Thread interrupter =
        new Thread("Interrupter") {
          @Override
          public void run() {
            task.interruptTask();
          }
        };
    interrupter.start();
    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    Thread interrupter =
        new Thread("Interrupter") {
          @Override
          public void run() {
            task.interruptTask();
          }
        };
    interrupter.start();
    // this will happen once the interrupt has been set which means that
    // 1. the runner has been woken up
    // 2. the interrupter is stuck in the call the Thread.interrupt()

    Interruptenator(Thread interruptee) {
      this(interruptee, new AtomicBoolean(false));
    }

    @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
    Interruptenator(Thread interruptee, AtomicBoolean shutdown) {
      super(
          () -> {
            while (!shutdown.get()) {
              interruptee.interrupt();
              Thread.yield();

    Interruptenator(Thread interruptee) {
      this(interruptee, new AtomicBoolean(false));
    }

    @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
    Interruptenator(Thread interruptee, AtomicBoolean shutdown) {
      super(
          () -> {
            while (!shutdown.get()) {
              interruptee.interrupt();
              Thread.yield();

  private static final class Interruptenator implements Runnable {
    private final Thread interruptee;
    private volatile boolean shouldStop = false;

    Interruptenator(Thread interruptee) {
      this.interruptee = interruptee;
    }

    @Override
    public void run() {
      while (!shouldStop) {
        interruptee.interrupt();
      }
    }

    void stopInterrupting() {
      shouldStop = true;

    assertFalse(Thread.interrupted());
    try {
      delayedFuture.get(20000, MILLISECONDS);
      fail("expected to be interrupted");
    } catch (InterruptedException expected) {
    } catch (TimeoutException e) {
      throw new RuntimeException(e);
    }

    // we were interrupted, but it's been cleared now
    assertFalse(Thread.interrupted());

    assertFalse(sleeper.completed);

    assertFalse(Thread.interrupted());
    try {
      delayedFuture.get(20000, MILLISECONDS);
      fail("expected to be interrupted");
    } catch (InterruptedException expected) {
    } catch (TimeoutException e) {
      throw new RuntimeException(e);
    }

    // we were interrupted, but it's been cleared now
    assertFalse(Thread.interrupted());

    assertFalse(sleeper.completed);

    fakePool.execute(() -> Thread.currentThread().interrupt());
    // Run a task that expects that it is not interrupted while it is running.
    e.execute(() -> assertThat(Thread.currentThread().isInterrupted()).isFalse());

    // Run these together.
    fakePool.runAll();

    // Check that this thread has been marked as interrupted again now that the thread has been

    fakePool.execute(() -> Thread.currentThread().interrupt());
    // Run a task that expects that it is not interrupted while it is running.
    e.execute(() -> assertThat(Thread.currentThread().isInterrupted()).isFalse());

    // Run these together.
    fakePool.runAll();

    // Check that this thread has been marked as interrupted again now that the thread has been

  /**
   * Waits until the given future {@linkplain Future#isDone is done}, invoking the garbage collector
   * as necessary to try to ensure that this will happen.
   *
   * @throws RuntimeException if timed out or interrupted while waiting
   */
  @SuppressWarnings("removal") // b/487687332
  public static void awaitDone(Future<?> future) {
    if (future.isDone()) {
      return;
    }
    long timeoutSeconds = timeoutSeconds();