ListenerCallQueue<Object> queue = new ListenerCallQueue<>();
    queue.addListener(listener, directExecutor());

    Multiset<Object> counters = ConcurrentHashMultiset.create();
    queue.enqueue(incrementingEvent(counters, listener, 1));
    queue.enqueue(THROWING_EVENT);
    queue.enqueue(incrementingEvent(counters, listener, 2));
    queue.enqueue(THROWING_EVENT);
    queue.enqueue(incrementingEvent(counters, listener, 3));

  private final Executor executor;

  @GuardedBy("queue")
  private final Deque<Runnable> queue = new ArrayDeque<>();

  /** see {@link WorkerRunningState} */
  @LazyInit
  @GuardedBy("queue")
  private WorkerRunningState workerRunningState = IDLE;

  /**
   * This counter prevents an ABA issue where a thread may successfully schedule the worker, the
   * worker runs and exhausts the queue, another thread enqueues a task and fails to schedule the

    return QueueTestSuiteBuilder.using(
            new TestStringQueueGenerator() {
              @Override
              public Queue<String> create(String[] elements) {
                Queue<String> queue = new LinkedList<>(MinimalCollection.of(elements));
                return Collections.checkedQueue(queue, String.class);
              }
            })
        .named("checkedQueue/LinkedList")
        .withFeatures(

    queue = (BlockingQueue<String>) constructor.newInstance(capacity);

    strings = new String[capacity];
    for (int i = 0; i < capacity; i++) {
      strings[i] = String.valueOf(Math.random());
    }
  }

  @Benchmark
  void addsAndRemoves(int reps) {
    int capacity = this.capacity;
    BlockingQueue<String> queue = this.queue;
    String[] strings = this.strings;

  /**
   * Constructs a new finalizable weak reference.
   *
   * @param referent to weakly reference
   * @param queue that should finalize the referent
   */
  protected FinalizableWeakReference(@CheckForNull T referent, FinalizableReferenceQueue queue) {
    super(referent, queue.queue);
    queue.cleanUp();
  }

import java.util.Collection;
import java.util.Iterator;
import java.util.Queue;
import junit.framework.TestCase;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * Tests for {@link Synchronized#queue} and {@link Queues#synchronizedQueue}.
 *
 * @author Kurt Alfred Kluever
 */
public class SynchronizedQueueTest extends TestCase {

  protected Queue<String> create() {
    TestQueue<String> inner = new TestQueue<>();

import java.util.NoSuchElementException;
import java.util.Queue;
import javax.annotation.CheckForNull;
import org.checkerframework.checker.nullness.qual.Nullable;

/**
 * A queue which forwards all its method calls to another queue. Subclasses should override one or
 * more methods to modify the behavior of the backing queue as desired per the <a

import java.util.Collection;
import java.util.Queue;

/**
 * A non-blocking queue which automatically evicts elements from the head of the queue when
 * attempting to add new elements onto the queue and it is full. This queue orders elements FIFO
 * (first-in-first-out). This data structure is logically equivalent to a circular buffer (i.e.,
 * cyclic buffer or ring buffer).
 *

    assertEquals(6, queue.size());
    assertEquals(8, queue.capacity());
    checkUnbounded(queue);
    checkNatural(queue);
  }

  public void testCreation_maximumSize_withContents() {
    MinMaxPriorityQueue<Integer> queue =
        rawtypeToWildcard(MinMaxPriorityQueue.maximumSize(42)).create(NUMBERS);
    assertEquals(6, queue.size());
    assertEquals(11, queue.capacity());
    assertEquals(42, queue.maximumSize);

  private final Queue<T> queue;

  ConsumingQueueIterator(Queue<T> queue) {
    this.queue = checkNotNull(queue);
  }

  @Override
  @CheckForNull
  protected T computeNext() {
    // TODO(b/192579700): Use a ternary once it no longer confuses our nullness checker.
    if (queue.isEmpty()) {
      return endOfData();
    }
    return queue.remove();
  }