*
 * <p>An evicting queue must be configured with a maximum size. Each time an element is added to a
 * full queue, the queue automatically removes its head element. This is different from conventional
 * bounded queues, which either block or reject new elements when full.
 *
 * <p>This class is not thread-safe, and does not accept null elements.
 *
 * @author Kurt Alfred Kluever
 * @since 15.0
 */
@GwtCompatible

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

/**
 * Tests for {@link Synchronized#deque} and {@link Queues#synchronizedDeque}.
 *
 * @author Kurt Alfred Kluever
 */
public class SynchronizedDequeTest extends TestCase {

  protected Deque<String> create() {
    TestDeque<String> inner = new TestDeque<>();

   */
  static final int DRAIN_THRESHOLD = 0x3F;

  /**
   * Maximum number of entries to be drained in a single cleanup run. This applies independently to
   * the cleanup queue and both reference queues.
   */
  // TODO(fry): empirically optimize this
  static final int DRAIN_MAX = 16;

  // Fields

  static final Logger logger = Logger.getLogger(LocalCache.class.getName());

  /**

   * segment's count matches its #elements (after cleanup), each segment is unlocked, each entry
   * contains a non-null key and value, and the eviction and expiration queues are consistent (see
   * {@link #checkEviction}, {@link #checkExpiration}).
   */
  static void checkValidState(Cache<?, ?> cache) {
    if (hasLocalCache(cache)) {
      checkValidState(toLocalCache(cache));
    }

 *
 * <p><b>Note:</b> by default, the returned cache uses equality comparisons (the {@link
 * Object#equals equals} method) to determine equality for keys or values. However, if {@link
 * #weakKeys} was specified, the cache uses identity ({@code ==}) comparisons instead for keys.
 * Likewise, if {@link #weakValues} or {@link #softValues} was specified, the cache uses identity
 * comparisons for values.
 *

    try {
      return count;
    } finally {
      monitor.leave();
    }
  }

  // this doc comment is a modified copy of the inherited doc comment,
  // without the reference to unlimited queues.
  /**
   * Returns the number of additional elements that this queue can ideally (in the absence of memory
   * or resource constraints) accept without blocking. This is always equal to the initial capacity

   * is not thread-safe.
   *
   * @param iterable the iterable to wrap
   * @return a view of the supplied iterable that wraps each generated iterator through {@link
   *     Iterators#consumingIterator(Iterator)}; for queues, an iterable that generates iterators
   *     that return and consume the queue's elements in queue order
   * @see Iterators#consumingIterator(Iterator)
   * @since 2.0
   */

soldiers did.  After these came the royal children; there were
ten of them, and the little dears came jumping merrily along hand
in hand, in couples:  they were all ornamented with hearts.  Next
came the guests, mostly Kings and Queens, and among them Alice
recognised the White Rabbit:  it was talking in a hurried nervous
manner, smiling at everything that was said, and went by without

   * {@code Ordering.natural()} if the left map uses the natural ordering of its elements. This
   * difference is an immutable snapshot of the state of the maps at the time this method is called.
   * It will never change, even if the maps change at a later time.
   *
   * <p>Since this method uses {@code TreeMap} instances internally, the keys of the right map must

 * the License.
 */

package com.google.common.eventbus;

import static com.google.common.base.Preconditions.checkNotNull;
import static java.util.Objects.requireNonNull;

import com.google.common.collect.Queues;
import java.util.Iterator;
import java.util.Queue;
import java.util.concurrent.ConcurrentLinkedQueue;

/**
 * Handler for dispatching events to subscribers, providing different event ordering guarantees that