private final Object lock = new Object();

    /*
     * Conceptually, these two variables describe the executor being in
     * one of three states:
     *   - Active: shutdown == false
     *   - Shutdown: runningTasks > 0 and shutdown == true
     *   - Terminated: runningTasks == 0 and shutdown == true
     */
    @GuardedBy("lock")

### `shutdown` event

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

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Here, the `shutdown` event handler function will write a text line `"Application shutdown"` to a file `log.txt`.

!!! info

하나 이상의 이벤트 핸들러 함수를 추가할 수도 있습니다.

그리고 응용 프로그램은 모든 `startup` 이벤트 핸들러가 완료될 때까지 요청을 받지 않습니다.

## `shutdown` 이벤트

응용 프로그램이 종료될 때 실행하려는 함수를 추가하려면 `"shutdown"` 이벤트로 선언합니다:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

이 예제에서 `shutdown` 이벤트 핸들러 함수는 `"Application shutdown"`이라는 텍스트가 적힌 `log.txt` 파일을 추가할 것입니다.

!!! info "정보"

		return srv.Server.Serve(l)
	}

	return
}

// Shutdown - shuts down HTTP server.
func (srv *Server) Shutdown() error {
	srv.listenerMutex.Lock()
	if srv.listener == nil {
		srv.listenerMutex.Unlock()
		return http.ErrServerClosed
	}
	srv.listenerMutex.Unlock()

	if atomic.AddUint32(&srv.inShutdown, 1) > 1 {
		// shutdown in progress
		return http.ErrServerClosed
	}

本例中，`startup` 事件处理器函数为项目数据库（只是**字典**）提供了一些初始值。

**FastAPI** 支持多个事件处理器函数。

只有所有 `startup` 事件处理器运行完毕，**FastAPI** 应用才开始接收请求。

## `shutdown` 事件

使用 `shutdown` 事件声明 `app` 关闭时运行的函数：

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

此处，`shutdown` 事件处理器函数在 `log.txt` 中写入一行文本 `Application shutdown`。

!!! info "说明"

    `open()` 函数中，`mode="a"` 指的是**追加**。因此这行文本会添加在文件已有内容之后，不会覆盖之前的内容。

!!! tip "提示"

👆 💪 🚮 🌅 🌘 1️⃣ 🎉 🐕‍🦺 🔢.

& 👆 🈸 🏆 🚫 ▶️ 📨 📨 ⏭ 🌐 `startup` 🎉 🐕‍🦺 ✔️ 🏁.

### `shutdown` 🎉

🚮 🔢 👈 🔜 🏃 🕐❔ 🈸 🤫 🔽, 📣 ⚫️ ⏮️ 🎉 `"shutdown"`:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

📥, `shutdown` 🎉 🐕‍🦺 🔢 🔜 ✍ ✍ ⏸ `"Application shutdown"` 📁 `log.txt`.

!!! info
     `open()` 🔢, `mode="a"` ⛓ "🎻",, ⏸ 🔜 🚮 ⏮️ ⚫️❔ 🔛 👈 📁, 🍵 📁 ⏮️ 🎚.

    Request request = new Request.Builder()
        .url("ws://echo.websocket.org")
        .build();
    client.newWebSocket(request, this);

    // Trigger shutdown of the dispatcher's executor so this process exits immediately.
    client.dispatcher().executorService().shutdown();
  }

  @Override public void onOpen(WebSocket webSocket, Response response) {
    webSocket.send("Hello...");
    webSocket.send("...World!");

### `shutdown`-Event

Um eine Funktion hinzuzufügen, die beim Herunterfahren der Anwendung ausgeführt werden soll, deklarieren Sie sie mit dem Event `shutdown`:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Hier schreibt die `shutdown`-Eventhandler-Funktion eine Textzeile `"Application shutdown"` in eine Datei `log.txt`.

!!! info

### Evento `shutdown`

Para adicionar uma função que deve ser executada quando a aplicação estiver encerrando, declare ela com o evento `"shutdown"`:

```Python hl_lines="6"
{!../../../docs_src/events/tutorial002.py!}
```

Aqui, a função de manipulação de evento `shutdown` irá escrever uma linha de texto `"Application shutdown"` no arquivo `log.txt`.

!!! info "Informação"

			if err := httpServer.Shutdown(); err != nil && !errors.Is(err, http.ErrServerClosed) {
				shutdownLogIf(context.Background(), err)
			}
		}

		if objAPI := newObjectLayerFn(); objAPI != nil {
			shutdownLogIf(context.Background(), objAPI.Shutdown(context.Background()))
		}

		if srv := newConsoleServerFn(); srv != nil {
			shutdownLogIf(context.Background(), srv.Shutdown())
		}