Fix error when using IPC with StaticSingleThreadExecutor (ros2#1520)

Signed-off-by: Mauro Passerino <[email protected]>

Author: mauropasse

rclcpp/src/rclcpp/executors/static_executor_entities_collector.cpp

@@ -323,8 +323,7 @@ StaticExecutorEntitiesCollector::add_callback_group(
     throw std::runtime_error("Callback group was already added to executor.");
   }
   if (is_new_node) {
-    rclcpp::node_interfaces::NodeBaseInterface::WeakPtr node_weak_ptr(node_ptr);
-    weak_nodes_to_guard_conditions_[node_weak_ptr] = node_ptr->get_notify_guard_condition();
+    weak_nodes_to_guard_conditions_[node_ptr] = node_ptr->get_notify_guard_condition();
     return true;
   }
   return false;

rclcpp/src/rclcpp/executors/static_single_threaded_executor.cpp

@@ -175,9 +175,10 @@ StaticSingleThreadedExecutor::execute_ready_executables()
   }
   // Execute all the ready waitables
   for (size_t i = 0; i < entities_collector_->get_number_of_waitables(); ++i) {
-    if (entities_collector_->get_waitable(i)->is_ready(&wait_set_)) {
-      std::shared_ptr<void> shared_ptr;
-      entities_collector_->get_waitable(i)->execute(shared_ptr);
+    auto waitable = entities_collector_->get_waitable(i);
+    if (waitable->is_ready(&wait_set_)) {
+      auto data = waitable->take_data();
+      waitable->execute(data);
     }
   }
 }