// We wait at most 1 second, so we don't ever turn multiple lost threads into
      // a test timeout failure.
      val waitTime = (entryTime + 1_000_000_000L - System.nanoTime())
      if (!queue.idleLatch().await(waitTime, TimeUnit.NANOSECONDS)) {
        TaskRunner.INSTANCE.withLock {
          TaskRunner.INSTANCE.cancelAll()
        }
        fail<Unit>("Queue still active after 1000 ms")
      }
    }
  }

백그라운드 작업으로 실행할 함수를 생성합니다.

이는 매개변수를 받을 수 있는 표준 함수일 뿐입니다.

`async def` 함수일 수도, 일반 `def` 함수일 수도 있으며, **FastAPI**가 이를 올바르게 처리하는 방법을 알고 있습니다.

이 경우 작업 함수는 파일에 쓰기를 수행합니다(이메일 전송을 시뮬레이션).

그리고 쓰기 작업은 `async`와 `await`를 사용하지 않으므로, 일반 `def`로 함수를 정의합니다:

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[6:9] *}

## 백그라운드 작업 추가 { #add-the-background-task }

*경로 처리 함수* 내부에서 `.add_task()` 메서드로 작업 함수를 *백그라운드 작업* 객체에 전달합니다:

        br.addElement(limitSize);
        final String msg = br.buildExceptionMessage();
        throw new Forced404NotFoundException(msg, UserMessages.empty()); // heavy attack!? so give no page to tell wasted action
    }

    protected void setupServletFileUpload(final JakartaServletDiskFileUpload upload, final HttpServletRequest request) {
        upload.setHeaderCharset(Charset.forName(request.getCharacterEncoding()));

      return if (!fieldType.isInstance(value)) null else fieldType.cast(value)
    } catch (_: NoSuchFieldException) {
    }

    c = c.superclass
  }

  // Didn't find the field we wanted. As a last gasp attempt,
  // try to find the value on a delegate.
  if (fieldName != "delegate") {
    val delegate = readFieldOrNull(instance, Any::class.java, "delegate")

   *
   * @param reference any array of the desired type
   * @param length the length of the new array
   */
  /*
   * The new array contains nulls, even if the old array did not. If we wanted to be accurate, we
   * would declare a return type of `@Nullable T[]`. However, we've decided not to think too hard
   * about arrays for now, as they're a mess.
   */

	var zb0001 uint32
	zb0001, err = dc.ReadArrayHeader()
	if err != nil {
		err = msgp.WrapError(err)
		return
	}
	if zb0001 != 7 {
		err = msgp.ArrayError{Wanted: 7, Got: zb0001}
		return
	}
	z.MuxID, err = dc.ReadUint64()
	if err != nil {
		err = msgp.WrapError(err, "MuxID")
		return
	}
	z.Seq, err = dc.ReadUint32()
	if err != nil {

Neste caso, a função da tarefa escreverá em um arquivo (simulando o envio de um e-mail).

E como a operação de escrita não usa `async` e `await`, definimos a função com um `def` normal:

{* ../../docs_src/background_tasks/tutorial001_py310.py hl[6:9] *}

## Adicione a tarefa em segundo plano { #add-the-background-task }

        CountDownLatch latch = new CountDownLatch(shards.size());
        for (int i = 0; i < shards.size(); i++) {
            consumer.consumeResult(shards.get(i), () -> latch.countDown());
        }
        latch.await();
        SearchPhaseController.ReducedQueryPhase phase = consumer.reduce();
        executor.shutdownNow();
        return phase;
    }

    ImmutableList.Builder<Future<?>> futures = ImmutableList.builder();
    for (int i = 0; i < threadCount; i++) {
      futures.add(
          executor.submit(
              () -> {
                barrier.await();
                Integer first = graph.nodes().iterator().next();
                for (Integer node : graph.nodes()) {
                  Set<Integer> unused = graph.successors(node);
                }
                /*

          object : WebSocketListener() {
            override fun onOpen(
              webSocket: WebSocket,
              response: Response,
            ) {
              try {
                latch.await() // The server can't respond to pings!
              } catch (e: InterruptedException) {
                throw AssertionError(e)
              }
            }
          },
        ).build(),
    )