2004/05/19 xchen

fix bug 55542 - [IM Event Gateway] EventService.AddEvent log message always contains 
useless null string. It seems that the reason is QueueSizeExceeded exception doesn't 
have detailed message. "Error","Smack Listener Processor","05/17/04","13:54:27",,
"Problem adding event for gateway XMPP jabberd - mousemail: null"


fix the QueueSizeExceeded to be ApplicationException type


<      public class QueueSizeExceeded extends Exception
->     public class QueueSizeExceeded extends ApplicationException
       {
           public int size = -1;
           public QueueSizeExceeded(int queuesize)
           {
               super();
               size = queuesize;
           }
       }
   
   

02/27/04: Tom Jordahl

Fix up comments and remove LGPL copyright.

 /**
<   * Created by Tom Jordahl
->  *
->  * This is a thread pool for Java, it is
->  * simple to use and gets the job done.
->  *
->  * Copyright 2001 by Jeff Heaton
->  * Provided to Macromedia under the Apache license
    *
<   * Date: Nov 17, 2003
<   * Time: 3:05:56 PM
<   * adding simple Java Thread Pool in the util package
->  * @author Jeff Heaton (http://www.jeffheaton.com)
->  * @version 1.0
    */
<  
   /**
<   *
<   * This is a thread pool for Java, it is
<   * simple to use and gets the job done. This program and
<   * all supporting files are distributed under the Limited
<   * GNU Public License (LGPL, http://www.gnu.org).
<   *
    * This is a very simple object that
    * allows the TheadPool to determine when
    * it is done. This object implements
    * a simple lock that the ThreadPool class
    * can wait on to determine completion.
    * Done is defined as the ThreadPool having
    * no more work to complete.
    *
<   * Copyright 2001 by Jeff Heaton
<   *
<   * @author Jeff Heaton (http://www.jeffheaton.com)
<   * @version 1.0
    */
<  


12/16/03: xchen

change miss wording found by Tom J

 /**
         * A problem occurred when attempting to add more assignments into the threadpool task queue.
<        * There is no space left in the queue to take more task.  Queue size is currently set to {size}.
->       * There is no space left in the queue to accept another task.  Queue size is currently set to {size}.
         * @author Xu Chen
         */


12/15/03: xchen

update threadpool to handle linklist


<  import java.util.*;
-> import java.util.LinkedList;
-> 
       /**
         * The backlog of assignments, which are waiting
         * for the thread pool.
->       *
->       * Replace with LinkedList instead of ArrayList due to efficiency concern
->       * this is double pointer linklist which can shrink easily but take more size.
         */
<       Collection assignments = new ArrayList(50);
->      LinkedList assignments = new LinkedList();
-> 
-> 
->      int queuesizelimit = -1;
-> 
->     /**
->      * The constructor.  which take both threadpool size and queue size
->      *
->      * @param size  How many threads in the thread pool.
->      */
->     public SimpleThreadPool(int size, int queuesize)
->     {
->        threads = new SimpleWorkerThread[size];
->        for (int i=0;i<threads.length;i++)
->        {
->            threads[i] = new SimpleWorkerThread(this);
->            threads[i].start();
->        }
-> 
->        queuesizelimit =  queuesize;
->     }
-> 
-> 
       /**
         * Add a task to the thread pool. Any class
         * which implements the Runnable interface
         * may be assienged. When this task runs, its
         * run method will be called.
         *
->       * if we do not assign a queuesize or our queuesize
->       * is smaller than limit size then we can add to assignment queue.
->       * Otherwise, we drop the request.
->       *
->       *
         * @param r   An object that implements the Runnable interface
->       * @throws Exception   -- indicating we are dropping messages
->       *
         */
<       public synchronized void assign(Runnable r)
->      public synchronized void assign(Runnable r) throws Exception
        {
<          done.workerBegin();
<          assignments.add(r);
<          notify();
->         if(queuesizelimit == -1 || queuesizelimit > assignments.size() )
->         {
->             done.workerBegin();
->             assignments.addLast(r);
->             notify();
->         }else
->         {
->             throw new QueueSizeExceeded(queuesizelimit);
->         }
        }
       public synchronized Runnable getAssignment()
        {
             try {
                  while ( !assignments.iterator().hasNext() )
                       wait();  //wait until there is work
   
<                 Runnable r = (Runnable)assignments.iterator().next();
<                 assignments.remove(r);
->                Runnable r = (Runnable)assignments.removeFirst();
                  return r;
             } catch (InterruptedException e) {
                  done.workerEnd();
                  return null;
             }
        }
-> 
->     /**
->       * A problem occurred when attempting to add more assignments into the threadpool task queue.
->       * There is no space left in the queue to take more task.  Queue size is currently set to {size}.
->       * @author Xu Chen
->       */
->     public class QueueSizeExceeded extends Exception
->     {
->         public int size = -1;
->         public QueueSizeExceeded(int queuesize)
->         {
->             super();
->             size = queuesize;
->         }
->     }
->