update comment

Signed-off-by: zhenpeng ge <zhenpeng.ge@qq.com>

nav2_costmap_2d/include/nav2_costmap_2d/costmap_2d_ros.hpp

@@ -311,7 +311,7 @@ class Costmap2DROS : public nav2_util::LifecycleNode
   rclcpp::Subscription<geometry_msgs::msg::Polygon>::SharedPtr footprint_sub_;
   rclcpp::Subscription<rcl_interfaces::msg::ParameterEvent>::SharedPtr parameter_sub_;
 
-  // Dedicated callback group and executor for plugins and filters
+  // Dedicated callback group and executor for tf timer_interface, costmap plugins and filters
   rclcpp::CallbackGroup::SharedPtr callback_group_;
   rclcpp::executors::SingleThreadedExecutor::SharedPtr executor_;
   std::unique_ptr<nav2_util::NodeThread> executor_thread_;

nav2_costmap_2d/plugins/costmap_filters/keepout_filter.cpp

@@ -65,7 +65,6 @@ void KeepoutFilter::initializeFilter(
 
   filter_info_topic_ = filter_info_topic;
 
-  // use dedicated callback group for filter info and mask subscriber
   auto sub_opt = rclcpp::SubscriptionOptions();
   sub_opt.callback_group = callback_group_;
 

nav2_costmap_2d/plugins/costmap_filters/speed_filter.cpp

@@ -73,7 +73,6 @@ void SpeedFilter::initializeFilter(
 
   filter_info_topic_ = filter_info_topic;
 
-  // use dedicated callback group for filter info and mask subscriber
   auto sub_opt = rclcpp::SubscriptionOptions();
   sub_opt.callback_group = callback_group_;
 

nav2_costmap_2d/plugins/obstacle_layer.cpp

@@ -119,7 +119,6 @@ void ObstacleLayer::onInitialize()
 
   global_frame_ = layered_costmap_->getGlobalFrameID();
 
-  // use a dedicated callback group for observation message subscriber
   auto sub_opt = rclcpp::SubscriptionOptions();
   sub_opt.callback_group = callback_group_;
 

nav2_costmap_2d/plugins/range_sensor_layer.cpp

@@ -128,7 +128,6 @@ void RangeSensorLayer::onInitialize()
     return;
   }
 
-  // create a separate callback group for range subscriber
   auto sub_opt = rclcpp::SubscriptionOptions();
   sub_opt.callback_group = callback_group_;