})
        .start();

    future.cancel(true);

    assertTrue(future.isCancelled());
    assertTrue(future.isDone());

    assertTrue(successLatch.await(200, MILLISECONDS));
    assertTrue(listenerLatch.await(200, MILLISECONDS));

    latch.countDown();

    exec.shutdown();
    exec.awaitTermination(100, MILLISECONDS);
  }

  /**

    assertTrue(latch.await(5, SECONDS));
    assertTrue(future.isDone());
    assertFalse(future.isCancelled());

    assertEquals(expectedValue, future.get());
  }

  public void testCancelledFuture() throws InterruptedException, ExecutionException {
    assertTrue(future.isDone());
    assertTrue(future.isCancelled());

    assertTrue(latch.await(5, SECONDS));
    assertTrue(future.isDone());

            })
        .start();

    future.cancel(true);

    assertTrue(future.isCancelled());
    assertTrue(future.isDone());

    assertTrue(successLatch.await(200, MILLISECONDS));
    assertTrue(listenerLatch.await(200, MILLISECONDS));

    latch.countDown();

    exec.shutdown();
    exec.awaitTermination(100, MILLISECONDS);
  }

  /**

          @Override
          protected void finalize() {
            latch.countDown();
          }
        };
    unused = null; // Hint to the JIT that unused is unreachable
    GcFinalization.await(latch);
    assertEquals(0, latch.getCount());
  }

  public void testAwaitDone_future() {
    SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object unused =
        new Object() {

          t: Throwable,
          response: Response?,
        ) {
          t.printStackTrace(System.out)
          latch.countDown()
        }
      },
    )

    check(latch.await(30, TimeUnit.SECONDS)) { "Timed out waiting for test $number to finish." }
    val endNanos = System.nanoTime()
    val tookMs = TimeUnit.NANOSECONDS.toMillis(endNanos - startNanos.get())
    println("Took ${tookMs}ms")
  }

    assertEquals(3L, countDownLatch.getCount());

    list.execute();

    // Verify that all of the runnables execute in a reasonable amount of time.
    assertTrue(countDownLatch.await(1L, SECONDS));
  }

  public void testExecute_idempotent() {
    AtomicInteger runCalled = new AtomicInteger();
    list.add(
        new Runnable() {
          @Override
          public void run() {

# 並行與 async / await

有關*路徑操作函式*的 `async def` 語法的細節與非同步 (asynchronous) 程式碼、並行 (concurrency) 與平行 (parallelism) 的一些背景知識。

## 趕時間嗎?

<abbr title="too long; didn't read（文長慎入）"><strong>TL;DR:</strong></abbr>

如果你正在使用要求你以 `await` 語法呼叫的第三方函式庫，例如：

```Python
results = await some_library()
```

然後，使用 `async def` 宣告你的*路徑操作函式*：


```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()

	var zb0001 uint32
	zb0001, bts, err = msgp.ReadArrayHeaderBytes(bts)
	if err != nil {
		err = msgp.WrapError(err)
		return o, err
	}
	if zb0001 != 4 {
		err = msgp.ArrayError{Wanted: 4, Got: zb0001}
		return o, err
	}
	bts, err = msgp.ReadExactBytes(bts, (x.VersionID)[:])
	if err != nil {
		err = msgp.WrapError(err, "VersionID")
		return o, err
	}

* `seek(offset)`: Переміщується до позиції `offset` (`int`) у файлі.
    * Наприклад, `await myfile.seek(0)` поверне курсор на початок файлу.
    * This is especially useful if you run `await myfile.read()` once and then need to read the contents again. Це особливо корисно, якщо Ви виконуєте await `await myfile.read()` один раз, а потім потрібно знову прочитати вміст.
* `close()`: Закриває файл.

# 并发 async / await

有关路径操作函数的 `async def` 语法以及异步代码、并发和并行的一些背景知识。

## 赶时间吗？

<abbr title="too long; didn't read(长文警告)"><strong>TL;DR:</strong></abbr>

如果你正在使用第三方库，它们会告诉你使用 `await` 关键字来调用它们，就像这样：

```Python
results = await some_library()
```

然后，通过 `async def` 声明你的 *路径操作函数*：

```Python hl_lines="2"
@app.get('/')
async def read_results():
    results = await some_library()
    return results
```

/// note