}

  @Test fun test() {
    val t1 = System.nanoTime() / 1e6

    val delays = mutableListOf(TimeUnit.MILLISECONDS.toNanos(1000), -1L)
    queue.schedule("task", TimeUnit.MILLISECONDS.toNanos(750)) {
      log.put("runOnce delays.size=${delays.size}")
      return@schedule delays.removeAt(0)
    }

    assertThat(log.take()).isEqualTo("runOnce delays.size=2")
    val t2 = System.nanoTime() / 1e6 - t1

    assertTrue(tryAcquireUninterruptibly(semaphore, LONG_DELAY_MS, MILLISECONDS));
    assertTimeNotPassed(stopwatch, LONG_DELAY_MS);
  }

  public void testTryAcquireTimeoutNoInterruptNotExpired() {
    TimedSemaphore semaphore = TimedSemaphore.createWithDelay(20);
    semaphore.tryAcquireSuccessfully(LONG_DELAY_MS);
    assertNotInterrupted();
  }

        public String call() throws InterruptedException {
          MILLISECONDS.sleep(DELAY_MS);
          return GOOD_CALLABLE_RESULT;
        }
      };
  private static final Callable<String> BAD_CALLABLE =
      new Callable<String>() {
        @Override
        public String call() throws InterruptedException, SampleException {
          MILLISECONDS.sleep(DELAY_MS);
          throw new SampleException();
        }
      };

  boolean called = false;

  private void assertSingleCallWithCorrectParameters(
      Runnable command, long initialDelay, long delay, TimeUnit unit) {
    assertFalse(called); // only called once.
    called = true;
    assertEquals(INITIAL_DELAY, initialDelay);
    assertEquals(DELAY, delay);
    assertEquals(UNIT, unit);
    assertEquals(testRunnable, command);
  }

  public void testFixedRateSchedule() {

        public String call() throws InterruptedException {
          MILLISECONDS.sleep(DELAY_MS);
          return GOOD_CALLABLE_RESULT;
        }
      };
  private static final Callable<String> BAD_CALLABLE =
      new Callable<String>() {
        @Override
        public String call() throws InterruptedException, SampleException {
          MILLISECONDS.sleep(DELAY_MS);
          throw new SampleException();
        }
      };

     * A value object that represents an absolute delay until a task should be invoked.
     *
     * @author Luke Sandberg
     * @since 11.0
     */
    protected static final class Schedule {

      private final long delay;
      private final TimeUnit unit;

      /**
       * @param delay the time from now to delay execution
       * @param unit the time unit of the delay parameter
       */

            long delay;

            do {
                delay = 2L;

                synchronized (t) {
                    long expire = t.ltime + t.delay;
                    long ctime = System.currentTimeMillis();

                    if (expire > ctime)
                        delay = expire - ctime;
                }

if (delay > 2)
System.out.println("delay=" + delay);

	delay := env.Get(EnvDelayLegacy, "")
	if delay == "" {
		delay = env.Get(EnvDelay, kvs.GetWithDefault(Delay, DefaultKVS))
	}
	cfg.Delay, err = strconv.ParseFloat(delay, 64)
	if err != nil {
		return err
	}
	maxWait := env.Get(EnvMaxWaitLegacy, "")
	if maxWait == "" {
		maxWait = env.Get(EnvMaxWait, kvs.GetWithDefault(MaxWait, DefaultKVS))
	}
	cfg.MaxWait, err = time.ParseDuration(maxWait)
	if err != nil {
		return err

```

## Adicionar a tarefa em segundo plano

Dentro de sua _função de operação de caminho_, passe sua função de tarefa para o objeto _tarefas em segundo plano_ com o método `.add_task()`:

```Python hl_lines="14"
{!../../../docs_src/background_tasks/tutorial001.py!}
```

`.add_task()` recebe como argumentos:

- Uma função de tarefa a ser executada em segundo plano (`write_notification`).

    assertTrue(tryAcquireUninterruptibly(semaphore, LONG_DELAY_MS, MILLISECONDS));
    assertTimeNotPassed(stopwatch, LONG_DELAY_MS);
  }

  public void testTryAcquireTimeoutNoInterruptNotExpired() {
    TimedSemaphore semaphore = TimedSemaphore.createWithDelay(20);
    semaphore.tryAcquireSuccessfully(LONG_DELAY_MS);
    assertNotInterrupted();
  }