001/* 002 * Copyright (c) 2007-2017 Xplenty, 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.management; 022 023import java.util.ArrayList; 024import java.util.Collection; 025import java.util.List; 026import java.util.concurrent.Callable; 027import java.util.concurrent.ExecutorService; 028import java.util.concurrent.Executors; 029import java.util.concurrent.Future; 030import java.util.concurrent.TimeUnit; 031 032/** 033 * Class UnitOfWorkExecutorStrategy uses a simple {@link Executors#newFixedThreadPool(int)} {@link ExecutorService} 034 * to spawn threads. 035 * <p/> 036 * This is the default spawn strategy. 037 */ 038public class UnitOfWorkExecutorStrategy implements UnitOfWorkSpawnStrategy 039 { 040 private ExecutorService executor; 041 042 public List<Future<Throwable>> start( UnitOfWork unitOfWork, int maxConcurrentThreads, Collection<Callable<Throwable>> values ) throws InterruptedException 043 { 044 executor = Executors.newFixedThreadPool( maxConcurrentThreads ); 045 046 List<Future<Throwable>> futures = new ArrayList<>(); 047 048 for( Callable<Throwable> value : values ) 049 futures.add( executor.submit( value ) ); 050 051 executor.shutdown(); // don't accept any more work 052 053 return futures; 054 } 055 056 @Override 057 public boolean isCompleted( UnitOfWork unitOfWork ) 058 { 059 return executor == null || executor.isTerminated(); 060 } 061 062 @Override 063 public void complete( UnitOfWork unitOfWork, int duration, TimeUnit unit ) throws InterruptedException 064 { 065 if( executor == null ) 066 return; 067 068 executor.awaitTermination( duration, unit ); 069 } 070 }