Merge pull request ros2#59 from mauropasse/mauro/fix-deadlock

Unlock queue mutex after taking event
mauropasse · Mar 29, 2021 · 2fe825b · 2fe825b
2 parents 02f4365 + b25bef8
commit 2fe825b
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Showing 2 changed files with 4 additions and 1 deletion.
diff --git a/rclcpp/include/rclcpp/experimental/buffers/events_queue.hpp b/rclcpp/include/rclcpp/experimental/buffers/events_queue.hpp
@@ -115,7 +115,7 @@ class EventsQueue
    * @brief gets a single entity event from the queue
    * @return a single entity event
   */
-  // TODO: find an alternative to pop_all_events and
+  // TODO(mauropasse): find an alternative to pop_all_events and
   // get_single_event to use standard queue interfaces
   RCLCPP_PUBLIC
   virtual

diff --git a/rclcpp/src/rclcpp/executors/events_executor.cpp b/rclcpp/src/rclcpp/executors/events_executor.cpp
@@ -141,6 +141,9 @@ EventsExecutor::spin_some_impl(std::chrono::nanoseconds max_duration, bool exhau
       if (has_event) {
         ExecutorEvent event = events_queue_->front();
         events_queue_->pop();
+        // Unlock the mutex, so if the execution of the event requires
+        // pushing an event into the queue we avoid a deadlock.
+        lock.unlock();
         this->execute_event(event);
         executed_events++;
         continue;