001/* 002 * Copyright (c) 2016-2017 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.management; 023 024import java.util.ArrayList; 025import java.util.Collection; 026import java.util.List; 027import java.util.concurrent.Callable; 028import java.util.concurrent.ExecutorService; 029import java.util.concurrent.Executors; 030import java.util.concurrent.Future; 031import java.util.concurrent.TimeUnit; 032 033/** 034 * Class UnitOfWorkExecutorStrategy uses a simple {@link Executors#newFixedThreadPool(int)} {@link ExecutorService} 035 * to spawn threads. 036 * <p> 037 * This is the default spawn strategy. 038 */ 039public class UnitOfWorkExecutorStrategy implements UnitOfWorkSpawnStrategy 040 { 041 private ExecutorService executor; 042 043 public List<Future<Throwable>> start( UnitOfWork unitOfWork, int maxConcurrentThreads, Collection<Callable<Throwable>> values ) throws InterruptedException 044 { 045 executor = Executors.newFixedThreadPool( maxConcurrentThreads ); 046 047 List<Future<Throwable>> futures = new ArrayList<>(); 048 049 for( Callable<Throwable> value : values ) 050 futures.add( executor.submit( value ) ); 051 052 executor.shutdown(); // don't accept any more work 053 054 return futures; 055 } 056 057 @Override 058 public boolean isCompleted( UnitOfWork unitOfWork ) 059 { 060 return executor == null || executor.isTerminated(); 061 } 062 063 @Override 064 public void complete( UnitOfWork unitOfWork, int duration, TimeUnit unit ) throws InterruptedException 065 { 066 if( executor == null ) 067 return; 068 069 executor.awaitTermination( duration, unit ); 070 } 071 }