001    /*
002     * Copyright (c) 2007-2015 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    
021    package cascading.flow.local.stream;
022    
023    import cascading.flow.FlowElement;
024    import cascading.flow.FlowProcess;
025    import cascading.flow.stream.Duct;
026    import cascading.flow.stream.MergeStage;
027    import cascading.tuple.TupleEntry;
028    
029    /** A version of Merge that synchronizes the receives for local mode */
030    public 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      }