shouldWait.set(true);

    final CountDownLatch computationStarted = new CountDownLatch(1);
    final CountDownLatch computationComplete = new CountDownLatch(1);
    new Thread(
            new Runnable() {
              @Override
              public void run() {
                computationStarted.countDown();
                cache.getUnchecked("b");
                computationComplete.countDown();

        super(0);
      }
    }

    public static final class DummyRunnable implements Runnable, Serializable {
      @Override
      public void run() {}
    }

    public static final class DummyThreadFactory implements ThreadFactory, Serializable {
      @Override
      public Thread newThread(Runnable r) {
        return new Thread(r);
      }
    }

    this.exec = Executors.newCachedThreadPool();
    this.future = checkNotNull(future);
    this.latch = new CountDownLatch(1);
  }

  public void setUp() {
    future.addListener(
        new Runnable() {
          @Override
          public void run() {
            latch.countDown();
          }
        },
        exec);

    assertEquals(1, latch.getCount());
    assertFalse(future.isDone());

  private final ListenableFuture<V> delegate;

  ForwardingFluentFuture(ListenableFuture<V> delegate) {
    this.delegate = checkNotNull(delegate);
  }

  @Override
  public void addListener(Runnable listener, Executor executor) {
    delegate.addListener(listener, executor);
  }

  @Override
  public boolean cancel(boolean mayInterruptIfRunning) {
    return delegate.cancel(mayInterruptIfRunning);
  }

  private TimeoutFuture(ListenableFuture<V> delegate) {
    this.delegateRef = Preconditions.checkNotNull(delegate);
  }

  /** A runnable that is called when the delegate or the timer completes. */
  private static final class Fire<V extends @Nullable Object> implements Runnable {
    @CheckForNull @LazyInit TimeoutFuture<V> timeoutFutureRef;

    Fire(TimeoutFuture<V> timeoutFuture) {
      this.timeoutFutureRef = timeoutFuture;

  @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);
      }
    }

import org.codelibs.core.lang.StringUtil;
import org.codelibs.core.log.Logger;

/**
 * Timerを扱うクラスです。
 *
 * @author higa
 *
 */
public class TimeoutManager implements Runnable {

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

    /**
     * シングルトンのためのインスタンスです。
     */
    protected static final TimeoutManager instance = new TimeoutManager();

        this.fileSuffix = fileSuffix;

        initializeCleanupMonitoring();
    }

    private void initializeCleanupMonitoring() {
        callerInfo = new NullPointerException().getStackTrace()[2];

        Runnable warning = this::maybeWarnAboutCleanUp;

        cleanupWarning = new Thread(warning);

        Runtime.getRuntime().addShutdownHook(cleanupWarning);
    }

    private void maybeWarnAboutCleanUp() {

    validations:
      required: true
  - type: textarea
    id: what-did-you-do
    attributes:
      label: "What did you do?"
      description: "If possible, provide a recipe for reproducing the error. A complete runnable program is good. A link on [go.dev/play](https://go.dev/play) is best."
    validations:
      required: true
  - type: textarea
    id: actual-behavior
    attributes:
      label: "What did you see happen?"

            }
          });

  @Override
  protected void setUp() throws Exception {
    super.setUp();

    exec = Executors.newCachedThreadPool();

    task.addListener(
        new Runnable() {
          @Override
          public void run() {
            listenerLatch.countDown();
          }
        },
        directExecutor());
  }

  @Override