allocate / deallocate ros message

rclcpp/include/rclcpp/Subscriber.h

@@ -25,6 +25,14 @@ public:
   SubscriberInterface(const ros_middleware_interface::SubscriberHandle &subscriber_handle, std::string topic_name)
     : subscriber_handle_(subscriber_handle), topic_name_(topic_name)
   {}
+  virtual void * create_message()
+  {
+    throw std::runtime_error("not implemented - should always use override from subclass");
+  }
+  virtual void delete_message(void * ros_message)
+  {
+    throw std::runtime_error("not implemented - should always use override from subclass");
+  }
 private:
   ros_middleware_interface::SubscriberHandle subscriber_handle_;
   std::string topic_name_;
@@ -40,6 +48,16 @@ public:
   Subscriber(const ros_middleware_interface::SubscriberHandle &subscriber_handle, std::string topic_name)
     : SubscriberInterface(subscriber_handle, topic_name)
   {}
+  void * create_message()
+  {
+    return new ROSMessage();
+  }
+  void delete_message(void * ros_message)
+  {
+    ROSMessage* msg = (ROSMessage*)ros_message;
+    delete msg;
+    ros_message = 0;
+  }
 };
 
 }

rclcpp/include/rclcpp/executor/SingleThreadExecutor.h

@@ -80,12 +80,13 @@ public:
             {
               // Do callback
               std::cout << "Callback for subscriber of topic: " << subscriber->topic_name_ << std::endl;
-              void * ros_msg = 0;
+              void * ros_msg = subscriber->create_message();
               bool taken = ros_middleware_interface::take(subscriber->subscriber_handle_, ros_msg);
               if (taken)
               {
                 std::cout << "- received message on topic: " << subscriber->topic_name_ << std::endl;
               }
+              subscriber->delete_message(ros_msg);
             }
           }
         }