}
  }

  public void testEmpty() throws Exception {
    for (BlockingQueue<Object> q : blockingQueues()) {
      checkEmpty(q);
    }
  }

  private void checkEmpty(BlockingQueue<Object> q) {
    assertDrained(q);
  }

  public void testNegativeMaxElements() throws Exception {
    for (BlockingQueue<Object> q : blockingQueues()) {
      checkNegativeMaxElements(q);
    }
  }

  @J2ktIncompatible
  @GwtIncompatible // BlockingQueue
  public static <E> int drain(
      BlockingQueue<E> q, Collection<? super E> buffer, int numElements, Duration timeout)
      throws InterruptedException {
    return drain(q, buffer, numElements, toNanosSaturated(timeout), NANOSECONDS);
  }

  /**
   * Drains the queue as {@link BlockingQueue#drainTo(Collection, int)}, but if the requested {@code

      if (interrupted) {
        Thread.currentThread().interrupt();
      }
    }
  }

  /** Invokes {@code queue.}{@link BlockingQueue#take() take()} uninterruptibly. */
  @J2ktIncompatible
  @GwtIncompatible // concurrency
  public static <E> E takeUninterruptibly(BlockingQueue<E> queue) {
    boolean interrupted = false;
    try {
      while (true) {
        try {
          return queue.take();

   * @since 33.4.0 (but since 28.0 in the JRE flavor)
   */
  @CanIgnoreReturnValue
  @J2ktIncompatible
  @GwtIncompatible // BlockingQueue
  @IgnoreJRERequirement // Users will use this only if they're already using Duration
  public static <E> int drain(
      BlockingQueue<E> q, Collection<? super E> buffer, int numElements, Duration timeout)
      throws InterruptedException {

   * like [poll]. It is only usable within task faker tasks.
   */
  private inner class TaskFakerBlockingQueue<T>(
    val delegate: BlockingQueue<T>,
  ) : AbstractQueue<T>(),
    BlockingQueue<T> {
    override val size: Int = delegate.size

    private var editCount = 0

    override fun poll(): T = delegate.poll()

    override fun poll(
      timeout: Long,

    fun nanoTime(): Long

    fun coordinatorNotify(taskRunner: TaskRunner)

    fun coordinatorWait(
      taskRunner: TaskRunner,
      nanos: Long,
    )

    fun <T> decorate(queue: BlockingQueue<T>): BlockingQueue<T>

    fun execute(
      taskRunner: TaskRunner,
      runnable: Runnable,
    )
  }

  class RealBackend(
    threadFactory: ThreadFactory,
  ) : Backend {
    val executor =

import java.util.SortedMap;
import java.util.SortedSet;
import java.util.TreeMap;
import java.util.TreeSet;
import java.util.UUID;
import java.util.concurrent.BlockingDeque;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.ConcurrentMap;
import java.util.concurrent.ConcurrentNavigableMap;
import java.util.concurrent.DelayQueue;
import java.util.concurrent.Executor;

import java.util.PriorityQueue;
import java.util.Queue;
import java.util.SortedSet;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * An unbounded {@linkplain BlockingQueue blocking queue} that uses the same ordering rules as class

import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.TimeUnit;
import org.jspecify.annotations.NullUnmarked;
import org.jspecify.annotations.Nullable;

/**
 * A bounded {@linkplain BlockingQueue blocking queue} backed by an array. This queue orders

import java.lang.Thread.State;
import java.util.ArrayList;
import java.util.Collections;
import java.util.List;
import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.Callable;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.CyclicBarrier;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.Executor;