ROS 2 rclcpp + rcl - humble  humble
ROS 2 C++ Client Library with ROS Client Library

executors → rcl Relation

File in rclcpp/include/rclcpp/executorsIncludes file in rcl
static_executor_entities_collector.hppinclude / rcl / guard_condition.h
static_executor_entities_collector.hppinclude / rcl / wait.h