} finally {
            monitor.leave();
          }
        });
    awaitUninterruptibly(enteredLatch);
  }

  @CanIgnoreReturnValue
  static Thread startThread(Runnable runnable) {
    Thread thread = new Thread(runnable);
    thread.setDaemon(true);
    thread.start();
    return thread;
  }

  /**
   * Generates a test case verifying that calling any enterXxx, tryEnterXxx, or waitForXxx method

        };
    addCallback(f, callback, directExecutor());
  }

  private static final class CountingSameThreadExecutor implements Executor {
    int runCount = 0;

    @Override
    public void execute(Runnable command) {
      command.run();
      runCount++;
    }
  }

  private static final class MockCallback implements FutureCallback<String> {
    @Nullable private String value = null;

   * this method to use a custom {@link Executor}, which may configure its worker thread with a
   * specific name, thread group or priority. The returned executor's {@link
   * Executor#execute(Runnable) execute()} method is called when this service is started and
   * stopped, and should return promptly.
   */
  protected Executor executor() {
    return command -> newThread(threadNameSupplier.get(), command).start();

  @SuppressWarnings("ThreadPriorityCheck") // TODO: b/175898629 - Consider onSpinWait.
  static void awaitWaiting(Thread t) {
    while (true) {
      Thread.State state = t.getState();
      switch (state) {
        case RUNNABLE:
        case BLOCKED:
          Thread.yield();
          break;
        case WAITING:
          return;
        default:
          throw new AssertionError("unexpected state: " + state);
      }

 *     ...
 *     this.serverSocket = new ServerSocket(...);
 *     this.cleanable = cleaner.register(this, closeServerSocketRunnable(serverSocket));
 *     ...
 *   }
 *
 *   private static Runnable closeServerSocketRunnable(ServerSocket serverSocket) {
 *     return () -> {
 *       if (!serverSocket.isClosed()) {
 *         ...log a message about how nobody called close()...
 *         try {

 *     ...
 *     this.serverSocket = new ServerSocket(...);
 *     this.cleanable = cleaner.register(this, closeServerSocketRunnable(serverSocket));
 *     ...
 *   }
 *
 *   private static Runnable closeServerSocketRunnable(ServerSocket serverSocket) {
 *     return () -> {
 *       if (!serverSocket.isClosed()) {
 *         ...log a message about how nobody called close()...
 *         try {

      this.adapterExecutor = checkNotNull(adapterExecutor);
    }

    @Override
    protected Future<V> delegate() {
      return delegate;
    }

    @Override
    public void addListener(Runnable listener, Executor exec) {
      executionList.add(listener, exec);

      // When a listener is first added, we run a task that will wait for the delegate to finish,
      // and when it is done will run the listeners.

 * collected, and this class can detect when the main class loader has been garbage collected and
 * stop itself.
 */
public class Finalizer implements Runnable {

  private static final Logger logger = Logger.getLogger(Finalizer.class.getName());

  /**
   * Starts the Finalizer thread. FinalizableReferenceQueue calls this method reflectively.
   *

    Service service =
        new TestService() {
          @Override
          protected Executor executor() {
            return new Executor() {
              @Override
              public void execute(Runnable command) {}
            };
          }

          @Override
          protected String serviceName() {
            return "Foo";
          }
        };
    TimeoutException e =

  }

  @SuppressWarnings("Java8ApiChecker")
  static class MyServerExampleWithCleaner implements AutoCloseable {
    private static final Cleaner cleaner = Cleaner.create();

    private static Runnable closeServerSocketRunnable(
        ServerSocket serverSocket, AtomicBoolean cleanerRan) {
      return () -> {
        try {
          serverSocket.close();
          cleanerRan.set(true);