In this case, the `startup` event handler function will initialize the items "database" (just a `dict`) with some values.

You can add more than one event handler function.

And your application won't start receiving requests until all the `startup` event handlers have completed.

### `shutdown` event { #shutdown-event }

To add a function that should be run when the application is shutting down, declare it with the event `"shutdown"`:

# Testing Events: lifespan and startup - shutdown { #testing-events-lifespan-and-startup-shutdown }

When you need `lifespan` to run in your tests, you can use the `TestClient` with a `with` statement:

{* ../../docs_src/app_testing/tutorial004.py hl[9:15,18,27:28,30:32,41:43] *}


You can read more details about the ["Running lifespan in tests in the official Starlette documentation site."](https://www.starlette.io/lifespan/#running-lifespan-in-tests)

{* ../../docs_src/events/tutorial003.py hl[14:19] *}

함수의 첫 번째 부분, 즉 `yield` 이전의 코드는 애플리케이션이 시작되기 **전에** 실행됩니다.

그리고 `yield` 이후의 부분은 애플리케이션이 완료된 후 **나중에** 실행됩니다.

### 비동기 컨텍스트 매니저

함수를 확인해보면, `@asynccontextmanager`로 장식되어 있습니다.

이것은 함수를 "**비동기 컨텍스트 매니저**"라고 불리는 것으로 변환시킵니다.

{* ../../docs_src/events/tutorial003.py hl[1,13] *}

    assertEquals("The dead event should wrap the original event.", EVENT, events.get(0).getEvent());
  }

  public void testDeadEventPosting() {
    GhostCatcher catcher = new GhostCatcher();
    bus.register(catcher);

    bus.post(new DeadEvent(this, EVENT));

    List<DeadEvent> events = catcher.getEvents();
    assertEquals("The explicit DeadEvent should be delivered.", 1, events.size());

  }

  /**
   * Enqueues an event to be run on currently known listeners.
   *
   * <p>The {@code toString} method of the Event itself will be used to describe the event in the
   * case of an error.
   *
   * @param event the callback to execute on {@link #dispatch}
   */
  public void enqueue(Event<L> event) {
    enqueueHelper(event, event);
  }

  /**

<database>"`

MinIO supports persistent event store. The persistent store will backup events if MySQL connection goes offline and then replays the stored events when the broken connection comes back up. The event store can be configured by setting a directory path in `queue_dir` field, and the maximum number of events, which can be stored in a `queue_dir`, in `queue_limit` field. For example, `queue_dir` can be set to `/home/events` and `queue_limit` can be set to `1000`. By default,...

  fun assertExhausted() {
    assertThat(events).isEmpty()
  }

  fun assertEvent(
    id: String?,
    type: String?,
    data: String,
  ) {
    assertThat(nextEvent()).isEqualTo(Event(id, type, data))
  }

  fun assertOpen(): EventSource {
    val event = nextEvent() as Open
    return event.eventSource
  }

  fun assertClose() {
    nextEvent() as Closed
  }

  fun assertFailure(

    @Subscribe
    public void listenForStrings(String event) {
      eventsReceived.add(event);
      ready = false;
      try {
        bus.post(SECOND);
      } finally {
        ready = true;
      }
    }

    @Subscribe
    public void listenForDoubles(Double event) {
      assertTrue("I received an event when I wasn't ready!", ready);
      eventsReceived.add(event);
    }
  }

public class StringCatcher {
  private final List<String> events = new ArrayList<>();

  @Subscribe
  public void hereHaveAString(@Nullable String string) {
    events.add(string);
  }

  public void methodWithoutAnnotation(@Nullable String string) {
    Assert.fail("Event bus must not call methods without @Subscribe!");
  }

  public List<String> getEvents() {
    return events;
  }

    // This dispatcher matches the original dispatch behavior of EventBus.

    /** Per-thread queue of events to dispatch. */
    @SuppressWarnings("ThreadLocalUsage") // Each Dispatcher needs its own state.
    private final ThreadLocal<Queue<Event>> queue =
        new ThreadLocal<Queue<Event>>() {
          @Override
          protected Queue<Event> initialValue() {
            return new ArrayDeque<>();
          }