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;
18 * A {@link LinkedBlockingQueue} that tracks the largest queue size for debugging.
20 * @author Thomas Pantelis
22 * @param <E> the element t.ype
24 public class TrackingLinkedBlockingQueue<E> extends LinkedBlockingQueue<E> {
25 private static final long serialVersionUID = 1L;
27 @SuppressWarnings("rawtypes")
28 private static final AtomicIntegerFieldUpdater<TrackingLinkedBlockingQueue> LARGEST_QUEUE_SIZE_UPDATER
29 = AtomicIntegerFieldUpdater.newUpdater(TrackingLinkedBlockingQueue.class, "largestQueueSize");
32 * Holds largestQueueSize, this long field should be only accessed
33 * using {@link #LARGEST_QUEUE_SIZE_UPDATER}.
35 private volatile int largestQueueSize = 0;
38 * @see LinkedBlockingQueue#LinkedBlockingQueue
40 public TrackingLinkedBlockingQueue() {
45 * @see LinkedBlockingQueue#LinkedBlockingQueue(Collection)
47 public TrackingLinkedBlockingQueue( final Collection<? extends E> c ) {
52 * @see LinkedBlockingQueue#LinkedBlockingQueue(int)
54 public TrackingLinkedBlockingQueue( final int capacity ) {
59 * Returns the largest queue size.
61 * <p>FIXME: the this return will be changed to int in a future release.
64 public long getLargestQueueSize() {
65 return largestQueueSize;
69 public boolean offer(final E e, final long timeout, final TimeUnit unit) throws InterruptedException {
70 if (super.offer( e, timeout, unit ) ) {
71 updateLargestQueueSize();
79 public boolean offer(final E e) {
80 if (super.offer( e ) ) {
81 updateLargestQueueSize();
89 public void put( final E e ) throws InterruptedException {
91 updateLargestQueueSize();
95 public boolean add(final E e) {
96 boolean result = super.add( e );
97 updateLargestQueueSize();
102 public boolean addAll(final Collection<? extends E> c) {
104 return super.addAll( c );
106 updateLargestQueueSize();
110 private void updateLargestQueueSize() {
111 final int size = size();
115 largest = largestQueueSize;
116 } while (size > largest && !LARGEST_QUEUE_SIZE_UPDATER.weakCompareAndSet(this, largest, size));