/**
   * Registers a listener to be {@linkplain Executor#execute(Runnable) run} on the given executor.
   * The listener will run when the {@code Future}'s computation is {@linkplain Future#isDone()
   * complete} or, if the computation is already complete, immediately.
   *
   * <p>There is no guaranteed ordering of execution of listeners, but any listener added through

      /** The future that represents the next execution of this task. */
      @GuardedBy("lock")
      private @Nullable SupplantableFuture cancellationDelegate;

      ReschedulableCallable(
          AbstractService service, ScheduledExecutorService executor, Runnable runnable) {
        this.wrappedRunnable = runnable;
        this.executor = executor;
        this.service = service;
      }

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

      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) {

      Executor executor) {
    return AbstractCatchingFuture.create(input, exceptionType, fallback, executor);
  }

  public static <V extends @Nullable Object> ListenableFuture<V> catchingAsync(
      ListenableFuture<? extends V> input,
      Class<Throwable> exceptionType,
      AsyncFunction<? super Throwable, ? extends V> fallback,
      Executor executor) {

    barrier.await(1, SECONDS);
    assertFalse(executor.isShutdown());
    assertFalse(executor.isTerminated());

    executor.shutdown();
    assertTrue(executor.isShutdown());
    assertThrows(RejectedExecutionException.class, () -> executor.submit(() -> {}));
    assertFalse(executor.isTerminated());

    // WAIT #2
    barrier.await(1, SECONDS);
    assertFalse(executor.awaitTermination(20, MILLISECONDS));

            }
          };
      executor.execute(errorTask);
      service.execute(barrierTask); // submit directly to the service
      // the barrier task runs after the error task so we know that the error has been observed by
      // SequentialExecutor by the time the barrier is satisfied
      barrier.await(1, SECONDS);
      executor.execute(barrierTask);
      // timeout means the second task wasn't even tried

import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;
import java.util.concurrent.ExecutorService;
import org.jspecify.annotations.NullUnmarked;

/**
 * Tests for {@link ClosingFuture} that exercise {@link
 * ClosingFuture#finishToValueAndCloser(ValueAndCloserConsumer, Executor)}.
 */
@NullUnmarked
@GwtIncompatible
@J2ktIncompatible

    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();
          }

    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();
          }