Cellumation Executors

A ROS2 packages providing alternative executor implementations. Currently only one executor is provided, the EventsCBGExecutor.

Features

• Compared to rclcpp::experimental::EventsExecutor
  • Multithread support
  • Support for mixing timers using different clocks (ROS_TIME/SYSTEM_TIME/STEADY_TIME)
  • Comparable performance in one thread mode
• 10-15% less CPU usage than rclcpp::SingleThreadedExecutor and rclcpp::MultiThreadedExecutor

Known bugs

• If the process is constantly overloaded and can not process the subscriptions timers etc, over time the events bag log will grow unbounded.

Usage

#include <cm_executors/events_cbg_executor.hpp>

int main(int argc, char ** argv)
{
  rclcpp::init(argc, argv);

  // multithreaded mode, use at least 2 thread or as many threads as processor cores detected
  int numThreads = 0;

  // Single threaded mode, has better latencies because of less context switches
  //int numThreads = 1;

  rclcpp::executors::EventsCBGExecutor executor(rclcpp::ExecutorOptions(), numThreads);

  // add nodes etc

  executor.spin()
}

Changelog for package cm_executors

0.9.1 (2025-08-13)

• feat: Added build and test action
  • Action test2
  • fix runs_on
  • use correct actionv ersion
• Test CI Build action
• chore: make cpplint happy
• chore: uncrustify
• fix: made ament_copyright happy
• fix(TimerQueue): Use specialized ClockConditionalVariable This fixes issues, were other calls to rclcpp::Clock::cancel_sleep_or_wait would wake up the timers manager. This also increases the performance, as the expensive registration of the shutdown callback on every sleep was moved to initialization / destruction of the TimerQueue.
• Update README.md
• Create README.md
• chore added license
• Fix missing test dependency
• fix: Clear timer reset callbacks, before deleting object involved in callback
• fix: Added missing mutex protection in sync_callback_groups
• fix: clear registered events on shutdown
• fix: Fixed invalid memory access on shutdown
• fix: Compile lib as shared
• fix: Don't add timer multiple times to running queue if reset was called
• fix: Handle exceptions in all threads
• feat: Added spin() with exception handler function
• chore: Removed outdated benchmark tests
• refactor: Cleaned up CMakeLists.txt
• refactor: Cleaned up RegisteredEntityCache
• fix: remove rcl polling thread
• fix: Don't wait on timer before before assiciated clock is ready
• feat: Don't expose internal data structures This allows us to change the executor, without breaking ABI / API
• fix: Don't start timer queue thread before initializing the class
• feat: Added PriorityScheduler
• chore: Remove log spam and outdated code
• fix(EventsCBGExecutor): Poll rcl layer for 'hidden' guard conditions
• fix(TimerManager): Use clock of registered timer for sleep This fixes the bug, that ROS_TIME timers were not switched to ros time as it is not attached to a time source.
• fix: Don't call 'call' on timer twice
• refactor: Major refactoring
• fix: implemented behaviour of spin_some of base executor
• fix: Replaced by queue event id with global event id
• fix: Made it compile
• Initial import from rclcpp