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 */ 017package org.apache.activemq.thread; 018 019import java.util.concurrent.Executor; 020import java.util.concurrent.ExecutorService; 021import java.util.concurrent.SynchronousQueue; 022import java.util.concurrent.ThreadFactory; 023import java.util.concurrent.ThreadPoolExecutor; 024import java.util.concurrent.TimeUnit; 025import java.util.concurrent.atomic.AtomicBoolean; 026import java.util.concurrent.atomic.AtomicLong; 027 028/** 029 * Manages the thread pool for long running tasks. Long running tasks are not 030 * always active but when they are active, they may need a few iterations of 031 * processing for them to become idle. The manager ensures that each task is 032 * processes but that no one task overtakes the system. This is kinda like 033 * cooperative multitasking. 034 * 035 * @org.apache.xbean.XBean 036 */ 037public class TaskRunnerFactory implements Executor { 038 039 private ExecutorService executor; 040 private int maxIterationsPerRun; 041 private String name; 042 private int priority; 043 private boolean daemon; 044 private AtomicLong id = new AtomicLong(0); 045 private boolean dedicatedTaskRunner; 046 private AtomicBoolean initDone = new AtomicBoolean(false); 047 048 public TaskRunnerFactory() { 049 this("ActiveMQ Task", Thread.NORM_PRIORITY, true, 1000); 050 } 051 052 private TaskRunnerFactory(String name, int priority, boolean daemon, int maxIterationsPerRun) { 053 this(name,priority,daemon,maxIterationsPerRun,false); 054 } 055 056 public TaskRunnerFactory(String name, int priority, boolean daemon, int maxIterationsPerRun, boolean dedicatedTaskRunner) { 057 this.name = name; 058 this.priority = priority; 059 this.daemon = daemon; 060 this.maxIterationsPerRun = maxIterationsPerRun; 061 this.dedicatedTaskRunner = dedicatedTaskRunner; 062 } 063 064 public void init() { 065 if (initDone.compareAndSet(false, true)) { 066 // If your OS/JVM combination has a good thread model, you may want to 067 // avoid using a thread pool to run tasks and use a DedicatedTaskRunner instead. 068 if (dedicatedTaskRunner || "true".equalsIgnoreCase(System.getProperty("org.apache.activemq.UseDedicatedTaskRunner"))) { 069 executor = null; 070 } else if (executor == null) { 071 executor = createDefaultExecutor(); 072 } 073 } 074 } 075 076 public void shutdown() { 077 if (executor != null) { 078 executor.shutdownNow(); 079 } 080 initDone.set(false); 081 } 082 083 public TaskRunner createTaskRunner(Task task, String name) { 084 init(); 085 if (executor != null) { 086 return new PooledTaskRunner(executor, task, maxIterationsPerRun); 087 } else { 088 return new DedicatedTaskRunner(task, name, priority, daemon); 089 } 090 } 091 092 public void execute(Runnable runnable) { 093 execute(runnable, "ActiveMQ Task"); 094 } 095 096 public void execute(Runnable runnable, String name) { 097 init(); 098 if (executor != null) { 099 executor.execute(runnable); 100 } else { 101 new Thread(runnable, name + "-" + id.incrementAndGet()).start(); 102 } 103 } 104 105 protected ExecutorService createDefaultExecutor() { 106 ThreadPoolExecutor rc = new ThreadPoolExecutor(0, Integer.MAX_VALUE, 30, TimeUnit.SECONDS, new SynchronousQueue<Runnable>(), new ThreadFactory() { 107 public Thread newThread(Runnable runnable) { 108 Thread thread = new Thread(runnable, name + "-" + id.incrementAndGet()); 109 thread.setDaemon(daemon); 110 thread.setPriority(priority); 111 return thread; 112 } 113 }); 114 return rc; 115 } 116 117 public ExecutorService getExecutor() { 118 return executor; 119 } 120 121 public void setExecutor(ExecutorService executor) { 122 this.executor = executor; 123 } 124 125 public int getMaxIterationsPerRun() { 126 return maxIterationsPerRun; 127 } 128 129 public void setMaxIterationsPerRun(int maxIterationsPerRun) { 130 this.maxIterationsPerRun = maxIterationsPerRun; 131 } 132 133 public String getName() { 134 return name; 135 } 136 137 public void setName(String name) { 138 this.name = name; 139 } 140 141 public int getPriority() { 142 return priority; 143 } 144 145 public void setPriority(int priority) { 146 this.priority = priority; 147 } 148 149 public boolean isDaemon() { 150 return daemon; 151 } 152 153 public void setDaemon(boolean daemon) { 154 this.daemon = daemon; 155 } 156 157 public boolean isDedicatedTaskRunner() { 158 return dedicatedTaskRunner; 159 } 160 161 public void setDedicatedTaskRunner(boolean dedicatedTaskRunner) { 162 this.dedicatedTaskRunner = dedicatedTaskRunner; 163 } 164}