/// info

The example above is actually an exception, because the `io.BytesIO` object is already in memory, so reading it won't block anything.

But in many cases reading a file or a file-like object would block.

///

/// tip

If you encounter a `RuntimeError: Task attached to a different loop` when integrating asynchronous function calls in your tests (e.g. when using [MongoDB's MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop)), remember to instantiate objects that need an event loop only within async functions, e.g. an `@app.on_event("startup")` callback.

由於測試函式現在是非同步的，你也可以在測試中呼叫（並 `await`）其他 `async` 函式，和在程式碼其他地方一樣。

/// tip

如果在將非同步呼叫整合進測試時遇到 `RuntimeError: Task attached to a different loop`（例如使用 [MongoDB 的 MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop) 時），請記得：需要事件迴圈的物件只應在非同步函式內實例化，例如在 `@app.on_event("startup")` 回呼中。

                private int callCount = 0;

                @Override
                public int generate(ExecutorService executorService, boolean cleanup) {
                    // Return 0 to exit the loop
                    if (callCount++ == 0) {
                        return 1;
                    }
                    return 0;
                }
            };

/// tip | 豆知識

テストに非同期関数呼び出しを統合した際に（例: [MongoDB の MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop) 使用時）、`RuntimeError: Task attached to a different loop` に遭遇した場合は、イベントループを必要とするオブジェクトは非同期関数内でのみインスタンス化するようにしてください。例えば `@app.on_event("startup")` コールバック内で行います。

/// tip | 提示

如果您在测试程序中集成异步函数调用的时候遇到一个 `RuntimeError: Task attached to a different loop` 的报错（例如，使用 [MongoDB 的 MotorClient](https://stackoverflow.com/questions/41584243/runtimeerror-task-attached-to-a-different-loop) 时），请记住，只能在异步函数中实例化需要事件循环的对象，例如在 `@app.on_event("startup")` 回调中初始化。

  private static void testBytes(int numBytes, long expectedCount) {
    testBytes(numBytes, expectedCount, 0, -1);
  }

  /**
   * Helper to run the loop to test all the permutations for the number of bytes specified. This
   * overload is useful for debugging to get the loop to start at a certain character.
   *
   * @param numBytes the number of bytes in the byte array

   * @return a long of a concatenated 8 bytes
   */
  static long load64(byte[] input, int offset) {
    // We don't want this in production code as this is the most critical part of the loop.
    assert input.length >= offset + 8;
    // Delegates to the fast (unsafe) version or the fallback.
    return byteArray.getLongLittleEndian(input, offset);
  }

  /**

       * non-final fields need to be reloaded inside the loop.
       *
       * And, no, defining (final or not) local variables out of the loop still isn't as good
       * because the null check on the theUnsafe object remains inside the loop and
       * BYTE_ARRAY_BASE_OFFSET doesn't get constant-folded.
       *

    /**
     * Default constructor.
     */
    public CoordinatorHelper() {
        // Default constructor
    }

    /**
     * Initializes the coordinator by sending an initial heartbeat and starting the poll loop.
     */
    @PostConstruct
    public void init() {
        instanceId = ComponentUtil.getSystemHelper().getInstanceId();
        lastEventCheckTime = System.currentTimeMillis();

        sendHeartbeat();