001 /* 002 * Copyright (c) 2007-2014 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.management; 022 023 import java.util.Collection; 024 import java.util.List; 025 import java.util.concurrent.Callable; 026 import java.util.concurrent.ExecutorService; 027 import java.util.concurrent.Executors; 028 import java.util.concurrent.Future; 029 import java.util.concurrent.TimeUnit; 030 031 /** 032 * Class UnitOfWorkExecutorStrategy uses a simple {@link Executors#newFixedThreadPool(int)} {@link ExecutorService} 033 * to spawn threads. 034 * <p/> 035 * This is the default spawn strategy. 036 */ 037 public class UnitOfWorkExecutorStrategy implements UnitOfWorkSpawnStrategy 038 { 039 private ExecutorService executor; 040 041 public List<Future<Throwable>> start( UnitOfWork unitOfWork, int maxConcurrentThreads, Collection<Callable<Throwable>> values ) throws InterruptedException 042 { 043 executor = Executors.newFixedThreadPool( maxConcurrentThreads ); 044 045 List<Future<Throwable>> futures = executor.invokeAll( values ); // todo: consider submit() 046 047 executor.shutdown(); // don't accept any more work 048 049 return futures; 050 } 051 052 @Override 053 public boolean isCompleted( UnitOfWork unitOfWork ) 054 { 055 return executor == null || executor.isTerminated(); 056 } 057 058 @Override 059 public void complete( UnitOfWork unitOfWork, int duration, TimeUnit unit ) throws InterruptedException 060 { 061 if( executor == null ) 062 return; 063 064 executor.awaitTermination( duration, unit ); 065 } 066 }