|
Jetty example source code file (QueuedThreadPool.java)
The Jetty QueuedThreadPool.java source code// ======================================================================== // Copyright 2004-2005 Mort Bay Consulting Pty. Ltd. // ------------------------------------------------------------------------ // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // http://www.apache.org/licenses/LICENSE-2.0 // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // ======================================================================== package org.mortbay.thread; import java.io.Serializable; import java.util.ArrayList; import java.util.HashSet; import java.util.Iterator; import java.util.LinkedList; import java.util.List; import java.util.Set; import org.mortbay.component.AbstractLifeCycle; import org.mortbay.log.Log; /* ------------------------------------------------------------ */ /** A pool of threads. * <p> * Avoids the expense of thread creation by pooling threads after * their run methods exit for reuse. * <p> * If the maximum pool size is reached, jobs wait for a free thread. * By default there is no maximum pool size. Idle threads timeout * and terminate until the minimum number of threads are running. * <p> * @author Greg Wilkins <gregw@mortbay.com> * @author Juancarlo Anez <juancarlo@modelistica.com> */ public class QueuedThreadPool extends AbstractLifeCycle implements Serializable, ThreadPool { private static int __id; private String _name; private Set _threads; private List _idle; private Runnable[] _jobs; private int _nextJob; private int _nextJobSlot; private int _queued; private boolean _daemon; private int _id; private final Object _threadLock = new Lock(); private final Object _idleLock = new Lock(); private final Object _jobsLock = new Lock(); private final Object _joinLock = new Lock(); private long _lastShrink; private int _maxIdleTimeMs=60000; private int _maxThreads=25; private int _minThreads=2; private boolean _warned=false; private int _lowThreads=0; private int _priority= Thread.NORM_PRIORITY; private int _spawnOrShrinkAt=0; /* ------------------------------------------------------------------- */ /* Construct */ public QueuedThreadPool() { _name="btpool"+__id++; } /* ------------------------------------------------------------ */ /** Run job. * @return true */ public boolean dispatch(Runnable job) { if (!isRunning() || job==null) return false; PoolThread thread=null; boolean spawn=false; // Look for an idle thread synchronized(_idleLock) { int idle=_idle.size(); if (idle>0) thread=(PoolThread)_idle.remove(idle-1); else { // Are we at max size? if (_threads.size()<_maxThreads) spawn=true; else { if (!_warned) { _warned=true; Log.debug("Out of threads for {}",this); } } } } if (thread!=null) thread.dispatch(job); else { synchronized(_jobsLock) { _queued++; _jobs[_nextJobSlot++]=job; if (_nextJobSlot==_jobs.length) _nextJobSlot=0; if (_nextJobSlot==_nextJob) { // Grow the job queue Runnable[] jobs= new Runnable[_jobs.length+_maxThreads]; int split=_jobs.length-_nextJob; if (split>0) System.arraycopy(_jobs,_nextJob,jobs,0,split); if (_nextJob!=0) System.arraycopy(_jobs,0,jobs,split,_nextJobSlot); _jobs=jobs; _nextJob=0; _nextJobSlot=_queued; } if (spawn && _queued<=_spawnOrShrinkAt) spawn=false; } if (spawn) newThread(); } return true; } /* ------------------------------------------------------------ */ /** Get the number of idle threads in the pool. * @see #getThreads * @return Number of threads */ public int getIdleThreads() { return _idle==null?0:_idle.size(); } /* ------------------------------------------------------------ */ /** * @return low resource threads threshhold */ public int getLowThreads() { return _lowThreads; } /* ------------------------------------------------------------ */ /** Get the maximum thread idle time. * Delegated to the named or anonymous Pool. * @see #setMaxIdleTimeMs * @return Max idle time in ms. */ public int getMaxIdleTimeMs() { return _maxIdleTimeMs; } /* ------------------------------------------------------------ */ /** Set the maximum number of threads. * Delegated to the named or anonymous Pool. * @see #setMaxThreads * @return maximum number of threads. */ public int getMaxThreads() { return _maxThreads; } /* ------------------------------------------------------------ */ /** Get the minimum number of threads. * Delegated to the named or anonymous Pool. * @see #setMinThreads * @return minimum number of threads. */ public int getMinThreads() { return _minThreads; } /* ------------------------------------------------------------ */ /** * @return The name of the BoundedThreadPool. */ public String getName() { return _name; } /* ------------------------------------------------------------ */ /** Get the number of threads in the pool. * @see #getIdleThreads * @return Number of threads */ public int getThreads() { return _threads.size(); } /* ------------------------------------------------------------ */ /** Get the priority of the pool threads. * @return the priority of the pool threads. */ public int getThreadsPriority() { return _priority; } /* ------------------------------------------------------------ */ public int getQueueSize() { return _queued; } /* ------------------------------------------------------------ */ /** * @return the spawnOrShrinkAt The number of queued jobs (or idle threads) needed * before the thread pool is grown (or shrunk) */ public int getSpawnOrShrinkAt() { return _spawnOrShrinkAt; } /* ------------------------------------------------------------ */ /** * @param spawnOrShrinkAt The number of queued jobs (or idle threads) needed * before the thread pool is grown (or shrunk) */ public void setSpawnOrShrinkAt(int spawnOrShrinkAt) { _spawnOrShrinkAt=spawnOrShrinkAt; } /* ------------------------------------------------------------ */ /** * Delegated to the named or anonymous Pool. */ public boolean isDaemon() { return _daemon; } /* ------------------------------------------------------------ */ public boolean isLowOnThreads() { return _queued>_lowThreads; } /* ------------------------------------------------------------ */ public void join() throws InterruptedException { synchronized (_joinLock) { while (isRunning()) _joinLock.wait(); } // TODO remove this semi busy loop! while (isStopping()) Thread.sleep(100); } /* ------------------------------------------------------------ */ /** * Delegated to the named or anonymous Pool. */ public void setDaemon(boolean daemon) { _daemon=daemon; } /* ------------------------------------------------------------ */ /** * @param lowThreads low resource threads threshhold */ public void setLowThreads(int lowThreads) { _lowThreads = lowThreads; } /* ------------------------------------------------------------ */ /** Set the maximum thread idle time. * Threads that are idle for longer than this period may be * stopped. * Delegated to the named or anonymous Pool. * @see #getMaxIdleTimeMs * @param maxIdleTimeMs Max idle time in ms. */ public void setMaxIdleTimeMs(int maxIdleTimeMs) { _maxIdleTimeMs=maxIdleTimeMs; } /* ------------------------------------------------------------ */ /** Set the maximum number of threads. * Delegated to the named or anonymous Pool. * @see #getMaxThreads * @param maxThreads maximum number of threads. */ public void setMaxThreads(int maxThreads) { if (isStarted() && maxThreads<_minThreads) throw new IllegalArgumentException("!minThreads<maxThreads"); _maxThreads=maxThreads; } /* ------------------------------------------------------------ */ /** Set the minimum number of threads. * Delegated to the named or anonymous Pool. * @see #getMinThreads * @param minThreads minimum number of threads */ public void setMinThreads(int minThreads) { if (isStarted() && (minThreads<=0 || minThreads>_maxThreads)) throw new IllegalArgumentException("!0<=minThreads |
... this post is sponsored by my books ... | |
#1 New Release! |
FP Best Seller |
Copyright 1998-2021 Alvin Alexander, alvinalexander.com
All Rights Reserved.
A percentage of advertising revenue from
pages under the /java/jwarehouse
URI on this website is
paid back to open source projects.