001 /** 002 * Licensed to the Apache Software Foundation (ASF) under one or more 003 * contributor license agreements. See the NOTICE file distributed with 004 * this work for additional information regarding copyright ownership. 005 * The ASF licenses this file to You under the Apache License, Version 2.0 006 * (the "License"); you may not use this file except in compliance with 007 * the License. You may obtain a copy of the License at 008 * 009 * http://www.apache.org/licenses/LICENSE-2.0 010 * 011 * Unless required by applicable law or agreed to in writing, software 012 * distributed under the License is distributed on an "AS IS" BASIS, 013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 014 * See the License for the specific language governing permissions and 015 * limitations under the License. 016 */ 017 package org.apache.activemq.thread; 018 019 import java.util.concurrent.Executor; 020 import java.util.concurrent.ExecutorService; 021 import java.util.concurrent.SynchronousQueue; 022 import java.util.concurrent.ThreadFactory; 023 import java.util.concurrent.ThreadPoolExecutor; 024 import java.util.concurrent.TimeUnit; 025 026 /** 027 * Manages the thread pool for long running tasks. Long running tasks are not 028 * always active but when they are active, they may need a few iterations of 029 * processing for them to become idle. The manager ensures that each task is 030 * processes but that no one task overtakes the system. This is kina like 031 * cooperative multitasking. 032 * 033 * @version $Revision: 1.5 $ 034 */ 035 public class TaskRunnerFactory implements Executor { 036 037 private ExecutorService executor; 038 private int maxIterationsPerRun; 039 private String name; 040 private int priority; 041 private boolean daemon; 042 043 public TaskRunnerFactory() { 044 this("ActiveMQ Task", Thread.NORM_PRIORITY, true, 1000); 045 } 046 047 private TaskRunnerFactory(String name, int priority, boolean daemon, int maxIterationsPerRun) { 048 this(name,priority,daemon,maxIterationsPerRun,false); 049 } 050 051 052 public TaskRunnerFactory(String name, int priority, boolean daemon, int maxIterationsPerRun, boolean dedicatedTaskRunner) { 053 054 this.name = name; 055 this.priority = priority; 056 this.daemon = daemon; 057 this.maxIterationsPerRun = maxIterationsPerRun; 058 059 // If your OS/JVM combination has a good thread model, you may want to 060 // avoid 061 // using a thread pool to run tasks and use a DedicatedTaskRunner 062 // instead. 063 if (dedicatedTaskRunner || "true".equalsIgnoreCase(System.getProperty("org.apache.activemq.UseDedicatedTaskRunner"))) { 064 executor = null; 065 } else { 066 executor = createDefaultExecutor(); 067 } 068 } 069 070 public void shutdown() { 071 if (executor != null) { 072 executor.shutdownNow(); 073 } 074 } 075 076 public TaskRunner createTaskRunner(Task task, String name) { 077 if (executor != null) { 078 return new PooledTaskRunner(executor, task, maxIterationsPerRun); 079 } else { 080 return new DedicatedTaskRunner(task, name, priority, daemon); 081 } 082 } 083 084 public void execute(Runnable runnable) { 085 execute(runnable, "ActiveMQ Task"); 086 } 087 088 public void execute(Runnable runnable, String name) { 089 if (executor != null) { 090 executor.execute(runnable); 091 } else { 092 new Thread(runnable, name).start(); 093 } 094 } 095 096 protected ExecutorService createDefaultExecutor() { 097 ThreadPoolExecutor rc = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 10, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new ThreadFactory() { 098 public Thread newThread(Runnable runnable) { 099 Thread thread = new Thread(runnable, name); 100 thread.setDaemon(daemon); 101 thread.setPriority(priority); 102 return thread; 103 } 104 }); 105 // rc.allowCoreThreadTimeOut(true); 106 return rc; 107 } 108 109 }