001/**
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements.  See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache License, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License.  You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the License for the specific language governing permissions and
015 * limitations under the License.
016 */
017package org.apache.activemq.util;
018
019import java.util.concurrent.atomic.AtomicLongFieldUpdater;
020
021/**
022 * Updated LongSequenceGenerator that uses an AtomicLongFieldUpdater for performance instead of
023 * synchronized methods
024 */
025public class LongSequenceGenerator {
026
027    private static final AtomicLongFieldUpdater<LongSequenceGenerator> SEQUENCE_UPDATER =
028            AtomicLongFieldUpdater.newUpdater(LongSequenceGenerator.class, "lastSequenceId");
029
030    private volatile long lastSequenceId;
031
032    public long getNextSequenceId() {
033        return SEQUENCE_UPDATER.incrementAndGet(this);
034    }
035
036    public long getLastSequenceId() {
037        return lastSequenceId;
038    }
039
040    public void setLastSequenceId(long l) {
041        SEQUENCE_UPDATER.set(this, l);
042    }
043}