public final class SimpleTimeLimiter implements TimeLimiter {

  private final ExecutorService executor;

  private SimpleTimeLimiter(ExecutorService executor) {
    this.executor = checkNotNull(executor);
  }

  /**
   * Creates a TimeLimiter instance using the given executor service to execute method calls.
   *
   * <p><b>Warning:</b> using a bounded executor may be counterproductive! If the thread pool fills

      final Runnable runnable;
      final Executor executor;

      RunnableExecutorPair(Runnable runnable, Executor executor) {
        this.runnable = runnable;
        this.executor = executor;
      }

      void execute() {
        try {
          executor.execute(runnable);
        } catch (RuntimeException e) {
          log.log(
              Level.SEVERE,

  /** Use {@link MoreExecutors#newSequentialExecutor} */
  SequentialExecutor(Executor executor) {
    this.executor = Preconditions.checkNotNull(executor);
  }

  /**
   * Adds a task to the queue and makes sure a worker thread is running.
   *
   * <p>If this method throws, e.g. a {@code RejectedExecutionException} from the delegate executor,
   * execution of tasks will stop until a call to this method is made.
   */

   *     returned future.
   * @param executor Executor to run the function in.
   * @return A future that holds result of the transformation.
   */
  public final <T extends @Nullable Object> FluentFuture<T> transform(
      Function<? super V, T> function, Executor executor) {
    return (FluentFuture<T>) Futures.transform(this, function, executor);
  }

  /**

  public void addListener(Runnable listener, Executor executor) {
    checkNotNull(listener, "Runnable was null.");
    checkNotNull(executor, "Executor was null.");
    try {
      executor.execute(listener);
    } catch (Exception e) { // sneaky checked exception
      // ListenableFuture's contract is that it will not throw unchecked exceptions, so log the bad
      // runnable and/or executor and swallow it.
      log.get()
          .log(

      Function<? super Throwable, ? extends V> fallback,
      Executor executor) {
    return (FluentFuture<V>) Futures.catching(this, exceptionType, fallback, executor);
  }

  public final FluentFuture<V> catchingAsync(
      Class<Throwable> exceptionType,
      AsyncFunction<? super Throwable, ? extends V> fallback,
      Executor executor) {

                  + runnable
                  + " with executor "
                  + executor,
              e);
    }
  }

  private static final class RunnableExecutorPair {
    final Runnable runnable;
    final Executor executor;
    @CheckForNull RunnableExecutorPair next;

    RunnableExecutorPair(
        Runnable runnable, Executor executor, @CheckForNull RunnableExecutorPair next) {

    final Executor delegate =
        new Executor() {
          @Override
          public void execute(Runnable task) {
            if (future.set(null)) {
              awaitUninterruptibly(latch);
            }
            throw new RejectedExecutionException();
          }
        };
    final SequentialExecutor executor = new SequentialExecutor(delegate);

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

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

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

    final AtomicReference<ScheduledExecutorService> executor = Atomics.newReference();
    AbstractScheduledService service =
        new AbstractScheduledService() {
          @Override
          protected void runOneIteration() throws Exception {}

          @Override
          protected ScheduledExecutorService executor() {
            executor.set(super.executor());
            return executor.get();
          }