1   
    2   
    3   /*
    4    * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
    5    * 
    6    * Copyright 1997-2007 Sun Microsystems, Inc. All rights reserved.
    7    * 
    8    * Portions Copyright Apache Software Foundation.
    9    * 
   10    * The contents of this file are subject to the terms of either the GNU
   11    * General Public License Version 2 only ("GPL") or the Common Development
   12    * and Distribution License("CDDL") (collectively, the "License").  You
   13    * may not use this file except in compliance with the License. You can obtain
   14    * a copy of the License at https://glassfish.dev.java.net/public/CDDL+GPL.html
   15    * or glassfish/bootstrap/legal/LICENSE.txt.  See the License for the specific
   16    * language governing permissions and limitations under the License.
   17    * 
   18    * When distributing the software, include this License Header Notice in each
   19    * file and include the License file at glassfish/bootstrap/legal/LICENSE.txt.
   20    * Sun designates this particular file as subject to the "Classpath" exception
   21    * as provided by Sun in the GPL Version 2 section of the License file that
   22    * accompanied this code.  If applicable, add the following below the License
   23    * Header, with the fields enclosed by brackets [] replaced by your own
   24    * identifying information: "Portions Copyrighted [year]
   25    * [name of copyright owner]"
   26    * 
   27    * Contributor(s):
   28    * 
   29    * If you wish your version of this file to be governed by only the CDDL or
   30    * only the GPL Version 2, indicate your decision by adding "[Contributor]
   31    * elects to include this software in this distribution under the [CDDL or GPL
   32    * Version 2] license."  If you don't indicate a single choice of license, a
   33    * recipient has the option to distribute your version of this file under
   34    * either the CDDL, the GPL Version 2 or to extend the choice of license to
   35    * its licensees as provided above.  However, if you add GPL Version 2 code
   36    * and therefore, elected the GPL Version 2 license, then the option applies
   37    * only if the new code is made subject to such option by the copyright
   38    * holder.
   39    */
   40   package org.apache.tomcat.util.threads;
   41   
   42   import org.apache.tomcat.util;
   43   
   44   /**
   45    * The reaper is a background thread with which ticks every minute
   46    * and calls registered objects to allow reaping of old session
   47    * data.
   48    * 
   49    * @author James Duncan Davidson [duncan@eng.sun.com]
   50    * @author Costin Manolache
   51    */
   52   public class Reaper extends Thread {
   53   
   54       private static com.sun.org.apache.commons.logging.Log log=
   55           com.sun.org.apache.commons.logging.LogFactory.getLog(Reaper.class );
   56   
   57       private boolean daemon=false;
   58   
   59       public Reaper() {
   60   	if( daemon )
   61               this.setDaemon(true);
   62   	this.setName("TomcatReaper");
   63       }
   64   
   65       public Reaper(String name) {
   66           if( daemon )
   67               this.setDaemon(true);
   68   	this.setName(name);
   69       }
   70   
   71       private long interval = 1000 * 60; //ms
   72       
   73       // XXX TODO Allow per/callback interval, find next, etc
   74       // Right now the "interval" is used for all callbacks
   75       // and it represent a sleep between runs.
   76       
   77       ThreadPoolRunnable cbacks[]=new ThreadPoolRunnable[30]; // XXX max
   78       Object tdata[][]=new Object[30][]; // XXX max
   79       int count=0;
   80   
   81       /** Adding and removing callbacks is synchronized
   82        */
   83       Object lock=new Object();
   84       private boolean running=true;
   85   
   86       // XXX Should be called 'interval' not defaultInterval
   87   
   88       public void setDefaultInterval( long t ) {
   89   	interval=t;
   90       }
   91   
   92       public long getDefaultIntervale() {
   93           return interval;
   94       }
   95   
   96       public int addCallback( ThreadPoolRunnable c, int interval ) {
   97   	synchronized( lock ) {
   98   	    cbacks[count]=c;
   99   	    count++;
  100   	    return count-1;
  101   	}
  102       }
  103   
  104       public void removeCallback( int idx ) {
  105   	synchronized( lock ) {
  106   	    count--;
  107   	    cbacks[idx]=cbacks[count];
  108   	    cbacks[count]=null;
  109   	}
  110       }
  111   
  112       public void startReaper() {
  113   	running=true;
  114   	this.start();
  115       }
  116   
  117       public synchronized void stopReaper() {
  118   	running=false;
  119           if (log.isDebugEnabled())
  120   	    log.debug("Stop reaper ");
  121   	this.interrupt(); // notify() doesn't stop sleep
  122       }
  123       
  124       public void run() {
  125   	while (running) {
  126   	    if( !running) break;
  127   	    try {
  128   		this.sleep(interval);
  129   	    } catch (InterruptedException ie) {
  130   		// sometimes will happen
  131   	    }
  132   
  133   	    if( !running) break;
  134   	    for( int i=0; i< count; i++ ) {
  135   		ThreadPoolRunnable callB=cbacks[i];
  136   		// it may be null if a callback is removed.
  137   		//  I think the code is correct
  138   		if( callB!= null ) {
  139   		    callB.runIt( tdata[i] );
  140   		}
  141   		if( !running) break;
  142   	    }
  143   	}
  144       }
  145   }