while (!isThreadBlockedOnInstanceOf(t, blocker)) {
      if (t.getState() == Thread.State.TERMINATED) {
        throw new RuntimeException("Thread " + t + " exited unexpectedly");
      }
      Thread.sleep(1);
    }
  }

  private static boolean isThreadBlockedOnInstanceOf(Thread t, Class<?> blocker) {
    return t.getState() == Thread.State.WAITING && blocker.isInstance(LockSupport.getBlocker(t));
  }

    while (!isThreadBlockedOnInstanceOf(t, blocker)) {
      if (t.getState() == Thread.State.TERMINATED) {
        throw new RuntimeException("Thread " + t + " exited unexpectedly");
      }
      Thread.sleep(1);
    }
  }

  private static boolean isThreadBlockedOnInstanceOf(Thread t, Class<?> blocker) {
    return t.getState() == Thread.State.WAITING && blocker.isInstance(LockSupport.getBlocker(t));
  }

    assertEquals(THREAD_PRIORITY, thread.getPriority());
    assertEquals(THREAD_DAEMON, thread.isDaemon());
    assertThat(thread.getUncaughtExceptionHandler()).isEqualTo(UNCAUGHT_EXCEPTION_HANDLER);
    assertThat(thread.getState()).isEqualTo(Thread.State.NEW);

    assertFalse(completed);
    thread.start();
    thread.join();
    assertTrue(completed);
  }

  public void testNulls() {

    void awaitWaiting() {
      while (!isBlocked()) {
        if (getState() == State.TERMINATED) {
          throw new RuntimeException("Thread exited");
        }
        Thread.yield();
      }
    }

    private boolean isBlocked() {
      return getState() == Thread.State.WAITING && LockSupport.getBlocker(this) == future;
    }
  }

      completed.assertCompletionExpected();
      assertEquals(Thread.State.TERMINATED, thread.getState());
    }

    void joinSuccessfully(long timeoutMillis) {
      Uninterruptibles.joinUninterruptibly(thread, timeoutMillis, MILLISECONDS);
      completed.assertCompletionExpected();
      assertEquals(Thread.State.TERMINATED, thread.getState());
    }

    void joinUnsuccessfully(long timeoutMillis) {

    assertEquals(THREAD_PRIORITY, thread.getPriority());
    assertEquals(THREAD_DAEMON, thread.isDaemon());
    assertThat(thread.getUncaughtExceptionHandler()).isEqualTo(UNCAUGHT_EXCEPTION_HANDLER);
    assertThat(thread.getState()).isEqualTo(Thread.State.NEW);

    assertFalse(completed);
    thread.start();
    thread.join();
    assertTrue(completed);
  }

  public void testNulls() {

    void awaitWaiting() {
      while (!isBlocked()) {
        if (getState() == State.TERMINATED) {
          throw new RuntimeException("Thread exited");
        }
        Thread.yield();
      }
    }

    private boolean isBlocked() {
      return getState() == Thread.State.WAITING && LockSupport.getBlocker(this) == future;
    }
  }

      completed.assertCompletionExpected();
      assertEquals(Thread.State.TERMINATED, thread.getState());
    }

    void joinSuccessfully(long timeoutMillis) {
      Uninterruptibles.joinUninterruptibly(thread, timeoutMillis, MILLISECONDS);
      completed.assertCompletionExpected();
      assertEquals(Thread.State.TERMINATED, thread.getState());
    }

    void joinUnsuccessfully(long timeoutMillis) {

        indexUpdater.start();

        // Poll for thread to process exceptions
        for (int i = 0; i < 20; i++) {
            if (!indexUpdater.isAlive() || indexUpdater.getState() == Thread.State.WAITING
                    || indexUpdater.getState() == Thread.State.TIMED_WAITING) {
                break;
            }
            Thread.sleep(100);
        }

        // Clean up the thread

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  void awaitTimedWaiting(Thread thread) {
    while (true) {
      switch (thread.getState()) {
        case BLOCKED:
        case NEW:
        case RUNNABLE:
        case WAITING:
          Thread.yield();
          break;
        case TIMED_WAITING:
          return;