assertFalse(service.startUpCalled);

    service.startAsync().awaitRunning();
    assertTrue(service.startUpCalled);
    assertEquals(Service.State.RUNNING, service.state());

    enterRun.await(); // to avoid stopping the service until run() is invoked

    service.stopAsync().awaitTerminated();
    assertTrue(service.shutDownCalled);
    assertEquals(Service.State.TERMINATED, service.state());

					await.Stop()
					return
				}
				await.Stop()
			}
		} else {
			// no items, wait for Push or stop
			select {
			case t := <-d.enqueue:
				d.mu.Lock()
				d.queue.Push(t)
				d.mu.Unlock()
			case <-stop:
				return
			}
		}
	}
}

// work takes a channel that signals to stop, and returns a channel that signals the worker has fully stopped

          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")
  }

# 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

    }

    @Override
    public Runnable getExecution() {
        return runnable;
    }

    @Override
    public T await() {
        boolean interrupted = false;
        while (true) {
            try {
                finished.await();
                break;
            } catch (InterruptedException e) {
                cancel();
                interrupted = true;
            }

            return;
        }
        try {
            cancellationToken.addCallback(cancellationHandler);
            notifier.run();
            changeOrCancellationArrived.await();
            while (!cancellationToken.isCancellationRequested()) {
                Instant now = nowFromMonotonicClock();
                Instant endOfQuietPeriod = lastChangeAt.plus(quietPeriod);
                if (!endOfQuietPeriod.isAfter(now)) {

        val (_, asyncResp2) = pendingTasks[1]
        assertThat(
            asyncResp2.await(),
            nullValue()
        )

        // only then the most recent request will be given its response
        assertThat(
            asyncRespLast.await(),
            sameInstance(respLast)
        )

        // and no other requests are left to process
        assertThat(

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

  public void testAwaitDone_Future() {
    final SettableFuture<@Nullable Void> future = SettableFuture.create();
    Object x =
        new Object() {

        @Override
        public void run() {
        }

        public void await() {
            try {
                latch.await();
            } catch (InterruptedException e) {
                throw UncheckedException.throwAsUncheckedException(e);
            }
        }

        public void completed() {
            latch.countDown();
        }
    }

                        }
                    })
                    logger.warn "Waiting for memory status events..."
                    osNotification.await()
                    jvmNotification.await()
                }
            }
        ''').stripIndent()
    }