///

使用 `with` 區塊可確保在產生器函式（包含 `yield` 的函式）完成後關閉該類檔案物件，也就是在送完回應之後。

在這個範例中因為是存在記憶體的假檔案（`io.BytesIO`），影響不大；但若是實際檔案，務必在處理完成後關閉檔案。

### 檔案與 Async { #files-and-async }

多數情況下，類檔案物件預設不相容於 async/await。

例如，它們沒有 `await file.read()`，也不支援 `async for chunk in file`。

而且在許多情況下，讀取它們會是阻塞操作（可能阻塞事件迴圈），因為資料是從磁碟或網路讀取。

/// info

上面的範例其實是例外，因為 `io.BytesIO` 物件已在記憶體中，讀取不會阻塞任何東西。

但在多數情況下，讀取檔案或類檔案物件會造成阻塞。

///

    val dispatcher: Dispatcher =
      object : Dispatcher() {
        override fun dispatch(request: RecordedRequest): MockResponse {
          if (request.url.encodedPath == firstRequest) {
            latch.await()
          }
          return MockResponse()
        }
      }
    mockWebServer.dispatcher = dispatcher
    val startsFirst = buildRequestThread(firstRequest, firstResponseCode)
    startsFirst.start()

        for (int i = 0; i < readerThreadCount; i++) {
            final int threadIndex = i;
            readerThreads[i] = new Thread(() -> {
                try {
                    startLatch.await(); // Wait for start signal
                    long endTime = System.currentTimeMillis() + testDurationMs;
                    while (System.currentTimeMillis() < endTime) {

    @Override
    public @Nullable Void call() throws InterruptedException {
      running = true;
      startLatch.countDown();
      stopLatch.await();
      running = false;
      return null;
    }

    void waitForStart() throws InterruptedException {
      startLatch.await();
    }

    void stop() {
      stopLatch.countDown();
    }

    boolean isRunning() {
      return running;
    }

```Python
with open("file.txt") as file:
    file.read()
```

In recent versions of Python, there's also an **async context manager**. You would use it with `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

with open("file.txt") as file:
    file.read()
```

Em versões mais recentes do Python, há também um **gerenciador de contexto assíncrono**. Você o usaria com `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

```Python
with open("file.txt") as file:
    file.read()
```

En versiones recientes de Python, también hay un **async context manager**. Lo usarías con `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

```Python
with open("file.txt") as file:
    file.read()
```

В последних версиях Python есть также асинхронный менеджер контекста. Его используют с `async with`:

```Python
async with lifespan(app):
    await do_stuff()
```

Когда вы создаёте менеджер контекста или асинхронный менеджер контекста, как выше, он перед входом в блок `with` выполнит код до `yield`, а после выхода из блока `with` выполнит код после `yield`.

    }
  }

  override fun cancel() {
    delegate.cancel()
  }

  override fun close() {
    javaNetSocket.close()
  }

  fun awaitClosed() {
    closedLatch.await()
  }

    file.read()
```

Dans les versions récentes de Python, il existe aussi un **gestionnaire de contexte asynchrone**. Vous l'utiliseriez avec `async with` :

```Python
async with lifespan(app):
    await do_stuff()
```