reaper.java

低版本的tomcat 对于有些老版本的应用还真的需要老版的中间件

/*
 * ====================================================================
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 * The Apache Software License, Version 1.1
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 * Copyright (c) 1999 The Apache Software Foundation.  All rights 
 * reserved.
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 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
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 *    distribution.
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 *    any, must include the following acknowlegement:  
 *       "This product includes software developed by the 
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowlegement may appear in the software itself,
 *    if and wherever such third-party acknowlegements normally appear.
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 * [Additional notices, if required by prior licensing conditions]
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package org.apache.tomcat.util;

import org.apache.tomcat.core.*;
import org.apache.tomcat.util.*;

/**
 * The reaper is a background thread with which ticks every minute
 * and calls registered objects to allow reaping of old session
 * data.
 * 
 * @author James Duncan Davidson [[e-mail]]
 * @author Costin Manolache
 */
public class Reaper extends Thread {

    public Reaper() {
	this.setDaemon(true);
	this.setName("TomcatReaper");
    }

    private int interval = 1000 * 60; //ms
    
    // XXX TODO Allow per/callback interval, find next, etc
    // Right now the "interval" is used for all callbacks
    // and it represent a sleep between runs.
    
    ThreadPoolRunnable cbacks[]=new ThreadPoolRunnable[30]; // XXX max
    Object tdata[][]=new Object[30][]; // XXX max
    int count=0;

    /** Adding and removing callbacks is synchronized
     */
    Object lock=new Object();
    static boolean running=true;
    
    public int addCallback( ThreadPoolRunnable c, int interval ) {
	synchronized( lock ) {
	    cbacks[count]=c;
	    count++;
	    return count-1;
	}
    }

    public void removeCallback( int idx ) {
	synchronized( lock ) {
	    count--;
	    cbacks[idx]=cbacks[count];
	    cbacks[count]=null;
	}
    }

    public void stopReaper() {
	running=false;
	this.notify();
    }
    
    public void run() {
	while (running) {
	    try {
		this.sleep(interval);
	    } catch (InterruptedException ie) {
		// sometimes will happen
	    }
	    
	    for( int i=0; i< count; i++ ) {
		ThreadPoolRunnable callB=cbacks[i];
		// it may be null if a callback is removed.
		//  I think the code is correct
		if( callB!= null ) {
		    callB.runIt( tdata[i] );
		}
	    }
	}
    }
}