2 * Copyright (c) 2014 Brocade Communications Systems, Inc. and others. All rights reserved.
4 * This program and the accompanying materials are made available under the
5 * terms of the Eclipse Public License v1.0 which accompanies this distribution,
6 * and is available at http://www.eclipse.org/legal/epl-v10.html
9 package org.opendaylight.yangtools.util.concurrent;
11 import com.google.common.annotations.Beta;
12 import java.util.Collection;
13 import java.util.concurrent.LinkedBlockingQueue;
14 import java.util.concurrent.TimeUnit;
15 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
16 import javax.annotation.Nonnull;
19 * A {@link LinkedBlockingQueue} that tracks the largest queue size for debugging.
21 * @author Thomas Pantelis
23 * @param <E> the element t.ype
25 public class TrackingLinkedBlockingQueue<E> extends LinkedBlockingQueue<E> {
26 private static final long serialVersionUID = 1L;
28 @SuppressWarnings("rawtypes")
29 private static final AtomicIntegerFieldUpdater<TrackingLinkedBlockingQueue> LARGEST_QUEUE_SIZE_UPDATER
30 = AtomicIntegerFieldUpdater.newUpdater(TrackingLinkedBlockingQueue.class, "largestQueueSize");
33 * Holds largestQueueSize, this long field should be only accessed
34 * using {@link #LARGEST_QUEUE_SIZE_UPDATER}.
36 private volatile int largestQueueSize = 0;
39 * @see LinkedBlockingQueue#LinkedBlockingQueue
41 public TrackingLinkedBlockingQueue() {
46 * @see LinkedBlockingQueue#LinkedBlockingQueue(Collection)
48 public TrackingLinkedBlockingQueue( final Collection<? extends E> c ) {
53 * @see LinkedBlockingQueue#LinkedBlockingQueue(int)
55 public TrackingLinkedBlockingQueue( final int capacity ) {
60 * Returns the largest queue size.
62 * <p>FIXME: the this return will be changed to int in a future release.
65 public long getLargestQueueSize() {
66 return largestQueueSize;
70 public boolean offer(final E e, final long timeout, final TimeUnit unit) throws InterruptedException {
71 if (super.offer( e, timeout, unit ) ) {
72 updateLargestQueueSize();
80 public boolean offer(@Nonnull final E e) {
81 if (super.offer( e ) ) {
82 updateLargestQueueSize();
90 public void put( final E e ) throws InterruptedException {
92 updateLargestQueueSize();
96 public boolean add(final E e) {
97 boolean result = super.add( e );
98 updateLargestQueueSize();
103 public boolean addAll(final Collection<? extends E> c) {
105 return super.addAll( c );
107 updateLargestQueueSize();
111 private void updateLargestQueueSize() {
112 final int size = size();
116 largest = largestQueueSize;
117 } while (size > largest && !LARGEST_QUEUE_SIZE_UPDATER.weakCompareAndSet(this, largest, size));