Merge pull request #1 from jefferyyjhsu/Adding-TimersManager-stop-function-mutex

Add mutex to prevent race condition in TimersManager destructor

Author: alsora

irobot_events_executor/include/rclcpp/timers_manager.hpp

@@ -486,6 +486,8 @@ class TimersManager
   std::thread timers_thread_;
   // Protects access to timers
   std::mutex timers_mutex_;
+  // Protects access to stop()
+  std::mutex stop_mutex_;
   // Notifies the timers thread whenever timers are added/removed
   std::condition_variable timers_cv_;
   // Flag used as predicate by timers_cv_ that denotes one or more timers being added/removed

irobot_events_executor/src/rclcpp/timers_manager.cpp

@@ -59,6 +59,8 @@ void TimersManager::start()
 
 void TimersManager::stop()
 {
+  // Lock stop() function to prevent race condition in destructor
+  std::unique_lock<std::mutex> lock(stop_mutex_);
   // Nothing to do if the timers thread is not running
   // or if another thread already signaled to stop.
   if (!running_.exchange(false)) {