// If the context's default exector is set to async, re-using that in
        // each thread would cause collectives to deadlock. For consistency we
        // create a new sync executor for every thread.
        //
        // TODO(allenl): We should have an async API that works with the
        // parallel device.
        device_(device),
        executor_(

public class ExecutionSequencerTest extends TestCase {

  ExecutorService executor;

  private ExecutionSequencer serializer;
  private SettableFuture<@Nullable Void> firstFuture;
  private TestCallable firstCallable;

  @Override
  public void setUp() throws Exception {
    executor = Executors.newCachedThreadPool();
    serializer = ExecutionSequencer.create();
    firstFuture = SettableFuture.create();

      assertEquals(Service.State.STOPPING, state());
      shutdownCalled++;
    }

    @Override
    protected Executor executor() {
      return executor;
    }

    @Override
    public void tearDown() throws Exception {
      executor.shutdown();
    }
  }

   *
   * @param executor The executor to decorate
   * @param nameSupplier The source of names for each task
   */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  static Executor renamingDecorator(final Executor executor, final Supplier<String> nameSupplier) {
    checkNotNull(executor);
    checkNotNull(nameSupplier);
    return new Executor() {
      @Override

    Future<?> first =
        blocked.submit(
            new Runnable() {
              @Override
              public void run() {
                executor.execute(Runnables.doNothing());
              }
            });
    future.get(10, SECONDS);
    assertThrows(RejectedExecutionException.class, () -> executor.execute(Runnables.doNothing()));
    latch.countDown();

    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertThrows(RejectedExecutionException.class, () -> executor.submit(doNothingRunnable));
    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

    // WAIT #3
    barrier.await(1, SECONDS);
    assertTrue(executor.awaitTermination(1, SECONDS));

public class ExecutionSequencerTest extends TestCase {

  ExecutorService executor;

  private ExecutionSequencer serializer;
  private SettableFuture<@Nullable Void> firstFuture;
  private TestCallable firstCallable;

  @Override
  public void setUp() throws Exception {
    executor = Executors.newCachedThreadPool();
    serializer = ExecutionSequencer.create();
    firstFuture = SettableFuture.create();

    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertThrows(RejectedExecutionException.class, () -> executor.submit(doNothingRunnable));
    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

    // WAIT #3
    barrier.await(1, SECONDS);
    assertTrue(executor.awaitTermination(1, SECONDS));

    Future<?> first =
        blocked.submit(
            new Runnable() {
              @Override
              public void run() {
                executor.execute(Runnables.doNothing());
              }
            });
    future.get(10, SECONDS);
    assertThrows(RejectedExecutionException.class, () -> executor.execute(Runnables.doNothing()));
    latch.countDown();

  }

  public void testCompletionFinishesWithDone() {
    ExecutorService executor = Executors.newFixedThreadPool(10);
    for (int i = 0; i < 50000; i++) {
      final AbstractFuture<String> future = new AbstractFuture<String>() {};
      final AtomicReference<String> errorMessage = Atomics.newReference();
      executor.execute(
          new Runnable() {
            @Override
            public void run() {