Select executor in node registration (#1898)

* Select executor

Signed-off-by: Hirokazu Ishida <[email protected]>

* Fix indent

Signed-off-by: Hirokazu Ishida <[email protected]>

Author: HiroIshida

rclcpp_components/cmake/rclcpp_components_register_node.cmake

@@ -28,7 +28,7 @@
 # :type RESOURCE_INDEX: string
 #
 macro(rclcpp_components_register_node target)
-  cmake_parse_arguments(ARGS "" "PLUGIN;EXECUTABLE;RESOURCE_INDEX" "" ${ARGN})
+  cmake_parse_arguments(ARGS "" "PLUGIN;EXECUTABLE;EXECUTOR;RESOURCE_INDEX" "" ${ARGN})
   if(ARGS_UNPARSED_ARGUMENTS)
     message(FATAL_ERROR "rclcpp_components_register_node() called with unused "
       "arguments: ${ARGS_UNPARSED_ARGUMENTS}")
@@ -46,6 +46,13 @@ macro(rclcpp_components_register_node target)
     message(STATUS "Setting component resource index to non-default value ${resource_index}")
   endif()
 
+  # default to executor if not specified otherwise
+  set(executor "SingleThreadedExecutor")
+  if(NOT "${ARGS_EXECUTOR}" STREQUAL "")
+    set(executor ${ARGS_EXECUTOR})
+    message(STATUS "Setting executor non-default value ${executor}")
+  endif()
+
   set(component ${ARGS_PLUGIN})
   set(node ${ARGS_EXECUTABLE})
   _rclcpp_components_register_package_hook()

rclcpp_components/src/node_main.cpp.in

@@ -27,7 +27,7 @@ int main(int argc, char * argv[])
 {
   auto args = rclcpp::init_and_remove_ros_arguments(argc, argv);
   rclcpp::Logger logger = rclcpp::get_logger(NODE_MAIN_LOGGER_NAME);
-  rclcpp::executors::SingleThreadedExecutor exec;
+  rclcpp::executors::@executor@ exec;
   rclcpp::NodeOptions options;
   options.arguments(args);
   std::vector<class_loader::ClassLoader * > loaders;