Source code

001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *   http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing,
013 * software distributed under the License is distributed on an
014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
015 * KIND, either express or implied.  See the License for the
016 * specific language governing permissions and limitations
017 * under the License.
018 */
019package org.apache.reef.wake.remote.impl;
020
021import java.net.SocketAddress;
022import java.util.concurrent.ConcurrentHashMap;
023import java.util.concurrent.ConcurrentMap;
024import java.util.concurrent.atomic.AtomicLong;
025
026
027/**
028 * Generates the sequence number for remote messages per destination.
029 */
030public class RemoteSeqNumGenerator {
031
032  private final ConcurrentMap<SocketAddress, AtomicLong> seqMap;
033
034  public RemoteSeqNumGenerator() {
035    seqMap = new ConcurrentHashMap<>();
036  }
037
038  public long getNextSeq(final SocketAddress addr) {
039    AtomicLong seq = seqMap.get(addr);
040    if (seq == null) {
041      seq = new AtomicLong(0);
042      if (seqMap.putIfAbsent(addr, seq) != null) {
043        seq = seqMap.get(addr);
044      }
045    }
046    return seq.getAndIncrement();
047  }
048
049}