* MoreExecutors#newDirectExecutorService} and subject to the same constraints.
   *
   * <p>Although all tasks are immediately executed in the thread that submitted the task, this
   * {@code ExecutorService} imposes a small locking overhead on each task submission in order to
   * implement shutdown and termination behavior.
   *
   * <p>Because of the nature of single-thread execution, the methods {@code scheduleAtFixedRate}

    boolean lockAcquired = tryLockUninterruptibly(lock, 500, MILLISECONDS);

    assertFalse(lockAcquired);
    assertAtLeastTimePassed(stopwatch, 500);
    assertNotInterrupted();

    // finish locking thread
    lockThread.interrupt();
  }

  public void testTryLockTimeoutNotExceeded() {
    Stopwatch stopwatch = Stopwatch.createStarted();
    Lock lock = new ReentrantLock();

     * for (Lock lock : locks) {
     *   lock.unlock();
     * }
     *
     * If we only held the int[] stripes, translating it on the fly to L's, the original locks might
     * be garbage collected after locking them, ending up in a huge mess.
     */
    @SuppressWarnings("unchecked") // we carefully replaced all keys with their respective L's
    List<L> asStripes = (List<L>) result;

      return "Ordering.arbitrary()";
    }

    /*
     * We need to be able to mock identityHashCode() calls for tests, because it
     * can take 1-10 seconds to find colliding objects. Mocking frameworks that
     * can do magic to mock static method calls still can't do so for a system
     * class, so we need the indirection. In production, Hotspot should still

   * uncommon to specify {@code concurrencyLevel(1)} in order to achieve more deterministic eviction
   * behavior.
   *
   * <p>Note that future implementations may abandon segment locking in favor of more advanced
   * concurrency controls.
   *
   * @return this {@code CacheBuilder} instance (for chaining)
   * @throws IllegalArgumentException if {@code concurrencyLevel} is nonpositive

                // this is so damn unreliable, needs another race-prone query if required
                haveAttributes = false;

                // This seems to be the only way to obtain a reliable (with respect to locking) file size here
                // It is more critical than other attributes because append mode depends on it.
                // We do only really care if we open for writing and not shared for writing

    /*
     * TODO(cpovirk): move ForwardingTestCase somewhere common, and use it to
     * test the forwarded methods
     */
  }

  @AndroidIncompatible // Mocking ExecutorService is forbidden there. TODO(b/218700094): Don't mock.
  public void testListeningDecorator_noWrapExecuteTask() {
    ExecutorService delegate = mock(ExecutorService.class);

    exec.awaitTermination(100, MILLISECONDS);
  }

  /**
   * Tests that all listeners complete, even if they were added before or after the future was
   * finishing. Also acts as a concurrency test to make sure the locking is done correctly when a
   * future is finishing so that no listeners can be lost.
   */
  public void testAllListenersCompleteSuccessfully()
      throws InterruptedException, ExecutionException {

    boolean lockAcquired = tryLockUninterruptibly(lock, 500, MILLISECONDS);

    assertFalse(lockAcquired);
    assertAtLeastTimePassed(stopwatch, 500);
    assertNotInterrupted();

    // finish locking thread
    lockThread.interrupt();
  }

  public void testTryLockTimeoutNotExceeded() {
    Stopwatch stopwatch = Stopwatch.createStarted();
    Lock lock = new ReentrantLock();

     *
     * <p>Note that because of concurrent set calls and uses of atomics, this bitCount is a (very)
     * close *estimate* of the actual number of bits set. It's not possible to do better than an
     * estimate without locking. Note that the number, if not exactly accurate, is *always*
     * underestimating, never overestimating.
     */
    long bitCount() {
      return bitCount.sum();
    }

    LockFreeBitArray copy() {