001/*
002 * Copyright (c) 2016 Chris K Wensel <chris@wensel.net>. All Rights Reserved.
003 * Copyright (c) 2007-2017 Xplenty, Inc. All Rights Reserved.
004 *
005 * Project and contact information: http://www.cascading.org/
006 *
007 * This file is part of the Cascading project.
008 *
009 * Licensed under the Apache License, Version 2.0 (the "License");
010 * you may not use this file except in compliance with the License.
011 * You may obtain a copy of the License at
012 *
013 *     http://www.apache.org/licenses/LICENSE-2.0
014 *
015 * Unless required by applicable law or agreed to in writing, software
016 * distributed under the License is distributed on an "AS IS" BASIS,
017 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
018 * See the License for the specific language governing permissions and
019 * limitations under the License.
020 */
021
022package cascading.flow.local.stream.element;
023
024import cascading.flow.FlowElement;
025import cascading.flow.FlowProcess;
026import cascading.flow.stream.duct.Duct;
027import cascading.flow.stream.element.MergeStage;
028import cascading.tuple.TupleEntry;
029
030/** A version of Merge that synchronizes the receives for local mode */
031public class SyncMergeStage extends MergeStage
032  {
033  public SyncMergeStage( FlowProcess flowProcess, FlowElement flowElement )
034    {
035    super( flowProcess, flowElement );
036    }
037
038  /**
039   * synchronized, as by default, each source gets its turn, no concurrent threads. Except in local mode
040   *
041   * @param previous
042   * @param ordinal
043   * @param tupleEntry
044   */
045  @Override
046  public synchronized void receive( Duct previous, int ordinal, TupleEntry tupleEntry )
047    {
048    super.receive( previous, ordinal, tupleEntry );
049    }
050  }