}

  /**
   * Wrapper around {@link Stopwatch} which also contains an "expected completion time." Creating a
   * {@code Completion} starts the underlying stopwatch.
   */
  private static final class Completion {
    final Stopwatch stopwatch;
    final long expectedCompletionWaitMillis;

    Completion(long expectedCompletionWaitMillis) {
      this.expectedCompletionWaitMillis = expectedCompletionWaitMillis;

   * Runnable}, and arrange that {@code get} will return the given result on successful completion.
   *
   * @param runnable the runnable task
   * @param result the result to return on successful completion. If you don't need a particular
   *     result, consider using constructions of the form: {@code ListenableFuture<?> f =

  //
  // * Be responsive to interruption
  // * Don't create Waiter nodes if you aren't going to park, this helps reduce contention on
  //   waitersField.
  // * Future completion is defined by when #valueField becomes non-null/non DelegatingToFuture
  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider

  //
  // * Be responsive to interruption
  // * Don't create Waiter nodes if you aren't going to park, this helps reduce contention on
  //   waitersField.
  // * Future completion is defined by when #valueField becomes non-null/non DelegatingToFuture
  // * Future completion can be observed if the waitersField field contains a TOMBSTONE

  // Timed Get
  // There are a few design constraints to consider

FIELD com.google.common.util.concurrent.ExecutionSequencer.ThreadConfinedTaskQueue.nextExecutor com.google.common.util.concurrent.ExecutionSequencer.TaskNonReentrantExecutor
# Real cycle, but the runningState field is null'ed on completion of the future.
FIELD com.google.common.util.concurrent.AggregateFuture.runningState
FIELD java.util.AbstractMap.keySet com.google.common.collect.AbstractMapBasedMultimap.NavigableKeySet

  internal fun executed(call: RealCall) = runningSyncCalls.add(call)

  /** Used by [AsyncCall.run] to signal completion. */
  internal fun finished(call: AsyncCall) {
    call.callsPerHost.decrementAndGet()
    finished(runningAsyncCalls, call)
  }

  /** Used by [Call.execute] to signal completion. */
  internal fun finished(call: RealCall) {
    finished(runningSyncCalls, call)
  }

   * {@code schedule}, {@code scheduleAtFixedRate}, and {@code scheduleWithFixedDelay}. In the case
   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the
   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link

            // Since the value of oldFuture can only ever be immediateFuture(null) or setFuture of
            // a future that eventually came from immediateFuture(null), this doesn't leak
            // throwables or completion values.
            newFuture.setFuture(oldFuture);
          } else if (outputFuture.isCancelled() && taskExecutor.trySetCancelled()) {

import java.util.concurrent.Future;
import java.util.concurrent.RejectedExecutionException;
import org.jspecify.annotations.NullMarked;
import org.jspecify.annotations.Nullable;

/**
 * A {@link Future} that accepts completion listeners. Each listener has an associated executor, and
 * it is invoked using this executor once the future's computation is {@linkplain Future#isDone()

   * {@code schedule}, {@code scheduleAtFixedRate}, and {@code scheduleWithFixedDelay}. In the case
   * of tasks submitted by {@code invokeAll} or {@code invokeAny}, tasks will run serially on the
   * calling thread. Tasks are run to completion before a {@code Future} is returned to the caller
   * (unless the executor has been shutdown).
   *
   * <p>The returned executor is backed by the executor returned by {@link