EventsExecutorEntitiesCollector: Use shared_from_this()

Author: Mauro Passerino

rclcpp/include/rclcpp/executors/events_executor_entities_collector.hpp

@@ -49,7 +49,9 @@ class EventsExecutor;
  * When this occurs, the execute API takes care of handling changes
  * in the entities currently used by the executor.
  */
-class EventsExecutorEntitiesCollector final : public EventWaitable
+class EventsExecutorEntitiesCollector final
+: public EventWaitable,
+  public std::enable_shared_from_this<EventsExecutorEntitiesCollector>
 {
 public:
   RCLCPP_SMART_PTR_DEFINITIONS(EventsExecutorEntitiesCollector)
@@ -63,6 +65,10 @@ class EventsExecutorEntitiesCollector final : public EventWaitable
   RCLCPP_PUBLIC
   ~EventsExecutorEntitiesCollector();
 
+  // Initialize entities collector
+  RCLCPP_PUBLIC
+  void init();
+
   // The purpose of "execute" is handling the situation of a new entity added to
   // a node, while the executor is already spinning.
   // This consists in setting that entitiy's callback.
@@ -237,6 +243,8 @@ class EventsExecutorEntitiesCollector final : public EventWaitable
   std::list<rclcpp::node_interfaces::NodeBaseInterface::WeakPtr> weak_nodes_;
 
   // Maps: entity identifiers to weak pointers from the entities registered in the executor
+  // so in the case of an event providing and ID, we can retrieve and own the corresponding
+  // entity while it performs work
   std::unordered_map<const void *, rclcpp::SubscriptionBase::WeakPtr> weak_subscriptions_map_;
   std::unordered_map<const void *, rclcpp::ServiceBase::WeakPtr> weak_services_map_;
   std::unordered_map<const void *, rclcpp::ClientBase::WeakPtr> weak_clients_map_;

rclcpp/src/rclcpp/executors/events_executor.cpp

@@ -31,6 +31,7 @@ EventsExecutor::EventsExecutor(
 {
   timers_manager_ = std::make_shared<TimersManager>(context_);
   entities_collector_ = std::make_shared<EventsExecutorEntitiesCollector>(this);
+  entities_collector_->init();
 
   // This API uses the wait_set only as a token to identify different executors.
   auto context_interrupt_gc = options.context->get_interrupt_guard_condition(&wait_set_);
@@ -42,7 +43,6 @@ EventsExecutor::EventsExecutor(
   executor_notifier_->add_guard_condition(&interrupt_guard_condition_);
   executor_notifier_->set_events_executor_callback(this, &EventsExecutor::push_event);
   entities_collector_->add_waitable(executor_notifier_);
-  entities_collector_->add_waitable(entities_collector_);
 }
 
 void

rclcpp/src/rclcpp/executors/events_executor_entities_collector.cpp

@@ -81,6 +81,13 @@ EventsExecutorEntitiesCollector::~EventsExecutorEntitiesCollector()
   weak_groups_to_nodes_associated_with_executor_.clear();
 }
 
+void
+EventsExecutorEntitiesCollector::init()
+{
+  // Add the EventsExecutorEntitiesCollector shared_ptr to waitables map
+  add_waitable(this->shared_from_this());
+}
+
 void
 EventsExecutorEntitiesCollector::add_node(
   rclcpp::node_interfaces::NodeBaseInterface::SharedPtr node_ptr)