001/*
002 * Copyright (c) 2007-2016 Concurrent, Inc. All Rights Reserved.
003 *
004 * Project and contact information: http://www.cascading.org/
005 *
006 * This file is part of the Cascading project.
007 *
008 * Licensed under the Apache License, Version 2.0 (the "License");
009 * you may not use this file except in compliance with the License.
010 * You may obtain a copy of the License at
011 *
012 *     http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing, software
015 * distributed under the License is distributed on an "AS IS" BASIS,
016 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
017 * See the License for the specific language governing permissions and
018 * limitations under the License.
019 */
020
021package cascading.flow.local.stream.element;
022
023import cascading.flow.FlowElement;
024import cascading.flow.FlowProcess;
025import cascading.flow.stream.duct.Duct;
026import cascading.flow.stream.element.MergeStage;
027import cascading.tuple.TupleEntry;
028
029/** A version of Merge that synchronizes the receives for local mode */
030public class SyncMergeStage extends MergeStage
031  {
032  public SyncMergeStage( FlowProcess flowProcess, FlowElement flowElement )
033    {
034    super( flowProcess, flowElement );
035    }
036
037  /**
038   * synchronized, as by default, each source gets its turn, no concurrent threads. Except in local mode
039   *
040   * @param previous
041   * @param tupleEntry
042   */
043  @Override
044  public synchronized void receive( Duct previous, TupleEntry tupleEntry )
045    {
046    super.receive( previous, tupleEntry );
047    }
048  }