DPL: reset the async queue on STOP

Author: ktf

Framework/Core/include/Framework/AsyncQueue.h

@@ -59,6 +59,9 @@ struct AsyncQueueHelpers {
   /// 2. then priority
   /// 3. only execute the highest (timeslice, debounce) value
   static void run(AsyncQueue& queue, TimesliceId oldestPossibleTimeslice);
+
+  /// Reset the queue to its initial state
+  static void reset(AsyncQueue& queue);
 };
 
 } // namespace o2::framework

Framework/Core/src/AsyncQueue.cxx

@@ -107,4 +107,10 @@ auto AsyncQueueHelpers::run(AsyncQueue& queue, TimesliceId oldestPossible) -> vo
                     queue.tasks.end());
 }
 
+auto AsyncQueueHelpers::reset(AsyncQueue& queue) -> void
+{
+  queue.tasks.clear();
+  queue.iteration = 0;
+}
+
 } // namespace o2::framework

Framework/Core/src/CommonServices.cxx

@@ -135,6 +135,10 @@ o2::framework::ServiceSpec CommonServices::asyncQueue()
     .name = "async-queue",
     .init = simpleServiceInit<AsyncQueue, AsyncQueue>(),
     .configure = noConfiguration(),
+    .stop = [](ServiceRegistryRef services, void* service) {
+      auto& queue = services.get<AsyncQueue>();
+      AsyncQueueHelpers::reset(queue);
+    },
     .kind = ServiceKind::Serial};
 }