[Iron] Add new node interface TypeDescriptionsInterface to provide Ge…

…tTypeDescription service (backport ros2#2224) (ros2#2236)

* Add new node interface TypeDescriptionsInterface to provide GetTypeDescription service (ros2#2224)

* TypeDescriptions interface with readonly param configuration

* Add parameter descriptor, to make read only

* example of spinning in thread for get_type_description service

* Add a basic test for the new interface

* Fix tests with new parameter

* Add comments about builtin parameters

* Hide new member for ABI stability

* Add typedescription interface smoke test

Signed-off-by: Emerson Knapp <emerson.b.knapp@gmail.com>
Signed-off-by: William Woodall <william@osrfoundation.org>

rclcpp/include/rclcpp/node.hpp

@@ -57,6 +57,7 @@
 #include "rclcpp/node_interfaces/node_timers_interface.hpp"
 #include "rclcpp/node_interfaces/node_topics_interface.hpp"
 #include "rclcpp/node_interfaces/node_type_descriptions_interface.hpp"
+#include "rclcpp/node_interfaces/node_type_descriptions_interface.hpp"
 #include "rclcpp/node_interfaces/node_waitables_interface.hpp"
 #include "rclcpp/node_options.hpp"
 #include "rclcpp/parameter.hpp"

rclcpp/src/rclcpp/node.cpp

@@ -17,7 +17,10 @@
 #include <limits>
 #include <map>
 #include <memory>
+#include <mutex>
+#include <shared_mutex>
 #include <string>
+#include <unordered_map>
 #include <utility>
 #include <vector>
 
@@ -234,6 +237,8 @@ Node::Node(
   sub_namespace_(""),
   effective_namespace_(create_effective_namespace(this->get_namespace(), sub_namespace_))
 {
+  backport_members_.add(this);
+
   // we have got what we wanted directly from the overrides,
   // but declare the parameters anyway so they are visible.
   rclcpp::detail::declare_qos_parameters(
@@ -296,6 +301,7 @@ Node::Node(
 Node::~Node()
 {
   // release sub-interfaces in an order that allows them to consult with node_base during tear-down
+  backport_members_.remove(this);
   node_waitables_.reset();
   node_time_source_.reset();
   node_parameters_.reset();

rclcpp/test/rclcpp/CMakeLists.txt

@@ -174,6 +174,11 @@ ament_add_gtest(test_node_interfaces__node_type_descriptions
 if(TARGET test_node_interfaces__node_type_descriptions)
   target_link_libraries(test_node_interfaces__node_type_descriptions ${PROJECT_NAME})
 endif()
+ament_add_gtest(test_node_interfaces__node_type_descriptions
+  node_interfaces/test_node_type_descriptions.cpp)
+if(TARGET test_node_interfaces__node_type_descriptions)
+  target_link_libraries(test_node_interfaces__node_type_descriptions ${PROJECT_NAME} mimick)
+endif()
 ament_add_gtest(test_node_interfaces__node_waitables
   node_interfaces/test_node_waitables.cpp)
 if(TARGET test_node_interfaces__node_waitables)

rclcpp_lifecycle/src/lifecycle_node.cpp

@@ -503,6 +503,12 @@ LifecycleNode::get_node_services_interface()
   return node_services_;
 }
 
+rclcpp::node_interfaces::NodeTypeDescriptionsInterface::SharedPtr
+LifecycleNode::get_node_type_descriptions_interface()
+{
+  return impl_->get_node_type_descriptions_interface();
+}
+
 rclcpp::node_interfaces::NodeParametersInterface::SharedPtr
 LifecycleNode::get_node_parameters_interface()
 {

rclcpp_lifecycle/src/lifecycle_node_interface_impl.cpp

@@ -31,6 +31,7 @@
 #include "rclcpp/node_interfaces/node_base_interface.hpp"
 #include "rclcpp/node_interfaces/node_logging_interface.hpp"
 #include "rclcpp/node_interfaces/node_services_interface.hpp"
+#include "rclcpp/node_interfaces/node_type_descriptions.hpp"
 
 #include "rclcpp_lifecycle/node_interfaces/lifecycle_node_interface.hpp"
 
@@ -595,4 +596,10 @@ LifecycleNode::LifecycleNodeInterfaceImpl::on_deactivate() const
   }
 }
 
+rclcpp::node_interfaces::NodeTypeDescriptionsInterface::SharedPtr
+LifecycleNode::LifecycleNodeInterfaceImpl::get_node_type_descriptions_interface()
+{
+  return node_type_descriptions_;
+}
+
 }  // namespace rclcpp_lifecycle

rclcpp_lifecycle/src/lifecycle_node_interface_impl.hpp

@@ -104,6 +104,9 @@ class LifecycleNode::LifecycleNodeInterfaceImpl final
   void
   add_timer_handle(std::shared_ptr<rclcpp::TimerBase> timer);
 
+  rclcpp::node_interfaces::NodeTypeDescriptionsInterface::SharedPtr
+  get_node_type_descriptions_interface();
+
 private:
   RCLCPP_DISABLE_COPY(LifecycleNodeInterfaceImpl)
 
@@ -176,6 +179,9 @@ class LifecycleNode::LifecycleNodeInterfaceImpl final
   // to controllable things
   std::vector<std::weak_ptr<rclcpp_lifecycle::ManagedEntityInterface>> weak_managed_entities_;
   std::vector<std::weak_ptr<rclcpp::TimerBase>> weak_timers_;
+
+  // Backported members hidden in impl
+  rclcpp::node_interfaces::NodeTypeDescriptionsInterface::SharedPtr node_type_descriptions_;
 };
 
 }  // namespace rclcpp_lifecycle