/*
 *
 * Copyright (c) 2006 The Apache Software Foundation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *    http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 *
 */
package org.apache.qpid.util;

import java.util.concurrent.ConcurrentLinkedQueue;
import java.util.concurrent.atomic.AtomicInteger;

public class ConcurrentLinkedQueueAtomicSize<E> extends ConcurrentLinkedQueue<E>
{
    AtomicInteger _size = new AtomicInteger(0);

    public int size()
    {
        return _size.get();
    }

    public boolean offer(E o)
    {

        if (super.offer(o))
        {
            _size.incrementAndGet();
            return true;
        }

        return false;
    }

    public E poll()
    {
        E e = super.poll();

        if (e != null)
        {
            _size.decrementAndGet();
        }

        return e;
    }
}
