public final void awaitTerminated() {
    monitor.enterWhenUninterruptibly(isStopped);
    try {
      checkCurrentState(TERMINATED);
    } finally {
      monitor.leave();
    }
  }

  @Override
  public final void awaitTerminated(long timeout, TimeUnit unit) throws TimeoutException {
    if (monitor.enterWhenUninterruptibly(isStopped, timeout, unit)) {
      try {
        checkCurrentState(TERMINATED);

   * known as the XON code used for software flow control in serial communications. The main use is
   * restarting the transmission after the communication has been stopped by the XOFF control code.
   *
   * @since 8.0
   */
  public static final byte XON = 17; // aka DC1

  /**
   * Device Control 2. Characters for the control of ancillary devices associated with data

room at all for any lesson-books!'

  And so she went on, taking first one side and then the other,
and making quite a conversation of it altogether; but after a few
minutes she heard a voice outside, and stopped to listen.

  `Mary Ann!  Mary Ann!' said the voice.  `Fetch me my gloves
this moment!'  Then came a little pattering of feet on the
stairs.  Alice knew it was the Rabbit coming to look for her, and

   * this initiates service shutdown and returns immediately. If the service is {@linkplain
   * State#NEW new}, it is {@linkplain State#TERMINATED terminated} without having been started nor
   * stopped. If the service has already been stopped, this method returns immediately without
   * taking action.
   *
   * @return this
   * @since 15.0
   */
  @CanIgnoreReturnValue
  Service stopAsync();

  /**

   */
  @CanIgnoreReturnValue
  public Stopwatch stop() {
    long tick = ticker.read();
    checkState(isRunning, "This stopwatch is already stopped.");
    isRunning = false;
    elapsedNanos += tick - startTick;
    return this;
  }

  /**
   * Sets the elapsed time for this stopwatch to zero, and places it in a stopped state.
   *

      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;


  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

      finalizeReferentCalled = true;
    }
  }

  /**
   * Keeps a weak reference to the underlying reference queue. When this reference is cleared, we
   * know that the background thread has stopped and released its strong reference.
   */
  private WeakReference<ReferenceQueue<Object>> queueReference;


  public void testThatFinalizerStops() {
    weaklyReferenceQueue();

    manager.awaitStopped(5, SECONDS); // no exception thrown
  }

  /**
   * This covers a case where if the last service to stop failed then the stopped callback would
   * never be called.
   */
  public void testSingleFailedServiceCallsStopped() {
    Service a = new FailStartService();
    ServiceManager manager = new ServiceManager(asList(a));

        Executors.newSingleThreadScheduledExecutor(new ThreadFactoryImpl());
    // Add a listener to shut down the executor after the service is stopped. This ensures that the
    // JVM shutdown will not be prevented from exiting after this service has stopped or failed.
    // Technically this listener is added after start() was called so it is a little gross, but it

        }
      };
  private static final ListenerCallQueue.Event<Listener> STOPPED_EVENT =
      new ListenerCallQueue.Event<Listener>() {
        @Override
        public void call(Listener listener) {
          listener.stopped();
        }

        @Override
        public String toString() {
          return "stopped()";
        }
      };

  /**