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 @SuppressWarnings("rawtypes")
26 private static final AtomicIntegerFieldUpdater<TrackingLinkedBlockingQueue> LARGEST_QUEUE_SIZE_UPDATER = AtomicIntegerFieldUpdater.newUpdater(TrackingLinkedBlockingQueue.class, "largestQueueSize");
27 private static final long serialVersionUID = 1L;
30 * Holds largestQueueSize, this long field should be only accessed
31 * using {@link #LARGEST_QUEUE_SIZE_UPDATER}
33 private volatile int largestQueueSize = 0;
36 * @see LinkedBlockingQueue#LinkedBlockingQueue
38 public TrackingLinkedBlockingQueue() {
43 * @see LinkedBlockingQueue#LinkedBlockingQueue(Collection)
45 public TrackingLinkedBlockingQueue( final Collection<? extends E> c ) {
50 * @see LinkedBlockingQueue#LinkedBlockingQueue(int)
52 public TrackingLinkedBlockingQueue( final int capacity ) {
57 * Returns the largest queue size.
59 * FIXME: the this return will be changed to int in a future release.
62 public long getLargestQueueSize() {
63 return largestQueueSize;
67 public boolean offer( final E e, final long timeout, final TimeUnit unit ) throws InterruptedException {
68 if (super.offer( e, timeout, unit ) ) {
69 updateLargestQueueSize();
77 public boolean offer( final E e ) {
78 if (super.offer( e ) ) {
79 updateLargestQueueSize();
87 public void put( final E e ) throws InterruptedException {
89 updateLargestQueueSize();
93 public boolean add( final E e ) {
94 boolean result = super.add( e );
95 updateLargestQueueSize();
100 public boolean addAll( final Collection<? extends E> c ) {
102 return super.addAll( c );
104 updateLargestQueueSize();
108 private void updateLargestQueueSize() {
109 final int size = size();
113 largest = largestQueueSize;
114 } while (size > largest && !LARGEST_QUEUE_SIZE_UPDATER.weakCompareAndSet(this, largest, size));