Add acceptable_buffer_backends field in SubscriptionOptionsBase

Signed-off-by: CY Chen <cyc@nvidia.com>

rclcpp/CHANGELOG.rst

@@ -2,6 +2,39 @@
 Changelog for package rclcpp
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
+30.1.5 (2026-02-09)
+-------------------
+* remove default: so that compiler can detect the missing case. (`#3048 <https://github.com/ros2/rclcpp/issues/3048>`_)
+* use weak_ptr for rcl entities in the memory strategy. (`#2988 <https://github.com/ros2/rclcpp/issues/2988>`_)
+* remove test_static_executor_entities_collector.cpp (`#3041 <https://github.com/ros2/rclcpp/issues/3041>`_)
+* include the 1st spin that might throw the exception. (`#3042 <https://github.com/ros2/rclcpp/issues/3042>`_)
+* print warning message on owner node if the parameter operation fails. (`#3037 <https://github.com/ros2/rclcpp/issues/3037>`_)
+* fix context in wait for message wait set (`#3030 <https://github.com/ros2/rclcpp/issues/3030>`_)
+* Revert "construct wait set with passed in context (`#3021 <https://github.com/ros2/rclcpp/issues/3021>`_)" (`#3028 <https://github.com/ros2/rclcpp/issues/3028>`_)
+* construct wait set with passed in context (`#3021 <https://github.com/ros2/rclcpp/issues/3021>`_)
+* Improve the robustness of the TopicEndpointInfo constructor (`#3013 <https://github.com/ros2/rclcpp/issues/3013>`_)
+* Deprecate the shared_ptr<MessageT> subscription callback signatures (`#2975 <https://github.com/ros2/rclcpp/issues/2975>`_)
+* Contributors: Barry Xu, Maurice Alexander Purnawan, Michael Carroll, Rahat Dhande, Tomoya Fujita
+
+30.1.4 (2025-12-23)
+-------------------
+* Updated deprecated ament_index_cpp API (`#3011 <https://github.com/ros2/rclcpp/issues/3011>`_)
+* Unified Node Interfaces: Add const version of get_node_x_interface() (`#3006 <https://github.com/ros2/rclcpp/issues/3006>`_)
+* Parameter Descriptor Simplification  (`#2179 <https://github.com/ros2/rclcpp/issues/2179>`_)
+* ParameterEventHandler support ContentFiltering (`#2971 <https://github.com/ros2/rclcpp/issues/2971>`_)
+* update policy_name_from_kind && test_qos (`#2156 <https://github.com/ros2/rclcpp/issues/2156>`_)
+* Add ability to disable and enable subscription's callbacks (`#2985 <https://github.com/ros2/rclcpp/issues/2985>`_)
+* Switch to isolated testing via rmw_test_fixture (`#2929 <https://github.com/ros2/rclcpp/issues/2929>`_)
+* remove I/O from signal handler. (`#2986 <https://github.com/ros2/rclcpp/issues/2986>`_)
+* Contributors: Alejandro Hernández Cordero, Andrianov Roman, Barry Xu, Lucas Wendland, Michael Orlov, Tomoya Fujita, fabianhirmann, yadunund
+
+30.1.3 (2025-11-18)
+-------------------
+* correct test function descriptions (`#2970 <https://github.com/ros2/rclcpp/issues/2970>`_)
+* add : get clients, servers info (`#2569 <https://github.com/ros2/rclcpp/issues/2569>`_)
+* Fix REP url locations (`#2987 <https://github.com/ros2/rclcpp/issues/2987>`_)
+* Contributors: Minju, Lee, Tim Clephas, Yuchen966
+
 30.1.2 (2025-10-21)
 -------------------
 * clear handles before node destruction in test_memory_strategy. (`#2969 <https://github.com/ros2/rclcpp/issues/2969>`_)

rclcpp/CMakeLists.txt

@@ -103,6 +103,7 @@ set(${PROJECT_NAME}_SRCS
   src/rclcpp/node_options.cpp
   src/rclcpp/parameter.cpp
   src/rclcpp/parameter_client.cpp
+  src/rclcpp/parameter_descriptor_wrapper.cpp
   src/rclcpp/parameter_event_handler.cpp
   src/rclcpp/parameter_events_filter.cpp
   src/rclcpp/parameter_map.cpp

rclcpp/QUALITY_DECLARATION.md

@@ -1,10 +1,10 @@
-This document is a declaration of software quality for the `rclcpp` package, based on the guidelines in [REP-2004](https://www.ros.org/reps/rep-2004.html).
+This document is a declaration of software quality for the `rclcpp` package, based on the guidelines in [REP-2004](https://reps.openrobotics.org/rep-2004/).
 
 # rclcpp Quality Declaration
 
 The package `rclcpp` claims to be in the **Quality Level 1** category when it is used with a **Quality Level 1** middleware.
 
-Below are the rationales, notes, and caveats for this claim, organized by each requirement listed in the [Package Requirements for Quality Level 1 in REP-2004](https://www.ros.org/reps/rep-2004.html).
+Below are the rationales, notes, and caveats for this claim, organized by each requirement listed in the [Package Requirements for Quality Level 1 in REP-2004](https://reps.openrobotics.org/rep-2004/).
 
 ## Version Policy [1]
 
@@ -55,7 +55,7 @@ All pull requests will be peer-reviewed, check [ROS 2 Developer Guide](https://d
 
 ### Continuous Integration [2.iv]
 
-All pull requests must pass CI on all [tier 1 platforms](https://www.ros.org/reps/rep-2000.html#support-tiers)
+All pull requests must pass CI on all [tier 1 platforms](https://reps.openrobotics.org/rep-2000/#support-tiers)
 
 Currently nightly results can be seen here:
 
@@ -213,7 +213,7 @@ It is **Quality Level 1**, see its [Quality Declaration document](https://github
 
 ## Platform Support [6]
 
-`rclcpp` supports all of the tier 1 platforms as described in [REP-2000](https://www.ros.org/reps/rep-2000.html#support-tiers), and tests each change against all of them.
+`rclcpp` supports all of the tier 1 platforms as described in [REP-2000](https://reps.openrobotics.org/rep-2000/#support-tiers), and tests each change against all of them.
 
 Currently nightly build status can be seen here:
 * [linux-aarch64_release](https://ci.ros2.org/view/nightly/job/nightly_linux-aarch64_release/lastBuild/rclcpp/)
@@ -225,4 +225,4 @@ Currently nightly build status can be seen here:
 
 ### Vulnerability Disclosure Policy [7.i]
 
-This package conforms to the Vulnerability Disclosure Policy in [REP-2006](https://www.ros.org/reps/rep-2006.html).
+This package conforms to the Vulnerability Disclosure Policy in [REP-2006](https://reps.openrobotics.org/rep-2006/).

rclcpp/include/rclcpp/allocator/allocator_common.hpp

@@ -27,10 +27,39 @@ namespace rclcpp
 namespace allocator
 {
 
+template<typename T>
+using clean_t = std::remove_cv_t<std::remove_reference_t<T>>;
+
+// Primary template: false
+template<typename, typename = std::void_t<>>
+struct has_get_rcl_allocator : std::false_type {};
+
+// Specialization: true if expression is valid
+template<typename T>
+struct has_get_rcl_allocator<T,
+  std::void_t<
+    decltype(std::declval<clean_t<T> &>().get_rcl_allocator())
+  >
+>
+  : std::bool_constant<
+    std::is_same_v<
+      decltype(std::declval<clean_t<T> &>().get_rcl_allocator()),
+      rcl_allocator_t
+    >
+  >
+{};
+
+// Helper variable template
+template<typename T>
+inline constexpr bool has_get_rcl_allocator_v =
+  has_get_rcl_allocator<T>::value;
+
 template<typename T, typename Alloc>
 using AllocRebind = typename std::allocator_traits<Alloc>::template rebind_traits<T>;
 
 template<typename Alloc>
+[[deprecated("Conversion of C++ allocators to C style is not valid, as the size on deallocate"
+  "can not be determined. This will be remove in future versions of ros.")]]
 void * retyped_allocate(size_t size, void * untyped_allocator)
 {
   auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
@@ -41,6 +70,8 @@ void * retyped_allocate(size_t size, void * untyped_allocator)
 }
 
 template<typename Alloc>
+[[deprecated("Conversion of C++ allocators to C style is not valid, as the size on deallocate"
+  "can not be determined. This will be remove in future versions of ros.")]]
 void * retyped_zero_allocate(size_t number_of_elem, size_t size_of_elem, void * untyped_allocator)
 {
   auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
@@ -57,6 +88,8 @@ void * retyped_zero_allocate(size_t number_of_elem, size_t size_of_elem, void *
 }
 
 template<typename T, typename Alloc>
+[[deprecated("Conversion of C++ allocators to C style is not valid, as the size on deallocate"
+  "can not be determined. This will be remove in future versions of ros.")]]
 void retyped_deallocate(void * untyped_pointer, void * untyped_allocator)
 {
   auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
@@ -68,6 +101,8 @@ void retyped_deallocate(void * untyped_pointer, void * untyped_allocator)
 }
 
 template<typename T, typename Alloc>
+[[deprecated("Conversion of C++ allocators to C style is not valid, as the size on deallocate"
+  "can not be determined. This will be remove in future versions of ros.")]]
 void * retyped_reallocate(void * untyped_pointer, size_t size, void * untyped_allocator)
 {
   auto typed_allocator = static_cast<Alloc *>(untyped_allocator);
@@ -85,6 +120,9 @@ template<
   typename T,
   typename Alloc,
   typename std::enable_if<!std::is_same<Alloc, std::allocator<void>>::value>::type * = nullptr>
+[[deprecated("Conversion of C++ allocators to C style is not valid, as the size on deallocate"
+  "can not be determined. This will be remove in future versions of ros. To suppress this warning"
+  "define the method 'rcl_allocator_t get_rcl_allocator()' on your allocator")]]
 rcl_allocator_t get_rcl_allocator(Alloc & allocator)
 {
   rcl_allocator_t rcl_allocator = rcl_get_default_allocator();

rclcpp/include/rclcpp/any_subscription_callback.hpp

@@ -15,8 +15,10 @@
 #ifndef RCLCPP__ANY_SUBSCRIPTION_CALLBACK_HPP_
 #define RCLCPP__ANY_SUBSCRIPTION_CALLBACK_HPP_
 
+#include <atomic>
 #include <functional>
 #include <memory>
+#include <mutex>
 #include <stdexcept>
 #include <type_traits>
 #include <utility>
@@ -375,7 +377,19 @@ public:
     allocator::set_allocator_for_deleter(&ros_message_type_deleter_, &ros_message_type_allocator_);
   }
 
-  AnySubscriptionCallback(const AnySubscriptionCallback &) = default;
+  AnySubscriptionCallback(const AnySubscriptionCallback & other)
+  : callback_variant_(other.callback_variant_),
+    callback_disabled_(other.callback_disabled_.load()),
+    subscribed_type_allocator_(other.subscribed_type_allocator_),
+    subscribed_type_deleter_(other.subscribed_type_deleter_),
+    ros_message_type_allocator_(other.ros_message_type_allocator_),
+    ros_message_type_deleter_(other.ros_message_type_deleter_),
+    serialized_message_allocator_(other.serialized_message_allocator_),
+    serialized_message_deleter_(other.serialized_message_deleter_)
+  {
+    allocator::set_allocator_for_deleter(&subscribed_type_deleter_, &subscribed_type_allocator_);
+    allocator::set_allocator_for_deleter(&ros_message_type_deleter_, &ros_message_type_allocator_);
+  }
 
   /// Generic function for setting the callback.
   /**
@@ -393,12 +407,91 @@ public:
     // converted to one another, e.g. shared_ptr and unique_ptr.
     using scbth = detail::SubscriptionCallbackTypeHelper<MessageT, CallbackT>;
 
-    callback_variant_ = static_cast<typename scbth::callback_type>(callback);
+    // Determine if the given CallbackT is a deprecated signature or not.
+    constexpr auto is_deprecated =
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<SubscribedType>)>
+      >::value ||
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<SubscribedType>, const rclcpp::MessageInfo &)>
+      >::value ||
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<ROSMessageType>)>
+      >::value ||
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<ROSMessageType>, const rclcpp::MessageInfo &)>
+      >::value ||
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<rclcpp::SerializedMessage>)>
+      >::value ||
+      rclcpp::function_traits::same_arguments<
+      typename scbth::callback_type,
+      std::function<void(std::shared_ptr<rclcpp::SerializedMessage>, const rclcpp::MessageInfo &)>
+      >::value;
+
+    // Use the discovered type to force the type of callback when assigning
+    // into the variant.
+    if constexpr (is_deprecated) {
+      // If deprecated, call sub-routine that is deprecated.
+      set_deprecated(static_cast<typename scbth::callback_type>(callback));
+    } else {
+      // Otherwise just assign it.
+      callback_variant_ = static_cast<typename scbth::callback_type>(callback);
+    }
 
     // Return copy of self for easier testing, normally will be compiled out.
     return *this;
   }
 
+  /// Function for shared_ptr to non-const MessageT, which is deprecated.
+  template<typename SetT>
+  // *INDENT-OFF*
+  #if !defined(RCLCPP_AVOID_DEPRECATIONS_FOR_UNIT_TESTS)
+  // suppress deprecation warnings in `test_any_subscription_callback.cpp`
+  [[deprecated("use 'void(std::shared_ptr<const MessageT>)' instead")]]
+  #endif
+  // *INDENT-ON*
+  void
+  set_deprecated(std::function<void(std::shared_ptr<SetT>)> callback)
+  {
+    callback_variant_ = callback;
+  }
+
+  /// Function for shared_ptr to non-const MessageT with MessageInfo, which is deprecated.
+  template<typename SetT>
+  // *INDENT-OFF*
+  #if !defined(RCLCPP_AVOID_DEPRECATIONS_FOR_UNIT_TESTS)
+  // suppress deprecation warnings in `test_any_subscription_callback.cpp`
+  [[deprecated(
+          "use 'void(std::shared_ptr<const MessageT>, const rclcpp::MessageInfo &)' instead"
+  )]]
+  #endif
+  // *INDENT-ON*
+  void
+  set_deprecated(std::function<void(std::shared_ptr<SetT>, const rclcpp::MessageInfo &)> callback)
+  {
+    callback_variant_ = callback;
+  }
+
+  /// Disable the callback from being called during dispatch.
+  void disable()
+  {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    callback_disabled_.store(true);
+  }
+
+  /// Enable the callback to be called during dispatch.
+  void enable()
+  {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    callback_disabled_.store(false);
+  }
+
   std::unique_ptr<ROSMessageType, ROSMessageTypeDeleter>
   create_ros_unique_ptr_from_ros_shared_ptr_message(
     const std::shared_ptr<const ROSMessageType> & message)
@@ -469,6 +562,10 @@ public:
     std::shared_ptr<ROSMessageType> message,
     const rclcpp::MessageInfo & message_info)
   {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    if (callback_disabled_.load()) {
+      return;
+    }
     TRACETOOLS_TRACEPOINT(callback_start, static_cast<const void *>(this), false);
     // Check if the variant is "unset", throw if it is.
     if (callback_variant_.index() == 0) {
@@ -569,6 +666,10 @@ public:
     std::shared_ptr<const rclcpp::SerializedMessage> serialized_message,
     const rclcpp::MessageInfo & message_info)
   {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    if (callback_disabled_.load()) {
+      return;
+    }
     TRACETOOLS_TRACEPOINT(callback_start, static_cast<const void *>(this), false);
     // Check if the variant is "unset", throw if it is.
     if (callback_variant_.index() == 0) {
@@ -648,6 +749,10 @@ public:
     std::shared_ptr<const SubscribedType> message,
     const rclcpp::MessageInfo & message_info)
   {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    if (callback_disabled_.load()) {
+      return;
+    }
     TRACETOOLS_TRACEPOINT(callback_start, static_cast<const void *>(this), true);
     // Check if the variant is "unset", throw if it is.
     if (callback_variant_.index() == 0) {
@@ -778,6 +883,10 @@ public:
     std::unique_ptr<SubscribedType, SubscribedTypeDeleter> message,
     const rclcpp::MessageInfo & message_info)
   {
+    std::unique_lock<std::recursive_mutex> callback_lock(callback_mutex_);
+    if (callback_disabled_.load()) {
+      return;
+    }
     TRACETOOLS_TRACEPOINT(callback_start, static_cast<const void *>(this), true);
     // Check if the variant is "unset", throw if it is.
     if (callback_variant_.index() == 0) {
@@ -972,6 +1081,8 @@ private:
   //   http://www.open-std.org/jtc1/sc22/wg21/docs/papers/2020/p2162r0.html
   // For now, compose the variant into this class as a private attribute.
   typename HelperT::variant_type callback_variant_;
+  std::recursive_mutex callback_mutex_;
+  std::atomic_bool callback_disabled_{false};
 
   SubscribedTypeAllocator subscribed_type_allocator_;
   SubscribedTypeDeleter subscribed_type_deleter_;

rclcpp/include/rclcpp/callback_group.hpp

@@ -97,7 +97,7 @@ public:
   RCLCPP_PUBLIC
   explicit CallbackGroup(
     CallbackGroupType group_type,
-    rclcpp::Context::WeakPtr context,
+    const rclcpp::Context::WeakPtr & context,
     bool automatically_add_to_executor_with_node = true);
 
   /// Default destructor.
@@ -106,35 +106,35 @@ public:
 
   template<typename Function>
   rclcpp::SubscriptionBase::SharedPtr
-  find_subscription_ptrs_if(Function func) const
+  find_subscription_ptrs_if(const Function & func) const
   {
     return _find_ptrs_if_impl<rclcpp::SubscriptionBase, Function>(func, subscription_ptrs_);
   }
 
   template<typename Function>
   rclcpp::TimerBase::SharedPtr
-  find_timer_ptrs_if(Function func) const
+  find_timer_ptrs_if(const Function & func) const
   {
     return _find_ptrs_if_impl<rclcpp::TimerBase, Function>(func, timer_ptrs_);
   }
 
   template<typename Function>
   rclcpp::ServiceBase::SharedPtr
-  find_service_ptrs_if(Function func) const
+  find_service_ptrs_if(const Function & func) const
   {
     return _find_ptrs_if_impl<rclcpp::ServiceBase, Function>(func, service_ptrs_);
   }
 
   template<typename Function>
   rclcpp::ClientBase::SharedPtr
-  find_client_ptrs_if(Function func) const
+  find_client_ptrs_if(const Function & func) const
   {
     return _find_ptrs_if_impl<rclcpp::ClientBase, Function>(func, client_ptrs_);
   }
 
   template<typename Function>
   rclcpp::Waitable::SharedPtr
-  find_waitable_ptrs_if(Function func) const
+  find_waitable_ptrs_if(const Function & func) const
   {
     return _find_ptrs_if_impl<rclcpp::Waitable, Function>(func, waitable_ptrs_);
   }
@@ -179,11 +179,11 @@ public:
   RCLCPP_PUBLIC
   void
   collect_all_ptrs(
-    std::function<void(const rclcpp::SubscriptionBase::SharedPtr &)> sub_func,
-    std::function<void(const rclcpp::ServiceBase::SharedPtr &)> service_func,
-    std::function<void(const rclcpp::ClientBase::SharedPtr &)> client_func,
-    std::function<void(const rclcpp::TimerBase::SharedPtr &)> timer_func,
-    std::function<void(const rclcpp::Waitable::SharedPtr &)> waitable_func) const;
+    const std::function<void(const rclcpp::SubscriptionBase::SharedPtr &)> & sub_func,
+    const std::function<void(const rclcpp::ServiceBase::SharedPtr &)> & service_func,
+    const std::function<void(const rclcpp::ClientBase::SharedPtr &)> & client_func,
+    const std::function<void(const rclcpp::TimerBase::SharedPtr &)> & timer_func,
+    const std::function<void(const rclcpp::Waitable::SharedPtr &)> & waitable_func) const;
 
   /// Return a reference to the 'associated with executor' atomic boolean.
   /**
@@ -228,31 +228,31 @@ protected:
 
   RCLCPP_PUBLIC
   void
-  add_publisher(const rclcpp::PublisherBase::SharedPtr publisher_ptr);
+  add_publisher(const rclcpp::PublisherBase::SharedPtr & publisher_ptr);
 
   RCLCPP_PUBLIC
   void
-  add_subscription(const rclcpp::SubscriptionBase::SharedPtr subscription_ptr);
+  add_subscription(const rclcpp::SubscriptionBase::SharedPtr & subscription_ptr);
 
   RCLCPP_PUBLIC
   void
-  add_timer(const rclcpp::TimerBase::SharedPtr timer_ptr);
+  add_timer(const rclcpp::TimerBase::SharedPtr & timer_ptr);
 
   RCLCPP_PUBLIC
   void
-  add_service(const rclcpp::ServiceBase::SharedPtr service_ptr);
+  add_service(const rclcpp::ServiceBase::SharedPtr & service_ptr);
 
   RCLCPP_PUBLIC
   void
-  add_client(const rclcpp::ClientBase::SharedPtr client_ptr);
+  add_client(const rclcpp::ClientBase::SharedPtr & client_ptr);
 
   RCLCPP_PUBLIC
   void
-  add_waitable(const rclcpp::Waitable::SharedPtr waitable_ptr);
+  add_waitable(const rclcpp::Waitable::SharedPtr & waitable_ptr);
 
   RCLCPP_PUBLIC
   void
-  remove_waitable(const rclcpp::Waitable::SharedPtr waitable_ptr) noexcept;
+  remove_waitable(const rclcpp::Waitable::SharedPtr & waitable_ptr) noexcept;
 
   CallbackGroupType type_;
   // Mutex to protect the subsequent vectors of pointers.
@@ -274,7 +274,7 @@ protected:
 private:
   template<typename TypeT, typename Function>
   typename TypeT::SharedPtr _find_ptrs_if_impl(
-    Function func, const std::vector<typename TypeT::WeakPtr> & vect_ptrs) const
+    const Function & func, const std::vector<typename TypeT::WeakPtr> & vect_ptrs) const
   {
     std::lock_guard<std::mutex> lock(mutex_);
     for (auto & weak_ptr : vect_ptrs) {

rclcpp/include/rclcpp/client.hpp

@@ -145,7 +145,7 @@ public:
   RCLCPP_PUBLIC
   ClientBase(
     rclcpp::node_interfaces::NodeBaseInterface * node_base,
-    rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph);
+    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph);
 
   RCLCPP_PUBLIC
   virtual ~ClientBase() = default;
@@ -221,7 +221,8 @@ public:
   virtual std::shared_ptr<void> create_response() = 0;
   virtual std::shared_ptr<rmw_request_id_t> create_request_header() = 0;
   virtual void handle_response(
-    std::shared_ptr<rmw_request_id_t> request_header, std::shared_ptr<void> response) = 0;
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & response) = 0;
 
   /// Exchange the "in use by wait set" state for this client.
   /**
@@ -296,7 +297,7 @@ public:
    * \param[in] callback functor to be called when a new response is received
    */
   void
-  set_on_new_response_callback(std::function<void(size_t)> callback)
+  set_on_new_response_callback(const std::function<void(size_t)> & callback)
   {
     if (!callback) {
       throw std::invalid_argument(
@@ -477,7 +478,7 @@ public:
    */
   Client(
     rclcpp::node_interfaces::NodeBaseInterface * node_base,
-    rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph,
+    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph,
     const std::string & service_name,
     rcl_client_options_t & client_options)
   : ClientBase(node_base, node_graph),
@@ -556,8 +557,8 @@ public:
    */
   void
   handle_response(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<void> response) override
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & response) override
   {
     std::optional<CallbackInfoVariant>
     optional_pending_request = this->get_and_erase_pending_request(request_header->sequence_number);
@@ -566,7 +567,7 @@ public:
     }
     auto & value = *optional_pending_request;
     auto typed_response = std::static_pointer_cast<typename ServiceT::Response>(
-      std::move(response));
+      response);
     if (std::holds_alternative<Promise>(value)) {
       auto & promise = std::get<Promise>(value);
       promise.set_value(std::move(typed_response));
@@ -617,7 +618,7 @@ public:
    * \return a FutureAndRequestId instance.
    */
   FutureAndRequestId
-  async_send_request(SharedRequest request)
+  async_send_request(const SharedRequest & request)
   {
     Promise promise;
     auto future = promise.get_future();
@@ -652,7 +653,7 @@ public:
     >::type * = nullptr
   >
   SharedFutureAndRequestId
-  async_send_request(SharedRequest request, CallbackT && cb)
+  async_send_request(const SharedRequest & request, CallbackT && cb)
   {
     Promise promise;
     auto shared_future = promise.get_future().share();
@@ -683,7 +684,7 @@ public:
     >::type * = nullptr
   >
   SharedFutureWithRequestAndRequestId
-  async_send_request(SharedRequest request, CallbackT && cb)
+  async_send_request(const SharedRequest & request, CallbackT && cb)
   {
     PromiseWithRequest promise;
     auto shared_future = promise.get_future().share();
@@ -795,7 +796,7 @@ public:
    */
   void
   configure_introspection(
-    Clock::SharedPtr clock, const QoS & qos_service_event_pub,
+    const Clock::SharedPtr & clock, const QoS & qos_service_event_pub,
     rcl_service_introspection_state_t introspection_state)
   {
     rcl_publisher_options_t pub_opts = rcl_publisher_get_default_options();

rclcpp/include/rclcpp/clock.hpp

@@ -117,8 +117,8 @@ public:
   RCLCPP_PUBLIC
   bool
   sleep_until(
-    Time until,
-    Context::SharedPtr context = contexts::get_global_default_context());
+    const Time & until,
+    const Context::SharedPtr & context = contexts::get_global_default_context());
 
   /**
    * Sleep for a specified Duration.
@@ -141,8 +141,8 @@ public:
   RCLCPP_PUBLIC
   bool
   sleep_for(
-    Duration rel_time,
-    Context::SharedPtr context = contexts::get_global_default_context());
+    const Duration & rel_time,
+    const Context::SharedPtr & context = contexts::get_global_default_context());
 
   /**
    * Check if the clock is started.
@@ -168,7 +168,7 @@ public:
    */
   RCLCPP_PUBLIC
   bool
-  wait_until_started(Context::SharedPtr context = contexts::get_global_default_context());
+  wait_until_started(const Context::SharedPtr & context = contexts::get_global_default_context());
 
   /**
    * Wait for clock to start, with timeout.
@@ -186,7 +186,7 @@ public:
   bool
   wait_until_started(
     const rclcpp::Duration & timeout,
-    Context::SharedPtr context = contexts::get_global_default_context(),
+    const Context::SharedPtr & context = contexts::get_global_default_context(),
     const rclcpp::Duration & wait_tick_ns = rclcpp::Duration(0, static_cast<uint32_t>(1e7)));
 
   /**
@@ -238,8 +238,8 @@ public:
   RCLCPP_PUBLIC
   JumpHandler::SharedPtr
   create_jump_callback(
-    JumpHandler::pre_callback_t pre_callback,
-    JumpHandler::post_callback_t post_callback,
+    const JumpHandler::pre_callback_t & pre_callback,
+    const JumpHandler::post_callback_t & post_callback,
     const rcl_jump_threshold_t & threshold);
 
 private:
@@ -327,7 +327,7 @@ public:
   RCLCPP_PUBLIC
   ClockConditionalVariable(
     const rclcpp::Clock::SharedPtr & clock,
-    rclcpp::Context::SharedPtr context = rclcpp::contexts::get_global_default_context());
+    const rclcpp::Context::SharedPtr & context = rclcpp::contexts::get_global_default_context());
   RCLCPP_PUBLIC
   ~ClockConditionalVariable();
 
@@ -347,7 +347,7 @@ public:
   RCLCPP_PUBLIC
   bool
   wait_until(
-    std::unique_lock<std::mutex> & lock, rclcpp::Time until,
+    std::unique_lock<std::mutex> & lock, const rclcpp::Time & until,
     const std::function<bool ()> & pred);
 
   /**

rclcpp/include/rclcpp/context.hpp

@@ -229,7 +229,7 @@ public:
   RCLCPP_PUBLIC
   virtual
   OnShutdownCallback
-  on_shutdown(OnShutdownCallback callback);
+  on_shutdown(const OnShutdownCallback & callback);
 
   /// Add a on_shutdown callback to be called when shutdown is called for this context.
   /**
@@ -253,7 +253,7 @@ public:
   RCLCPP_PUBLIC
   virtual
   OnShutdownCallbackHandle
-  add_on_shutdown_callback(OnShutdownCallback callback);
+  add_on_shutdown_callback(const OnShutdownCallback & callback);
 
   /// Remove an registered on_shutdown callbacks.
   /**
@@ -280,7 +280,7 @@ public:
   RCLCPP_PUBLIC
   virtual
   PreShutdownCallbackHandle
-  add_pre_shutdown_callback(PreShutdownCallback callback);
+  add_pre_shutdown_callback(const PreShutdownCallback & callback);
 
   /// Remove an registered pre_shutdown callback.
   /**
@@ -417,7 +417,7 @@ private:
   RCLCPP_LOCAL
   ShutdownCallbackHandle
   add_shutdown_callback(
-    ShutdownCallback callback);
+    const ShutdownCallback & callback);
 
   template<ShutdownType shutdown_type>
   RCLCPP_LOCAL

rclcpp/include/rclcpp/create_generic_client.hpp

@@ -46,13 +46,13 @@ namespace rclcpp
 RCLCPP_PUBLIC
 rclcpp::GenericClient::SharedPtr
 create_generic_client(
-  std::shared_ptr<node_interfaces::NodeBaseInterface> node_base,
-  std::shared_ptr<node_interfaces::NodeGraphInterface> node_graph,
-  std::shared_ptr<node_interfaces::NodeServicesInterface> node_services,
+  const std::shared_ptr<node_interfaces::NodeBaseInterface> & node_base,
+  const std::shared_ptr<node_interfaces::NodeGraphInterface> & node_graph,
+  const std::shared_ptr<node_interfaces::NodeServicesInterface> & node_services,
   const std::string & service_name,
   const std::string & service_type,
   const rclcpp::QoS & qos = rclcpp::ServicesQoS(),
-  rclcpp::CallbackGroup::SharedPtr group = nullptr);
+  const rclcpp::CallbackGroup::SharedPtr & group = rclcpp::CallbackGroup::SharedPtr());
 
 /// Create a generic service client with a name of given type.
 /**

rclcpp/include/rclcpp/detail/qos_parameters.hpp

@@ -270,8 +270,8 @@ apply_qos_override(
       RCLCPP_DETAIL_APPLY_QOS_OVERRIDE_FROM_PARAMETER_STRING(
         reliability, RELIABILITY, value, qos);
       break;
-    default:
-      throw std::invalid_argument{"unknown QosPolicyKind"};
+    case QosPolicyKind::Invalid:
+      throw std::invalid_argument{"invalid QosPolicyKind"};
   }
 }
 
@@ -332,9 +332,11 @@ get_default_qos_param_value(rclcpp::QosPolicyKind kind, const rclcpp::QoS & qos)
       return ParameterValue(
         check_if_stringified_policy_is_null(
           rmw_qos_reliability_policy_to_str(rmw_qos.reliability), kind));
-    default:
-      throw std::invalid_argument{"unknown QoS policy kind"};
+    case QosPolicyKind::Invalid:
+      throw std::invalid_argument{"invalid QoS policy kind"};
   }
+
+  return ParameterValue();
 }
 
 }  // namespace detail

rclcpp/include/rclcpp/detail/resolve_enable_topic_statistics.hpp

@@ -29,7 +29,7 @@ template<typename OptionsT, typename NodeBaseT>
 bool
 resolve_enable_topic_statistics(const OptionsT & options, const NodeBaseT & node_base)
 {
-  bool topic_stats_enabled;
+  bool topic_stats_enabled = false;
   switch (options.topic_stats_options.state) {
     case TopicStatisticsState::Enable:
       topic_stats_enabled = true;

rclcpp/include/rclcpp/detail/resolve_use_intra_process.hpp

@@ -30,7 +30,7 @@ template<typename OptionsT, typename NodeBaseT>
 bool
 resolve_use_intra_process(const OptionsT & options, const NodeBaseT & node_base)
 {
-  bool use_intra_process;
+  bool use_intra_process = false;
   switch (options.use_intra_process_comm) {
     case IntraProcessSetting::Enable:
       use_intra_process = true;
@@ -43,7 +43,6 @@ resolve_use_intra_process(const OptionsT & options, const NodeBaseT & node_base)
       break;
     default:
       throw std::runtime_error("Unrecognized IntraProcessSetting value");
-      break;
   }
 
   return use_intra_process;

rclcpp/include/rclcpp/event_handler.hpp

@@ -15,6 +15,7 @@
 #ifndef RCLCPP__EVENT_HANDLER_HPP_
 #define RCLCPP__EVENT_HANDLER_HPP_
 
+#include <atomic>
 #include <functional>
 #include <memory>
 #include <mutex>
@@ -110,6 +111,14 @@ public:
   RCLCPP_PUBLIC
   virtual ~EventHandlerBase();
 
+  RCLCPP_PUBLIC
+  virtual
+  void enable() = 0;
+
+  RCLCPP_PUBLIC
+  virtual
+  void disable() = 0;
+
   /// Get the number of ready events
   RCLCPP_PUBLIC
   size_t
@@ -192,7 +201,7 @@ public:
         }
       };
 
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_event_callback_mutex_);
 
     // Set it temporarily to the new callback, while we replace the old one.
     // This two-step setting, prevents a gap where the old std::function has
@@ -215,7 +224,7 @@ public:
   void
   clear_on_ready_callback() override
   {
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_event_callback_mutex_);
     if (on_new_event_callback_) {
       set_on_new_event_callback(nullptr, nullptr);
       on_new_event_callback_ = nullptr;
@@ -234,7 +243,7 @@ protected:
   void
   set_on_new_event_callback(rcl_event_callback_t callback, const void * user_data);
 
-  std::recursive_mutex callback_mutex_;
+  std::recursive_mutex on_new_event_callback_mutex_;
   std::function<void(size_t)> on_new_event_callback_{nullptr};
 
   rcl_event_t event_handle_;
@@ -302,6 +311,10 @@ public:
   void
   execute(const std::shared_ptr<void> & data) override
   {
+    std::unique_lock<std::mutex> event_callback_lock(event_callback_mutex_);
+    if (disabled_.load()) {
+      return;
+    }
     if (!data) {
       throw std::runtime_error("'data' is empty");
     }
@@ -310,12 +323,53 @@ public:
     callback_ptr.reset();
   }
 
+  /// Disable the event callback from being called when execute(..) invoked
+  /**
+   * This will also temporarily remove the on_new_event_callback from the underlying rmw layer,
+   *  so that it is not called from the middleware while disabled.
+   */
+  void disable() override
+  {
+    {
+      // Temporary remove the on_new_event_callback_ to prevent it from being called
+      std::lock_guard<std::recursive_mutex> on_new_event_lock(on_new_event_callback_mutex_);
+      if (on_new_event_callback_) {
+        set_on_new_event_callback(nullptr, nullptr);
+      }
+    }
+    std::lock_guard<std::mutex> event_callback_lock(event_callback_mutex_);
+    disabled_.store(true);
+  }
+
+  /// Enable the event callback to be called when execute(..) invoked
+  /**
+   * This will also set back the on_new_event_callback to the underlying rmw layer, if it was
+   * previously removed with disable().
+   */
+  void enable() override
+  {
+    {
+      // Set callback again if it was previously removed in disable()
+      std::lock_guard<std::recursive_mutex> on_new_event_lock(on_new_event_callback_mutex_);
+      if (on_new_event_callback_) {
+        set_on_new_event_callback(
+          rclcpp::detail::cpp_callback_trampoline<
+            decltype(on_new_event_callback_), const void *, size_t>,
+          static_cast<const void *>(&on_new_event_callback_));
+      }
+    }
+    std::lock_guard<std::mutex> event_callback_lock(event_callback_mutex_);
+    disabled_.store(false);
+  }
+
 private:
   using EventCallbackInfoT = typename std::remove_reference<typename
       rclcpp::function_traits::function_traits<EventCallbackT>::template argument_type<0>>::type;
 
   ParentHandleT parent_handle_;
   EventCallbackT event_callback_;
+  std::mutex event_callback_mutex_;
+  std::atomic_bool disabled_{false};
 };
 }  // namespace rclcpp
 

rclcpp/include/rclcpp/executor.hpp

@@ -102,8 +102,8 @@ public:
   RCLCPP_PUBLIC
   virtual void
   add_callback_group(
-    rclcpp::CallbackGroup::SharedPtr group_ptr,
-    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+    const rclcpp::CallbackGroup::SharedPtr & group_ptr,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
     bool notify = true);
 
   /// Get callback groups that belong to executor.
@@ -173,7 +173,7 @@ public:
   RCLCPP_PUBLIC
   virtual void
   remove_callback_group(
-    rclcpp::CallbackGroup::SharedPtr group_ptr,
+    const rclcpp::CallbackGroup::SharedPtr & group_ptr,
     bool notify = true);
 
   /// Add a node to the executor.
@@ -197,7 +197,9 @@ public:
    */
   RCLCPP_PUBLIC
   virtual void
-  add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify = true);
+  add_node(
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+    bool notify = true);
 
   /// Convenience function which takes Node and forwards NodeBaseInterface.
   /**
@@ -205,7 +207,7 @@ public:
    */
   RCLCPP_PUBLIC
   virtual void
-  add_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true);
+  add_node(const std::shared_ptr<rclcpp::Node> & node_ptr, bool notify = true);
 
   /// Remove a node from the executor.
   /**
@@ -225,7 +227,9 @@ public:
    */
   RCLCPP_PUBLIC
   virtual void
-  remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify = true);
+  remove_node(
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+    bool notify = true);
 
   /// Convenience function which takes Node and forwards NodeBaseInterface.
   /**
@@ -233,7 +237,7 @@ public:
    */
   RCLCPP_PUBLIC
   virtual void
-  remove_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify = true);
+  remove_node(const std::shared_ptr<rclcpp::Node> & node_ptr, bool notify = true);
 
   /// Add a node to executor, execute the next available unit of work, and remove the node.
   /**
@@ -245,7 +249,7 @@ public:
   template<typename RepT = int64_t, typename T = std::milli>
   void
   spin_node_once(
-    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node,
     std::chrono::duration<RepT, T> timeout = std::chrono::duration<RepT, T>(-1))
   {
     return spin_node_once_nanoseconds(
@@ -258,7 +262,7 @@ public:
   template<typename NodeT = rclcpp::Node, typename RepT = int64_t, typename T = std::milli>
   void
   spin_node_once(
-    std::shared_ptr<NodeT> node,
+    const std::shared_ptr<NodeT> & node,
     std::chrono::duration<RepT, T> timeout = std::chrono::duration<RepT, T>(-1))
   {
     return spin_node_once_nanoseconds(
@@ -273,12 +277,12 @@ public:
    */
   RCLCPP_PUBLIC
   virtual void
-  spin_node_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node);
+  spin_node_some(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node);
 
   /// Convenience function which takes Node and forwards NodeBaseInterface.
   RCLCPP_PUBLIC
   virtual void
-  spin_node_some(std::shared_ptr<rclcpp::Node> node);
+  spin_node_some(const std::shared_ptr<rclcpp::Node> & node);
 
   /// Collect work once and execute all available work, optionally within a max duration.
   /**
@@ -321,13 +325,13 @@ public:
   RCLCPP_PUBLIC
   virtual void
   spin_node_all(
-    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node,
     std::chrono::nanoseconds max_duration);
 
   /// Convenience function which takes Node and forwards NodeBaseInterface.
   RCLCPP_PUBLIC
   virtual void
-  spin_node_all(std::shared_ptr<rclcpp::Node> node, std::chrono::nanoseconds max_duration);
+  spin_node_all(const std::shared_ptr<rclcpp::Node> & node, std::chrono::nanoseconds max_duration);
 
   /// Collect and execute work repeatedly within a duration or until no more work is available.
   /**
@@ -427,7 +431,7 @@ protected:
   RCLCPP_PUBLIC
   void
   spin_node_once_nanoseconds(
-    rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node,
     std::chrono::nanoseconds timeout);
 
   /// Spin (blocking) until the future is complete, it times out waiting, or rclcpp is interrupted.
@@ -478,7 +482,7 @@ protected:
   RCLCPP_PUBLIC
   static void
   execute_subscription(
-    rclcpp::SubscriptionBase::SharedPtr subscription);
+    const rclcpp::SubscriptionBase::SharedPtr & subscription);
 
   /// Run timer executable.
   /**
@@ -487,7 +491,7 @@ protected:
    */
   RCLCPP_PUBLIC
   static void
-  execute_timer(rclcpp::TimerBase::SharedPtr timer, const std::shared_ptr<void> & data_ptr);
+  execute_timer(const rclcpp::TimerBase::SharedPtr & timer, const std::shared_ptr<void> & data_ptr);
 
   /// Run service server executable.
   /**
@@ -496,7 +500,7 @@ protected:
    */
   RCLCPP_PUBLIC
   static void
-  execute_service(rclcpp::ServiceBase::SharedPtr service);
+  execute_service(const rclcpp::ServiceBase::SharedPtr & service);
 
   /// Run service client executable.
   /**
@@ -505,7 +509,7 @@ protected:
    */
   RCLCPP_PUBLIC
   static void
-  execute_client(rclcpp::ClientBase::SharedPtr client);
+  execute_client(const rclcpp::ClientBase::SharedPtr & client);
 
   /// Gather all of the waitable entities from associated nodes and callback groups.
   RCLCPP_PUBLIC

rclcpp/include/rclcpp/executors.hpp

@@ -47,7 +47,7 @@ namespace rclcpp
 RCLCPP_PUBLIC
 void
 spin_all(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
   std::chrono::nanoseconds max_duration);
 
 /**
@@ -68,7 +68,7 @@ spin_all(
 [[deprecated("use SingleThreadedExecutor::spin_all instead")]]
 RCLCPP_PUBLIC
 void
-spin_all(rclcpp::Node::SharedPtr node_ptr, std::chrono::nanoseconds max_duration);
+spin_all(const rclcpp::Node::SharedPtr & node_ptr, std::chrono::nanoseconds max_duration);
 
 /**
  * @brief Create a default single-threaded executor and execute any immediately available work.
@@ -87,7 +87,7 @@ spin_all(rclcpp::Node::SharedPtr node_ptr, std::chrono::nanoseconds max_duration
 [[deprecated("use SingleThreadedExecutor::spin_some instead")]]
 RCLCPP_PUBLIC
 void
-spin_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+spin_some(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr);
 
 /**
  * @brief Create a default single-threaded executor and execute any immediately available work.
@@ -106,17 +106,17 @@ spin_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
 [[deprecated("use SingleThreadedExecutor::spin_some instead")]]
 RCLCPP_PUBLIC
 void
-spin_some(rclcpp::Node::SharedPtr node_ptr);
+spin_some(const rclcpp::Node::SharedPtr & node_ptr);
 
 /// Create a default single-threaded executor and spin the specified node.
 /** \param[in] node_ptr Shared pointer to the node to spin. */
 RCLCPP_PUBLIC
 void
-spin(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+spin(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr);
 
 RCLCPP_PUBLIC
 void
-spin(rclcpp::Node::SharedPtr node_ptr);
+spin(const rclcpp::Node::SharedPtr & node_ptr);
 
 namespace executors
 {
@@ -140,7 +140,7 @@ template<typename FutureT, typename TimeRepT = int64_t, typename TimeT = std::mi
 rclcpp::FutureReturnCode
 spin_node_until_future_complete(
   rclcpp::Executor & executor,
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
   const FutureT & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
@@ -157,7 +157,7 @@ template<typename NodeT = rclcpp::Node, typename FutureT, typename TimeRepT = in
 rclcpp::FutureReturnCode
 spin_node_until_future_complete(
   rclcpp::Executor & executor,
-  std::shared_ptr<NodeT> node_ptr,
+  const std::shared_ptr<NodeT> & node_ptr,
   const FutureT & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
@@ -173,7 +173,7 @@ spin_node_until_future_complete(
 template<typename FutureT, typename TimeRepT = int64_t, typename TimeT = std::milli>
 rclcpp::FutureReturnCode
 spin_until_future_complete(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
   const FutureT & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {
@@ -187,7 +187,7 @@ template<typename NodeT = rclcpp::Node, typename FutureT, typename TimeRepT = in
   typename TimeT = std::milli>
 rclcpp::FutureReturnCode
 spin_until_future_complete(
-  std::shared_ptr<NodeT> node_ptr,
+  const std::shared_ptr<NodeT> & node_ptr,
   const FutureT & future,
   std::chrono::duration<TimeRepT, TimeT> timeout = std::chrono::duration<TimeRepT, TimeT>(-1))
 {

rclcpp/include/rclcpp/executors/executor_entities_collector.hpp

@@ -63,7 +63,7 @@ public:
    */
   RCLCPP_PUBLIC
   explicit ExecutorEntitiesCollector(
-    std::shared_ptr<ExecutorNotifyWaitable> notify_waitable);
+    const std::shared_ptr<ExecutorNotifyWaitable> & notify_waitable);
 
   /// Destructor
   RCLCPP_PUBLIC
@@ -82,7 +82,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+  add_node(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr);
 
   /// Remove a node from the entity collector
   /**
@@ -92,7 +92,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr);
+  remove_node(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr);
 
   /// Add a callback group to the entity collector
   /**
@@ -101,7 +101,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  add_callback_group(rclcpp::CallbackGroup::SharedPtr group_ptr);
+  add_callback_group(const rclcpp::CallbackGroup::SharedPtr & group_ptr);
 
   /// Remove a callback group from the entity collector
   /**
@@ -111,7 +111,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  remove_callback_group(rclcpp::CallbackGroup::SharedPtr group_ptr);
+  remove_callback_group(const rclcpp::CallbackGroup::SharedPtr & group_ptr);
 
   /// Get all callback groups known to this entity collector
   /**
@@ -211,7 +211,7 @@ protected:
   RCLCPP_PUBLIC
   void
   add_callback_group_to_collection(
-    rclcpp::CallbackGroup::SharedPtr group_ptr,
+    const rclcpp::CallbackGroup::SharedPtr & group_ptr,
     CallbackGroupCollection & collection)  RCPPUTILS_TSA_REQUIRES(mutex_);
 
   /// Iterate over queued added/remove nodes and callback_groups

rclcpp/include/rclcpp/executors/executor_notify_waitable.hpp

@@ -43,7 +43,8 @@ public:
    */
   RCLCPP_PUBLIC
   explicit ExecutorNotifyWaitable(
-    std::function<void(void)> on_execute_callback = {}, const rclcpp::Context::SharedPtr & context =
+    const std::function<void(void)> & on_execute_callback = {},
+    const rclcpp::Context::SharedPtr & context =
     rclcpp::contexts::get_global_default_context());
 
   // Destructor
@@ -115,7 +116,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  add_guard_condition(rclcpp::GuardCondition::WeakPtr guard_condition);
+  add_guard_condition(const rclcpp::GuardCondition::WeakPtr & guard_condition);
 
   /// Unset any callback registered via set_on_ready_callback.
   /**
@@ -139,7 +140,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  remove_guard_condition(rclcpp::GuardCondition::WeakPtr weak_guard_condition);
+  remove_guard_condition(const rclcpp::GuardCondition::WeakPtr & weak_guard_condition);
 
   /// Get the number of ready guard_conditions
   /**

rclcpp/include/rclcpp/experimental/create_intra_process_buffer.hpp

@@ -82,10 +82,9 @@ create_intra_process_buffer(
 
         break;
       }
-    default:
+    case IntraProcessBufferType::CallbackDefault:
       {
-        throw std::runtime_error("Unrecognized IntraProcessBufferType value");
-        break;
+        throw std::runtime_error("IntraProcessBufferType::CallbackDefault is not allowed");
       }
   }
 

rclcpp/include/rclcpp/experimental/intra_process_manager.hpp

@@ -19,6 +19,7 @@
 
 #include <shared_mutex>
 
+#include <algorithm>
 #include <iterator>
 #include <memory>
 #include <stdexcept>
@@ -118,7 +119,8 @@ public:
     typename Alloc = std::allocator<ROSMessageType>
   >
   uint64_t
-  add_subscription(rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr subscription)
+  add_subscription(
+    const rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr & subscription)
   {
     std::unique_lock<std::shared_timed_mutex> lock(mutex_);
 
@@ -175,8 +177,8 @@ public:
   RCLCPP_PUBLIC
   uint64_t
   add_publisher(
-    rclcpp::PublisherBase::SharedPtr publisher,
-    rclcpp::experimental::buffers::IntraProcessBufferBase::SharedPtr buffer =
+    const rclcpp::PublisherBase::SharedPtr & publisher,
+    const rclcpp::experimental::buffers::IntraProcessBufferBase::SharedPtr & buffer =
     rclcpp::experimental::buffers::IntraProcessBufferBase::SharedPtr());
 
   /// Unregister a publisher using the publisher's unique id.
@@ -386,6 +388,39 @@ private:
     std::vector<uint64_t> take_ownership_subscriptions;
   };
 
+  /// Hash function for rmw_gid_t to enable use in unordered_map
+  struct rmw_gid_hash
+  {
+    std::size_t operator()(const rmw_gid_t & gid) const noexcept
+    {
+      // Using the FNV-1a hash algorithm on the gid data
+      constexpr std::size_t FNV_prime = 1099511628211u;
+      std::size_t result = 14695981039346656037u;
+
+      for (std::size_t i = 0; i < RMW_GID_STORAGE_SIZE; ++i) {
+        result ^= gid.data[i];
+        result *= FNV_prime;
+      }
+      return result;
+    }
+  };
+
+  /// Equality comparison for rmw_gid_t to enable use in unordered_map
+  struct rmw_gid_equal
+  {
+    bool operator()(const rmw_gid_t & lhs, const rmw_gid_t & rhs) const noexcept
+    {
+      // Compare the data bytes only.
+      // implementation_identifier pointer comparison is not used here because
+      // intra-process communication is always within the same process and RMW,
+      // and pointer comparison is fragile across dynamically loaded components.
+      return std::equal(
+        std::begin(lhs.data),
+        std::end(lhs.data),
+        std::begin(rhs.data));
+    }
+  };
+
   using SubscriptionMap =
     std::unordered_map<uint64_t, rclcpp::experimental::SubscriptionIntraProcessBase::WeakPtr>;
 
@@ -398,6 +433,16 @@ private:
   using PublisherToSubscriptionIdsMap =
     std::unordered_map<uint64_t, SplittedSubscriptions>;
 
+  /// Structure to store publisher information in GID lookup map
+  struct PublisherInfo
+  {
+    uint64_t pub_id;
+    rclcpp::PublisherBase::WeakPtr publisher;
+  };
+
+  using GidToPublisherInfoMap =
+    std::unordered_map<rmw_gid_t, PublisherInfo, rmw_gid_hash, rmw_gid_equal>;
+
   RCLCPP_PUBLIC
   static
   uint64_t
@@ -410,8 +455,8 @@ private:
   RCLCPP_PUBLIC
   bool
   can_communicate(
-    rclcpp::PublisherBase::SharedPtr pub,
-    rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr sub) const;
+    const rclcpp::PublisherBase::SharedPtr & pub,
+    const rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr & sub) const;
 
   template<
     typename ROSMessageType,
@@ -642,6 +687,8 @@ private:
   PublisherBufferMap publisher_buffers_;
 
   mutable std::shared_timed_mutex mutex_;
+
+  GidToPublisherInfoMap gid_to_publisher_info_;
 };
 
 }  // namespace experimental

rclcpp/include/rclcpp/experimental/subscription_intra_process.hpp

@@ -154,6 +154,29 @@ public:
     execute_impl<SubscribedType>(data);
   }
 
+  /// Disable callbacks from being called
+  /**
+    * This method will block, until any subscription's callbacks currently being executed are
+    * finished.
+    * This method is thread safe, and provides a safe way to atomically disable the callbacks.
+    */
+  void disable_callbacks() override
+  {
+    SubscriptionIntraProcessBase::disable_callbacks();
+    any_callback_.disable();
+  }
+
+  /// Enable the callbacks to be called
+  /**
+    * This method is thread safe, and provides a safe way to atomically enable the callbacks
+    * in a multithreaded environment.
+    */
+  void enable_callbacks() override
+  {
+    SubscriptionIntraProcessBase::enable_callbacks();
+    any_callback_.enable();
+  }
+
 protected:
   template<typename T>
   typename std::enable_if<std::is_same<T, rcl_serialized_message_t>::value, void>::type

rclcpp/include/rclcpp/experimental/subscription_intra_process_base.hpp

@@ -87,6 +87,22 @@ public:
   void
   execute(const std::shared_ptr<void> & data) override = 0;
 
+  /// Disable callbacks from being called
+  /**
+   * This function temporary disable on_new_message_callback to prevent it from being called.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  void disable_callbacks();
+
+  /// Enable the callbacks to be called
+  /**
+    * This function enable the on_new_message_callback if it was previously set.
+    */
+  RCLCPP_PUBLIC
+  virtual
+  void enable_callbacks();
+
   virtual
   bool
   use_take_shared_method() const = 0;
@@ -158,7 +174,7 @@ public:
         }
       };
 
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
     on_new_message_callback_ = new_callback;
 
     if (unread_count_ > 0) {
@@ -176,7 +192,7 @@ public:
   void
   clear_on_ready_callback() override
   {
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
     on_new_message_callback_ = nullptr;
   }
 
@@ -188,8 +204,9 @@ public:
   }
 
 protected:
-  std::recursive_mutex callback_mutex_;
+  std::recursive_mutex on_new_message_callback_mutex_;
   std::function<void(size_t)> on_new_message_callback_ {nullptr};
+  bool on_new_message_callback_disabled_{false};
   size_t unread_count_{0};
   rclcpp::GuardCondition gc_;
 
@@ -199,11 +216,13 @@ protected:
   void
   invoke_on_new_message()
   {
-    std::lock_guard<std::recursive_mutex> lock(this->callback_mutex_);
-    if (this->on_new_message_callback_) {
-      this->on_new_message_callback_(1);
-    } else {
-      this->unread_count_++;
+    std::lock_guard<std::recursive_mutex> lock(this->on_new_message_callback_mutex_);
+    if (!on_new_message_callback_disabled_) {
+      if (this->on_new_message_callback_) {
+        this->on_new_message_callback_(1);
+      } else {
+        this->unread_count_++;
+      }
     }
   }
 

rclcpp/include/rclcpp/experimental/timers_manager.hpp

@@ -103,7 +103,7 @@ public:
    * @throws std::invalid_argument if timer is a nullptr.
    */
   RCLCPP_PUBLIC
-  void add_timer(rclcpp::TimerBase::SharedPtr timer);
+  void add_timer(const rclcpp::TimerBase::SharedPtr & timer);
 
   /**
    * @brief Remove a single timer from the object storage.
@@ -113,7 +113,7 @@ public:
    * @param timer the timer to remove.
    */
   RCLCPP_PUBLIC
-  void remove_timer(rclcpp::TimerBase::SharedPtr timer);
+  void remove_timer(const rclcpp::TimerBase::SharedPtr & timer);
 
   /**
    * @brief Remove all the timers stored in the object.

rclcpp/include/rclcpp/generic_client.hpp

@@ -95,7 +95,7 @@ public:
 
   GenericClient(
     rclcpp::node_interfaces::NodeBaseInterface * node_base,
-    rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph,
+    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph,
     const std::string & service_name,
     const std::string & service_type,
     rcl_client_options_t & client_options);
@@ -111,8 +111,8 @@ public:
   RCLCPP_PUBLIC
   void
   handle_response(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<void> response) override;
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & response) override;
 
   /// Send a request to the service server.
   /**
@@ -144,7 +144,7 @@ public:
    */
   RCLCPP_PUBLIC
   FutureAndRequestId
-  async_send_request(const Request request);
+  async_send_request(const Request & request);
 
   /// Send a request to the service server and schedule a callback in the executor.
   /**
@@ -172,7 +172,7 @@ public:
     >::type * = nullptr
   >
   SharedFutureAndRequestId
-  async_send_request(const Request request, CallbackT && cb)
+  async_send_request(const Request & request, CallbackT && cb)
   {
     Promise promise;
     auto shared_future = promise.get_future().share();
@@ -280,7 +280,7 @@ protected:
   RCLCPP_PUBLIC
   int64_t
   async_send_request_impl(
-    const Request request,
+    const Request & request,
     CallbackInfoVariant value);
 
   std::optional<CallbackInfoVariant>

rclcpp/include/rclcpp/generic_service.hpp

@@ -159,10 +159,10 @@ public:
     if (std::holds_alternative<SharedPtrCallback>(callback_)) {
       (void)request_header;
       const auto & cb = std::get<SharedPtrCallback>(callback_);
-      cb(std::move(request), std::move(response));
+      cb(std::move(request), response);
     } else if (std::holds_alternative<SharedPtrWithRequestHeaderCallback>(callback_)) {
       const auto & cb = std::get<SharedPtrWithRequestHeaderCallback>(callback_);
-      cb(request_header, std::move(request), std::move(response));
+      cb(request_header, std::move(request), response);
     }
     TRACETOOLS_TRACEPOINT(callback_end, static_cast<const void *>(this));
     return response;
@@ -245,7 +245,7 @@ public:
    */
   RCLCPP_PUBLIC
   GenericService(
-    std::shared_ptr<rcl_node_t> node_handle,
+    const std::shared_ptr<rcl_node_t> & node_handle,
     const std::string & service_name,
     const std::string & service_type,
     GenericServiceCallback any_callback,
@@ -270,7 +270,7 @@ public:
    */
   RCLCPP_PUBLIC
   bool
-  take_request(SharedRequest request_out, rmw_request_id_t & request_id_out);
+  take_request(SharedRequest & request_out, rmw_request_id_t & request_id_out);
 
   RCLCPP_PUBLIC
   std::shared_ptr<void>
@@ -287,8 +287,8 @@ public:
   RCLCPP_PUBLIC
   void
   handle_request(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<void> request) override;
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & request) override;
 
   RCLCPP_PUBLIC
   void

rclcpp/include/rclcpp/generic_subscription.hpp

@@ -80,7 +80,7 @@ public:
       node_base,
       *rclcpp::get_message_typesupport_handle(topic_type, "rosidl_typesupport_cpp", *ts_lib),
       topic_name,
-      options.to_rcl_subscription_options(qos),
+      force_cpu_buffer_backend_(options).to_rcl_subscription_options(qos),
       options.event_callbacks,
       options.use_default_callbacks,
       DeliveredMessageKind::SERIALIZED_MESSAGE),
@@ -111,6 +111,26 @@ public:
   RCLCPP_PUBLIC
   std::shared_ptr<rclcpp::SerializedMessage> create_serialized_message() override;
 
+  /// Disable callbacks from being called
+  /**
+    * This method will block, until any subscription's callbacks provided during construction
+    * currently being executed are finished.
+    * \note This method also temporary removes the on new message callback and all
+    * on new event callbacks from the rmw layer to prevent them from being called. However, this
+    * method will not block and wait until the currently executing on_new_[message]event callbacks
+    * are finished.
+    */
+  RCLCPP_PUBLIC
+  void disable_callbacks() override;
+
+  /// Enable the callbacks to be called
+  /**
+    * This method is thread safe, and provides a safe way to atomically enable the callbacks
+    * in a multithreaded environment.
+    */
+  RCLCPP_PUBLIC
+  void enable_callbacks() override;
+
   /// Cast the message to a rclcpp::SerializedMessage and call the callback.
   RCLCPP_PUBLIC
   void handle_message(
@@ -162,6 +182,17 @@ public:
 
 private:
   RCLCPP_DISABLE_COPY(GenericSubscription)
+
+  template<typename AllocatorT>
+  static rclcpp::SubscriptionOptionsWithAllocator<AllocatorT>
+  force_cpu_buffer_backend_(
+    const rclcpp::SubscriptionOptionsWithAllocator<AllocatorT> & options)
+  {
+    auto opts = options;
+    opts.acceptable_buffer_backends = "cpu";
+    return opts;
+  }
+
   AnySubscriptionCallback<rclcpp::SerializedMessage, std::allocator<void>> any_callback_;
   // The type support library should stay loaded, so it is stored in the GenericSubscription
   std::shared_ptr<rcpputils::SharedLibrary> ts_lib_;

rclcpp/include/rclcpp/guard_condition.hpp

@@ -120,7 +120,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  set_on_trigger_callback(std::function<void(size_t)> callback);
+  set_on_trigger_callback(const std::function<void(size_t)> & callback);
 
 protected:
   rcl_guard_condition_t rcl_guard_condition_;

rclcpp/include/rclcpp/message_memory_strategy.hpp

@@ -18,6 +18,7 @@
 #include <memory>
 #include <stdexcept>
 
+#include "rcl/allocator.h"
 #include "rcl/types.h"
 
 #include "rclcpp/allocator/allocator_common.hpp"
@@ -61,7 +62,16 @@ public:
     message_allocator_ = std::make_shared<MessageAlloc>();
     serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>();
     buffer_allocator_ = std::make_shared<BufferAlloc>();
-    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
+    if constexpr (std::is_same_v<Alloc, std::allocator<void>>) {
+      rcutils_allocator_ = rcl_get_default_allocator();
+    } else {
+      if constexpr (rclcpp::allocator::has_get_rcl_allocator_v<Alloc>) {
+        rcutils_allocator_ = message_allocator_->get_rcl_allocator();
+      } else {
+        rcutils_allocator_ = allocator::get_rcl_allocator<char,
+            BufferAlloc>(*buffer_allocator_.get());
+      }
+    }
   }
 
   explicit MessageMemoryStrategy(std::shared_ptr<Alloc> allocator)
@@ -69,7 +79,16 @@ public:
     message_allocator_ = std::make_shared<MessageAlloc>(*allocator.get());
     serialized_message_allocator_ = std::make_shared<SerializedMessageAlloc>(*allocator.get());
     buffer_allocator_ = std::make_shared<BufferAlloc>(*allocator.get());
-    rcutils_allocator_ = allocator::get_rcl_allocator<char, BufferAlloc>(*buffer_allocator_.get());
+    if constexpr (std::is_same_v<Alloc, std::allocator<void>>) {
+      rcutils_allocator_ = rcl_get_default_allocator();
+    } else {
+      if constexpr (rclcpp::allocator::has_get_rcl_allocator_v<Alloc>) {
+        rcutils_allocator_ = allocator->get_rcl_allocator();
+      } else {
+        rcutils_allocator_ = allocator::get_rcl_allocator<char,
+            BufferAlloc>(*buffer_allocator_.get());
+      }
+    }
   }
 
   virtual ~MessageMemoryStrategy() = default;

rclcpp/include/rclcpp/node.hpp

@@ -242,7 +242,7 @@ public:
   create_wall_timer(
     std::chrono::duration<DurationRepT, DurationT> period,
     CallbackT callback,
-    rclcpp::CallbackGroup::SharedPtr group = nullptr,
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr,
     bool autostart = true);
 
   /// Create a timer that uses the node clock to drive the callback.
@@ -256,7 +256,7 @@ public:
   create_timer(
     std::chrono::duration<DurationRepT, DurationT> period,
     CallbackT callback,
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /// Create and return a Client.
   /**
@@ -270,7 +270,7 @@ public:
   create_client(
     const std::string & service_name,
     const rclcpp::QoS & qos = rclcpp::ServicesQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /// Create and return a Service.
   /**
@@ -286,7 +286,7 @@ public:
     const std::string & service_name,
     CallbackT && callback,
     const rclcpp::QoS & qos = rclcpp::ServicesQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /// Create and return a GenericClient.
   /**
@@ -302,7 +302,7 @@ public:
     const std::string & service_name,
     const std::string & service_type,
     const rclcpp::QoS & qos = rclcpp::ServicesQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /// Create and return a GenericService.
   /**
@@ -320,7 +320,7 @@ public:
     const std::string & service_type,
     CallbackT && callback,
     const rclcpp::QoS & qos = rclcpp::ServicesQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /// Create and return a GenericPublisher.
   /**
@@ -1388,6 +1388,66 @@ public:
   std::vector<rclcpp::TopicEndpointInfo>
   get_subscriptions_info_by_topic(const std::string & topic_name, bool no_mangle = false) const;
 
+  /// Return the service endpoint information about clients on a given service.
+  /**
+   * The returned parameter is a list of service endpoint information, where each item will contain
+   * the node name, node namespace, service type, endpoint type, endpoint count,
+   * service endpoint's GIDs, and its QoS profiles.
+   *
+   * When the `no_mangle` parameter is `true`, the provided `service_name` should be a valid service
+   * name for the middleware (useful when combining ROS with native middleware apps).
+   * When the `no_mangle` parameter is `false`, the provided `service_name` should follow
+   * ROS service name conventions. In DDS-based RMWs, services are implemented as topics with mangled
+   * names (e.g., `rq/my_serviceRequest` and `rp/my_serviceReply`), so `no_mangle = true` is not
+   * supported and will result in an error. Use `get_publishers_info_by_topic` or
+   * `get_subscriptions_info_by_topic` for unmangled topic queries in such cases. Other RMWs
+   * (e.g., Zenoh) may support `no_mangle = true` if they natively handle services without topic-based
+   *
+   * 'service_name` may be a relative, private, or fully qualified service name.
+   * A relative or private service will be expanded using this node's namespace and name.
+   * The queried `service_name` is not remapped.
+   *
+   * \param[in] service_name the actual service name used; it will not be automatically remapped.
+   * \param[in] no_mangle if `true`, `service_name` needs to be a valid middleware service name,
+   *   otherwise it should be a valid ROS service name. Defaults to `false`.
+   * \return a list of SeviceEndpointInfo representing all the clients on this service.
+   * \throws InvalidServiceNameError if the given service_name is invalid.
+   * \throws std::runtime_error if internal error happens.
+   */
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_clients_info_by_service(const std::string & service_name, bool no_mangle = false) const;
+
+  /// Return the service endpoint information about servers on a given service.
+  /**
+   * The returned parameter is a list of service endpoint information, where each item will contain
+   * the node name, node namespace, service type, endpoint type, endpoint count,
+   * service endpoint's GIDs, and its QoS profiles.
+   *
+   * When the `no_mangle` parameter is `true`, the provided `service_name` should be a valid service
+   * name for the middleware (useful when combining ROS with native middleware apps).
+   * When the `no_mangle` parameter is `false`, the provided `service_name` should follow
+   * ROS service name conventions. In DDS-based RMWs, services are implemented as topics with mangled
+   * names (e.g., `rq/my_serviceRequest` and `rp/my_serviceReply`), so `no_mangle = true` is not
+   * supported and will result in an error. Use `rcl_get_publishers_info_by_topic` or
+   * `rcl_get_subscriptions_info_by_topic` for unmangled topic queries in such cases. Other RMWs
+   * (e.g., Zenoh) may support `no_mangle = true` if they natively handle services without topic-based
+   *
+   * 'service_name` may be a relative, private, or fully qualified service name.
+   * A relative or private service will be expanded using this node's namespace and name.
+   * The queried `service_name` is not remapped.
+   *
+   * \param[in] service_name the actual service name used; it will not be automatically remapped.
+   * \param[in] no_mangle if `true`, `service_name` needs to be a valid middleware service name,
+   *   otherwise it should be a valid ROS service name. Defaults to `false`.
+   * \return a list of SeviceEndpointInfo representing all the servers on this service.
+   * \throws InvalidServiceNameError if the given service_name is invalid.
+   * \throws std::runtime_error if internal error happens.
+   */
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_servers_info_by_service(const std::string & service_name, bool no_mangle = false) const;
+
   /// Return a graph event, which will be set anytime a graph change occurs.
   /* The graph Event object is a loan which must be returned.
    * The Event object is scoped and therefore to return the loan just let it go
@@ -1411,7 +1471,7 @@ public:
   RCLCPP_PUBLIC
   void
   wait_for_graph_change(
-    rclcpp::Event::SharedPtr event,
+    const rclcpp::Event::SharedPtr & event,
     std::chrono::nanoseconds timeout);
 
   /// Get a clock as a non-const shared pointer which is managed by the node.

rclcpp/include/rclcpp/node_impl.hpp

@@ -111,7 +111,7 @@ typename rclcpp::WallTimer<CallbackT>::SharedPtr
 Node::create_wall_timer(
   std::chrono::duration<DurationRepT, DurationT> period,
   CallbackT callback,
-  rclcpp::CallbackGroup::SharedPtr group,
+  const rclcpp::CallbackGroup::SharedPtr & group,
   bool autostart)
 {
   return rclcpp::create_wall_timer(
@@ -128,7 +128,7 @@ typename rclcpp::GenericTimer<CallbackT>::SharedPtr
 Node::create_timer(
   std::chrono::duration<DurationRepT, DurationT> period,
   CallbackT callback,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   return rclcpp::create_timer(
     this->get_clock(),
@@ -144,7 +144,7 @@ typename Client<ServiceT>::SharedPtr
 Node::create_client(
   const std::string & service_name,
   const rclcpp::QoS & qos,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   return rclcpp::create_client<ServiceT>(
     node_base_,
@@ -161,7 +161,7 @@ Node::create_service(
   const std::string & service_name,
   CallbackT && callback,
   const rclcpp::QoS & qos,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   return rclcpp::create_service<ServiceT, CallbackT>(
     node_base_,
@@ -179,7 +179,7 @@ Node::create_generic_service(
   const std::string & service_type,
   CallbackT && callback,
   const rclcpp::QoS & qos,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   return rclcpp::create_generic_service<CallbackT>(
     node_base_,

rclcpp/include/rclcpp/node_interfaces/detail/node_interfaces_helpers.hpp

@@ -199,6 +199,12 @@ init_tuple(NodeT & n)
     { \
       return StorageClassT::template get<NodeInterfaceType>(); \
     } \
+ \
+    std::shared_ptr<const NodeInterfaceType> \
+    get_node_ ## NodeInterfaceName ## _interface() const \
+    { \
+      return StorageClassT::template get<NodeInterfaceType>(); \
+    } \
   }; \
   }  // namespace rclcpp::node_interfaces::detail
 // *INDENT-ON*

rclcpp/include/rclcpp/node_interfaces/node_graph.hpp

@@ -33,6 +33,7 @@
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_graph_interface.hpp"
 #include "rclcpp/visibility_control.hpp"
+#include "rmw/service_endpoint_info_array.h"
 #include "rmw/topic_endpoint_info_array.h"
 
 namespace rclcpp
@@ -159,6 +160,18 @@ public:
     const std::string & topic_name,
     bool no_mangle = false) const override;
 
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_clients_info_by_service(
+    const std::string & service_name,
+    bool no_mangle = false) const override;
+
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_servers_info_by_service(
+    const std::string & service_name,
+    bool no_mangle = false) const override;
+
 private:
   RCLCPP_DISABLE_COPY(NodeGraph)
 

rclcpp/include/rclcpp/node_interfaces/node_graph_interface.hpp

@@ -18,6 +18,8 @@
 #include <algorithm>
 #include <array>
 #include <chrono>
+#include <cstddef>
+#include <cstdint>
 #include <map>
 #include <string>
 #include <tuple>
@@ -40,7 +42,9 @@ enum class EndpointType
 {
   Invalid = RMW_ENDPOINT_INVALID,
   Publisher = RMW_ENDPOINT_PUBLISHER,
-  Subscription = RMW_ENDPOINT_SUBSCRIPTION
+  Subscription = RMW_ENDPOINT_SUBSCRIPTION,
+  Client = RMW_ENDPOINT_CLIENT,
+  Server = RMW_ENDPOINT_SERVER
 };
 
 /**
@@ -53,13 +57,17 @@ public:
   /// Construct a TopicEndpointInfo from a rcl_topic_endpoint_info_t.
   RCLCPP_PUBLIC
   explicit TopicEndpointInfo(const rcl_topic_endpoint_info_t & info)
-  : node_name_(info.node_name),
-    node_namespace_(info.node_namespace),
-    topic_type_(info.topic_type),
-    endpoint_type_(static_cast<rclcpp::EndpointType>(info.endpoint_type)),
+  : endpoint_type_(static_cast<rclcpp::EndpointType>(info.endpoint_type)),
     qos_profile_({info.qos_profile.history, info.qos_profile.depth}, info.qos_profile),
     topic_type_hash_(info.topic_type_hash)
   {
+    if (!info.node_name || !info.node_namespace || !info.topic_type) {
+      throw std::invalid_argument("Constructor TopicEndpointInfo with invalid topic endpoint info");
+    }
+    node_name_ = info.node_name;
+    node_namespace_ = info.node_namespace;
+    topic_type_ = info.topic_type;
+
     std::copy(info.endpoint_gid, info.endpoint_gid + RMW_GID_STORAGE_SIZE, endpoint_gid_.begin());
   }
 
@@ -143,6 +151,125 @@ private:
   rosidl_type_hash_t topic_type_hash_;
 };
 
+/**
+ * Struct that contains service endpoint information like the associated node name, node namespace,
+ * service type, endpoint type, endpoint count, endpoint GIDs, and its QoS profiles.
+ */
+class ServiceEndpointInfo
+{
+public:
+  /// Construct a ServiceEndpointInfo from a rcl_service_endpoint_info_t.
+  RCLCPP_PUBLIC
+  explicit ServiceEndpointInfo(const rcl_service_endpoint_info_t & info)
+  : node_name_(info.node_name),
+    node_namespace_(info.node_namespace),
+    service_type_(info.service_type),
+    endpoint_type_(static_cast<rclcpp::EndpointType>(info.endpoint_type)),
+    service_type_hash_(info.service_type_hash),
+    endpoint_count_(info.endpoint_count)
+  {
+    for(size_t i = 0; i < endpoint_count_; i++) {
+      std::array<uint8_t, RMW_GID_STORAGE_SIZE> gid;
+      std::copy(info.endpoint_gids[i], info.endpoint_gids[i] + RMW_GID_STORAGE_SIZE, gid.begin());
+      endpoint_gids_.push_back(gid);
+
+      rclcpp::QoS qos(
+        {info.qos_profiles[i].history, info.qos_profiles[i].depth}, info.qos_profiles[i]);
+      qos_profiles_.push_back(qos);
+    }
+  }
+
+  /// Get a mutable reference to the node name.
+  RCLCPP_PUBLIC
+  std::string &
+  node_name();
+
+  /// Get a const reference to the node name.
+  RCLCPP_PUBLIC
+  const std::string &
+  node_name() const;
+
+  /// Get a mutable reference to the node namespace.
+  RCLCPP_PUBLIC
+  std::string &
+  node_namespace();
+
+  /// Get a const reference to the node namespace.
+  RCLCPP_PUBLIC
+  const std::string &
+  node_namespace() const;
+
+  /// Get a mutable reference to the service type string.
+  RCLCPP_PUBLIC
+  std::string &
+  service_type();
+
+  /// Get a const reference to the service type string.
+  RCLCPP_PUBLIC
+  const std::string &
+  service_type() const;
+
+  /// Get a mutable reference to the service endpoint type.
+  RCLCPP_PUBLIC
+  rclcpp::EndpointType &
+  endpoint_type();
+
+  /// Get a const reference to the service endpoint type.
+  RCLCPP_PUBLIC
+  const rclcpp::EndpointType &
+  endpoint_type() const;
+
+  /// Get a mutable reference to the endpoint count.
+  RCLCPP_PUBLIC
+  size_t &
+  endpoint_count();
+
+  /// Get a const reference to the endpoint count.
+  RCLCPP_PUBLIC
+  const size_t &
+  endpoint_count() const;
+
+  /// Get a mutable reference to the GID of the service endpoint.
+  RCLCPP_PUBLIC
+  std::vector<std::array<uint8_t, RMW_GID_STORAGE_SIZE>> &
+  endpoint_gids();
+
+  /// Get a const reference to the GID of the service endpoint.
+  RCLCPP_PUBLIC
+  const std::vector<std::array<uint8_t, RMW_GID_STORAGE_SIZE>> &
+  endpoint_gids() const;
+
+  /// Get a mutable reference to the QoS profile of the service endpoint.
+  RCLCPP_PUBLIC
+  std::vector<rclcpp::QoS> &
+  qos_profiles();
+
+  /// Get a const reference to the QoS profile of the service endpoint.
+  RCLCPP_PUBLIC
+  const std::vector<rclcpp::QoS> &
+  qos_profiles() const;
+
+  /// Get a mutable reference to the type hash of the service endpoint.
+  RCLCPP_PUBLIC
+  rosidl_type_hash_t &
+  service_type_hash();
+
+  /// Get a const reference to the type hash of the service endpoint.
+  RCLCPP_PUBLIC
+  const rosidl_type_hash_t &
+  service_type_hash() const;
+
+private:
+  std::string node_name_;
+  std::string node_namespace_;
+  std::string service_type_;
+  rclcpp::EndpointType endpoint_type_;
+  std::vector<std::array<uint8_t, RMW_GID_STORAGE_SIZE>> endpoint_gids_;
+  std::vector<rclcpp::QoS> qos_profiles_;
+  rosidl_type_hash_t service_type_hash_;
+  size_t endpoint_count_;
+};
+
 namespace node_interfaces
 {
 
@@ -408,6 +535,30 @@ public:
   virtual
   std::vector<rclcpp::TopicEndpointInfo>
   get_subscriptions_info_by_topic(const std::string & topic_name, bool no_mangle = false) const = 0;
+
+  /// Return the service endpoint information about clients on a given service.
+  /**
+   * \param[in] service_name the actual service name used; it will not be automatically remapped.
+   * \param[in] no_mangle if `true`, `service_name` needs to be a valid middleware service name,
+   *   otherwise it should be a valid ROS service name.
+   * \sa rclcpp::Node::get_clients_info_by_service
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_clients_info_by_service(const std::string & service_name, bool no_mangle = false) const = 0;
+
+  /// Return the service endpoint information about servers on a given service.
+  /**
+   * \param[in] service_name the actual service name used; it will not be automatically remapped.
+   * \param[in] no_mangle if `true`, `service_name` needs to be a valid middleware service name,
+   *   otherwise it should be a valid ROS service name.
+   * \sa rclcpp::Node::get_servers_info_by_service
+   */
+  RCLCPP_PUBLIC
+  virtual
+  std::vector<rclcpp::ServiceEndpointInfo>
+  get_servers_info_by_service(const std::string & service_name, bool no_mangle = false) const = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_logging.hpp

@@ -38,7 +38,7 @@ public:
   RCLCPP_SMART_PTR_ALIASES_ONLY(NodeLoggingInterface)
 
   RCLCPP_PUBLIC
-  explicit NodeLogging(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base);
+  explicit NodeLogging(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base);
 
   RCLCPP_PUBLIC
   virtual
@@ -55,7 +55,7 @@ public:
   RCLCPP_PUBLIC
   void
   create_logger_services(
-    node_interfaces::NodeServicesInterface::SharedPtr node_services) override;
+    const node_interfaces::NodeServicesInterface::SharedPtr & node_services) override;
 
 private:
   RCLCPP_DISABLE_COPY(NodeLogging)

rclcpp/include/rclcpp/node_interfaces/node_logging_interface.hpp

@@ -61,7 +61,7 @@ public:
   virtual
   void
   create_logger_services(
-    node_interfaces::NodeServicesInterface::SharedPtr node_services) = 0;
+    const node_interfaces::NodeServicesInterface::SharedPtr & node_services) = 0;
 };
 
 }  // namespace node_interfaces

rclcpp/include/rclcpp/node_interfaces/node_type_descriptions.hpp

@@ -39,10 +39,10 @@ public:
 
   RCLCPP_PUBLIC
   explicit NodeTypeDescriptions(
-    NodeBaseInterface::SharedPtr node_base,
-    NodeLoggingInterface::SharedPtr node_logging,
-    NodeParametersInterface::SharedPtr node_parameters,
-    NodeServicesInterface::SharedPtr node_services);
+    const NodeBaseInterface::SharedPtr & node_base,
+    const NodeLoggingInterface::SharedPtr & node_logging,
+    const NodeParametersInterface::SharedPtr & node_parameters,
+    const NodeServicesInterface::SharedPtr & node_services);
 
   RCLCPP_PUBLIC
   virtual

rclcpp/include/rclcpp/node_options.hpp

@@ -100,7 +100,7 @@ public:
   /// Set the context, return this for parameter idiom.
   RCLCPP_PUBLIC
   NodeOptions &
-  context(rclcpp::Context::SharedPtr context);
+  context(const rclcpp::Context::SharedPtr & context);
 
   /// Return a reference to the list of arguments for the node.
   RCLCPP_PUBLIC

rclcpp/include/rclcpp/parameter_client.hpp

@@ -64,13 +64,13 @@ public:
    */
   RCLCPP_PUBLIC
   AsyncParametersClient(
-    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface,
-    const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface,
-    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
-    const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_interface,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base_interface,
+    const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr & node_topics_interface,
+    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph_interface,
+    const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr & node_services_interface,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr);
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr);
 
   /**
    * \param[in] node The async parameters client will be added to this node.
@@ -80,10 +80,10 @@ public:
    */
   template<typename NodeT>
   explicit AsyncParametersClient(
-    const std::shared_ptr<NodeT> node,
+    const std::shared_ptr<NodeT> & node,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr)
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr)
   : AsyncParametersClient(
       node->get_node_base_interface(),
       node->get_node_topics_interface(),
@@ -105,7 +105,7 @@ public:
     NodeT * node,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS(),
-    rclcpp::CallbackGroup::SharedPtr group = nullptr)
+    const rclcpp::CallbackGroup::SharedPtr & group = nullptr)
   : AsyncParametersClient(
       node->get_node_base_interface(),
       node->get_node_topics_interface(),
@@ -120,41 +120,41 @@ public:
   std::shared_future<std::vector<rclcpp::Parameter>>
   get_parameters(
     const std::vector<std::string> & names,
-    std::function<
+    const std::function<
       void(std::shared_future<std::vector<rclcpp::Parameter>>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   RCLCPP_PUBLIC
   std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>
   describe_parameters(
     const std::vector<std::string> & names,
-    std::function<
+    const std::function<
       void(std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   RCLCPP_PUBLIC
   std::shared_future<std::vector<rclcpp::ParameterType>>
   get_parameter_types(
     const std::vector<std::string> & names,
-    std::function<
+    const std::function<
       void(std::shared_future<std::vector<rclcpp::ParameterType>>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   RCLCPP_PUBLIC
   std::shared_future<std::vector<rcl_interfaces::msg::SetParametersResult>>
   set_parameters(
     const std::vector<rclcpp::Parameter> & parameters,
-    std::function<
+    const std::function<
       void(std::shared_future<std::vector<rcl_interfaces::msg::SetParametersResult>>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   RCLCPP_PUBLIC
   std::shared_future<rcl_interfaces::msg::SetParametersResult>
   set_parameters_atomically(
     const std::vector<rclcpp::Parameter> & parameters,
-    std::function<
+    const std::function<
       void(std::shared_future<rcl_interfaces::msg::SetParametersResult>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   /// Delete several parameters at once.
   /**
@@ -200,9 +200,9 @@ public:
   list_parameters(
     const std::vector<std::string> & prefixes,
     uint64_t depth,
-    std::function<
+    const std::function<
       void(std::shared_future<rcl_interfaces::msg::ListParametersResult>)
-    > callback = nullptr);
+    > & callback = nullptr);
 
   template<
     typename CallbackT,
@@ -304,7 +304,7 @@ public:
 
   template<typename NodeT>
   explicit SyncParametersClient(
-    std::shared_ptr<NodeT> node,
+    const std::shared_ptr<NodeT> & node,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS())
   : SyncParametersClient(
@@ -316,8 +316,8 @@ public:
 
   template<typename NodeT>
   SyncParametersClient(
-    rclcpp::Executor::SharedPtr executor,
-    std::shared_ptr<NodeT> node,
+    const rclcpp::Executor::SharedPtr & executor,
+    const std::shared_ptr<NodeT> & node,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS())
   : SyncParametersClient(
@@ -344,7 +344,7 @@ public:
 
   template<typename NodeT>
   SyncParametersClient(
-    rclcpp::Executor::SharedPtr executor,
+    const rclcpp::Executor::SharedPtr & executor,
     NodeT * node,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS())
@@ -360,11 +360,11 @@ public:
 
   RCLCPP_PUBLIC
   SyncParametersClient(
-    rclcpp::Executor::SharedPtr executor,
-    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface,
-    const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface,
-    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
-    const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_interface,
+    const rclcpp::Executor::SharedPtr & executor,
+    const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base_interface,
+    const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr & node_topics_interface,
+    const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph_interface,
+    const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr & node_services_interface,
     const std::string & remote_node_name = "",
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS())
   : executor_(executor), node_base_interface_(node_base_interface)

rclcpp/include/rclcpp/parameter_descriptor_wrapper.hpp

@@ -0,0 +1,82 @@
+// Copyright 2023 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__PARAMETER_DESCRIPTOR_WRAPPER_HPP_
+#define RCLCPP__PARAMETER_DESCRIPTOR_WRAPPER_HPP_
+
+// C++ Standard library includes
+#include <functional>
+#include <utility>
+#include <memory>
+#include <string>
+
+// Additional ROS libraries needed
+#include "rcl_interfaces/msg/parameter_descriptor.hpp"
+
+#include "rclcpp/node.hpp"
+#include "rclcpp/parameter_value.hpp"
+#include "rclcpp/node_interfaces/get_node_parameters_interface.hpp"
+#include "rclcpp/visibility_control.hpp"
+#include "node_interfaces/node_parameters_interface.hpp"
+
+namespace rclcpp
+{
+
+// Implements ParameterDesription class with builder design pattern
+class ParameterDescription
+{
+public:
+  RCLCPP_SMART_PTR_DEFINITIONS(ParameterDescription)
+
+  // List of classes the builder manages
+  RCLCPP_PUBLIC
+  ParameterDescription();
+
+  // Our Main build methods which will construct the base class
+  RCLCPP_PUBLIC rcl_interfaces::msg::ParameterDescriptor build() const;
+
+  // Builder Methods:
+  // Describes the instances in a parameter_description object
+  RCLCPP_PUBLIC ParameterDescription & set_name(const std::string & name);
+  RCLCPP_PUBLIC ParameterDescription & set_type(std::uint8_t type);
+  RCLCPP_PUBLIC ParameterDescription & set_description_text(const std::string & description);
+  RCLCPP_PUBLIC ParameterDescription & set_additional_constraints(const std::string & constraints);
+  RCLCPP_PUBLIC ParameterDescription & set_read_only(bool read_only);
+  RCLCPP_PUBLIC ParameterDescription & set_dynamic_typing(bool dynamic_typing);
+  RCLCPP_PUBLIC ParameterDescription & set_floating_point_description_range(
+    float min, float max, float step);
+  RCLCPP_PUBLIC ParameterDescription & set_integer_description_range(int min, int max, int step);
+
+  // Need the current node in order to begin the configuration state
+  // for it via the declare_parameter function
+  template<typename NodeT>
+  ParameterDescription & declare_parameter(
+    const rclcpp::ParameterValue & default_value,
+    NodeT && node)
+  {
+    auto node_param = rclcpp::node_interfaces::get_node_parameters_interface(node);
+    node_param->declare_parameter(
+      parameter_descriptor.name, default_value,
+      parameter_descriptor);
+    return *this;
+  }
+
+private:
+  // The main descriptor object we're meant to initialize and adjust
+  rcl_interfaces::msg::ParameterDescriptor parameter_descriptor;
+};
+
+}  // namespace rclcpp
+
+#endif  // RCLCPP__PARAMETER_DESCRIPTOR_WRAPPER_HPP_

rclcpp/include/rclcpp/parameter_event_handler.hpp

@@ -184,7 +184,7 @@ public:
    */
   template<typename NodeT>
   explicit ParameterEventHandler(
-    NodeT node,
+    const 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))
@@ -217,7 +217,7 @@ public:
   RCUTILS_WARN_UNUSED
   ParameterEventCallbackHandle::SharedPtr
   add_parameter_event_callback(
-    ParameterEventCallbackType callback);
+    const ParameterEventCallbackType & callback);
 
   /// Remove parameter event callback registered with add_parameter_event_callback.
   /**
@@ -226,7 +226,7 @@ public:
   RCLCPP_PUBLIC
   void
   remove_parameter_event_callback(
-    ParameterEventCallbackHandle::SharedPtr callback_handle);
+    const ParameterEventCallbackHandle::SharedPtr & callback_handle);
 
   using ParameterCallbackType = ParameterCallbackHandle::ParameterCallbackType;
 
@@ -234,6 +234,10 @@ public:
   /**
    * If a node_name is not provided, defaults to the current node.
    *
+   * The configure_nodes_filter() function will affect the behavior of this function.
+   * If the node specified in this function isn't included in the nodes specified in
+   * configure_nodes_filter(), the callback will never be called.
+   *
    * Note: if the returned callback handle smart pointer is not captured, the callback
    * is immediately unregistered. A compiler warning should be generated to warn
    * of this.
@@ -248,9 +252,34 @@ public:
   ParameterCallbackHandle::SharedPtr
   add_parameter_callback(
     const std::string & parameter_name,
-    ParameterCallbackType callback,
+    const ParameterCallbackType & callback,
     const std::string & node_name = "");
 
+  /// Configure which node parameter events will be received.
+  /**
+   * This function depends on rmw implementation support for content filtering.
+   * If middleware doesn't support contentfilter, return false.
+   *
+   * If node_names is empty, the configured node filter will be cleared.
+   *
+   * If this function return true, only parameter events from the specified node will be received.
+   * It affects the behavior of the following two functions.
+   * - add_parameter_event_callback()
+   *   The callback will only be called for parameter events from the specified nodes which are
+   *   configured in this function.
+   * - add_parameter_callback()
+   *   The callback will only be called for parameter events from the specified nodes which are
+   *   configured in this function and add_parameter_callback().
+   *   If the nodes specified in this function is different from the nodes specified in
+   *   add_parameter_callback(), the callback will never be called.
+   *
+   * \param[in] node_names Node names to filter parameter events from.
+   * \returns true if configuring was successfully applied, false otherwise.
+   * \throws rclcpp::exceptions::RCLError if internal error occurred when calling the rcl function.
+   */
+  RCLCPP_PUBLIC
+  bool configure_nodes_filter(const std::vector<std::string> & node_names);
+
   /// Remove a parameter callback registered with add_parameter_callback.
   /**
    * The parameter name and node name are inspected from the callback handle. The callback handle
@@ -262,7 +291,7 @@ public:
   RCLCPP_PUBLIC
   void
   remove_parameter_callback(
-    ParameterCallbackHandle::SharedPtr callback_handle);
+    const ParameterCallbackHandle::SharedPtr & callback_handle);
 
   /// Get an rclcpp::Parameter from a parameter event.
   /**

rclcpp/include/rclcpp/parameter_service.hpp

@@ -42,8 +42,8 @@ public:
 
   RCLCPP_PUBLIC
   ParameterService(
-    const std::shared_ptr<node_interfaces::NodeBaseInterface> node_base,
-    const std::shared_ptr<node_interfaces::NodeServicesInterface> node_services,
+    const std::shared_ptr<node_interfaces::NodeBaseInterface> & node_base,
+    const std::shared_ptr<node_interfaces::NodeServicesInterface> & node_services,
     rclcpp::node_interfaces::NodeParametersInterface * node_params,
     const rclcpp::QoS & qos_profile = rclcpp::ParametersQoS());
 

rclcpp/include/rclcpp/publisher_base.hpp

@@ -210,7 +210,7 @@ public:
   void
   setup_intra_process(
     uint64_t intra_process_publisher_id,
-    IntraProcessManagerSharedPtr ipm);
+    const IntraProcessManagerSharedPtr & ipm);
 
   /// Get network flow endpoints
   /**
@@ -300,7 +300,7 @@ public:
    */
   void
   set_on_new_qos_event_callback(
-    std::function<void(size_t)> callback,
+    const std::function<void(size_t)> & callback,
     rcl_publisher_event_type_t event_type)
   {
     if (event_handlers_.count(event_type) == 0) {
@@ -319,7 +319,7 @@ public:
     // The on_ready_callback signature has an extra `int` argument used to disambiguate between
     // possible different entities within a generic waitable.
     // We hide that detail to users of this method.
-    std::function<void(size_t, int)> new_callback = std::bind(callback, std::placeholders::_1);
+    std::function<void(size_t, int)> new_callback = [callback] (size_t nr, int) {callback(nr);};
     event_handlers_[event_type]->set_on_ready_callback(new_callback);
   }
 

rclcpp/include/rclcpp/publisher_options.hpp

@@ -123,11 +123,20 @@ private:
   rcl_allocator_t
   get_rcl_allocator() const
   {
-    if (!plain_allocator_storage_) {
-      plain_allocator_storage_ =
-        std::make_shared<PlainAllocator>(*this->get_allocator());
+    if constexpr (std::is_same_v<Allocator, std::allocator<void>>) {
+      return rcl_get_default_allocator();
+    } else {
+      if constexpr (rclcpp::allocator::has_get_rcl_allocator_v<Allocator>) {
+        return get_allocator()->get_rcl_allocator();
+      } else {
+        if (!plain_allocator_storage_) {
+          plain_allocator_storage_ =
+            std::make_shared<PlainAllocator>(*this->get_allocator());
+        }
+
+        return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
+      }
     }
-    return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
   }
 
   // This is a temporal workaround, to make sure that get_allocator()

rclcpp/include/rclcpp/rate.hpp

@@ -58,12 +58,12 @@ public:
   RCLCPP_PUBLIC
   explicit Rate(
     const double rate,
-    Clock::SharedPtr clock = std::make_shared<Clock>(RCL_SYSTEM_TIME));
+    const Clock::SharedPtr & clock = std::make_shared<Clock>(RCL_SYSTEM_TIME));
 
   RCLCPP_PUBLIC
   explicit Rate(
     const Duration & period,
-    Clock::SharedPtr clock = std::make_shared<Clock>(RCL_SYSTEM_TIME));
+    const Clock::SharedPtr & clock = std::make_shared<Clock>(RCL_SYSTEM_TIME));
 
   RCLCPP_PUBLIC
   virtual bool

rclcpp/include/rclcpp/rclcpp.hpp

@@ -175,6 +175,7 @@
 #include "rclcpp/parameter_event_handler.hpp"
 #include "rclcpp/parameter.hpp"
 #include "rclcpp/parameter_service.hpp"
+#include "rclcpp/parameter_descriptor_wrapper.hpp"
 #include "rclcpp/rate.hpp"
 #include "rclcpp/time.hpp"
 #include "rclcpp/utilities.hpp"

rclcpp/include/rclcpp/serialized_message.hpp

@@ -58,10 +58,10 @@ public:
   explicit SerializedMessage(const rcl_serialized_message_t & other);
 
   /// Move Constructor for a SerializedMessage
-  SerializedMessage(SerializedMessage && other);
+  SerializedMessage(SerializedMessage && other) noexcept;
 
   /// Constructor for a SerializedMessage from a moved rcl_serialized_message_t
-  explicit SerializedMessage(rcl_serialized_message_t && other);
+  explicit SerializedMessage(rcl_serialized_message_t && other) noexcept;
 
   /// Copy assignment operator
   SerializedMessage & operator=(const SerializedMessage & other);
@@ -70,10 +70,10 @@ public:
   SerializedMessage & operator=(const rcl_serialized_message_t & other);
 
   /// Move assignment operator
-  SerializedMessage & operator=(SerializedMessage && other);
+  SerializedMessage & operator=(SerializedMessage && other) noexcept;
 
   /// Move assignment operator from a rcl_serialized_message_t
-  SerializedMessage & operator=(rcl_serialized_message_t && other);
+  SerializedMessage & operator=(rcl_serialized_message_t && other) noexcept;
 
   /// Destructor for a SerializedMessage
   virtual ~SerializedMessage();

rclcpp/include/rclcpp/service.hpp

@@ -22,6 +22,7 @@
 #include <mutex>
 #include <sstream>
 #include <string>
+#include <utility>
 
 #include "rcl/error_handling.h"
 #include "rcl/event_callback.h"
@@ -54,7 +55,7 @@ public:
   RCLCPP_SMART_PTR_DEFINITIONS_NOT_COPYABLE(ServiceBase)
 
   RCLCPP_PUBLIC
-  explicit ServiceBase(std::shared_ptr<rcl_node_t> node_handle);
+  explicit ServiceBase(const std::shared_ptr<rcl_node_t> & node_handle);
 
   RCLCPP_PUBLIC
   virtual ~ServiceBase() = default;
@@ -113,8 +114,8 @@ public:
   virtual
   void
   handle_request(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<void> request) = 0;
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & request) = 0;
 
   /// Exchange the "in use by wait set" state for this service.
   /**
@@ -190,7 +191,7 @@ public:
    * \param[in] callback functor to be called when a new request is received
    */
   void
-  set_on_new_request_callback(std::function<void(size_t)> callback)
+  set_on_new_request_callback(const std::function<void(size_t)> & callback)
   {
     if (!callback) {
       throw std::invalid_argument(
@@ -286,6 +287,7 @@ class Service
   public std::enable_shared_from_this<Service<ServiceT>>
 {
 public:
+  using ServiceType = ServiceT;
   using CallbackType = std::function<
     void (
       const std::shared_ptr<typename ServiceT::Request>,
@@ -372,10 +374,10 @@ public:
    * \param[in] any_callback User defined callback to call when a client request is received.
    */
   Service(
-    std::shared_ptr<rcl_node_t> node_handle,
-    std::shared_ptr<rcl_service_t> service_handle,
+    const std::shared_ptr<rcl_node_t> & node_handle,
+    const std::shared_ptr<rcl_service_t> & service_handle,
     AnyServiceCallback<ServiceT> any_callback)
-  : ServiceBase(node_handle), any_callback_(any_callback),
+  : ServiceBase(node_handle), any_callback_(std::move(any_callback)),
     srv_type_support_handle_(rosidl_typesupport_cpp::get_service_type_support_handle<ServiceT>())
   {
     // check if service handle was initialized
@@ -407,10 +409,10 @@ public:
    * \param[in] any_callback User defined callback to call when a client request is received.
    */
   Service(
-    std::shared_ptr<rcl_node_t> node_handle,
+    const std::shared_ptr<rcl_node_t> & node_handle,
     rcl_service_t * service_handle,
     AnyServiceCallback<ServiceT> any_callback)
-  : ServiceBase(node_handle), any_callback_(any_callback),
+  : ServiceBase(node_handle), any_callback_(std::move(any_callback)),
     srv_type_support_handle_(rosidl_typesupport_cpp::get_service_type_support_handle<ServiceT>())
   {
     // check if service handle was initialized
@@ -471,8 +473,8 @@ public:
 
   void
   handle_request(
-    std::shared_ptr<rmw_request_id_t> request_header,
-    std::shared_ptr<void> request) override
+    const std::shared_ptr<rmw_request_id_t> & request_header,
+    const std::shared_ptr<void> & request) override
   {
     auto typed_request = std::static_pointer_cast<typename ServiceT::Request>(request);
     auto response = any_callback_.dispatch(this->shared_from_this(), request_header, typed_request);
@@ -510,7 +512,7 @@ public:
    */
   void
   configure_introspection(
-    Clock::SharedPtr clock, const QoS & qos_service_event_pub,
+    const Clock::SharedPtr & clock, const QoS & qos_service_event_pub,
     rcl_service_introspection_state_t introspection_state)
   {
     rcl_publisher_options_t pub_opts = rcl_publisher_get_default_options();

rclcpp/include/rclcpp/strategies/allocator_memory_strategy.hpp

@@ -99,49 +99,92 @@ public:
     // Important to use subscription_handles_.size() instead of wait set's size since
     // there may be more subscriptions in the wait set due to Waitables added to the end.
     // The same logic applies for other entities.
+
+    // Mark corresponding weak_ptr as expired for entities that are null in the wait set
+    size_t valid_subscription_count = 0;
     for (size_t i = 0; i < subscription_handles_.size(); ++i) {
-      if (!wait_set->subscriptions[i]) {
-        subscription_handles_[i].reset();
+      if (valid_subscription_count < wait_set->size_of_subscriptions &&
+        !wait_set->subscriptions[valid_subscription_count])
+      {
+        subscription_handles_[i] = std::weak_ptr<const rcl_subscription_t>{};
+      }
+      if (subscription_handles_[i].lock()) {
+        ++valid_subscription_count;
       }
     }
+
+    size_t valid_service_count = 0;
     for (size_t i = 0; i < service_handles_.size(); ++i) {
-      if (!wait_set->services[i]) {
-        service_handles_[i].reset();
+      if (valid_service_count < wait_set->size_of_services &&
+        !wait_set->services[valid_service_count])
+      {
+        service_handles_[i] = std::weak_ptr<const rcl_service_t>{};
+      }
+      if (service_handles_[i].lock()) {
+        ++valid_service_count;
       }
     }
+
+    size_t valid_client_count = 0;
     for (size_t i = 0; i < client_handles_.size(); ++i) {
-      if (!wait_set->clients[i]) {
-        client_handles_[i].reset();
+      if (valid_client_count < wait_set->size_of_clients &&
+        !wait_set->clients[valid_client_count])
+      {
+        client_handles_[i] = std::weak_ptr<const rcl_client_t>{};
+      }
+      if (client_handles_[i].lock()) {
+        ++valid_client_count;
       }
     }
+
+    size_t valid_timer_count = 0;
     for (size_t i = 0; i < timer_handles_.size(); ++i) {
-      if (!wait_set->timers[i]) {
-        timer_handles_[i].reset();
+      if (valid_timer_count < wait_set->size_of_timers &&
+        !wait_set->timers[valid_timer_count])
+      {
+        timer_handles_[i] = std::weak_ptr<const rcl_timer_t>{};
+      }
+      if (timer_handles_[i].lock()) {
+        ++valid_timer_count;
       }
     }
+
     for (size_t i = 0; i < waitable_handles_.size(); ++i) {
       if (!waitable_handles_[i]->is_ready(*wait_set)) {
         waitable_handles_[i].reset();
       }
     }
 
+    // Remove expired weak_ptr instances
     subscription_handles_.erase(
-      std::remove(subscription_handles_.begin(), subscription_handles_.end(), nullptr),
+      std::remove_if(subscription_handles_.begin(), subscription_handles_.end(),
+      [](const std::weak_ptr<const rcl_subscription_t> & weak_ptr) {
+        return weak_ptr.expired();
+        }),
       subscription_handles_.end()
     );
 
     service_handles_.erase(
-      std::remove(service_handles_.begin(), service_handles_.end(), nullptr),
+      std::remove_if(service_handles_.begin(), service_handles_.end(),
+      [](const std::weak_ptr<const rcl_service_t> & weak_ptr) {
+        return weak_ptr.expired();
+        }),
       service_handles_.end()
     );
 
     client_handles_.erase(
-      std::remove(client_handles_.begin(), client_handles_.end(), nullptr),
+      std::remove_if(client_handles_.begin(), client_handles_.end(),
+      [](const std::weak_ptr<const rcl_client_t> & weak_ptr) {
+        return weak_ptr.expired();
+        }),
       client_handles_.end()
     );
 
     timer_handles_.erase(
-      std::remove(timer_handles_.begin(), timer_handles_.end(), nullptr),
+      std::remove_if(timer_handles_.begin(), timer_handles_.end(),
+      [](const std::weak_ptr<const rcl_timer_t> & weak_ptr) {
+        return weak_ptr.expired();
+        }),
       timer_handles_.end()
     );
 
@@ -196,7 +239,13 @@ public:
 
   bool add_handles_to_wait_set(rcl_wait_set_t * wait_set) override
   {
-    for (const std::shared_ptr<const rcl_subscription_t> & subscription : subscription_handles_) {
+    for (const std::weak_ptr<const rcl_subscription_t> & weak_subscription :
+      subscription_handles_)
+    {
+      auto subscription = weak_subscription.lock();
+      if (!subscription) {
+        continue;  // Skip expired handles
+      }
       if (rcl_wait_set_add_subscription(wait_set, subscription.get(), NULL) != RCL_RET_OK) {
         RCUTILS_LOG_ERROR_NAMED(
           "rclcpp",
@@ -206,7 +255,11 @@ public:
       }
     }
 
-    for (const std::shared_ptr<const rcl_client_t> & client : client_handles_) {
+    for (const std::weak_ptr<const rcl_client_t> & weak_client : client_handles_) {
+      auto client = weak_client.lock();
+      if (!client) {
+        continue;  // Skip expired handles
+      }
       if (rcl_wait_set_add_client(wait_set, client.get(), NULL) != RCL_RET_OK) {
         RCUTILS_LOG_ERROR_NAMED(
           "rclcpp",
@@ -216,7 +269,11 @@ public:
       }
     }
 
-    for (const std::shared_ptr<const rcl_service_t> & service : service_handles_) {
+    for (const std::weak_ptr<const rcl_service_t> & weak_service : service_handles_) {
+      auto service = weak_service.lock();
+      if (!service) {
+        continue;  // Skip expired handles
+      }
       if (rcl_wait_set_add_service(wait_set, service.get(), NULL) != RCL_RET_OK) {
         RCUTILS_LOG_ERROR_NAMED(
           "rclcpp",
@@ -226,7 +283,11 @@ public:
       }
     }
 
-    for (const std::shared_ptr<const rcl_timer_t> & timer : timer_handles_) {
+    for (const std::weak_ptr<const rcl_timer_t> & weak_timer : timer_handles_) {
+      auto timer = weak_timer.lock();
+      if (!timer) {
+        continue;  // Skip expired handles
+      }
       if (rcl_wait_set_add_timer(wait_set, timer.get(), NULL) != RCL_RET_OK) {
         RCUTILS_LOG_ERROR_NAMED(
           "rclcpp",
@@ -253,7 +314,13 @@ public:
   {
     auto it = subscription_handles_.begin();
     while (it != subscription_handles_.end()) {
-      auto subscription = get_subscription_by_handle(*it, weak_groups_to_nodes);
+      auto subscription_handle = it->lock();
+      if (!subscription_handle) {
+        // Handle expired, remove it and continue
+        it = subscription_handles_.erase(it);
+        continue;
+      }
+      auto subscription = get_subscription_by_handle(subscription_handle, weak_groups_to_nodes);
       if (subscription) {
         // Find the group for this handle and see if it can be serviced
         auto group = get_group_by_subscription(subscription, weak_groups_to_nodes);
@@ -288,7 +355,13 @@ public:
   {
     auto it = service_handles_.begin();
     while (it != service_handles_.end()) {
-      auto service = get_service_by_handle(*it, weak_groups_to_nodes);
+      auto service_handle = it->lock();
+      if (!service_handle) {
+        // Handle expired, remove it and continue
+        it = service_handles_.erase(it);
+        continue;
+      }
+      auto service = get_service_by_handle(service_handle, weak_groups_to_nodes);
       if (service) {
         // Find the group for this handle and see if it can be serviced
         auto group = get_group_by_service(service, weak_groups_to_nodes);
@@ -323,7 +396,13 @@ public:
   {
     auto it = client_handles_.begin();
     while (it != client_handles_.end()) {
-      auto client = get_client_by_handle(*it, weak_groups_to_nodes);
+      auto client_handle = it->lock();
+      if (!client_handle) {
+        // Handle expired, remove it and continue
+        it = client_handles_.erase(it);
+        continue;
+      }
+      auto client = get_client_by_handle(client_handle, weak_groups_to_nodes);
       if (client) {
         // Find the group for this handle and see if it can be serviced
         auto group = get_group_by_client(client, weak_groups_to_nodes);
@@ -358,7 +437,13 @@ public:
   {
     auto it = timer_handles_.begin();
     while (it != timer_handles_.end()) {
-      auto timer = get_timer_by_handle(*it, weak_groups_to_nodes);
+      auto timer_handle = it->lock();
+      if (!timer_handle) {
+        // Handle expired, remove it and continue
+        it = timer_handles_.erase(it);
+        continue;
+      }
+      auto timer = get_timer_by_handle(timer_handle, weak_groups_to_nodes);
       if (timer) {
         // Find the group for this handle and see if it can be serviced
         auto group = get_group_by_timer(timer, weak_groups_to_nodes);
@@ -430,12 +515,22 @@ public:
 
   rcl_allocator_t get_allocator() override
   {
-    return rclcpp::allocator::get_rcl_allocator<void *, VoidAlloc>(*allocator_.get());
+    if constexpr (std::is_same_v<Alloc, std::allocator<void>>) {
+      return rcl_get_default_allocator();
+    } else {
+      return rclcpp::allocator::get_rcl_allocator<void *, VoidAlloc>(*allocator_.get());
+    }
   }
 
   size_t number_of_ready_subscriptions() const override
   {
-    size_t number_of_subscriptions = subscription_handles_.size();
+    size_t number_of_subscriptions = 0;
+    // Count only non-expired weak_ptr references
+    for (const auto & weak_subscription : subscription_handles_) {
+      if (!weak_subscription.expired()) {
+        ++number_of_subscriptions;
+      }
+    }
     for (const std::shared_ptr<Waitable> & waitable : waitable_handles_) {
       number_of_subscriptions += waitable->get_number_of_ready_subscriptions();
     }
@@ -444,7 +539,13 @@ public:
 
   size_t number_of_ready_services() const override
   {
-    size_t number_of_services = service_handles_.size();
+    size_t number_of_services = 0;
+    // Count only non-expired weak_ptr references
+    for (const auto & weak_service : service_handles_) {
+      if (!weak_service.expired()) {
+        ++number_of_services;
+      }
+    }
     for (const std::shared_ptr<Waitable> & waitable : waitable_handles_) {
       number_of_services += waitable->get_number_of_ready_services();
     }
@@ -462,7 +563,13 @@ public:
 
   size_t number_of_ready_clients() const override
   {
-    size_t number_of_clients = client_handles_.size();
+    size_t number_of_clients = 0;
+    // Count only non-expired weak_ptr references
+    for (const auto & weak_client : client_handles_) {
+      if (!weak_client.expired()) {
+        ++number_of_clients;
+      }
+    }
     for (const std::shared_ptr<Waitable> & waitable : waitable_handles_) {
       number_of_clients += waitable->get_number_of_ready_clients();
     }
@@ -480,7 +587,13 @@ public:
 
   size_t number_of_ready_timers() const override
   {
-    size_t number_of_timers = timer_handles_.size();
+    size_t number_of_timers = 0;
+    // Count only non-expired weak_ptr references
+    for (const auto & weak_timer : timer_handles_) {
+      if (!weak_timer.expired()) {
+        ++number_of_timers;
+      }
+    }
     for (const std::shared_ptr<Waitable> & waitable : waitable_handles_) {
       number_of_timers += waitable->get_number_of_ready_timers();
     }
@@ -499,10 +612,10 @@ private:
 
   VectorRebind<const rclcpp::GuardCondition *> guard_conditions_;
 
-  VectorRebind<std::shared_ptr<const rcl_subscription_t>> subscription_handles_;
-  VectorRebind<std::shared_ptr<const rcl_service_t>> service_handles_;
-  VectorRebind<std::shared_ptr<const rcl_client_t>> client_handles_;
-  VectorRebind<std::shared_ptr<const rcl_timer_t>> timer_handles_;
+  VectorRebind<std::weak_ptr<const rcl_subscription_t>> subscription_handles_;
+  VectorRebind<std::weak_ptr<const rcl_service_t>> service_handles_;
+  VectorRebind<std::weak_ptr<const rcl_client_t>> client_handles_;
+  VectorRebind<std::weak_ptr<const rcl_timer_t>> timer_handles_;
   VectorRebind<std::shared_ptr<Waitable>> waitable_handles_;
 
   std::shared_ptr<VoidAlloc> allocator_;

rclcpp/include/rclcpp/subscription.hpp

@@ -279,6 +279,50 @@ public:
     return message_memory_strategy_->borrow_serialized_message();
   }
 
+  /// Disable callbacks from being called
+  /**
+    * This method will block, until any subscription's callbacks provided during construction
+    * currently being executed are finished.
+    * \note This method also temporary removes the on new message callback and all
+    * on new event callbacks from the rmw layer to prevent them from being called. However, this
+    * method will not block and wait until the currently executing on_new_[message]event callbacks
+    * are finished.
+    */
+  void
+  disable_callbacks() override
+  {
+    SubscriptionBase::disable_callbacks();
+    any_callback_.disable();
+    if (subscription_intra_process_) {
+      subscription_intra_process_->disable_callbacks();
+    }
+    for (const auto & [_, event_ptr] : event_handlers_) {
+      if (event_ptr) {
+        event_ptr->disable();
+      }
+    }
+  }
+
+  /// Enable the callbacks to be called
+  /**
+    * This method is thread safe, and provides a safe way to atomically enable the callbacks
+    * in a multithreaded environment.
+    */
+  void
+  enable_callbacks() override
+  {
+    SubscriptionBase::enable_callbacks();
+    any_callback_.enable();
+    if (subscription_intra_process_) {
+      subscription_intra_process_->enable_callbacks();
+    }
+    for (const auto & [_, event_ptr] : event_handlers_) {
+      if (event_ptr) {
+        event_ptr->enable();
+      }
+    }
+  }
+
   void
   handle_message(
     std::shared_ptr<void> & message,

rclcpp/include/rclcpp/subscription_base.hpp

@@ -212,6 +212,23 @@ public:
   std::shared_ptr<rclcpp::SerializedMessage>
   create_serialized_message() = 0;
 
+  /// Disable callbacks from being called
+  /**
+   * This function temporary removes the on_new_message_callback to prevent it from being called.
+   */
+  RCLCPP_PUBLIC
+  virtual
+  void disable_callbacks();
+
+  /// Enable the callbacks to be called
+  /**
+    * This function sets back the on_new_message_callback if it was previously removed in
+    * disable_callbacks().
+    */
+  RCLCPP_PUBLIC
+  virtual
+  void enable_callbacks();
+
   /// Check if we need to handle the message, and execute the callback if we do.
   /**
    * \param[in] message Shared pointer to the message to handle.
@@ -355,7 +372,7 @@ public:
    * \param[in] callback functor to be called when a new message is received
    */
   void
-  set_on_new_message_callback(std::function<void(size_t)> callback)
+  set_on_new_message_callback(const std::function<void(size_t)> & callback)
   {
     if (!callback) {
       throw std::invalid_argument(
@@ -383,7 +400,7 @@ public:
         }
       };
 
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
 
     // Set it temporarily to the new callback, while we replace the old one.
     // This two-step setting, prevents a gap where the old std::function has
@@ -406,7 +423,7 @@ public:
   void
   clear_on_new_message_callback()
   {
-    std::lock_guard<std::recursive_mutex> lock(callback_mutex_);
+    std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
 
     if (on_new_message_callback_) {
       set_on_new_message_callback(nullptr, nullptr);
@@ -433,7 +450,7 @@ public:
    * \param[in] callback functor to be called when a new message is received
    */
   void
-  set_on_new_intra_process_message_callback(std::function<void(size_t)> callback)
+  set_on_new_intra_process_message_callback(const std::function<void(size_t)> & callback)
   {
     if (!use_intra_process_) {
       RCLCPP_WARN(
@@ -451,7 +468,7 @@ public:
     // The on_ready_callback signature has an extra `int` argument used to disambiguate between
     // possible different entities within a generic waitable.
     // We hide that detail to users of this method.
-    std::function<void(size_t, int)> new_callback = std::bind(callback, std::placeholders::_1);
+    std::function<void(size_t, int)> new_callback = [callback] (size_t nr, int) {callback(nr);};
     subscription_intra_process_->set_on_ready_callback(new_callback);
   }
 
@@ -497,7 +514,7 @@ public:
    */
   void
   set_on_new_qos_event_callback(
-    std::function<void(size_t)> callback,
+    const std::function<void(size_t)> & callback,
     rcl_subscription_event_type_t event_type)
   {
     if (event_handlers_.count(event_type) == 0) {
@@ -516,7 +533,7 @@ public:
     // The on_ready_callback signature has an extra `int` argument used to disambiguate between
     // possible different entities within a generic waitable.
     // We hide that detail to users of this method.
-    std::function<void(size_t, int)> new_callback = std::bind(callback, std::placeholders::_1);
+    std::function<void(size_t, int)> new_callback = [callback] (size_t nr, int) {callback(nr);};
     event_handlers_[event_type]->set_on_ready_callback(new_callback);
   }
 
@@ -646,7 +663,7 @@ protected:
 
   std::shared_ptr<rcl_node_t> node_handle_;
 
-  std::recursive_mutex callback_mutex_;
+  std::recursive_mutex on_new_message_callback_mutex_;
   // It is important to declare on_new_message_callback_ before
   // subscription_handle_, so on destruction the subscription is
   // destroyed first. Otherwise, the rmw subscription callback

rclcpp/include/rclcpp/subscription_options.hpp

@@ -89,6 +89,15 @@ struct SubscriptionOptionsBase
   QosOverridingOptions qos_overriding_options;
 
   ContentFilterOptions content_filter_options;
+
+  /// Acceptable buffer backend names for this subscription.
+  /**
+   * Empty string or "cpu" means CPU-only (default for backward compatibility).
+   * "any" means all installed backends are acceptable.
+   * Comma-separated for specific backends, e.g. "cuda,demo".
+   * CPU is always implicitly acceptable regardless of this value.
+   */
+  std::string acceptable_buffer_backends{"cpu"};
 };
 
 /// Structure containing optional configuration for Subscriptions.
@@ -145,6 +154,11 @@ struct SubscriptionOptionsWithAllocator : public SubscriptionOptionsBase
       }
     }
 
+    if (!acceptable_buffer_backends.empty()) {
+      result.rmw_subscription_options.acceptable_buffer_backends =
+        acceptable_buffer_backends.c_str();
+    }
+
     return result;
   }
 
@@ -167,11 +181,20 @@ private:
   rcl_allocator_t
   get_rcl_allocator() const
   {
-    if (!plain_allocator_storage_) {
-      plain_allocator_storage_ =
-        std::make_shared<PlainAllocator>(*this->get_allocator());
+    if constexpr (std::is_same_v<Allocator, std::allocator<void>>) {
+      return rcl_get_default_allocator();
+    } else {
+      if constexpr (rclcpp::allocator::has_get_rcl_allocator_v<Allocator>) {
+        return get_allocator()->get_rcl_allocator();
+      } else {
+        if (!plain_allocator_storage_) {
+          plain_allocator_storage_ =
+            std::make_shared<PlainAllocator>(*this->get_allocator());
+        }
+
+        return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
+      }
     }
-    return rclcpp::allocator::get_rcl_allocator<char>(*plain_allocator_storage_);
   }
 
   // This is a temporal workaround, to make sure that get_allocator()

rclcpp/include/rclcpp/time_source.hpp

@@ -60,7 +60,7 @@ public:
    */
   RCLCPP_PUBLIC
   explicit TimeSource(
-    rclcpp::Node::SharedPtr node,
+    const rclcpp::Node::SharedPtr & node,
     const rclcpp::QoS & qos = rclcpp::ClockQoS(),
     bool use_clock_thread = true);
 
@@ -89,7 +89,7 @@ public:
    * \param node std::shared pointer to a initialized node
    */
   RCLCPP_PUBLIC
-  void attachNode(rclcpp::Node::SharedPtr node);
+  void attachNode(const rclcpp::Node::SharedPtr & node);
 
   /// Attach node to the time source.
   /**
@@ -124,11 +124,11 @@ public:
    * \throws std::invalid_argument the time source must be a RCL_ROS_TIME otherwise throws an exception
    */
   RCLCPP_PUBLIC
-  void attachClock(rclcpp::Clock::SharedPtr clock);
+  void attachClock(const rclcpp::Clock::SharedPtr & clock);
 
   /// Detach a clock from the time source
   RCLCPP_PUBLIC
-  void detachClock(rclcpp::Clock::SharedPtr clock);
+  void detachClock(const rclcpp::Clock::SharedPtr & clock);
 
   /// Get whether a separate clock thread is used or not
   RCLCPP_PUBLIC

rclcpp/include/rclcpp/timer.hpp

@@ -183,7 +183,7 @@ public:
    */
   RCLCPP_PUBLIC
   void
-  set_on_reset_callback(std::function<void(size_t)> callback);
+  set_on_reset_callback(const std::function<void(size_t)> & callback);
 
   /// Unset the callback registered for reset timer
   RCLCPP_PUBLIC

rclcpp/include/rclcpp/utilities.hpp

@@ -22,6 +22,7 @@
 #include <vector>
 
 #include "rclcpp/context.hpp"
+#include "rclcpp/contexts/default_context.hpp"
 #include "rclcpp/init_options.hpp"
 #include "rclcpp/visibility_control.hpp"
 
@@ -173,7 +174,7 @@ remove_ros_arguments(int argc, char const * const * argv);
  */
 RCLCPP_PUBLIC
 bool
-ok(rclcpp::Context::SharedPtr context = nullptr);
+ok(const rclcpp::Context::SharedPtr & context = rclcpp::contexts::get_global_default_context());
 
 /// Shutdown rclcpp context, invalidating it for derived entities.
 /**
@@ -192,7 +193,7 @@ ok(rclcpp::Context::SharedPtr context = nullptr);
 RCLCPP_PUBLIC
 bool
 shutdown(
-  rclcpp::Context::SharedPtr context = nullptr,
+  const rclcpp::Context::SharedPtr & context = rclcpp::contexts::get_global_default_context(),
   const std::string & reason = "user called rclcpp::shutdown()");
 
 /// Register a function to be called when shutdown is called on the context.
@@ -212,7 +213,9 @@ shutdown(
  */
 RCLCPP_PUBLIC
 void
-on_shutdown(std::function<void()> callback, rclcpp::Context::SharedPtr context = nullptr);
+on_shutdown(
+  const std::function<void()> & callback,
+  const rclcpp::Context::SharedPtr & context = rclcpp::contexts::get_global_default_context());
 
 /// Use the global condition variable to block for the specified amount of time.
 /**
@@ -231,7 +234,7 @@ RCLCPP_PUBLIC
 bool
 sleep_for(
   const std::chrono::nanoseconds & nanoseconds,
-  rclcpp::Context::SharedPtr context = nullptr);
+  const rclcpp::Context::SharedPtr & context = rclcpp::contexts::get_global_default_context());
 
 /// Safely check if addition will overflow.
 /**

rclcpp/include/rclcpp/wait_for_message.hpp

@@ -56,7 +56,7 @@ bool wait_for_message(
       }
     });
 
-  rclcpp::WaitSet wait_set;
+  rclcpp::WaitSet wait_set({}, {}, {}, {}, {}, {}, context);
   wait_set.add_subscription(subscription);
   RCPPUTILS_SCOPE_EXIT(wait_set.remove_subscription(subscription); );
   wait_set.add_guard_condition(gc);

rclcpp/include/rclcpp/wait_set_template.hpp

@@ -704,10 +704,12 @@ public:
             return WaitResult<WaitSetTemplate>::from_timeout_wait_result_kind();
           case WaitResultKind::Empty:
             return WaitResult<WaitSetTemplate>::from_empty_wait_result_kind();
-          default:
-            auto msg = "unknown WaitResultKind with value: " + std::to_string(wait_result_kind);
+          case WaitResultKind::Invalid:
+            auto msg = "invalid WaitResultKind with value: " + std::to_string(wait_result_kind);
             throw std::runtime_error(msg);
         }
+        // This should never be reached, but is needed to satisfy the compiler
+        throw std::runtime_error("unreachable code in wait result kind switch");
       }
     );
   }

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>30.1.2</version>
+  <version>30.1.5</version>
   <description>The ROS client library in C++.</description>
 
   <maintainer email="ivanpauno@ekumenlabs.com">Ivan Paunovic</maintainer>
@@ -47,9 +47,9 @@
   <depend>statistics_msgs</depend>
   <depend>tracetools</depend>
 
-  <test_depend>ament_cmake_gmock</test_depend>
   <test_depend>ament_cmake_google_benchmark</test_depend>
   <test_depend>ament_cmake_gtest</test_depend>
+  <test_depend>ament_cmake_ros</test_depend>
   <test_depend>ament_lint_auto</test_depend>
   <test_depend>ament_lint_common</test_depend>
   <test_depend>mimick_vendor</test_depend>

rclcpp/src/rclcpp/callback_group.cpp

@@ -31,7 +31,7 @@ using rclcpp::CallbackGroupType;
 
 CallbackGroup::CallbackGroup(
   CallbackGroupType group_type,
-  rclcpp::Context::WeakPtr context,
+  const rclcpp::Context::WeakPtr & context,
   bool automatically_add_to_executor_with_node)
 : type_(group_type), associated_with_executor_(false),
   can_be_taken_from_(true),
@@ -59,6 +59,7 @@ CallbackGroup::type() const
 size_t
 CallbackGroup::size() const
 {
+  std::lock_guard<std::mutex> lock(mutex_);
   return
     subscription_ptrs_.size() +
     service_ptrs_.size() +
@@ -68,11 +69,11 @@ CallbackGroup::size() const
 }
 
 void CallbackGroup::collect_all_ptrs(
-  std::function<void(const rclcpp::SubscriptionBase::SharedPtr &)> sub_func,
-  std::function<void(const rclcpp::ServiceBase::SharedPtr &)> service_func,
-  std::function<void(const rclcpp::ClientBase::SharedPtr &)> client_func,
-  std::function<void(const rclcpp::TimerBase::SharedPtr &)> timer_func,
-  std::function<void(const rclcpp::Waitable::SharedPtr &)> waitable_func) const
+  const std::function<void(const rclcpp::SubscriptionBase::SharedPtr &)> & sub_func,
+  const std::function<void(const rclcpp::ServiceBase::SharedPtr &)> & service_func,
+  const std::function<void(const rclcpp::ClientBase::SharedPtr &)> & client_func,
+  const std::function<void(const rclcpp::TimerBase::SharedPtr &)> & timer_func,
+  const std::function<void(const rclcpp::Waitable::SharedPtr &)> & waitable_func) const
 {
   std::lock_guard<std::mutex> lock(mutex_);
 
@@ -149,7 +150,7 @@ CallbackGroup::trigger_notify_guard_condition()
 
 void
 CallbackGroup::add_subscription(
-  const rclcpp::SubscriptionBase::SharedPtr subscription_ptr)
+  const rclcpp::SubscriptionBase::SharedPtr & subscription_ptr)
 {
   std::lock_guard<std::mutex> lock(mutex_);
   subscription_ptrs_.push_back(subscription_ptr);
@@ -157,12 +158,12 @@ CallbackGroup::add_subscription(
     std::remove_if(
       subscription_ptrs_.begin(),
       subscription_ptrs_.end(),
-      [](rclcpp::SubscriptionBase::WeakPtr x) {return x.expired();}),
+      [](const rclcpp::SubscriptionBase::WeakPtr & x) {return x.expired();}),
     subscription_ptrs_.end());
 }
 
 void
-CallbackGroup::add_timer(const rclcpp::TimerBase::SharedPtr timer_ptr)
+CallbackGroup::add_timer(const rclcpp::TimerBase::SharedPtr & timer_ptr)
 {
   std::lock_guard<std::mutex> lock(mutex_);
   timer_ptrs_.push_back(timer_ptr);
@@ -170,12 +171,12 @@ CallbackGroup::add_timer(const rclcpp::TimerBase::SharedPtr timer_ptr)
     std::remove_if(
       timer_ptrs_.begin(),
       timer_ptrs_.end(),
-      [](rclcpp::TimerBase::WeakPtr x) {return x.expired();}),
+      [](const rclcpp::TimerBase::WeakPtr & x) {return x.expired();}),
     timer_ptrs_.end());
 }
 
 void
-CallbackGroup::add_service(const rclcpp::ServiceBase::SharedPtr service_ptr)
+CallbackGroup::add_service(const rclcpp::ServiceBase::SharedPtr & service_ptr)
 {
   std::lock_guard<std::mutex> lock(mutex_);
   service_ptrs_.push_back(service_ptr);
@@ -183,12 +184,12 @@ CallbackGroup::add_service(const rclcpp::ServiceBase::SharedPtr service_ptr)
     std::remove_if(
       service_ptrs_.begin(),
       service_ptrs_.end(),
-      [](rclcpp::ServiceBase::WeakPtr x) {return x.expired();}),
+      [](const rclcpp::ServiceBase::WeakPtr & x) {return x.expired();}),
     service_ptrs_.end());
 }
 
 void
-CallbackGroup::add_client(const rclcpp::ClientBase::SharedPtr client_ptr)
+CallbackGroup::add_client(const rclcpp::ClientBase::SharedPtr & client_ptr)
 {
   std::lock_guard<std::mutex> lock(mutex_);
   client_ptrs_.push_back(client_ptr);
@@ -196,12 +197,12 @@ CallbackGroup::add_client(const rclcpp::ClientBase::SharedPtr client_ptr)
     std::remove_if(
       client_ptrs_.begin(),
       client_ptrs_.end(),
-      [](rclcpp::ClientBase::WeakPtr x) {return x.expired();}),
+      [](const rclcpp::ClientBase::WeakPtr & x) {return x.expired();}),
     client_ptrs_.end());
 }
 
 void
-CallbackGroup::add_waitable(const rclcpp::Waitable::SharedPtr waitable_ptr)
+CallbackGroup::add_waitable(const rclcpp::Waitable::SharedPtr & waitable_ptr)
 {
   std::lock_guard<std::mutex> lock(mutex_);
   waitable_ptrs_.push_back(waitable_ptr);
@@ -209,12 +210,12 @@ CallbackGroup::add_waitable(const rclcpp::Waitable::SharedPtr waitable_ptr)
     std::remove_if(
       waitable_ptrs_.begin(),
       waitable_ptrs_.end(),
-      [](rclcpp::Waitable::WeakPtr x) {return x.expired();}),
+      [](const rclcpp::Waitable::WeakPtr & x) {return x.expired();}),
     waitable_ptrs_.end());
 }
 
 void
-CallbackGroup::remove_waitable(const rclcpp::Waitable::SharedPtr waitable_ptr) noexcept
+CallbackGroup::remove_waitable(const rclcpp::Waitable::SharedPtr & waitable_ptr) noexcept
 {
   std::lock_guard<std::mutex> lock(mutex_);
   for (auto iter = waitable_ptrs_.begin(); iter != waitable_ptrs_.end(); ++iter) {

rclcpp/src/rclcpp/client.cpp

@@ -37,7 +37,7 @@ using rclcpp::exceptions::throw_from_rcl_error;
 
 ClientBase::ClientBase(
   rclcpp::node_interfaces::NodeBaseInterface * node_base,
-  rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph)
+  const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph)
 : node_graph_(node_graph),
   node_handle_(node_base->get_shared_rcl_node_handle()),
   context_(node_base->get_context()),

rclcpp/src/rclcpp/clock.cpp

@@ -60,8 +60,8 @@ JumpHandler::JumpHandler(
   pre_callback_t pre_callback,
   post_callback_t post_callback,
   const rcl_jump_threshold_t & threshold)
-: pre_callback(pre_callback),
-  post_callback(post_callback),
+: pre_callback(std::move(pre_callback)),
+  post_callback(std::move(post_callback)),
   notice_threshold(threshold)
 {}
 
@@ -85,8 +85,8 @@ Clock::now() const
 
 bool
 Clock::sleep_until(
-  Time until,
-  Context::SharedPtr context)
+  const Time & until,
+  const Context::SharedPtr & context)
 {
   if (!context || !context->is_valid()) {
     throw std::runtime_error("context cannot be slept with because it's invalid");
@@ -194,7 +194,7 @@ Clock::sleep_until(
 }
 
 bool
-Clock::sleep_for(Duration rel_time, Context::SharedPtr context)
+Clock::sleep_for(const Duration & rel_time, const Context::SharedPtr & context)
 {
   return sleep_until(now() + rel_time, context);
 }
@@ -209,7 +209,7 @@ Clock::started()
 }
 
 bool
-Clock::wait_until_started(Context::SharedPtr context)
+Clock::wait_until_started(const Context::SharedPtr & context)
 {
   if (!context || !context->is_valid()) {
     throw std::runtime_error("context cannot be slept with because it's invalid");
@@ -229,7 +229,7 @@ Clock::wait_until_started(Context::SharedPtr context)
 bool
 Clock::wait_until_started(
   const Duration & timeout,
-  Context::SharedPtr context,
+  const Context::SharedPtr & context,
   const Duration & wait_tick_ns)
 {
   if (!context || !context->is_valid()) {
@@ -318,8 +318,8 @@ Clock::on_time_jump(
 
 JumpHandler::SharedPtr
 Clock::create_jump_callback(
-  JumpHandler::pre_callback_t pre_callback,
-  JumpHandler::post_callback_t post_callback,
+  const JumpHandler::pre_callback_t & pre_callback,
+  const JumpHandler::post_callback_t & post_callback,
   const rcl_jump_threshold_t & threshold)
 {
   // Allocate a new jump handler
@@ -516,7 +516,7 @@ class ClockConditionalVariable::Impl
   ClockWaiter::UniquePtr clock_;
 
 public:
-  Impl(const rclcpp::Clock::SharedPtr & clock, rclcpp::Context::SharedPtr context)
+  Impl(const rclcpp::Clock::SharedPtr & clock, const rclcpp::Context::SharedPtr & context)
   :context_(context),
     clock_(std::make_unique<ClockWaiter>(clock))
   {
@@ -541,7 +541,7 @@ public:
 
   bool
   wait_until(
-    std::unique_lock<std::mutex> & lock, rclcpp::Time until,
+    std::unique_lock<std::mutex> & lock, const rclcpp::Time & until,
     const std::function<bool ()> & pred)
   {
     if(lock.mutex() != &pred_mutex_) {
@@ -571,7 +571,7 @@ public:
 
 ClockConditionalVariable::ClockConditionalVariable(
   const rclcpp::Clock::SharedPtr & clock,
-  rclcpp::Context::SharedPtr context)
+  const rclcpp::Context::SharedPtr & context)
 :impl_(std::make_unique<Impl>(clock, context))
 {
 }
@@ -586,7 +586,7 @@ ClockConditionalVariable::notify_one()
 
 bool
 ClockConditionalVariable::wait_until(
-  std::unique_lock<std::mutex> & lock, rclcpp::Time until,
+  std::unique_lock<std::mutex> & lock, const rclcpp::Time & until,
   const std::function<bool ()> & pred)
 {
   return impl_->wait_until(lock, until, pred);

rclcpp/src/rclcpp/context.cpp

@@ -59,7 +59,7 @@ public:
       std::remove_if(
         weak_contexts_.begin(),
         weak_contexts_.end(),
-        [context](const Context::WeakPtr weak_context) {
+        [context](const Context::WeakPtr & weak_context) {
           auto locked_context = weak_context.lock();
           if (!locked_context) {
             // take advantage and removed expired contexts
@@ -388,14 +388,14 @@ Context::shutdown(const std::string & reason)
 }
 
 rclcpp::Context::OnShutdownCallback
-Context::on_shutdown(OnShutdownCallback callback)
+Context::on_shutdown(const OnShutdownCallback & callback)
 {
   add_on_shutdown_callback(callback);
   return callback;
 }
 
 rclcpp::OnShutdownCallbackHandle
-Context::add_on_shutdown_callback(OnShutdownCallback callback)
+Context::add_on_shutdown_callback(const OnShutdownCallback & callback)
 {
   return add_shutdown_callback<ShutdownType::on_shutdown>(callback);
 }
@@ -407,7 +407,7 @@ Context::remove_on_shutdown_callback(const OnShutdownCallbackHandle & callback_h
 }
 
 rclcpp::PreShutdownCallbackHandle
-Context::add_pre_shutdown_callback(PreShutdownCallback callback)
+Context::add_pre_shutdown_callback(const PreShutdownCallback & callback)
 {
   return add_shutdown_callback<ShutdownType::pre_shutdown>(callback);
 }
@@ -422,7 +422,7 @@ Context::remove_pre_shutdown_callback(
 template<Context::ShutdownType shutdown_type>
 rclcpp::ShutdownCallbackHandle
 Context::add_shutdown_callback(
-  ShutdownCallback callback)
+  const ShutdownCallback & callback)
 {
   auto callback_shared_ptr =
     std::make_shared<ShutdownCallbackHandle::ShutdownCallbackType>(callback);
@@ -497,8 +497,9 @@ Context::get_shutdown_callback() const
   const auto get_callback_vector = [](auto & mutex, auto & callback_set) {
       const std::lock_guard<std::recursive_mutex> lock(mutex);
       std::vector<rclcpp::Context::ShutdownCallback> callbacks;
+      callbacks.reserve(callback_set.size());
       for (auto & callback : callback_set) {
-        callbacks.push_back(*callback);
+        callbacks.emplace_back(*callback);
       }
       return callbacks;
     };

rclcpp/src/rclcpp/create_generic_client.cpp

@@ -19,13 +19,13 @@ namespace rclcpp
 {
 rclcpp::GenericClient::SharedPtr
 create_generic_client(
-  std::shared_ptr<node_interfaces::NodeBaseInterface> node_base,
-  std::shared_ptr<node_interfaces::NodeGraphInterface> node_graph,
-  std::shared_ptr<node_interfaces::NodeServicesInterface> node_services,
+  const std::shared_ptr<node_interfaces::NodeBaseInterface> & node_base,
+  const std::shared_ptr<node_interfaces::NodeGraphInterface> & node_graph,
+  const std::shared_ptr<node_interfaces::NodeServicesInterface> & node_services,
   const std::string & service_name,
   const std::string & service_type,
   const rclcpp::QoS & qos,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   rcl_client_options_t options = rcl_client_get_default_options();
   options.qos = qos.get_rmw_qos_profile();

rclcpp/src/rclcpp/executor.cpp

@@ -99,29 +99,29 @@ Executor::~Executor()
   notify_waitable_->remove_guard_condition(shutdown_guard_condition_);
   current_collection_.timers.update(
     {}, {},
-    [this](auto timer) {wait_set_.remove_timer(timer);});
+    [this](auto timer) {wait_set_.remove_timer(std::move(timer));});
 
   current_collection_.subscriptions.update(
     {}, {},
     [this](auto subscription) {
-      wait_set_.remove_subscription(subscription, kDefaultSubscriptionMask);
+      wait_set_.remove_subscription(std::move(subscription), kDefaultSubscriptionMask);
     });
 
   current_collection_.clients.update(
     {}, {},
-    [this](auto client) {wait_set_.remove_client(client);});
+    [this](auto client) {wait_set_.remove_client(std::move(client));});
 
   current_collection_.services.update(
     {}, {},
-    [this](auto service) {wait_set_.remove_service(service);});
+    [this](auto service) {wait_set_.remove_service(std::move(service));});
 
   current_collection_.guard_conditions.update(
     {}, {},
-    [this](auto guard_condition) {wait_set_.remove_guard_condition(guard_condition);});
+    [this](auto guard_condition) {wait_set_.remove_guard_condition(std::move(guard_condition));});
 
   current_collection_.waitables.update(
     {}, {},
-    [this](auto waitable) {wait_set_.remove_waitable(waitable);});
+    [this](auto waitable) {wait_set_.remove_waitable(std::move(waitable));});
 
   // Remove shutdown callback handle registered to Context
   if (!context_->remove_on_shutdown_callback(shutdown_callback_handle_)) {
@@ -170,8 +170,8 @@ Executor::get_automatically_added_callback_groups_from_nodes()
 
 void
 Executor::add_callback_group(
-  rclcpp::CallbackGroup::SharedPtr group_ptr,
-  [[maybe_unused]] rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+  const rclcpp::CallbackGroup::SharedPtr & group_ptr,
+  [[maybe_unused]] const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
   bool notify)
 {
   this->collector_.add_callback_group(group_ptr);
@@ -186,7 +186,9 @@ Executor::add_callback_group(
 }
 
 void
-Executor::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify)
+Executor::add_node(
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+  bool notify)
 {
   if (node_ptr->get_context() != context_) {
     throw std::runtime_error(
@@ -206,7 +208,7 @@ Executor::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_pt
 
 void
 Executor::remove_callback_group(
-  rclcpp::CallbackGroup::SharedPtr group_ptr,
+  const rclcpp::CallbackGroup::SharedPtr & group_ptr,
   bool notify)
 {
   this->collector_.remove_callback_group(group_ptr);
@@ -221,13 +223,15 @@ Executor::remove_callback_group(
 }
 
 void
-Executor::add_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify)
+Executor::add_node(const std::shared_ptr<rclcpp::Node> & node_ptr, bool notify)
 {
   this->add_node(node_ptr->get_node_base_interface(), notify);
 }
 
 void
-Executor::remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr, bool notify)
+Executor::remove_node(
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
+  bool notify)
 {
   this->collector_.remove_node(node_ptr);
 
@@ -241,14 +245,14 @@ Executor::remove_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node
 }
 
 void
-Executor::remove_node(std::shared_ptr<rclcpp::Node> node_ptr, bool notify)
+Executor::remove_node(const std::shared_ptr<rclcpp::Node> & node_ptr, bool notify)
 {
   this->remove_node(node_ptr->get_node_base_interface(), notify);
 }
 
 void
 Executor::spin_node_once_nanoseconds(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node,
   std::chrono::nanoseconds timeout)
 {
   this->add_node(node, false);
@@ -311,7 +315,7 @@ Executor::spin_until_future_complete_impl(
 }
 
 void
-Executor::spin_node_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node)
+Executor::spin_node_some(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node)
 {
   this->add_node(node, false);
   spin_some();
@@ -319,7 +323,7 @@ Executor::spin_node_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr n
 }
 
 void
-Executor::spin_node_some(std::shared_ptr<rclcpp::Node> node)
+Executor::spin_node_some(const std::shared_ptr<rclcpp::Node> & node)
 {
   this->spin_node_some(node->get_node_base_interface());
 }
@@ -331,7 +335,7 @@ void Executor::spin_some(std::chrono::nanoseconds max_duration)
 
 void
 Executor::spin_node_all(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node,
   std::chrono::nanoseconds max_duration)
 {
   this->add_node(node, false);
@@ -340,7 +344,9 @@ Executor::spin_node_all(
 }
 
 void
-Executor::spin_node_all(std::shared_ptr<rclcpp::Node> node, std::chrono::nanoseconds max_duration)
+Executor::spin_node_all(
+  const std::shared_ptr<rclcpp::Node> & node,
+  std::chrono::nanoseconds max_duration)
 {
   this->spin_node_all(node->get_node_base_interface(), max_duration);
 }
@@ -546,7 +552,7 @@ take_and_do_error_handling(
 }
 
 void
-Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
+Executor::execute_subscription(const rclcpp::SubscriptionBase::SharedPtr & subscription)
 {
   using rclcpp::dynamic_typesupport::DynamicMessage;
 
@@ -640,7 +646,7 @@ Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
         throw std::runtime_error("Unimplemented");
       }
 
-    default:
+    case rclcpp::DeliveredMessageKind::INVALID:
       {
         throw std::runtime_error("Delivered message kind is not supported");
       }
@@ -648,13 +654,15 @@ Executor::execute_subscription(rclcpp::SubscriptionBase::SharedPtr subscription)
 }
 
 void
-Executor::execute_timer(rclcpp::TimerBase::SharedPtr timer, const std::shared_ptr<void> & data_ptr)
+Executor::execute_timer(
+  const rclcpp::TimerBase::SharedPtr & timer,
+  const std::shared_ptr<void> & data_ptr)
 {
   timer->execute_callback(data_ptr);
 }
 
 void
-Executor::execute_service(rclcpp::ServiceBase::SharedPtr service)
+Executor::execute_service(const rclcpp::ServiceBase::SharedPtr & service)
 {
   auto request_header = service->create_request_header();
   std::shared_ptr<void> request = service->create_request();
@@ -666,7 +674,7 @@ Executor::execute_service(rclcpp::ServiceBase::SharedPtr service)
 }
 
 void
-Executor::execute_client(rclcpp::ClientBase::SharedPtr client)
+Executor::execute_client(const rclcpp::ClientBase::SharedPtr & client)
 {
   auto request_header = client->create_request_header();
   std::shared_ptr<void> response = client->create_response();
@@ -708,37 +716,37 @@ Executor::collect_entities()
   // from the wait set as necessary.
   current_collection_.timers.update(
     collection.timers,
-    [this](auto timer) {wait_set_.add_timer(timer);},
-    [this](auto timer) {wait_set_.remove_timer(timer);});
+    [this](auto timer) {wait_set_.add_timer(std::move(timer));},
+    [this](auto timer) {wait_set_.remove_timer(std::move(timer));});
 
   current_collection_.subscriptions.update(
     collection.subscriptions,
     [this](auto subscription) {
-      wait_set_.add_subscription(subscription, kDefaultSubscriptionMask);
+      wait_set_.add_subscription(std::move(subscription), kDefaultSubscriptionMask);
     },
     [this](auto subscription) {
-      wait_set_.remove_subscription(subscription, kDefaultSubscriptionMask);
+      wait_set_.remove_subscription(std::move(subscription), kDefaultSubscriptionMask);
     });
 
   current_collection_.clients.update(
     collection.clients,
-    [this](auto client) {wait_set_.add_client(client);},
-    [this](auto client) {wait_set_.remove_client(client);});
+    [this](auto client) {wait_set_.add_client(std::move(client));},
+    [this](auto client) {wait_set_.remove_client(std::move(client));});
 
   current_collection_.services.update(
     collection.services,
-    [this](auto service) {wait_set_.add_service(service);},
-    [this](auto service) {wait_set_.remove_service(service);});
+    [this](auto service) {wait_set_.add_service(std::move(service));},
+    [this](auto service) {wait_set_.remove_service(std::move(service));});
 
   current_collection_.guard_conditions.update(
     collection.guard_conditions,
-    [this](auto guard_condition) {wait_set_.add_guard_condition(guard_condition);},
-    [this](auto guard_condition) {wait_set_.remove_guard_condition(guard_condition);});
+    [this](auto guard_condition) {wait_set_.add_guard_condition(std::move(guard_condition));},
+    [this](auto guard_condition) {wait_set_.remove_guard_condition(std::move(guard_condition));});
 
   current_collection_.waitables.update(
     collection.waitables,
-    [this](auto waitable) {wait_set_.add_waitable(waitable);},
-    [this](auto waitable) {wait_set_.remove_waitable(waitable);});
+    [this](auto waitable) {wait_set_.add_waitable(std::move(waitable));},
+    [this](auto waitable) {wait_set_.remove_waitable(std::move(waitable));});
 
   // In the case that an entity already has an expired weak pointer
   // before being removed from the waitset, additionally prune the waitset.

rclcpp/src/rclcpp/executors.cpp

@@ -17,7 +17,7 @@
 
 void
 rclcpp::spin_all(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr,
   std::chrono::nanoseconds max_duration)
 {
   rclcpp::ExecutorOptions options;
@@ -27,7 +27,7 @@ rclcpp::spin_all(
 }
 
 void
-rclcpp::spin_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)
+rclcpp::spin_some(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr)
 {
   rclcpp::ExecutorOptions options;
   options.context = node_ptr->get_context();
@@ -36,7 +36,7 @@ rclcpp::spin_some(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr
 }
 
 void
-rclcpp::spin(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)
+rclcpp::spin(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr)
 {
   rclcpp::ExecutorOptions options;
   options.context = node_ptr->get_context();
@@ -47,13 +47,13 @@ rclcpp::spin(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)
 }
 
 void
-rclcpp::spin(rclcpp::Node::SharedPtr node_ptr)
+rclcpp::spin(const rclcpp::Node::SharedPtr & node_ptr)
 {
   rclcpp::spin(node_ptr->get_node_base_interface());
 }
 
 void
-rclcpp::spin_all(rclcpp::Node::SharedPtr node_ptr, std::chrono::nanoseconds max_duration)
+rclcpp::spin_all(const rclcpp::Node::SharedPtr & node_ptr, std::chrono::nanoseconds max_duration)
 {
   RCPPUTILS_DEPRECATION_WARNING_OFF_START
   rclcpp::spin_all(node_ptr->get_node_base_interface(), max_duration);
@@ -61,7 +61,7 @@ rclcpp::spin_all(rclcpp::Node::SharedPtr node_ptr, std::chrono::nanoseconds max_
 }
 
 void
-rclcpp::spin_some(rclcpp::Node::SharedPtr node_ptr)
+rclcpp::spin_some(const rclcpp::Node::SharedPtr & node_ptr)
 {
   RCPPUTILS_DEPRECATION_WARNING_OFF_START
   rclcpp::spin_some(node_ptr->get_node_base_interface());

rclcpp/src/rclcpp/executors/executor_entities_collection.cpp

@@ -70,7 +70,7 @@ build_entities_collection(
 {
   collection.clear();
 
-  for (auto weak_group_ptr : callback_groups) {
+  for (const auto & weak_group_ptr : callback_groups) {
     auto group_ptr = weak_group_ptr.lock();
     if (!group_ptr) {
       continue;

rclcpp/src/rclcpp/executors/executor_entities_collector.cpp

@@ -24,7 +24,7 @@ namespace executors
 {
 
 ExecutorEntitiesCollector::ExecutorEntitiesCollector(
-  std::shared_ptr<ExecutorNotifyWaitable> notify_waitable)
+  const std::shared_ptr<ExecutorNotifyWaitable> & notify_waitable)
 : notify_waitable_(notify_waitable)
 {
 }
@@ -47,7 +47,7 @@ ExecutorEntitiesCollector::~ExecutorEntitiesCollector()
     weak_group_it = remove_weak_callback_group(weak_group_it, manually_added_groups_);
   }
 
-  for (auto weak_node_ptr : pending_added_nodes_) {
+  for (const auto & weak_node_ptr : pending_added_nodes_) {
     auto node_ptr = weak_node_ptr.lock();
     if (node_ptr) {
       node_ptr->get_associated_with_executor_atomic().store(false);
@@ -56,7 +56,7 @@ ExecutorEntitiesCollector::~ExecutorEntitiesCollector()
   pending_added_nodes_.clear();
   pending_removed_nodes_.clear();
 
-  for (auto weak_group_ptr : pending_manually_added_groups_) {
+  for (const auto & weak_group_ptr : pending_manually_added_groups_) {
     auto group_ptr = weak_group_ptr.lock();
     if (group_ptr) {
       group_ptr->get_associated_with_executor_atomic().store(false);
@@ -83,7 +83,8 @@ ExecutorEntitiesCollector::has_pending() const
 }
 
 void
-ExecutorEntitiesCollector::add_node(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)
+ExecutorEntitiesCollector::add_node(
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr)
 {
   // If the node already has an executor
   std::atomic_bool & has_executor = node_ptr->get_associated_with_executor_atomic();
@@ -109,7 +110,7 @@ ExecutorEntitiesCollector::add_node(rclcpp::node_interfaces::NodeBaseInterface::
 
 void
 ExecutorEntitiesCollector::remove_node(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_ptr)
 {
   std::atomic_bool & has_executor = node_ptr->get_associated_with_executor_atomic();
   if (!has_executor.exchange(false)) {
@@ -133,7 +134,7 @@ ExecutorEntitiesCollector::remove_node(
 }
 
 void
-ExecutorEntitiesCollector::add_callback_group(rclcpp::CallbackGroup::SharedPtr group_ptr)
+ExecutorEntitiesCollector::add_callback_group(const rclcpp::CallbackGroup::SharedPtr & group_ptr)
 {
   std::atomic_bool & has_executor = group_ptr->get_associated_with_executor_atomic();
   if (has_executor.exchange(true)) {
@@ -158,7 +159,7 @@ ExecutorEntitiesCollector::add_callback_group(rclcpp::CallbackGroup::SharedPtr g
 }
 
 void
-ExecutorEntitiesCollector::remove_callback_group(rclcpp::CallbackGroup::SharedPtr group_ptr)
+ExecutorEntitiesCollector::remove_callback_group(const rclcpp::CallbackGroup::SharedPtr & group_ptr)
 {
   if (!group_ptr->get_associated_with_executor_atomic().load()) {
     throw std::runtime_error("Callback group needs to be associated with an executor.");
@@ -288,7 +289,7 @@ ExecutorEntitiesCollector::remove_weak_callback_group(
 
 void
 ExecutorEntitiesCollector::add_callback_group_to_collection(
-  rclcpp::CallbackGroup::SharedPtr group_ptr,
+  const rclcpp::CallbackGroup::SharedPtr & group_ptr,
   CallbackGroupCollection & collection)
 {
   auto iter = collection.insert(group_ptr);
@@ -305,7 +306,7 @@ ExecutorEntitiesCollector::add_callback_group_to_collection(
 void
 ExecutorEntitiesCollector::process_queues()
 {
-  for (auto weak_node_ptr : pending_added_nodes_) {
+  for (const auto & weak_node_ptr : pending_added_nodes_) {
     auto node_ptr = weak_node_ptr.lock();
     if (!node_ptr) {
       continue;
@@ -320,7 +321,7 @@ ExecutorEntitiesCollector::process_queues()
   }
   pending_added_nodes_.clear();
 
-  for (auto weak_node_ptr : pending_removed_nodes_) {
+  for (const auto & weak_node_ptr : pending_removed_nodes_) {
     auto node_it = weak_nodes_.find(weak_node_ptr);
     if (node_it != weak_nodes_.end()) {
       remove_weak_node(node_it);
@@ -348,7 +349,7 @@ ExecutorEntitiesCollector::process_queues()
   }
   pending_removed_nodes_.clear();
 
-  for (auto weak_group_ptr : pending_manually_added_groups_) {
+  for (const auto & weak_group_ptr : pending_manually_added_groups_) {
     auto group_ptr = weak_group_ptr.lock();
     if (group_ptr) {
       this->add_callback_group_to_collection(group_ptr, manually_added_groups_);
@@ -363,7 +364,7 @@ ExecutorEntitiesCollector::process_queues()
   }
   pending_manually_added_groups_.clear();
 
-  for (auto weak_group_ptr : pending_manually_removed_groups_) {
+  for (const auto & weak_group_ptr : pending_manually_removed_groups_) {
     auto group_ptr = weak_group_ptr.lock();
     if (group_ptr) {
       auto group_it = manually_added_groups_.find(group_ptr);
@@ -386,7 +387,7 @@ ExecutorEntitiesCollector::add_automatically_associated_callback_groups(
     auto node = weak_node.lock();
     if (node) {
       node->for_each_callback_group(
-        [this, node](rclcpp::CallbackGroup::SharedPtr group_ptr)
+        [this, node](const rclcpp::CallbackGroup::SharedPtr & group_ptr)
         {
           if (!group_ptr->get_associated_with_executor_atomic().load() &&
           group_ptr->automatically_add_to_executor_with_node())

rclcpp/src/rclcpp/executors/executor_notify_waitable.cpp

@@ -21,7 +21,7 @@ namespace executors
 {
 
 ExecutorNotifyWaitable::ExecutorNotifyWaitable(
-  std::function<void(void)> on_execute_callback,
+  const std::function<void(void)> & on_execute_callback,
   const rclcpp::Context::SharedPtr & context)
 : execute_callback_(on_execute_callback),
   guard_condition_(std::make_shared<rclcpp::GuardCondition>(context))
@@ -144,13 +144,13 @@ ExecutorNotifyWaitable::take_data_by_entity_id([[maybe_unused]] size_t id)
 }
 
 void
-ExecutorNotifyWaitable::set_on_ready_callback(std::function<void(size_t, int)> callback)
+ExecutorNotifyWaitable::set_on_ready_callback(std::function<void(size_t, int)> callback_in)
 {
   // The second argument of the callback could be used to identify which guard condition
   // triggered the event.
   // We could indicate which of the guard conditions was triggered, but the executor
   // is already going to check that.
-  auto gc_callback = [callback](size_t count) {
+  auto gc_callback = [callback = std::move(callback_in)](size_t count) {
       callback(count, 0);
     };
 
@@ -179,11 +179,12 @@ void
 ExecutorNotifyWaitable::set_execute_callback(std::function<void(void)> on_execute_callback)
 {
   std::lock_guard<std::mutex> lock(execute_mutex_);
-  execute_callback_ = on_execute_callback;
+  execute_callback_ = std::move(on_execute_callback);
 }
 
 void
-ExecutorNotifyWaitable::add_guard_condition(rclcpp::GuardCondition::WeakPtr weak_guard_condition)
+ExecutorNotifyWaitable::add_guard_condition(
+  const rclcpp::GuardCondition::WeakPtr & weak_guard_condition)
 {
   std::lock_guard<std::mutex> lock(guard_condition_mutex_);
   const auto & guard_condition = weak_guard_condition.lock();
@@ -196,7 +197,8 @@ ExecutorNotifyWaitable::add_guard_condition(rclcpp::GuardCondition::WeakPtr weak
 }
 
 void
-ExecutorNotifyWaitable::remove_guard_condition(rclcpp::GuardCondition::WeakPtr weak_guard_condition)
+ExecutorNotifyWaitable::remove_guard_condition(
+  const rclcpp::GuardCondition::WeakPtr & weak_guard_condition)
 {
   std::lock_guard<std::mutex> lock(guard_condition_mutex_);
   const auto & guard_condition = weak_guard_condition.lock();

rclcpp/src/rclcpp/experimental/timers_manager.cpp

@@ -29,7 +29,7 @@ TimersManager::TimersManager(
   std::shared_ptr<rclcpp::Context> context,
   std::function<void(const rclcpp::TimerBase *, const std::shared_ptr<void> &)> on_ready_callback)
 : on_ready_callback_(on_ready_callback),
-  context_(context)
+  context_(std::move(context))
 {
 }
 
@@ -42,7 +42,7 @@ TimersManager::~TimersManager()
   this->stop();
 }
 
-void TimersManager::add_timer(rclcpp::TimerBase::SharedPtr timer)
+void TimersManager::add_timer(const rclcpp::TimerBase::SharedPtr & timer)
 {
   if (!timer) {
     throw std::invalid_argument("TimersManager::add_timer() trying to add nullptr timer");
@@ -311,7 +311,7 @@ void TimersManager::clear()
   timers_cv_.notify_one();
 }
 
-void TimersManager::remove_timer(TimerPtr timer)
+void TimersManager::remove_timer(const TimerPtr & timer)
 {
   bool removed = false;
   {

rclcpp/src/rclcpp/generic_client.cpp

@@ -25,7 +25,7 @@ namespace rclcpp
 {
 GenericClient::GenericClient(
   rclcpp::node_interfaces::NodeBaseInterface * node_base,
-  rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph,
+  const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph,
   const std::string & service_name,
   const std::string & service_type,
   rcl_client_options_t & client_options)
@@ -97,8 +97,8 @@ GenericClient::create_request_header()
 
 void
 GenericClient::handle_response(
-  std::shared_ptr<rmw_request_id_t> request_header,
-  std::shared_ptr<void> response)
+  const std::shared_ptr<rmw_request_id_t> & request_header,
+  const std::shared_ptr<void> & response)
 {
   auto optional_pending_request =
     this->get_and_erase_pending_request(request_header->sequence_number);
@@ -108,13 +108,13 @@ GenericClient::handle_response(
   auto & value = *optional_pending_request;
   if (std::holds_alternative<Promise>(value)) {
     auto & promise = std::get<Promise>(value);
-    promise.set_value(std::move(response));
+    promise.set_value(response);
   } else if (std::holds_alternative<CallbackTypeValueVariant>(value)) {
     auto & inner = std::get<CallbackTypeValueVariant>(value);
     const auto & callback = std::get<CallbackType>(inner);
     auto & promise = std::get<Promise>(inner);
     auto & future = std::get<SharedFuture>(inner);
-    promise.set_value(std::move(response));
+    promise.set_value(response);
     callback(std::move(future));
   }
 }
@@ -164,7 +164,7 @@ GenericClient::get_and_erase_pending_request(int64_t request_number)
 }
 
 GenericClient::FutureAndRequestId
-GenericClient::async_send_request(const Request request)
+GenericClient::async_send_request(const Request & request)
 {
   Promise promise;
   auto future = promise.get_future();
@@ -175,7 +175,7 @@ GenericClient::async_send_request(const Request request)
 }
 
 int64_t
-GenericClient::async_send_request_impl(const Request request, CallbackInfoVariant value)
+GenericClient::async_send_request_impl(const Request & request, CallbackInfoVariant value)
 {
   int64_t sequence_number;
   std::lock_guard<std::mutex> lock(pending_requests_mutex_);

rclcpp/src/rclcpp/generic_service.cpp

@@ -17,13 +17,13 @@
 namespace rclcpp
 {
 GenericService::GenericService(
-  std::shared_ptr<rcl_node_t> node_handle,
+  const std::shared_ptr<rcl_node_t> & node_handle,
   const std::string & service_name,
   const std::string & service_type,
   GenericServiceCallback any_callback,
   rcl_service_options_t & service_options)
 : ServiceBase(node_handle),
-  any_callback_(any_callback)
+  any_callback_(std::move(any_callback))
 {
   const rosidl_service_type_support_t * service_ts;
   try {
@@ -98,7 +98,7 @@ GenericService::GenericService(
 
 bool
 GenericService::take_request(
-  SharedRequest request_out,
+  SharedRequest & request_out,
   rmw_request_id_t & request_id_out)
 {
   request_out = create_request();
@@ -141,8 +141,8 @@ GenericService::create_request_header()
 
 void
 GenericService::handle_request(
-  std::shared_ptr<rmw_request_id_t> request_header,
-  std::shared_ptr<void> request)
+  const std::shared_ptr<rmw_request_id_t> & request_header,
+  const std::shared_ptr<void> & request)
 {
   auto response = any_callback_.dispatch(
     this->shared_from_this(), request_header, request, create_response());

rclcpp/src/rclcpp/generic_subscription.cpp

@@ -37,6 +37,30 @@ GenericSubscription::create_serialized_message()
   return std::make_shared<rclcpp::SerializedMessage>(0);
 }
 
+void
+GenericSubscription::disable_callbacks()
+{
+  SubscriptionBase::disable_callbacks();
+  any_callback_.disable();
+  for (const auto & [_, event_ptr] : event_handlers_) {
+    if (event_ptr) {
+      event_ptr->disable();
+    }
+  }
+}
+
+void
+GenericSubscription::enable_callbacks()
+{
+  SubscriptionBase::enable_callbacks();
+  any_callback_.enable();
+  for (const auto & [_, event_ptr] : event_handlers_) {
+    if (event_ptr) {
+      event_ptr->enable();
+    }
+  }
+}
+
 void
 GenericSubscription::handle_message(
   std::shared_ptr<void> &,

rclcpp/src/rclcpp/guard_condition.cpp

@@ -112,7 +112,7 @@ GuardCondition::add_to_wait_set(rcl_wait_set_t & wait_set)
 }
 
 void
-GuardCondition::set_on_trigger_callback(std::function<void(size_t)> callback)
+GuardCondition::set_on_trigger_callback(const std::function<void(size_t)> & callback)
 {
   std::lock_guard<std::recursive_mutex> lock(reentrant_mutex_);
 

rclcpp/src/rclcpp/intra_process_manager.cpp

@@ -33,8 +33,8 @@ IntraProcessManager::~IntraProcessManager()
 
 uint64_t
 IntraProcessManager::add_publisher(
-  rclcpp::PublisherBase::SharedPtr publisher,
-  rclcpp::experimental::buffers::IntraProcessBufferBase::SharedPtr buffer)
+  const rclcpp::PublisherBase::SharedPtr & publisher,
+  const rclcpp::experimental::buffers::IntraProcessBufferBase::SharedPtr & buffer)
 {
   std::unique_lock<std::shared_timed_mutex> lock(mutex_);
 
@@ -51,6 +51,9 @@ IntraProcessManager::add_publisher(
     }
   }
 
+  // Add GID to publisher info mapping for fast lookups (stores both ID and weak_ptr)
+  gid_to_publisher_info_[publisher->get_gid()] = {pub_id, publisher};
+
   // Initialize the subscriptions storage for this publisher.
   pub_to_subs_[pub_id] = SplittedSubscriptions();
 
@@ -98,6 +101,24 @@ IntraProcessManager::remove_publisher(uint64_t intra_process_publisher_id)
 {
   std::unique_lock<std::shared_timed_mutex> lock(mutex_);
 
+  // Remove GID to publisher info mapping.
+  // First try via the publisher's own GID (fast path).
+  auto pub_it = publishers_.find(intra_process_publisher_id);
+  if (pub_it != publishers_.end()) {
+    auto publisher = pub_it->second.lock();
+    if (publisher) {
+      gid_to_publisher_info_.erase(publisher->get_gid());
+    } else {
+      // Publisher weak_ptr already expired, fall back to linear scan by pub_id.
+      for (auto git = gid_to_publisher_info_.begin(); git != gid_to_publisher_info_.end(); ++git) {
+        if (git->second.pub_id == intra_process_publisher_id) {
+          gid_to_publisher_info_.erase(git);
+          break;
+        }
+      }
+    }
+  }
+
   publishers_.erase(intra_process_publisher_id);
   publisher_buffers_.erase(intra_process_publisher_id);
   pub_to_subs_.erase(intra_process_publisher_id);
@@ -108,16 +129,15 @@ IntraProcessManager::matches_any_publishers(const rmw_gid_t * id) const
 {
   std::shared_lock<std::shared_timed_mutex> lock(mutex_);
 
-  for (auto & publisher_pair : publishers_) {
-    auto publisher = publisher_pair.second.lock();
-    if (!publisher) {
-      continue;
-    }
-    if (*publisher.get() == id) {
-      return true;
-    }
+  // Single O(1) hash map lookup - struct contains both ID and weak_ptr
+  auto it = gid_to_publisher_info_.find(*id);
+  if (it == gid_to_publisher_info_.end()) {
+    return false;
   }
-  return false;
+
+  // Verify the publisher still exists by checking the weak_ptr
+  auto publisher = it->second.publisher.lock();
+  return publisher != nullptr;
 }
 
 size_t
@@ -197,8 +217,8 @@ IntraProcessManager::insert_sub_id_for_pub(
 
 bool
 IntraProcessManager::can_communicate(
-  rclcpp::PublisherBase::SharedPtr pub,
-  rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr sub) const
+  const rclcpp::PublisherBase::SharedPtr & pub,
+  const rclcpp::experimental::SubscriptionIntraProcessBase::SharedPtr & sub) const
 {
   // publisher and subscription must be on the same topic
   if (strcmp(pub->get_topic_name(), sub->get_topic_name()) != 0) {

rclcpp/src/rclcpp/node.cpp

@@ -547,6 +547,18 @@ Node::get_subscriptions_info_by_topic(const std::string & topic_name, bool no_ma
   return node_graph_->get_subscriptions_info_by_topic(topic_name, no_mangle);
 }
 
+std::vector<rclcpp::ServiceEndpointInfo>
+Node::get_clients_info_by_service(const std::string & service_name, bool no_mangle) const
+{
+  return node_graph_->get_clients_info_by_service(service_name, no_mangle);
+}
+
+std::vector<rclcpp::ServiceEndpointInfo>
+Node::get_servers_info_by_service(const std::string & service_name, bool no_mangle) const
+{
+  return node_graph_->get_servers_info_by_service(service_name, no_mangle);
+}
+
 void
 Node::for_each_callback_group(
   const node_interfaces::NodeBaseInterface::CallbackGroupFunction & func)
@@ -562,7 +574,7 @@ Node::get_graph_event()
 
 void
 Node::wait_for_graph_change(
-  rclcpp::Event::SharedPtr event,
+  const rclcpp::Event::SharedPtr & event,
   std::chrono::nanoseconds timeout)
 {
   node_graph_->wait_for_graph_change(event, timeout);
@@ -683,7 +695,7 @@ Node::create_generic_client(
   const std::string & service_name,
   const std::string & service_type,
   const rclcpp::QoS & qos,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 {
   return rclcpp::create_generic_client(
     node_base_,

rclcpp/src/rclcpp/node_interfaces/node_base.cpp

@@ -42,13 +42,13 @@ NodeBase::NodeBase(
   bool use_intra_process_default,
   bool enable_topic_statistics_default,
   rclcpp::CallbackGroup::SharedPtr default_callback_group)
-: context_(context),
+: context_(std::move(context)),
   use_intra_process_default_(use_intra_process_default),
   enable_topic_statistics_default_(enable_topic_statistics_default),
   node_handle_(nullptr),
-  default_callback_group_(default_callback_group),
+  default_callback_group_(std::move(default_callback_group)),
   associated_with_executor_(false),
-  notify_guard_condition_(std::make_shared<rclcpp::GuardCondition>(context)),
+  notify_guard_condition_(std::make_shared<rclcpp::GuardCondition>(context_)),
   notify_guard_condition_is_valid_(false)
 {
   // Create the rcl node and store it in a shared_ptr with a custom destructor.

rclcpp/src/rclcpp/node_interfaces/node_clock.cpp

@@ -26,11 +26,11 @@ NodeClock::NodeClock(
   rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services,
   rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
   rcl_clock_type_t clock_type)
-: node_base_(node_base),
-  node_topics_(node_topics),
-  node_graph_(node_graph),
-  node_services_(node_services),
-  node_logging_(node_logging),
+: node_base_(std::move(node_base)),
+  node_topics_(std::move(node_topics)),
+  node_graph_(std::move(node_graph)),
+  node_services_(std::move(node_services)),
+  node_logging_(std::move(node_logging)),
   clock_(std::make_shared<rclcpp::Clock>(clock_type))
 {}
 

rclcpp/src/rclcpp/node_interfaces/node_graph.cpp

@@ -15,6 +15,7 @@
 #include "rclcpp/node_interfaces/node_graph.hpp"
 
 #include <algorithm>
+#include <cstddef>
 #include <map>
 #include <string>
 #include <tuple>
@@ -644,8 +645,9 @@ std::vector<rclcpp::TopicEndpointInfo>
 convert_to_topic_info_list(const rcl_topic_endpoint_info_array_t & info_array)
 {
   std::vector<rclcpp::TopicEndpointInfo> topic_info_list;
+  topic_info_list.reserve(info_array.size);
   for (size_t i = 0; i < info_array.size; ++i) {
-    topic_info_list.push_back(rclcpp::TopicEndpointInfo(info_array.info_array[i]));
+    topic_info_list.emplace_back(info_array.info_array[i]);
   }
   return topic_info_list;
 }
@@ -753,6 +755,123 @@ NodeGraph::get_subscriptions_info_by_topic(
     rcl_get_subscriptions_info_by_topic);
 }
 
+static
+std::vector<rclcpp::ServiceEndpointInfo>
+convert_to_service_info_list(const rcl_service_endpoint_info_array_t & info_array)
+{
+  std::vector<rclcpp::ServiceEndpointInfo> service_info_list;
+  service_info_list.reserve(info_array.size);
+  for (size_t i = 0; i < info_array.size; ++i) {
+    service_info_list.emplace_back(info_array.info_array[i]);
+  }
+  return service_info_list;
+}
+
+template<const char * EndpointType, typename FunctionT>
+static std::vector<rclcpp::ServiceEndpointInfo>
+get_info_by_service(
+  rclcpp::node_interfaces::NodeBaseInterface * node_base,
+  const std::string & service_name,
+  bool no_mangle,
+  FunctionT rcl_get_info_by_service)
+{
+  std::string fqdn;
+  auto rcl_node_handle = node_base->get_rcl_node_handle();
+
+  if (no_mangle) {
+    fqdn = service_name;
+  } else {
+    fqdn = rclcpp::expand_topic_or_service_name(
+      service_name,
+      rcl_node_get_name(rcl_node_handle),
+      rcl_node_get_namespace(rcl_node_handle),
+      true);
+
+    // Get the node options
+    const rcl_node_options_t * node_options = rcl_node_get_options(rcl_node_handle);
+    if (nullptr == node_options) {
+      throw std::runtime_error("Need valid node options in get_info_by_service()");
+    }
+    const rcl_arguments_t * global_args = nullptr;
+    if (node_options->use_global_arguments) {
+      global_args = &(rcl_node_handle->context->global_arguments);
+    }
+
+    char * remapped_service_name = nullptr;
+    rcl_ret_t ret = rcl_remap_service_name(
+      &(node_options->arguments),
+      global_args,
+      fqdn.c_str(),
+      rcl_node_get_name(rcl_node_handle),
+      rcl_node_get_namespace(rcl_node_handle),
+      node_options->allocator,
+      &remapped_service_name);
+    if (RCL_RET_OK != ret) {
+      throw_from_rcl_error(ret, std::string("Failed to remap service name ") + fqdn);
+    } else if (nullptr != remapped_service_name) {
+      fqdn = remapped_service_name;
+      node_options->allocator.deallocate(remapped_service_name, node_options->allocator.state);
+    }
+  }
+
+  rcutils_allocator_t allocator = rcutils_get_default_allocator();
+  rcl_service_endpoint_info_array_t info_array =
+    rcl_get_zero_initialized_service_endpoint_info_array();
+  rcl_ret_t ret =
+    rcl_get_info_by_service(rcl_node_handle, &allocator, fqdn.c_str(), no_mangle, &info_array);
+  if (RCL_RET_OK != ret) {
+    auto error_msg =
+      std::string("Failed to get information by service for ") + EndpointType + std::string(":");
+    if (RCL_RET_UNSUPPORTED == ret) {
+      error_msg += std::string("function not supported by RMW_IMPLEMENTATION");
+    } else {
+      error_msg += rcl_get_error_string().str;
+    }
+    rcl_reset_error();
+    if (RCL_RET_OK != rcl_service_endpoint_info_array_fini(&info_array, &allocator)) {
+      error_msg += std::string(", failed also to cleanup service info array, leaking memory: ") +
+        rcl_get_error_string().str;
+      rcl_reset_error();
+    }
+    throw_from_rcl_error(ret, error_msg);
+  }
+
+  std::vector<rclcpp::ServiceEndpointInfo> service_info_list =
+    convert_to_service_info_list(info_array);
+  ret = rcl_service_endpoint_info_array_fini(&info_array, &allocator);
+  if (RCL_RET_OK != ret) {
+    throw_from_rcl_error(ret, "rcl_service_info_array_fini failed.");
+  }
+
+  return service_info_list;
+}
+
+static constexpr char kClientEndpointTypeName[] = "clients";
+std::vector<rclcpp::ServiceEndpointInfo>
+NodeGraph::get_clients_info_by_service(
+  const std::string & service_name,
+  bool no_mangle) const
+{
+  return get_info_by_service<kClientEndpointTypeName>(
+    node_base_,
+    service_name,
+    no_mangle,
+    rcl_get_clients_info_by_service);
+}
+
+static constexpr char kServerEndpointTypeName[] = "servers";
+std::vector<rclcpp::ServiceEndpointInfo>
+NodeGraph::get_servers_info_by_service(
+  const std::string & service_name,
+  bool no_mangle) const
+{
+  return get_info_by_service<kServerEndpointTypeName>(
+    node_base_,
+    service_name,
+    no_mangle,
+    rcl_get_servers_info_by_service);
+}
+
 std::string &
 rclcpp::TopicEndpointInfo::node_name()
 {
@@ -836,3 +955,99 @@ rclcpp::TopicEndpointInfo::topic_type_hash() const
 {
   return topic_type_hash_;
 }
+
+std::string &
+rclcpp::ServiceEndpointInfo::node_name()
+{
+  return node_name_;
+}
+
+const std::string &
+rclcpp::ServiceEndpointInfo::node_name() const
+{
+  return node_name_;
+}
+
+std::string &
+rclcpp::ServiceEndpointInfo::node_namespace()
+{
+  return node_namespace_;
+}
+
+const std::string &
+rclcpp::ServiceEndpointInfo::node_namespace() const
+{
+  return node_namespace_;
+}
+
+std::string &
+rclcpp::ServiceEndpointInfo::service_type()
+{
+  return service_type_;
+}
+
+const std::string &
+rclcpp::ServiceEndpointInfo::service_type() const
+{
+  return service_type_;
+}
+
+rclcpp::EndpointType &
+rclcpp::ServiceEndpointInfo::endpoint_type()
+{
+  return endpoint_type_;
+}
+
+const rclcpp::EndpointType &
+rclcpp::ServiceEndpointInfo::endpoint_type() const
+{
+  return endpoint_type_;
+}
+
+size_t &
+rclcpp::ServiceEndpointInfo::endpoint_count()
+{
+  return endpoint_count_;
+}
+
+const size_t &
+rclcpp::ServiceEndpointInfo::endpoint_count() const
+{
+  return endpoint_count_;
+}
+
+std::vector<std::array<uint8_t, RMW_GID_STORAGE_SIZE>> &
+rclcpp::ServiceEndpointInfo::endpoint_gids()
+{
+  return endpoint_gids_;
+}
+
+const std::vector<std::array<uint8_t, RMW_GID_STORAGE_SIZE>> &
+rclcpp::ServiceEndpointInfo::endpoint_gids() const
+{
+  return endpoint_gids_;
+}
+
+std::vector<rclcpp::QoS> &
+rclcpp::ServiceEndpointInfo::qos_profiles()
+{
+  return qos_profiles_;
+}
+
+const std::vector<rclcpp::QoS> &
+rclcpp::ServiceEndpointInfo::qos_profiles() const
+{
+  return qos_profiles_;
+}
+
+rosidl_type_hash_t &
+rclcpp::ServiceEndpointInfo::service_type_hash()
+{
+  return service_type_hash_;
+}
+
+const rosidl_type_hash_t &
+rclcpp::ServiceEndpointInfo::service_type_hash() const
+{
+  return service_type_hash_;
+}

rclcpp/src/rclcpp/node_interfaces/node_logging.cpp

@@ -18,7 +18,7 @@
 
 using rclcpp::node_interfaces::NodeLogging;
 
-NodeLogging::NodeLogging(rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base)
+NodeLogging::NodeLogging(const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base)
 : node_base_(node_base)
 {
   logger_ = rclcpp::get_logger(NodeLogging::get_logger_name());
@@ -41,7 +41,7 @@ NodeLogging::get_logger_name() const
 }
 
 void NodeLogging::create_logger_services(
-  node_interfaces::NodeServicesInterface::SharedPtr node_services)
+  const node_interfaces::NodeServicesInterface::SharedPtr & node_services)
 {
   rclcpp::ServicesQoS qos_profile;
   const std::string node_name = node_base_->get_name();
@@ -51,8 +51,8 @@ void NodeLogging::create_logger_services(
     node_base_, node_services,
     node_name + "/get_logger_levels",
     [](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::GetLoggerLevels::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::GetLoggerLevels::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::GetLoggerLevels::Response> response)
     {
       for (auto & name : request->names) {
@@ -73,8 +73,8 @@ void NodeLogging::create_logger_services(
     node_base_, node_services,
     node_name + "/set_logger_levels",
     [](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::SetLoggerLevels::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::SetLoggerLevels::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::SetLoggerLevels::Response> response)
     {
       rcl_interfaces::msg::SetLoggerLevelsResult result;

rclcpp/src/rclcpp/node_interfaces/node_time_source.cpp

@@ -29,13 +29,13 @@ NodeTimeSource::NodeTimeSource(
   rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters,
   const rclcpp::QoS & qos,
   bool use_clock_thread)
-: node_base_(node_base),
-  node_topics_(node_topics),
-  node_graph_(node_graph),
-  node_services_(node_services),
-  node_logging_(node_logging),
-  node_clock_(node_clock),
-  node_parameters_(node_parameters),
+: node_base_(std::move(node_base)),
+  node_topics_(std::move(node_topics)),
+  node_graph_(std::move(node_graph)),
+  node_services_(std::move(node_services)),
+  node_logging_(std::move(node_logging)),
+  node_clock_(std::move(node_clock)),
+  node_parameters_(std::move(node_parameters)),
   time_source_(qos, use_clock_thread)
 {
   time_source_.attachNode(

rclcpp/src/rclcpp/node_interfaces/node_type_descriptions.cpp

@@ -59,11 +59,11 @@ public:
 
   NodeTypeDescriptionsImpl(
     rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base,
-    rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
-    rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters,
-    rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services)
+    const rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr & node_logging,
+    const rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & node_parameters,
+    const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr & node_services)
   : logger_(node_logging->get_logger()),
-    node_base_(node_base)
+    node_base_(std::move(node_base))
   {
     rclcpp::ParameterValue enable_param;
     const std::string enable_param_name = "start_type_description_service";
@@ -92,7 +92,7 @@ public:
     }
 
     if (enable_param.get<bool>()) {
-      auto * rcl_node = node_base->get_rcl_node_handle();
+      auto * rcl_node = node_base_->get_rcl_node_handle();
       std::shared_ptr<rcl_service_t> rcl_srv(
         new rcl_service_t,
         [rcl_node, logger = this->logger_](rcl_service_t * service)
@@ -121,9 +121,9 @@ public:
       rclcpp::AnyServiceCallback<ServiceT> cb;
       cb.set(
         [this](
-          std::shared_ptr<rmw_request_id_t> header,
-          std::shared_ptr<ServiceT::Request> request,
-          std::shared_ptr<ServiceT::Response> response
+          const std::shared_ptr<rmw_request_id_t> & header,
+          const std::shared_ptr<ServiceT::Request> & request,
+          const std::shared_ptr<ServiceT::Response> & response
         ) {
           rcl_node_type_description_service_handle_request(
             node_base_->get_rcl_node_handle(),
@@ -144,10 +144,10 @@ public:
 };
 
 NodeTypeDescriptions::NodeTypeDescriptions(
-  rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base,
-  rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr node_logging,
-  rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters,
-  rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services)
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base,
+  const rclcpp::node_interfaces::NodeLoggingInterface::SharedPtr & node_logging,
+  const rclcpp::node_interfaces::NodeParametersInterface::SharedPtr & node_parameters,
+  const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr & node_services)
 : impl_(new NodeTypeDescriptionsImpl(
       node_base,
       node_logging,

rclcpp/src/rclcpp/node_options.cpp

@@ -143,7 +143,7 @@ NodeOptions::context() const
 }
 
 NodeOptions &
-NodeOptions::context(rclcpp::Context::SharedPtr context)
+NodeOptions::context(const rclcpp::Context::SharedPtr & context)
 {
   this->context_ = context;
   return *this;

rclcpp/src/rclcpp/parameter_client.cpp

@@ -30,13 +30,13 @@ using rclcpp::AsyncParametersClient;
 using rclcpp::SyncParametersClient;
 
 AsyncParametersClient::AsyncParametersClient(
-  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_base_interface,
-  const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr node_topics_interface,
-  const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr node_graph_interface,
-  const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr node_services_interface,
+  const rclcpp::node_interfaces::NodeBaseInterface::SharedPtr & node_base_interface,
+  const rclcpp::node_interfaces::NodeTopicsInterface::SharedPtr & node_topics_interface,
+  const rclcpp::node_interfaces::NodeGraphInterface::SharedPtr & node_graph_interface,
+  const rclcpp::node_interfaces::NodeServicesInterface::SharedPtr & node_services_interface,
   const std::string & remote_node_name,
   const rclcpp::QoS & qos_profile,
-  rclcpp::CallbackGroup::SharedPtr group)
+  const rclcpp::CallbackGroup::SharedPtr & group)
 : node_topics_interface_(node_topics_interface)
 {
   if (remote_node_name != "") {
@@ -107,9 +107,9 @@ AsyncParametersClient::AsyncParametersClient(
 std::shared_future<std::vector<rclcpp::Parameter>>
 AsyncParametersClient::get_parameters(
   const std::vector<std::string> & names,
-  std::function<
+  const std::function<
     void(std::shared_future<std::vector<rclcpp::Parameter>>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<std::vector<rclcpp::Parameter>>>();
@@ -147,9 +147,9 @@ AsyncParametersClient::get_parameters(
 std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>
 AsyncParametersClient::describe_parameters(
   const std::vector<std::string> & names,
-  std::function<
+  const std::function<
     void(std::shared_future<std::vector<rcl_interfaces::msg::ParameterDescriptor>>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<std::vector<rcl_interfaces::msg::ParameterDescriptor>>>();
@@ -176,9 +176,9 @@ AsyncParametersClient::describe_parameters(
 std::shared_future<std::vector<rclcpp::ParameterType>>
 AsyncParametersClient::get_parameter_types(
   const std::vector<std::string> & names,
-  std::function<
+  const std::function<
     void(std::shared_future<std::vector<rclcpp::ParameterType>>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<std::vector<rclcpp::ParameterType>>>();
@@ -210,9 +210,9 @@ AsyncParametersClient::get_parameter_types(
 std::shared_future<std::vector<rcl_interfaces::msg::SetParametersResult>>
 AsyncParametersClient::set_parameters(
   const std::vector<rclcpp::Parameter> & parameters,
-  std::function<
+  const std::function<
     void(std::shared_future<std::vector<rcl_interfaces::msg::SetParametersResult>>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<std::vector<rcl_interfaces::msg::SetParametersResult>>>();
@@ -243,9 +243,9 @@ AsyncParametersClient::set_parameters(
 std::shared_future<rcl_interfaces::msg::SetParametersResult>
 AsyncParametersClient::set_parameters_atomically(
   const std::vector<rclcpp::Parameter> & parameters,
-  std::function<
+  const std::function<
     void(std::shared_future<rcl_interfaces::msg::SetParametersResult>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<rcl_interfaces::msg::SetParametersResult>>();
@@ -322,9 +322,9 @@ std::shared_future<rcl_interfaces::msg::ListParametersResult>
 AsyncParametersClient::list_parameters(
   const std::vector<std::string> & prefixes,
   uint64_t depth,
-  std::function<
+  const std::function<
     void(std::shared_future<rcl_interfaces::msg::ListParametersResult>)
-  > callback)
+  > & callback)
 {
   auto promise_result =
     std::make_shared<std::promise<rcl_interfaces::msg::ListParametersResult>>();

rclcpp/src/rclcpp/parameter_descriptor_wrapper.cpp

@@ -0,0 +1,97 @@
+// Copyright 2023 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/parameter_descriptor_wrapper.hpp"
+
+namespace rclcpp
+{
+
+ParameterDescription::ParameterDescription()
+{
+  // Need to set this in the constructor, but it doesn't necessarily need to be used
+  parameter_descriptor.type = rcl_interfaces::msg::ParameterType::PARAMETER_NOT_SET;
+}
+
+rcl_interfaces::msg::ParameterDescriptor ParameterDescription::build() const
+{
+  // Return some some sort message
+  return parameter_descriptor;
+}
+
+// Builder methods which set up the original class
+// They all follow the same format of initing the value given within the base class
+// then returning the current class
+ParameterDescription & ParameterDescription::set_name(const std::string & name)
+{
+  parameter_descriptor.name = name;
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_type(std::uint8_t type)
+{
+  parameter_descriptor.type = type;
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_description_text(const std::string & description)
+{
+  parameter_descriptor.description = description;
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_additional_constraints(
+  const std::string & constraints)
+{
+  parameter_descriptor.additional_constraints = constraints;
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_read_only(bool read_only)
+{
+  parameter_descriptor.read_only = read_only;
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_dynamic_typing(bool dynamic_typing)
+{
+  parameter_descriptor.dynamic_typing = dynamic_typing;
+  return *this;
+}
+
+// Here is the Specific range function for this parameter description
+ParameterDescription & ParameterDescription::set_floating_point_description_range(
+  float min, float max, float step)
+{
+  if (parameter_descriptor.type == rcl_interfaces::msg::ParameterType::PARAMETER_DOUBLE) {
+    parameter_descriptor.floating_point_range.resize(1);
+    parameter_descriptor.floating_point_range.at(0).from_value = min;
+    parameter_descriptor.floating_point_range.at(0).to_value = max;
+    parameter_descriptor.floating_point_range.at(0).step = step;
+  }
+  return *this;
+}
+
+ParameterDescription & ParameterDescription::set_integer_description_range(
+  int min, int max, int step)
+{
+  if (parameter_descriptor.type == rcl_interfaces::msg::ParameterType::PARAMETER_INTEGER) {
+    parameter_descriptor.integer_range.resize(1);
+    parameter_descriptor.integer_range.at(0).from_value = min;
+    parameter_descriptor.integer_range.at(0).to_value = max;
+    parameter_descriptor.integer_range.at(0).step = step;
+  }
+  return *this;
+}
+
+}  // namespace rclcpp

rclcpp/src/rclcpp/parameter_event_handler.cpp

@@ -27,7 +27,7 @@ namespace rclcpp
 
 ParameterEventCallbackHandle::SharedPtr
 ParameterEventHandler::add_parameter_event_callback(
-  ParameterEventCallbackType callback)
+  const ParameterEventCallbackType & callback)
 {
   std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto handle = std::make_shared<ParameterEventCallbackHandle>();
@@ -39,7 +39,7 @@ ParameterEventHandler::add_parameter_event_callback(
 
 void
 ParameterEventHandler::remove_parameter_event_callback(
-  ParameterEventCallbackHandle::SharedPtr callback_handle)
+  const ParameterEventCallbackHandle::SharedPtr & callback_handle)
 {
   std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto it = std::find_if(
@@ -58,7 +58,7 @@ ParameterEventHandler::remove_parameter_event_callback(
 ParameterCallbackHandle::SharedPtr
 ParameterEventHandler::add_parameter_callback(
   const std::string & parameter_name,
-  ParameterCallbackType callback,
+  const ParameterCallbackType & callback,
   const std::string & node_name)
 {
   std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
@@ -74,9 +74,41 @@ ParameterEventHandler::add_parameter_callback(
   return handle;
 }
 
+bool
+ParameterEventHandler::configure_nodes_filter(const std::vector<std::string> & node_names)
+{
+  if (node_names.empty()) {
+    // Clear content filter
+    event_subscription_->set_content_filter("");
+    if (event_subscription_->is_cft_enabled()) {
+      return false;
+    }
+    return true;
+  }
+
+  std::string filter_expression;
+  size_t total = node_names.size();
+  for (size_t i = 0; i < total; ++i) {
+    filter_expression += "node = %" + std::to_string(i);
+    if (i < total - 1) {
+      filter_expression += " OR ";
+    }
+  }
+
+  // Enclose each node name in "'".
+  std::vector<std::string> quoted_node_names;
+  for (const auto & name : node_names) {
+    quoted_node_names.push_back("'" + resolve_path(name) + "'");
+  }
+
+  event_subscription_->set_content_filter(filter_expression, quoted_node_names);
+
+  return event_subscription_->is_cft_enabled();
+}
+
 void
 ParameterEventHandler::remove_parameter_callback(
-  ParameterCallbackHandle::SharedPtr callback_handle)
+  const ParameterCallbackHandle::SharedPtr & callback_handle)
 {
   std::lock_guard<std::recursive_mutex> lock(callbacks_->mutex_);
   auto handle = callback_handle.get();

rclcpp/src/rclcpp/parameter_events_filter.cpp

@@ -26,13 +26,13 @@ ParameterEventsFilter::ParameterEventsFilter(
   std::shared_ptr<const rcl_interfaces::msg::ParameterEvent> event,
   const std::vector<std::string> & names,
   const std::vector<EventType> & types)
-: event_(event)
+: event_(std::move(event))
 {
-  if (!event) {
+  if (!event_) {
     throw std::invalid_argument("event cannot be null");
   }
   if (std::find(types.begin(), types.end(), EventType::NEW) != types.end()) {
-    for (auto & new_parameter : event->new_parameters) {
+    for (auto & new_parameter : event_->new_parameters) {
       if (std::find(names.begin(), names.end(), new_parameter.name) != names.end()) {
         result_.push_back(
           EventPair(EventType::NEW, &new_parameter));
@@ -40,7 +40,7 @@ ParameterEventsFilter::ParameterEventsFilter(
     }
   }
   if (std::find(types.begin(), types.end(), EventType::CHANGED) != types.end()) {
-    for (auto & changed_parameter : event->changed_parameters) {
+    for (auto & changed_parameter : event_->changed_parameters) {
       if (std::find(names.begin(), names.end(), changed_parameter.name) != names.end()) {
         result_.push_back(
           EventPair(EventType::CHANGED, &changed_parameter));
@@ -48,7 +48,7 @@ ParameterEventsFilter::ParameterEventsFilter(
     }
   }
   if (std::find(types.begin(), types.end(), EventType::DELETED) != types.end()) {
-    for (auto & deleted_parameter : event->deleted_parameters) {
+    for (auto & deleted_parameter : event_->deleted_parameters) {
       if (std::find(names.begin(), names.end(), deleted_parameter.name) != names.end()) {
         result_.push_back(
           EventPair(EventType::DELETED, &deleted_parameter));

rclcpp/src/rclcpp/parameter_service.cpp

@@ -26,8 +26,8 @@
 using rclcpp::ParameterService;
 
 ParameterService::ParameterService(
-  const std::shared_ptr<rclcpp::node_interfaces::NodeBaseInterface> node_base,
-  const std::shared_ptr<rclcpp::node_interfaces::NodeServicesInterface> node_services,
+  const std::shared_ptr<rclcpp::node_interfaces::NodeBaseInterface> & node_base,
+  const std::shared_ptr<rclcpp::node_interfaces::NodeServicesInterface> & node_services,
   rclcpp::node_interfaces::NodeParametersInterface * node_params,
   const rclcpp::QoS & qos_profile)
 {
@@ -37,8 +37,8 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::get_parameters,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::GetParameters::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::GetParameters::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::GetParameters::Response> response)
     {
       try {
@@ -47,9 +47,9 @@ ParameterService::ParameterService(
           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());
+        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to get parameters: %s", ex.what());
       } catch (const rclcpp::exceptions::ParameterUninitializedException & ex) {
-        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to get parameters: %s", ex.what());
+        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to get parameters: %s", ex.what());
       }
     },
     qos_profile, nullptr);
@@ -58,8 +58,8 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::get_parameter_types,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::GetParameterTypes::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::GetParameterTypes::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::GetParameterTypes::Response> response)
     {
       try {
@@ -70,7 +70,7 @@ ParameterService::ParameterService(
             return static_cast<rclcpp::ParameterType>(type);
           });
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to get parameter types: %s", ex.what());
+        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to get parameter types: %s", ex.what());
       }
     },
     qos_profile, nullptr);
@@ -79,8 +79,8 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::set_parameters,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::SetParameters::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::SetParameters::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::SetParameters::Response> response)
     {
       // Set parameters one-by-one, since there's no way to return a partial result if
@@ -91,7 +91,7 @@ ParameterService::ParameterService(
           result = node_params->set_parameters_atomically(
             {rclcpp::Parameter::from_parameter_msg(p)});
         } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-          RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to set parameter: %s", ex.what());
+          RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to set parameter: %s", ex.what());
           result.successful = false;
           result.reason = ex.what();
         }
@@ -104,8 +104,8 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::set_parameters_atomically,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::SetParametersAtomically::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::SetParametersAtomically::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::SetParametersAtomically::Response> response)
     {
       std::vector<rclcpp::Parameter> pvariants;
@@ -119,7 +119,7 @@ ParameterService::ParameterService(
         auto result = node_params->set_parameters_atomically(pvariants);
         response->result = result;
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_DEBUG(
+        RCLCPP_WARN(
           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";
@@ -131,15 +131,15 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::describe_parameters,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::DescribeParameters::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::DescribeParameters::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::DescribeParameters::Response> response)
     {
       try {
         auto descriptors = node_params->describe_parameters(request->names);
         response->descriptors = descriptors;
       } catch (const rclcpp::exceptions::ParameterNotDeclaredException & ex) {
-        RCLCPP_DEBUG(rclcpp::get_logger("rclcpp"), "Failed to describe parameters: %s", ex.what());
+        RCLCPP_WARN(rclcpp::get_logger("rclcpp"), "Failed to describe parameters: %s", ex.what());
       }
     },
     qos_profile, nullptr);
@@ -148,8 +148,8 @@ ParameterService::ParameterService(
     node_base, node_services,
     node_name + "/" + parameter_service_names::list_parameters,
     [node_params](
-      const std::shared_ptr<rmw_request_id_t>,
-      const std::shared_ptr<rcl_interfaces::srv::ListParameters::Request> request,
+      const std::shared_ptr<rmw_request_id_t> &,
+      const std::shared_ptr<rcl_interfaces::srv::ListParameters::Request> & request,
       std::shared_ptr<rcl_interfaces::srv::ListParameters::Response> response)
     {
       auto result = node_params->list_parameters(request->prefixes, request->depth);

rclcpp/src/rclcpp/parameter_value.cpp

@@ -44,9 +44,9 @@ rclcpp::to_string(const ParameterType type)
       return "double_array";
     case ParameterType::PARAMETER_STRING_ARRAY:
       return "string_array";
-    default:
-      return "unknown type";
   }
+
+  return "unknown type";
 }
 
 std::ostream &
@@ -103,9 +103,9 @@ rclcpp::to_string(const ParameterValue & value)
       return array_to_string(value.get<std::vector<double>>());
     case ParameterType::PARAMETER_STRING_ARRAY:
       return array_to_string(value.get<std::vector<std::string>>());
-    default:
-      return "unknown type";
   }
+
+  return "unknown type";
 }
 
 ParameterValue::ParameterValue()

rclcpp/src/rclcpp/publisher_base.cpp

@@ -344,7 +344,7 @@ PublisherBase::operator==(const rmw_gid_t * gid) const
 void
 PublisherBase::setup_intra_process(
   uint64_t intra_process_publisher_id,
-  IntraProcessManagerSharedPtr ipm)
+  const IntraProcessManagerSharedPtr & ipm)
 {
   intra_process_publisher_id_ = intra_process_publisher_id;
   weak_ipm_ = ipm;
@@ -396,10 +396,10 @@ std::vector<rclcpp::NetworkFlowEndpoint> PublisherBase::get_network_flow_endpoin
   }
 
   std::vector<rclcpp::NetworkFlowEndpoint> network_flow_endpoint_vector;
+  network_flow_endpoint_vector.reserve(network_flow_endpoint_array.size);
   for (size_t i = 0; i < network_flow_endpoint_array.size; ++i) {
-    network_flow_endpoint_vector.push_back(
-      rclcpp::NetworkFlowEndpoint(
-        network_flow_endpoint_array.network_flow_endpoint[i]));
+    network_flow_endpoint_vector.emplace_back(
+        network_flow_endpoint_array.network_flow_endpoint[i]);
   }
 
   ret = rcl_network_flow_endpoint_array_fini(&network_flow_endpoint_array);

rclcpp/src/rclcpp/qos.cpp

@@ -40,6 +40,12 @@ std::string qos_policy_name_from_kind(rmw_qos_policy_kind_t policy_kind)
       return "HISTORY_QOS_POLICY";
     case RMW_QOS_POLICY_LIFESPAN:
       return "LIFESPAN_QOS_POLICY";
+    case RMW_QOS_POLICY_DEPTH:
+      return "DEPTH_QOS_POLICY";
+    case RMW_QOS_POLICY_LIVELINESS_LEASE_DURATION:
+      return "LIVELINESS_LEASE_DURATION_QOS_POLICY";
+    case RMW_QOS_POLICY_AVOID_ROS_NAMESPACE_CONVENTIONS:
+      return "AVOID_ROS_NAMESPACE_CONVENTIONS_QOS_POLICY";
     default:
       return "INVALID_QOS_POLICY";
   }

rclcpp/src/rclcpp/qos_overriding_options.cpp

@@ -60,7 +60,7 @@ QosOverridingOptions::with_default_policies(
   QosCallback validation_callback,
   std::string id)
 {
-  return QosOverridingOptions{kDefaultPolicies, validation_callback, id};
+  return QosOverridingOptions{kDefaultPolicies, std::move(validation_callback), id};
 }
 
 const std::string &

rclcpp/src/rclcpp/rate.cpp

@@ -21,7 +21,7 @@ namespace rclcpp
 {
 
 Rate::Rate(
-  const double rate, Clock::SharedPtr clock)
+  const double rate, const Clock::SharedPtr & clock)
 : clock_(clock), period_(0, 0), last_interval_(clock_->now())
 {
   if (rate <= 0.0) {
@@ -31,7 +31,7 @@ Rate::Rate(
 }
 
 Rate::Rate(
-  const Duration & period, Clock::SharedPtr clock)
+  const Duration & period, const Clock::SharedPtr & clock)
 : clock_(clock), period_(period), last_interval_(clock_->now())
 {
   if (period <= Duration(0, 0)) {

rclcpp/src/rclcpp/serialized_message.cpp

@@ -70,12 +70,12 @@ SerializedMessage::SerializedMessage(const rcl_serialized_message_t & other)
   copy_rcl_message(other, serialized_message_);
 }
 
-SerializedMessage::SerializedMessage(SerializedMessage && other)
+SerializedMessage::SerializedMessage(SerializedMessage && other) noexcept
 : serialized_message_(
     std::exchange(other.serialized_message_, rmw_get_zero_initialized_serialized_message()))
 {}
 
-SerializedMessage::SerializedMessage(rcl_serialized_message_t && other)
+SerializedMessage::SerializedMessage(rcl_serialized_message_t && other) noexcept
 : serialized_message_(
     std::exchange(other, rmw_get_zero_initialized_serialized_message()))
 {}
@@ -98,7 +98,7 @@ SerializedMessage & SerializedMessage::operator=(const rcl_serialized_message_t
   return *this;
 }
 
-SerializedMessage & SerializedMessage::operator=(SerializedMessage && other)
+SerializedMessage & SerializedMessage::operator=(SerializedMessage && other) noexcept
 {
   if (this != &other) {
     if (nullptr != serialized_message_.buffer) {
@@ -116,7 +116,7 @@ SerializedMessage & SerializedMessage::operator=(SerializedMessage && other)
   return *this;
 }
 
-SerializedMessage & SerializedMessage::operator=(rcl_serialized_message_t && other)
+SerializedMessage & SerializedMessage::operator=(rcl_serialized_message_t && other) noexcept
 {
   if (&serialized_message_ != &other) {
     if (nullptr != serialized_message_.buffer) {

rclcpp/src/rclcpp/service.cpp

@@ -28,7 +28,7 @@
 
 using rclcpp::ServiceBase;
 
-ServiceBase::ServiceBase(std::shared_ptr<rcl_node_t> node_handle)
+ServiceBase::ServiceBase(const std::shared_ptr<rcl_node_t> & node_handle)
 : node_handle_(node_handle),
   node_logger_(rclcpp::get_node_logger(node_handle_.get()))
 {}

rclcpp/src/rclcpp/signal_handler.cpp

@@ -68,7 +68,6 @@ void
 SignalHandler::signal_handler(
   int signum, siginfo_t * siginfo, void * context)
 {
-  RCLCPP_INFO(SignalHandler::get_logger(), "signal_handler(signum=%d)", signum);
   auto & instance = SignalHandler::get_global_signal_handler();
 
   auto old_signal_handler = instance.get_old_signal_handler(signum);
@@ -85,13 +84,12 @@ SignalHandler::signal_handler(
       old_signal_handler.sa_handler(signum);
     }
   }
-  instance.signal_handler_common();
+  instance.signal_handler_common(signum);
 }
 #else
 void
 SignalHandler::signal_handler(int signum)
 {
-  RCLCPP_INFO(SignalHandler::get_logger(), "signal_handler(signum=%d)", signum);
   auto & instance = SignalHandler::get_global_signal_handler();
   auto old_signal_handler = instance.get_old_signal_handler(signum);
   if (
@@ -100,7 +98,7 @@ SignalHandler::signal_handler(int signum)
   {
     old_signal_handler(signum);
   }
-  instance.signal_handler_common();
+  instance.signal_handler_common(signum);
 }
 #endif
 
@@ -245,13 +243,11 @@ SignalHandler::get_old_signal_handler(int signum)
 }
 
 void
-SignalHandler::signal_handler_common()
+SignalHandler::signal_handler_common(int signum)
 {
   auto & instance = SignalHandler::get_global_signal_handler();
+  instance.signal_number_.store(signum);
   instance.signal_received_.store(true);
-  RCLCPP_DEBUG(
-    get_logger(),
-    "signal_handler(): notifying deferred signal handler");
   instance.notify_signal_handler();
 }
 
@@ -260,8 +256,10 @@ SignalHandler::deferred_signal_handler()
 {
   while (true) {
     if (signal_received_.exchange(false)) {
+      int signum = signal_number_.load();
+      RCLCPP_INFO(get_logger(), "signal_handler(signum=%d)", signum);
       RCLCPP_DEBUG(get_logger(), "deferred_signal_handler(): shutting down");
-      for (auto context_ptr : rclcpp::get_contexts()) {
+      for (const auto & context_ptr : rclcpp::get_contexts()) {
         if (context_ptr->get_init_options().shutdown_on_signal) {
           RCLCPP_DEBUG(
             get_logger(),

rclcpp/src/rclcpp/signal_handler.hpp

@@ -116,7 +116,7 @@ private:
 
   /// Common signal handler code between sigaction and non-sigaction versions.
   void
-  signal_handler_common();
+  signal_handler_common(int signum);
 
 #if defined(RCLCPP_HAS_SIGACTION)
   /// Signal handler function.
@@ -189,6 +189,8 @@ private:
 
   // Whether or not a signal has been received.
   std::atomic_bool signal_received_ = false;
+  // The signal number that was received.
+  std::atomic_int signal_number_ = 0;
   // A thread to which signal handling tasks are deferred.
   std::thread signal_handler_thread_;
 

rclcpp/src/rclcpp/subscription_base.cpp

@@ -323,7 +323,7 @@ SubscriptionBase::setup_intra_process(
   IntraProcessManagerWeakPtr weak_ipm)
 {
   intra_process_subscription_id_ = intra_process_subscription_id;
-  weak_ipm_ = weak_ipm;
+  weak_ipm_ = std::move(weak_ipm);
   use_intra_process_ = true;
 }
 
@@ -449,11 +449,11 @@ SubscriptionBase::get_network_flow_endpoints() const
   }
 
   std::vector<rclcpp::NetworkFlowEndpoint> network_flow_endpoint_vector;
+  network_flow_endpoint_vector.reserve(network_flow_endpoint_array.size);
   for (size_t i = 0; i < network_flow_endpoint_array.size; ++i) {
-    network_flow_endpoint_vector.push_back(
-      rclcpp::NetworkFlowEndpoint(
+    network_flow_endpoint_vector.emplace_back(
         network_flow_endpoint_array.
-        network_flow_endpoint[i]));
+      network_flow_endpoint[i]);
   }
 
   ret = rcl_network_flow_endpoint_array_fini(&network_flow_endpoint_array);
@@ -577,3 +577,26 @@ SubscriptionBase::take_dynamic_message(
   throw std::runtime_error("Unimplemented");
   return false;
 }
+
+void
+SubscriptionBase::disable_callbacks()
+{
+  // Temporary remove the on_new_message_callback_ to prevent it from being called
+  std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
+  if (on_new_message_callback_) {
+    set_on_new_message_callback(nullptr, nullptr);
+  }
+}
+
+void
+SubscriptionBase::enable_callbacks()
+{
+  // Set callback again if it was previously removed in disable_callbacks()
+  std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
+  if (on_new_message_callback_) {
+    set_on_new_message_callback(
+      rclcpp::detail::cpp_callback_trampoline<
+        decltype(on_new_message_callback_), const void *, size_t>,
+      static_cast<const void *>(&on_new_message_callback_));
+  }
+}

rclcpp/src/rclcpp/subscription_intra_process_base.cpp

@@ -40,3 +40,17 @@ SubscriptionIntraProcessBase::is_durability_transient_local() const
 {
   return qos_profile_.durability() == rclcpp::DurabilityPolicy::TransientLocal;
 }
+
+void
+SubscriptionIntraProcessBase::disable_callbacks()
+{
+  std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
+  on_new_message_callback_disabled_ = true;
+}
+
+void
+SubscriptionIntraProcessBase::enable_callbacks()
+{
+  std::lock_guard<std::recursive_mutex> lock(on_new_message_callback_mutex_);
+  on_new_message_callback_disabled_ = false;
+}

rclcpp/src/rclcpp/time_source.cpp

@@ -81,7 +81,7 @@ public:
   }
 
   // Attach a clock
-  void attachClock(rclcpp::Clock::SharedPtr clock)
+  void attachClock(const rclcpp::Clock::SharedPtr & clock)
   {
     {
       std::lock_guard<std::mutex> clock_guard(clock->get_clock_mutex());
@@ -97,7 +97,7 @@ public:
   }
 
   // Detach a clock
-  void detachClock(rclcpp::Clock::SharedPtr clock)
+  void detachClock(const rclcpp::Clock::SharedPtr & clock)
   {
     std::lock_guard<std::mutex> guard(clock_list_lock_);
     auto removed = associated_clocks_.erase(clock);
@@ -108,9 +108,9 @@ public:
 
   // Internal helper function used inside iterators
   static void set_clock(
-    const builtin_interfaces::msg::Time::SharedPtr msg,
+    const builtin_interfaces::msg::Time::SharedPtr & msg,
     bool set_ros_time_enabled,
-    rclcpp::Clock::SharedPtr clock)
+    const rclcpp::Clock::SharedPtr & clock)
   {
     std::lock_guard<std::mutex> clock_guard(clock->get_clock_mutex());
 
@@ -145,7 +145,7 @@ public:
 
   // Internal helper function
   void set_all_clocks(
-    const builtin_interfaces::msg::Time::SharedPtr msg,
+    const builtin_interfaces::msg::Time::SharedPtr & msg,
     bool set_ros_time_enabled)
   {
     std::lock_guard<std::mutex> guard(clock_list_lock_);
@@ -155,7 +155,7 @@ public:
   }
 
   // Cache the last clock message received
-  void cache_last_msg(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg)
+  void cache_last_msg(const std::shared_ptr<const rosgraph_msgs::msg::Clock> & msg)
   {
     last_time_msg_ = std::make_shared<builtin_interfaces::msg::Time>(msg->clock);
   }
@@ -237,13 +237,13 @@ public:
     rclcpp::node_interfaces::NodeParametersInterface::SharedPtr node_parameters_interface)
   {
     std::lock_guard<std::mutex> guard(node_base_lock_);
-    node_base_ = node_base_interface;
-    node_topics_ = node_topics_interface;
-    node_graph_ = node_graph_interface;
-    node_services_ = node_services_interface;
-    node_logging_ = node_logging_interface;
-    node_clock_ = node_clock_interface;
-    node_parameters_ = node_parameters_interface;
+    node_base_ = std::move(node_base_interface);
+    node_topics_ = std::move(node_topics_interface);
+    node_graph_ = std::move(node_graph_interface);
+    node_services_ = std::move(node_services_interface);
+    node_logging_ = std::move(node_logging_interface);
+    node_clock_ = std::move(node_clock_interface);
+    node_parameters_ = std::move(node_parameters_interface);
     // TODO(tfoote): Update QOS
 
     logger_ = node_logging_->get_logger();
@@ -262,7 +262,7 @@ public:
     }
     if (use_sim_time_param.get_type() == rclcpp::PARAMETER_BOOL) {
       if (use_sim_time_param.get<bool>()) {
-        parameter_state_ = SET_TRUE;
+        sim_time_parameter_state_ = true;
         clocks_state_.enable_ros_time();
         create_clock_sub();
       }
@@ -305,14 +305,14 @@ public:
     node_parameters_.reset();
   }
 
-  void attachClock(std::shared_ptr<rclcpp::Clock> clock)
+  void attachClock(const std::shared_ptr<rclcpp::Clock> & clock)
   {
-    clocks_state_.attachClock(std::move(clock));
+    clocks_state_.attachClock(clock);
   }
 
-  void detachClock(std::shared_ptr<rclcpp::Clock> clock)
+  void detachClock(const std::shared_ptr<rclcpp::Clock> & clock)
   {
-    clocks_state_.detachClock(std::move(clock));
+    clocks_state_.detachClock(clock);
   }
 
 private:
@@ -346,16 +346,16 @@ private:
   rclcpp::executors::SingleThreadedExecutor::SharedPtr clock_executor_;
 
   // The clock callback itself
-  void clock_cb(std::shared_ptr<const rosgraph_msgs::msg::Clock> msg)
+  void clock_cb(const std::shared_ptr<const rosgraph_msgs::msg::Clock> & msg)
   {
-    if (!clocks_state_.is_ros_time_active() && SET_TRUE == this->parameter_state_) {
+    if (!clocks_state_.is_ros_time_active() && sim_time_parameter_state_) {
       clocks_state_.enable_ros_time();
     }
     // Cache the last message in case a new clock is attached.
     clocks_state_.cache_last_msg(msg);
     auto time_msg = std::make_shared<builtin_interfaces::msg::Time>(msg->clock);
 
-    if (SET_TRUE == this->parameter_state_) {
+    if (sim_time_parameter_state_) {
       clocks_state_.set_all_clocks(time_msg, true);
     }
   }
@@ -403,7 +403,7 @@ private:
       node_topics_,
       "/clock",
       qos_,
-      [this](std::shared_ptr<const rosgraph_msgs::msg::Clock> msg) {
+      [this](const std::shared_ptr<const rosgraph_msgs::msg::Clock> & msg) {
         bool execute_cb = false;
         {
           std::lock_guard<std::mutex> guard(node_base_lock_);
@@ -466,11 +466,11 @@ private:
     for (const auto & param : parameters) {
       if (param.get_name() == "use_sim_time") {
         if (param.as_bool()) {
-          parameter_state_ = SET_TRUE;
+          sim_time_parameter_state_ = true;
           clocks_state_.enable_ros_time();
           create_clock_sub();
         } else {
-          parameter_state_ = SET_FALSE;
+          sim_time_parameter_state_ = false;
           destroy_clock_sub();
           clocks_state_.disable_ros_time();
         }
@@ -478,13 +478,11 @@ private:
     }
   }
 
-  // An enum to hold the parameter state
-  enum UseSimTimeParameterState {SET_TRUE, SET_FALSE};
-  UseSimTimeParameterState parameter_state_;
+  bool sim_time_parameter_state_ = false;
 };
 
 TimeSource::TimeSource(
-  std::shared_ptr<rclcpp::Node> node,
+  const std::shared_ptr<rclcpp::Node> & node,
   const rclcpp::QoS & qos,
   bool use_clock_thread)
 : TimeSource(qos, use_clock_thread)
@@ -501,7 +499,7 @@ TimeSource::TimeSource(
   node_state_ = std::make_shared<NodeState>(qos, use_clock_thread);
 }
 
-void TimeSource::attachNode(rclcpp::Node::SharedPtr node)
+void TimeSource::attachNode(const rclcpp::Node::SharedPtr & node)
 {
   node_state_->set_use_clock_thread(node->get_node_options().use_clock_thread());
   attachNode(
@@ -541,14 +539,14 @@ void TimeSource::detachNode()
     constructed_use_clock_thread_);
 }
 
-void TimeSource::attachClock(std::shared_ptr<rclcpp::Clock> clock)
+void TimeSource::attachClock(const std::shared_ptr<rclcpp::Clock> & clock)
 {
-  node_state_->attachClock(std::move(clock));
+  node_state_->attachClock(clock);
 }
 
-void TimeSource::detachClock(std::shared_ptr<rclcpp::Clock> clock)
+void TimeSource::detachClock(const std::shared_ptr<rclcpp::Clock> & clock)
 {
-  node_state_->detachClock(std::move(clock));
+  node_state_->detachClock(clock);
 }
 
 bool TimeSource::get_use_clock_thread()

rclcpp/src/rclcpp/timer.cpp

@@ -150,7 +150,7 @@ TimerBase::exchange_in_use_by_wait_set_state(bool in_use_state)
 }
 
 void
-TimerBase::set_on_reset_callback(std::function<void(size_t)> callback)
+TimerBase::set_on_reset_callback(const std::function<void(size_t)> & callback)
 {
   if (!callback) {
     throw std::invalid_argument(

rclcpp/src/rclcpp/typesupport_helpers.cpp

@@ -123,27 +123,27 @@ std::string get_typesupport_library_path(
 {
   const char * dynamic_library_folder;
 #ifdef _WIN32
-  dynamic_library_folder = "/bin/";
+  dynamic_library_folder = "bin";
 #elif __APPLE__
-  dynamic_library_folder = "/lib/";
+  dynamic_library_folder = "lib";
 #else
-  dynamic_library_folder = "/lib/";
+  dynamic_library_folder = "lib";
 #endif
 
-  std::string package_prefix;
+  std::filesystem::path package_prefix;
   try {
-    package_prefix = ament_index_cpp::get_package_prefix(package_name);
+    ament_index_cpp::get_package_prefix(package_name, package_prefix);
   } catch (ament_index_cpp::PackageNotFoundError & e) {
     throw std::runtime_error(e.what());
   }
 
   const std::string library_path = rcpputils::path_for_library(
-    package_prefix + dynamic_library_folder,
+    (package_prefix / dynamic_library_folder).string(),
     package_name + "__" + typesupport_identifier);
   if (library_path.empty()) {
     throw std::runtime_error(
-      "Typesupport library for " + package_name + " does not exist in '" + package_prefix +
-        "'.");
+      "Typesupport library for " + package_name + " does not exist in '" +
+        package_prefix.string() + "'.");
   }
   return library_path;
 }