*/
@NullUnmarked
public class ListenableFutureTaskTest extends TestCase {

  private ExecutorService exec;

  protected final CountDownLatch runLatch = new CountDownLatch(1);
  protected final CountDownLatch taskLatch = new CountDownLatch(1);
  protected final CountDownLatch listenerLatch = new CountDownLatch(1);

  protected volatile boolean throwException = false;

  protected final ListenableFutureTask<Integer> task =

    @Test
    public void testThreadSafeListenerManagement() throws Exception {
        final int numThreads = 10;
        final ExecutorService executor = Executors.newFixedThreadPool(numThreads);
        final CountDownLatch latch = new CountDownLatch(numThreads);
        final AtomicInteger callbackCount = new AtomicInteger(0);

        // Add listeners concurrently from multiple threads
        for (int i = 0; i < numThreads; i++) {

        try {
            assertEquals(0, cbWithTracking.getActiveRequests(), "Initial active requests should be 0");

            CountDownLatch startLatch = new CountDownLatch(1);
            CountDownLatch holdLatch = new CountDownLatch(1);
            CountDownLatch completeLatch = new CountDownLatch(1);

            // Start a long-running operation
            Thread longRunningThread = new Thread(() -> {
                try {

            } catch (InterruptedException ignore) {}
            deferred.resolve(new SuggestResponse("", 0, Collections.emptyList(), 0, null));
        });
        th.start();

        final CountDownLatch latch = new CountDownLatch(1);
        deferred.promise().then(response -> latch.countDown());
        assertTrue(latch.await(10, TimeUnit.SECONDS));
    }

    @Test
    public void test_doneAfterResolve() throws Exception {

    assertTrue(successLatch.await(200, MILLISECONDS));

    latch.countDown();
  }

  public void testListenersNotifiedOnError() throws Exception {
    CountDownLatch successLatch = new CountDownLatch(1);
    CountDownLatch listenerLatch = new CountDownLatch(1);

    ExecutorService exec = newCachedThreadPool();

    future.addListener(listenerLatch::countDown, exec);

    new Thread(
            () -> {

            .build(computingFunction);

    // seed the map, so its segment's count > 0
    cache.getUnchecked("a");
    shouldWait.set(true);

    CountDownLatch computationStarted = new CountDownLatch(1);
    CountDownLatch computationComplete = new CountDownLatch(1);
    new Thread(
            new Runnable() {
              @Override
              public void run() {
                computationStarted.countDown();

      throws Exception {
    ExecutorService executorService = newFixedThreadPool(numberOfThreads);
    CountDownLatch startLatch = new CountDownLatch(numberOfThreads);
    CountDownLatch doneLatch = new CountDownLatch(numberOfThreads);
    for (int i = numberOfThreads; i > 0; i--) {
      @SuppressWarnings("unused") // https://errorprone.info/bugpattern/FutureReturnValueIgnored

        void testConcurrentReceived() throws InterruptedException {
            int threadCount = 10;
            CountDownLatch startLatch = new CountDownLatch(1);
            CountDownLatch endLatch = new CountDownLatch(threadCount);

            for (int i = 0; i < threadCount; i++) {
                new Thread(() -> {
                    try {

 */
@NullUnmarked
public class AbstractExecutionThreadServiceTest extends TestCase {

  private final TearDownStack tearDownStack = new TearDownStack(true);
  private final CountDownLatch enterRun = new CountDownLatch(1);
  private final CountDownLatch exitRun = new CountDownLatch(1);

  private Thread executionThread;
  private Throwable thrownByExecutionThread;
  private final Executor exceptionCatchingExecutor =
      new Executor() {

    ExecutorService service = newFixedThreadPool(4);
    ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    try {
      queue.addListener(listener, service);

      CountDownLatch latch = new CountDownLatch(1);
      Multiset<Object> counters = ConcurrentHashMultiset.create();
      queue.enqueue(incrementingEvent(counters, listener, 1));
      queue.enqueue(incrementingEvent(counters, listener, 2));