Added lost mutex.

arangodb · neunhoef · Jan 8, 2019 · Jul 23, 2018 · Jul 24, 2018 · Jul 25, 2018
commit a61a809dd47fca8472d635f599a4882c65e26e3d
diff --git a/arangod/VocBase/Methods/Tasks.cpp b/arangod/VocBase/Methods/Tasks.cpp
@@ -305,6 +305,11 @@ void Task::start() {
              ExecContext::CURRENT->isAdminUser() ||
              (!_user.empty() && ExecContext::CURRENT->user() == _user));
 
+  {
+    MUTEX_LOCKER(lock, _taskHandleMutex);
+    _taskHandle.reset();
+  }
+
   if (_offset.count() <= 0) {
     _offset = std::chrono::microseconds(1);
   }
@@ -314,12 +319,14 @@ void Task::start() {
 }
 
 void Task::queue(std::chrono::microseconds offset) {
+  MUTEX_LOCKER(lock, _taskHandleMutex);
   _taskHandle = SchedulerFeature::SCHEDULER->queueDelay(RequestLane::INTERNAL_LOW, offset, callbackFunction());
 }
 
 void Task::cancel() {
   // this will prevent the task from dispatching itself again
   _periodic.store(false);
+  MUTEX_LOCKER(lock, _taskHandleMutex);
   _taskHandle.reset();
 }
 

diff --git a/arangod/VocBase/Methods/Tasks.h b/arangod/VocBase/Methods/Tasks.h
@@ -95,6 +95,7 @@ class Task : public std::enable_shared_from_this<Task> {
   std::string _user;
 
   rest::Scheduler::WorkHandle _taskHandle;
+  Mutex _taskHandleMutex;
 
   // guard to make sure the database is not dropped while used by us
   std::unique_ptr<DatabaseGuard> _dbGuard;