src/org/apache/xml/utils/ThreadControllerWrapper.java

/*
 * The Apache Software License, Version 1.1
 *
 *
 * Copyright (c) 1999-2003 The Apache Software Foundation.  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
 *        Apache Software Foundation (http://www.apache.org/)."
 *    Alternately, this acknowledgment may appear in the software itself,
 *    if and wherever such third-party acknowledgments normally appear.
 *
 * 4. The names "Xalan" and "Apache Software Foundation" must
 *    not be used to endorse or promote products derived from this
 *    software without prior written permission. For written 
 *    permission, please contact apache@apache.org.
 *
 * 5. Products derived from this software may not be called "Apache",
 *    nor may "Apache" appear in their name, without prior written
 *    permission of the Apache Software Foundation.
 *
 * 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 APACHE SOFTWARE FOUNDATION 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 Apache Software Foundation and was
 * originally based on software copyright (c) 1999, Lotus
 * Development Corporation., http://www.lotus.com.  For more
 * information on the Apache Software Foundation, please see
 * <http://www.apache.org/>.
 */
package org.apache.xml.utils;

/**
 * A utility class that wraps the ThreadController, which is used
 * by IncrementalSAXSource for the incremental building of DTM.
 */
public class ThreadControllerWrapper
{
  
  /** The ThreadController pool   */
  static ThreadController m_tpool = new ThreadController();

  /**
   * Change the ThreadController that will be used to
   * manage the transform threads.
   *
   * @param tp A ThreadController object
   */
  public static void setThreadController(ThreadController tpool)
  {
    m_tpool = tpool;
  }
  
  public static Thread runThread(Runnable runnable, int priority)
  {
    return m_tpool.run(runnable, priority);
  }
  
  public static void waitThread(Thread worker, Runnable task)
    throws InterruptedException
  {
    m_tpool.waitThread(worker, task);
  }
  
  /**
   * Thread controller utility class for incremental SAX source. Must 
   * be overriden with a derived class to support thread pooling.
   *
   * All thread-related stuff is in this class.
   */
  public static class ThreadController
  {

    /**
     * Will get a thread from the pool, execute the task
     *  and return the thread to the pool.
     *
     *  The return value is used only to wait for completion
     *
     *
     * NEEDSDOC @param task
     * @param priority if >0 the task will run with the given priority
     *  ( doesn't seem to be used in xalan, since it's allways the default )
     * @returns The thread that is running the task, can be used
     *          to wait for completion
     *
     * NEEDSDOC ($objectName$) @return
     */
    public Thread run(Runnable task, int priority)
    {

      Thread t = new Thread(task);

      t.start();

      //       if( priority > 0 )
      //      t.setPriority( priority );
      return t;
    }

    /**
     *  Wait until the task is completed on the worker
     *  thread.
     *
     * NEEDSDOC @param worker
     * NEEDSDOC @param task
     *
     * @throws InterruptedException
     */
    public void waitThread(Thread worker, Runnable task)
            throws InterruptedException
    {

      // This should wait until the transformThread is considered not alive.
      worker.join();
    }
  }
 
}