Jake Slack | 03928ae | 2014-05-13 18:41:56 -0700 | [diff] [blame] | 1 | // |
| 2 | // ======================================================================== |
| 3 | // Copyright (c) 1995-2014 Mort Bay Consulting Pty. Ltd. |
| 4 | // ------------------------------------------------------------------------ |
| 5 | // All rights reserved. This program and the accompanying materials |
| 6 | // are made available under the terms of the Eclipse Public License v1.0 |
| 7 | // and Apache License v2.0 which accompanies this distribution. |
| 8 | // |
| 9 | // The Eclipse Public License is available at |
| 10 | // http://www.eclipse.org/legal/epl-v10.html |
| 11 | // |
| 12 | // The Apache License v2.0 is available at |
| 13 | // http://www.opensource.org/licenses/apache2.0.php |
| 14 | // |
| 15 | // You may elect to redistribute this code under either of these licenses. |
| 16 | // ======================================================================== |
| 17 | // |
| 18 | |
| 19 | package org.eclipse.jetty.util.thread; |
| 20 | |
| 21 | import java.util.concurrent.ArrayBlockingQueue; |
| 22 | import java.util.concurrent.BlockingQueue; |
| 23 | import java.util.concurrent.ExecutorService; |
| 24 | import java.util.concurrent.LinkedBlockingQueue; |
| 25 | import java.util.concurrent.RejectedExecutionException; |
| 26 | import java.util.concurrent.SynchronousQueue; |
| 27 | import java.util.concurrent.ThreadPoolExecutor; |
| 28 | import java.util.concurrent.TimeUnit; |
| 29 | |
| 30 | import org.eclipse.jetty.util.component.AbstractLifeCycle; |
| 31 | import org.eclipse.jetty.util.component.LifeCycle; |
| 32 | import org.eclipse.jetty.util.log.Log; |
| 33 | import org.eclipse.jetty.util.log.Logger; |
| 34 | |
| 35 | /* ------------------------------------------------------------ */ |
| 36 | /** |
| 37 | * Jetty ThreadPool using java 5 ThreadPoolExecutor |
| 38 | * This class wraps a {@link ExecutorService} as a {@link ThreadPool} and |
| 39 | * {@link LifeCycle} interfaces so that it may be used by the Jetty <code>org.eclipse.jetty.server.Server</code> |
| 40 | */ |
| 41 | public class ExecutorThreadPool extends AbstractLifeCycle implements ThreadPool, LifeCycle |
| 42 | { |
| 43 | private static final Logger LOG = Log.getLogger(ExecutorThreadPool.class); |
| 44 | private final ExecutorService _executor; |
| 45 | |
| 46 | /* ------------------------------------------------------------ */ |
| 47 | public ExecutorThreadPool(ExecutorService executor) |
| 48 | { |
| 49 | _executor = executor; |
| 50 | } |
| 51 | |
| 52 | /* ------------------------------------------------------------ */ |
| 53 | /** |
| 54 | * Wraps an {@link ThreadPoolExecutor}. |
| 55 | * Max pool size is 256, pool thread timeout after 60 seconds and |
| 56 | * an unbounded {@link LinkedBlockingQueue} is used for the job queue; |
| 57 | */ |
| 58 | public ExecutorThreadPool() |
| 59 | { |
| 60 | // Using an unbounded queue makes the maxThreads parameter useless |
| 61 | // Refer to ThreadPoolExecutor javadocs for details |
| 62 | this(new ThreadPoolExecutor(256, 256, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>())); |
| 63 | } |
| 64 | |
| 65 | /* ------------------------------------------------------------ */ |
| 66 | /** |
| 67 | * Wraps an {@link ThreadPoolExecutor}. |
| 68 | * Max pool size is 256, pool thread timeout after 60 seconds, and core pool size is 32 when queueSize >= 0. |
| 69 | * @param queueSize can be -1 for using an unbounded {@link LinkedBlockingQueue}, 0 for using a |
| 70 | * {@link SynchronousQueue}, greater than 0 for using a {@link ArrayBlockingQueue} of the given size. |
| 71 | */ |
| 72 | public ExecutorThreadPool(int queueSize) |
| 73 | { |
| 74 | this(queueSize < 0 ? new ThreadPoolExecutor(256, 256, 60, TimeUnit.SECONDS, new LinkedBlockingQueue<Runnable>()) : |
| 75 | queueSize == 0 ? new ThreadPoolExecutor(32, 256, 60, TimeUnit.SECONDS, new SynchronousQueue<Runnable>()) : |
| 76 | new ThreadPoolExecutor(32, 256, 60, TimeUnit.SECONDS, new ArrayBlockingQueue<Runnable>(queueSize))); |
| 77 | } |
| 78 | |
| 79 | /* ------------------------------------------------------------ */ |
| 80 | /** |
| 81 | * Wraps an {@link ThreadPoolExecutor} using |
| 82 | * an unbounded {@link LinkedBlockingQueue} is used for the jobs queue; |
| 83 | * @param corePoolSize must be equal to maximumPoolSize |
| 84 | * @param maximumPoolSize the maximum number of threads to allow in the pool |
| 85 | * @param keepAliveTime the max time a thread can remain idle, in milliseconds |
| 86 | */ |
| 87 | public ExecutorThreadPool(int corePoolSize, int maximumPoolSize, long keepAliveTime) |
| 88 | { |
| 89 | this(corePoolSize, maximumPoolSize, keepAliveTime, TimeUnit.MILLISECONDS); |
| 90 | } |
| 91 | |
| 92 | /* ------------------------------------------------------------ */ |
| 93 | /** |
| 94 | * Wraps an {@link ThreadPoolExecutor} using |
| 95 | * an unbounded {@link LinkedBlockingQueue} is used for the jobs queue. |
| 96 | * @param corePoolSize must be equal to maximumPoolSize |
| 97 | * @param maximumPoolSize the maximum number of threads to allow in the pool |
| 98 | * @param keepAliveTime the max time a thread can remain idle |
| 99 | * @param unit the unit for the keepAliveTime |
| 100 | */ |
| 101 | public ExecutorThreadPool(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit) |
| 102 | { |
| 103 | this(corePoolSize, maximumPoolSize, keepAliveTime, unit, new LinkedBlockingQueue<Runnable>()); |
| 104 | } |
| 105 | |
| 106 | /* ------------------------------------------------------------ */ |
| 107 | |
| 108 | /** |
| 109 | * Wraps an {@link ThreadPoolExecutor} |
| 110 | * @param corePoolSize the number of threads to keep in the pool, even if they are idle |
| 111 | * @param maximumPoolSize the maximum number of threads to allow in the pool |
| 112 | * @param keepAliveTime the max time a thread can remain idle |
| 113 | * @param unit the unit for the keepAliveTime |
| 114 | * @param workQueue the queue to use for holding tasks before they are executed |
| 115 | */ |
| 116 | public ExecutorThreadPool(int corePoolSize, int maximumPoolSize, long keepAliveTime, TimeUnit unit, BlockingQueue<Runnable> workQueue) |
| 117 | { |
| 118 | this(new ThreadPoolExecutor(corePoolSize, maximumPoolSize, keepAliveTime, unit, workQueue)); |
| 119 | } |
| 120 | |
| 121 | /* ------------------------------------------------------------ */ |
| 122 | public boolean dispatch(Runnable job) |
| 123 | { |
| 124 | try |
| 125 | { |
| 126 | _executor.execute(job); |
| 127 | return true; |
| 128 | } |
| 129 | catch(RejectedExecutionException e) |
| 130 | { |
| 131 | LOG.warn(e); |
| 132 | return false; |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | /* ------------------------------------------------------------ */ |
| 137 | public int getIdleThreads() |
| 138 | { |
| 139 | if (_executor instanceof ThreadPoolExecutor) |
| 140 | { |
| 141 | final ThreadPoolExecutor tpe = (ThreadPoolExecutor)_executor; |
| 142 | return tpe.getPoolSize() - tpe.getActiveCount(); |
| 143 | } |
| 144 | return -1; |
| 145 | } |
| 146 | |
| 147 | /* ------------------------------------------------------------ */ |
| 148 | public int getThreads() |
| 149 | { |
| 150 | if (_executor instanceof ThreadPoolExecutor) |
| 151 | { |
| 152 | final ThreadPoolExecutor tpe = (ThreadPoolExecutor)_executor; |
| 153 | return tpe.getPoolSize(); |
| 154 | } |
| 155 | return -1; |
| 156 | } |
| 157 | |
| 158 | /* ------------------------------------------------------------ */ |
| 159 | public boolean isLowOnThreads() |
| 160 | { |
| 161 | if (_executor instanceof ThreadPoolExecutor) |
| 162 | { |
| 163 | final ThreadPoolExecutor tpe = (ThreadPoolExecutor)_executor; |
| 164 | // getActiveCount() locks the thread pool, so execute it last |
| 165 | return tpe.getPoolSize() == tpe.getMaximumPoolSize() && |
| 166 | tpe.getQueue().size() >= tpe.getPoolSize() - tpe.getActiveCount(); |
| 167 | } |
| 168 | return false; |
| 169 | } |
| 170 | |
| 171 | /* ------------------------------------------------------------ */ |
| 172 | public void join() throws InterruptedException |
| 173 | { |
| 174 | _executor.awaitTermination(Long.MAX_VALUE, TimeUnit.MILLISECONDS); |
| 175 | } |
| 176 | |
| 177 | /* ------------------------------------------------------------ */ |
| 178 | @Override |
| 179 | protected void doStop() throws Exception |
| 180 | { |
| 181 | super.doStop(); |
| 182 | _executor.shutdownNow(); |
| 183 | } |
| 184 | } |