threadpool.java

pos机交易实现源代码 含金融卡交易8583协议实现 开发环境：linux 典型应用：嵌入系统开发 仅供参考

/*
 * Copyright (c) 2000 jPOS.org.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 *
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 *
 * 3. The end-user documentation included with the redistribution,
 *    if any, must include the following acknowledgment:
 *    "This product includes software developed by the jPOS project 
 *    (http://www.jpos.org/)". Alternately, this acknowledgment may 
 *    appear in the software itself, if and wherever such third-party 
 *    acknowledgments normally appear.
 *
 * 4. The names "jPOS" and "jPOS.org" must not be used to endorse 
 *    or promote products derived from this software without prior 
 *    written permission. For written permission, please contact 
 *    [e-mail].
 *
 * 5. Products derived from this software may not be called "jPOS",
 *    nor may "jPOS" appear in their name, without prior written
 *    permission of the jPOS project.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.  
 * IN NO EVENT SHALL THE JPOS PROJECT OR ITS CONTRIBUTORS BE LIABLE FOR 
 * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, 
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING 
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE 
 * POSSIBILITY OF SUCH DAMAGE.
 * ====================================================================
 *
 * This software consists of voluntary contributions made by many
 * individuals on behalf of the jPOS Project.  For more
 * information please see <http://www.jpos.org/>.
 */

package org.jpos.util;

import java.io.PrintStream;
import org.jpos.util.BlockingQueue.Closed;

/**
 * Implements a ThreadPool with the ability to run simple Runnable
 * tasks as well as Jobs (supervised Runnable tasks)
 * @since 1.1
 * @author [e-mail]
 */
public class ThreadPool extends ThreadGroup implements LogSource, Loggeable 
{
    private static int poolNumber=0;
    private static int threadNumber=0;
    private int maxPoolSize = 1;
    private BlockingQueue pool = new BlockingQueue();
    private Logger logger;
    private String realm;
    private int jobs = 0;

    public interface Supervised {
	public boolean expired ();
    }

    private class PooledThread extends Thread {
	Object currentJob = null;

	public PooledThread() {
	    super ((ThreadGroup) ThreadPool.this, 
		"PooledThread-" + (threadNumber++));
	    setDaemon(true);
	}
	public void run () {
	    String name = getName();
	    try {
		while (pool.ready()) {
		    Object job = pool.dequeue();
		    if (job instanceof Runnable) {
			setName (name + "-running");
			synchronized (this) {
			    currentJob = job;
			}
			((Runnable) job).run();
			setName (name + "-idle");
			synchronized (this) {
			    currentJob = null;
			}
		    }
		}
	    } catch (InterruptedException e) {
	    } catch (Closed e) {
	    }
	}
	public synchronized void supervise () {
	    if (currentJob != null && currentJob instanceof Supervised) 
		if ( ((Supervised)currentJob).expired() )
		    this.interrupt();
	}
    }

    /**
     * @param poolSize starting pool size
     * @param maxPoolSize maximum number of threads on this pool
     */
    public ThreadPool (int poolSize, int maxPoolSize) {
	super ("ThreadPool-" + poolNumber++);
	this.maxPoolSize = maxPoolSize;
	while (activeCount() < Math.min (poolSize, maxPoolSize))
	    new PooledThread().start();
    }
    public void close () {
	pool.close();
    }
    public synchronized void execute (Runnable action) throws Closed
    {
	if (!pool.ready())
	    throw new Closed();

	if (++jobs % 100 == 0 || pool.consumerCount() <= 0)
	    supervise();

	synchronized (pool) {
	    if (activeCount() < maxPoolSize && pool.consumerCount() <= 0)
		new PooledThread().start();
	}
	pool.enqueue (action);
    }
    public void dump (PrintStream p, String indent) {
	String inner = indent + "  ";
	p.println (indent + "<ThreadPool name=\""+getName()+"\">");
	if (!pool.ready())
	    p.println (inner  + "<closed/>");
	p.println (inner  + "<jobs>" +jobs+"</jobs>");
	p.println (inner  + "<size>" +activeCount()+"</size>");
	p.println (inner  + "<max>"  +maxPoolSize+"</max>");
	p.println (inner  + "<idle>"  + pool.consumerCount() +"</idle>");
	p.println (inner  + "<pending>"  +pool.pending()+"</pending>");
	p.println (indent + "</ThreadPool>");
    }

    /**
     * @return number of jobs processed by this pool
     */
    public int getJobCount () {
        return jobs;
    }
    /**
     * @return number of active threads
     */
    public int getPoolSize () {
        return activeCount();
    }
    /**
     * @return max number of active threads allowed
     */
    public int getMaxPoolSize () {
        return maxPoolSize;
    }
    /**
     * @return number of idle threads
     */
    public int getIdleCount () {
        return pool.consumerCount ();
    }
    /**
     * @return number of Pending jobs
     */
    public int getPendingCount () {
        return pool.pending ();
    }

    public void supervise () {
	Thread[] t = new Thread[maxPoolSize];
	int cnt = enumerate (t);
	for (int i=0; i<cnt; i++) 
	    if (t[i] instanceof PooledThread)
		((PooledThread) t[i]).supervise();
    }

    public void setLogger (Logger logger, String realm) {
	this.logger = logger;
	this.realm  = realm;
    }
    public String getRealm () {
	return realm;
    }
    public Logger getLogger() {
	return logger;
    }
}