}

  private static class SingleCallListener implements Runnable {

    private boolean expectCall = false;
    private final CountDownLatch calledCountDown = new CountDownLatch(1);

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());

        final Deferred<SuggestResponse> deferred = new Deferred<>();
        final AtomicInteger callbackCount = new AtomicInteger(0);
        final CountDownLatch startLatch = new CountDownLatch(1);
        final CountDownLatch doneLatch = new CountDownLatch(threadCount);

        deferred.promise().then(response -> callbackCount.incrementAndGet());

        // Start multiple threads that all try to resolve

        int threadCount = 10;
        int opsPerThread = 100;
        ExecutorService executor = Executors.newFixedThreadPool(threadCount);
        CountDownLatch startLatch = new CountDownLatch(1);
        CountDownLatch endLatch = new CountDownLatch(threadCount);
        AtomicInteger successCount = new AtomicInteger(0);
        List<Exception> exceptions = Collections.synchronizedList(new ArrayList<>());

    @Test
    public void test_concurrentSearcherRegistration() throws Exception {
        final int numThreads = 10;
        final int searchersPerThread = 5;
        final CountDownLatch startLatch = new CountDownLatch(1);
        final CountDownLatch endLatch = new CountDownLatch(numThreads);
        final AtomicInteger registeredCount = new AtomicInteger(0);

        try (RankFusionProcessor processor = new RankFusionProcessor()) {

        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 {

    static final Set<FinalizableReference> references = newConcurrentHashSet();

    static void register(Object referent, CountDownLatch latch) {
      references.add(new FinalizableReference(referent, latch));
    }

    final CountDownLatch latch;

    FinalizableReference(Object referent, CountDownLatch latch) {
      super(referent, referenceQueue);
      this.latch = latch;
    }

    @Override

  }

  private static class SingleCallListener implements Runnable {

    private boolean expectCall = false;
    private final CountDownLatch calledCountDown = new CountDownLatch(1);

    @Override
    public void run() {
      assertTrue("Listener called before it was expected", expectCall);
      assertFalse("Listener called more than once", wasCalled());

        setPrivateField(transport, "smb2", true);
        setPrivateField(transport, "negotiated", negotiateResponse);

        int threadCount = 10;
        CountDownLatch startLatch = new CountDownLatch(1);
        CountDownLatch doneLatch = new CountDownLatch(threadCount);
        ExecutorService executor = Executors.newFixedThreadPool(threadCount);

        // Create test data
        byte[] testData = new byte[64];

        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 {

   * even permanently blocked.
   */
  public void testListenerDeadlock() throws InterruptedException {
    CountDownLatch failEnter = new CountDownLatch(1);
    CountDownLatch failLeave = new CountDownLatch(1);
    CountDownLatch afterStarted = new CountDownLatch(1);
    Service failRunService =
        new AbstractService() {
          @Override
          protected void doStart() {