LockEnabled: true,
	}

	expiryWorker := func(wg *sync.WaitGroup, readyCh chan<- struct{}, taskCh <-chan expiryOp, gotExpired *[]ObjectToDelete) {
		defer wg.Done()
		// signal the calling goroutine that the worker is ready tor receive tasks
		close(readyCh)
		var expired []ObjectToDelete
		for t := range taskCh {
			switch v := t.(type) {
			case noncurrentVersionsTask:
				expired = append(expired, v.versions...)

{* ../../docs_src/background_tasks/tutorial001.py hl[6:9] *}

## Add the background task { #add-the-background-task }

Inside of your *path operation function*, pass your task function to the *background tasks* object with the method `.add_task()`:

{* ../../docs_src/background_tasks/tutorial001.py hl[14] *}

`.add_task()` receives as arguments:

* A task function to be run in the background (`write_notification`).

							task.event.StorageClass, task.objInfo.Bucket, task.objInfo.Name, task.objInfo.VersionID, err))
					}
				}
			} else {
				ts := tierStats{
					TotalSize:   uint64(task.objInfo.Size),
					NumVersions: 1,
				}
				if task.objInfo.IsLatest {
					ts.NumObjects = 1
				}
				t.addLastDayStats(task.event.StorageClass, ts)
			}
			t.activeTasks.Add(-1)

        try {
          while (true) {
            currentThread.name = task.name
            val delayNanos =
              logger.logElapsed(task, task.queue!!) {
                task.runOnce()
              }

            // A task ran successfully. Update the execution state and take the next task.
            task = withLock {
              afterRun(task, delayNanos, true)
              awaitTaskToRun()
            } ?: return

    operation ->> client: Return response to client
    Note over client,operation: Response is already sent, can't change it anymore
    opt Tasks
        operation -->> tasks: Send background tasks
    end
    opt Raise other exception
        tasks -->> tasks: Handle exceptions in the background task code
    end
```

/// info

                    if (logger.isDebugEnabled()) {
                        logger.debug("Add thumbnail task: {}", task);
                    }
                    if (!thumbnailTaskQueue.offer(task)) {
                        logger.warn("Failed to add thumbnail task: {}", task);
                    }
                    return true;
                }
                return false;
            }
        }

        return registrations.size();
    }

    @Override
    public void close() {
        // Stop all async notification tasks first
        List<CompletableFuture<Void>> taskFutures = new ArrayList<>(asyncNotifyTasks.values());
        for (CompletableFuture<Void> task : taskFutures) {
            task.cancel(true);
        }
        asyncNotifyTasks.clear();

        // Unregister all active registrations

			if serverDebugLog {
				fmt.Printf("Task in the queue: %#v\n", task)
			}
		default:
			// task queue is full, no more workers, we shall move on and heal later.
			return nil
		}
		// Don't wait for result
		return nil
	}

	// respCh must be set to wait for result.
	// We make it size 1, so a result can always be written
	// even if we aren't listening.

            directExecutor());

    // Wait for the first task to be started in the background. It will block until we explicitly
    // stop it.
    blockingCallable.waitForStart();

    // Give the second task a chance to (incorrectly) start up while the first task is running.
    assertThat(future2.isDone()).isFalse();

    // Stop the first task. The second task should then run.
    blockingCallable.stop();

...
BUILD SUCCESSFUL in 1m 30s
63 actionable tasks: 61 executed, 2 up-to-date

```