+
+  {
+    std::vector<std::string> names{"foo"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(1u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
+  }
+
+  {
+    std::vector<std::string> names{"bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(1u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_types[0]);
+  }
+
+  {
+    std::vector<std::string> names{"foo", "bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(2u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_types[1]);
+  }
+}
+
+/*
+  Coverage for sync get_parameter_types with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, sync_parameter_get_parameter_types_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<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(1u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_types[0]);
+  }
+
+  {
+    std::vector<std::string> names{"none", "foo", "bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(3u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_NOT_SET, parameter_types[0]);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[1]);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_types[2]);
+  }
+
+  {
+    std::vector<std::string> names{"foo"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(1u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
+  }
+
+  {
+    std::vector<std::string> names{"bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(1u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_types[0]);
+  }
+
+  {
+    std::vector<std::string> names{"foo", "bar"};
+    std::vector<rclcpp::ParameterType> parameter_types =
+      synchronous_client->get_parameter_types(names, 10s);
+    ASSERT_EQ(2u, parameter_types.size());
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_INTEGER, parameter_types[0]);
+    ASSERT_EQ(rclcpp::ParameterType::PARAMETER_STRING, parameter_types[1]);
+  }
+}
+
+/*
+  Coverage for sync get_parameters
+ */
+TEST_F(TestParameterClient, sync_parameter_get_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<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(0u, parameters.size());
+  }
+
+  {
+    std::vector<std::string> names{"none", "foo", "bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(0u, parameters.size());
+  }
+
+  {
+    std::vector<std::string> names{"foo"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(1u, parameters.size());
+    ASSERT_EQ("foo", parameters[0].get_name());
+    ASSERT_EQ(4u, parameters[0].as_int());
+  }
+
+  {
+    std::vector<std::string> names{"bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(1u, parameters.size());
+    ASSERT_EQ("bar", parameters[0].get_name());
+    ASSERT_EQ("this is bar", parameters[0].as_string());
+  }
+
+  {
+    std::vector<std::string> names{"foo", "bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(2u, parameters.size());
+    ASSERT_EQ("foo", parameters[0].get_name());
+    ASSERT_EQ(4u, parameters[0].as_int());
+    ASSERT_EQ("bar", parameters[1].get_name());
+    ASSERT_EQ("this is bar", parameters[1].as_string());
+  }
+}
+
+/*
+  Coverage for sync get_parameters with allow_undeclared_ enabled
+ */
+TEST_F(TestParameterClient, sync_parameter_get_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<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(1u, parameters.size());
+  }
+
+  {
+    std::vector<std::string> names{"none", "foo", "bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(3u, parameters.size());
+    ASSERT_EQ("foo", parameters[1].get_name());
+    ASSERT_EQ(4u, parameters[1].as_int());
+    ASSERT_EQ("bar", parameters[2].get_name());
+    ASSERT_EQ("this is bar", parameters[2].as_string());
+  }
+
+  {
+    std::vector<std::string> names{"foo"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(1u, parameters.size());
+    ASSERT_EQ("foo", parameters[0].get_name());
+    ASSERT_EQ(4u, parameters[0].as_int());
+  }
+
+  {
+    std::vector<std::string> names{"bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(1u, parameters.size());
+    ASSERT_EQ("bar", parameters[0].get_name());
+    ASSERT_EQ("this is bar", parameters[0].as_string());
+  }
+
+  {
+    std::vector<std::string> names{"foo", "bar"};
+    std::vector<rclcpp::Parameter> parameters = synchronous_client->get_parameters(names, 10s);
+    ASSERT_EQ(2u, parameters.size());
+    ASSERT_EQ("foo", parameters[0].get_name());
+    ASSERT_EQ(4u, parameters[0].as_int());
+    ASSERT_EQ("bar", parameters[1].get_name());
+    ASSERT_EQ("this is bar", parameters[1].as_string());
+  }
 }
 
 /*

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_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:

rclcpp/test/rclcpp/test_qos_parameters.cpp

@@ -234,7 +234,8 @@ TEST(TestQosParameters, declare_no_parameters_interface) {
 
   std::map<std::string, rclcpp::Parameter> qos_params;
   EXPECT_FALSE(
-    node->get_node_parameters_interface()->get_parameters_by_prefix("qos_overrides", qos_params));
+    node->get_node_parameters_interface()->get_parameters_by_prefix(
+      "qos_overrides./my/fully/qualified/topic_name", qos_params));
 
   rclcpp::shutdown();
 }

rclcpp/test/rclcpp/test_subscription.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
-
 using namespace std::chrono_literals;
 
 class TestSubscription : public ::testing::Test

rclcpp_action/CHANGELOG.rst

@@ -3,6 +3,15 @@ Changelog for package rclcpp_action
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 
+7.0.1 (2021-03-22)
+------------------
+
+7.0.0 (2021-03-18)
+------------------
+* Add support for rmw_connextdds (`#1574 <https://github.com/ros2/rclcpp/issues/1574>`_)
+* node_handle must be destroyed after client_handle to prevent memory leak (`#1562 <https://github.com/ros2/rclcpp/issues/1562>`_)
+* Contributors: Andrea Sorbini, Tomoya Fujita
+
 6.3.1 (2021-02-08)
 ------------------
 * Finalize rcl_handle to prevent leak (`#1528 <https://github.com/ros2/rclcpp/issues/1528>`_) (`#1529 <https://github.com/ros2/rclcpp/issues/1529>`_)

rclcpp_action/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_action</name>
-  <version>6.3.1</version>
+  <version>7.0.1</version>
   <description>Adds action APIs for C++.</description>
   <maintainer email="ivanpauno@ekumenlabs.com">Ivan Paunovic</maintainer>
   <maintainer email="mabel@openrobotics.org">Mabel Zhang</maintainer>

rclcpp_action/src/client.cpp

@@ -102,8 +102,9 @@ public:
 
   rclcpp::Context::SharedPtr context_;
   rclcpp::node_interfaces::NodeGraphInterface::WeakPtr node_graph_;
-  std::shared_ptr<rcl_action_client_t> client_handle{nullptr};
+  // node_handle must be destroyed after client_handle to prevent memory leak
   std::shared_ptr<rcl_node_t> node_handle{nullptr};
+  std::shared_ptr<rcl_action_client_t> client_handle{nullptr};
   rclcpp::Logger logger;
 
   using ResponseCallback = std::function<void (std::shared_ptr<void> response)>;

rclcpp_action/test/test_server.cpp

@@ -29,10 +29,6 @@
 #include "rclcpp_action/server.hpp"
 #include "./mocking_utils/patch.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 Fibonacci = test_msgs::action::Fibonacci;
 using CancelResponse = typename Fibonacci::Impl::CancelGoalService::Response;
 using GoalUUID = rclcpp_action::GoalUUID;

rclcpp_components/CHANGELOG.rst

@@ -2,6 +2,12 @@
 Changelog for package rclcpp_components
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+7.0.1 (2021-03-22)
+------------------
+
+7.0.0 (2021-03-18)
+------------------
+
 6.3.1 (2021-02-08)
 ------------------
 

rclcpp_components/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_components</name>
-  <version>6.3.1</version>
+  <version>7.0.1</version>
   <description>Package containing tools for dynamically loadable components</description>
   <maintainer email="ivanpauno@ekumenlabs.com">Ivan Paunovic</maintainer>
   <maintainer email="mabel@openrobotics.org">Mabel Zhang</maintainer>

rclcpp_lifecycle/CHANGELOG.rst

@@ -3,6 +3,16 @@ Changelog for package rclcpp_lifecycle
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
 
+7.0.1 (2021-03-22)
+------------------
+
+7.0.0 (2021-03-18)
+------------------
+* Add support for rmw_connextdds (`#1574 <https://github.com/ros2/rclcpp/issues/1574>`_)
+* Fix SEGV caused by order of destruction of Node sub-interfaces (`#1469 <https://github.com/ros2/rclcpp/issues/1469>`_)
+* Enforce static parameter types (`#1522 <https://github.com/ros2/rclcpp/issues/1522>`_)
+* Contributors: Andrea Sorbini, Colin MacKenzie, Ivan Santiago Paunovic
+
 6.3.1 (2021-02-08)
 ------------------
 

rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node.hpp

@@ -282,9 +282,39 @@ 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());
+    rcl_interfaces::msg::ParameterDescriptor(),
+    bool ignore_override = false);
+
+  /// Declare and initialize a parameter, return the effective value.
+  /**
+   * \sa rclcpp::Node::declare_parameter
+   */
+  RCLCPP_LIFECYCLE_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_LIFECYCLE_PUBLIC
+  const rclcpp::ParameterValue &
+  declare_parameter(const std::string & name);
 
   /// Declare and initialize a parameter with a type.
   /**
@@ -296,7 +326,20 @@ public:
     const std::string & name,
     const ParameterT & default_value,
     const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor =
-    rcl_interfaces::msg::ParameterDescriptor());
+    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.
   /**

rclcpp_lifecycle/include/rclcpp_lifecycle/lifecycle_node_impl.hpp

@@ -135,12 +135,32 @@ auto
 LifecycleNode::declare_parameter(
   const std::string & name,
   const ParameterT & default_value,
-  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor)
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
 {
   return this->declare_parameter(
     name,
     rclcpp::ParameterValue(default_value),
-    parameter_descriptor
+    parameter_descriptor,
+    ignore_override
+  ).get<ParameterT>();
+}
+
+template<typename ParameterT>
+auto
+LifecycleNode::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>();
 }
 

rclcpp_lifecycle/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_lifecycle</name>
-  <version>6.3.1</version>
+  <version>7.0.1</version>
   <description>Package containing a prototype for lifecycle implementation</description>
   <maintainer email="ivanpauno@ekumenlabs.com">Ivan Paunovic</maintainer>
   <maintainer email="mabel@openrobotics.org">Mabel Zhang</maintainer>

rclcpp_lifecycle/src/lifecycle_node.cpp

@@ -128,7 +128,18 @@ LifecycleNode::LifecycleNode(
 }
 
 LifecycleNode::~LifecycleNode()
-{}
+{
+  // 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 *
 LifecycleNode::get_name() const
@@ -159,9 +170,43 @@ const rclcpp::ParameterValue &
 LifecycleNode::declare_parameter(
   const std::string & name,
   const rclcpp::ParameterValue & default_value,
-  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor)
+  const rcl_interfaces::msg::ParameterDescriptor & parameter_descriptor,
+  bool ignore_override)
 {
-  return this->node_parameters_->declare_parameter(name, default_value, parameter_descriptor);
+  return this->node_parameters_->declare_parameter(
+    name, default_value, parameter_descriptor, ignore_override);
+}
+
+const rclcpp::ParameterValue &
+LifecycleNode::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 &
+LifecycleNode::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

rclcpp_lifecycle/test/test_lifecycle_node.cpp

@@ -31,10 +31,6 @@
 
 #include "./mocking_utils/patch.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 lifecycle_msgs::msg::State;
 using lifecycle_msgs::msg::Transition;
 
@@ -425,7 +421,9 @@ TEST_F(TestDefaultStateMachine, check_parameters) {
     rclcpp::exceptions::ParameterNotDeclaredException);
 
   // Default descriptor overload
-  test_node->declare_parameter(bool_name, rclcpp::ParameterValue(true));
+  rcl_interfaces::msg::ParameterDescriptor bool_descriptor;
+  bool_descriptor.dynamic_typing = true;
+  test_node->declare_parameter(bool_name, rclcpp::ParameterValue(true), bool_descriptor);
 
   // Explicit descriptor overload
   rcl_interfaces::msg::ParameterDescriptor int_descriptor;

rclcpp_lifecycle/test/test_lifecycle_service_client.cpp

@@ -52,10 +52,6 @@ constexpr char const * node_get_transition_graph_topic =
   "/lc_talker/get_transition_graph";
 const lifecycle_msgs::msg::State unknown_state = lifecycle_msgs::msg::State();
 
-// 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 EmptyLifecycleNode : public rclcpp_lifecycle::LifecycleNode
 {
 public: