rot.java

jacob is a connection between java and windows

/*
 * Copyright (c) 1999 Dan Adler, 315 E72 St. NY, NY, 10021, USA.
 * mailto:[e-mail]. 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. Redistributions in any form must be accompanied by information on
 *    how to obtain complete source code for the JACOB software.
 *
 * Redistribution of the JACOB software is not permitted as part of any
 * commercial product that is targeted primarily at Java developers.
 * Such products include, but are not limited to: Java virtual machines,
 * integrated development environments, code libraries, and application
 * server products. Licensing terms for such distribution may be
 * obtained from the copyright holder.
 *
 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS 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 COPYRIGHT HOLDER 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.
 */
package com.jacob.com;
import java.util.Hashtable;
import java.util.Vector;

/**
 * The Running Object Table (ROT) maps each thread to a vector of
 * all the JacobObjects that were created in that thread. It always
 * operates on the current thread so all the methods are static and
 * they implicitly get the current thread.
 * Conceptually, this is similar to the ThreadLocal class of Java 1.2
 * but we are also supporting Java 1.6
 * The clearObjects method is used to release all the COM objects
 * created by Jacob in the current thread prior to uninitializing COM
 * for that thread. If we leave this job to the garbage collector,
 * then finalize might get called from a separate thread which is not
 * initialized for COM, and also the component itself may have been
 * freed.
 */
public abstract class ROT
{
    private static Hashtable rot = new Hashtable();

    protected static void addThread()
    {
      String t_name = Thread.currentThread().getName();
      if (rot.contains(t_name)) return;
      Vector v = new Vector();
      rot.put(t_name, v);
    }

    protected static void clearObjects()
    {
      String t_name = Thread.currentThread().getName();
      Vector v = (Vector)rot.get(t_name);
      if (v != null)
      {
        while (!v.isEmpty())
        {
          JacobObject o = (JacobObject)v.elementAt(0);
          //System.out.println(t_name + "  release:"+o+"->"+o.getClass().getName());
          if (o != null) o.release();
          v.removeElementAt(0);
        }
        rot.remove(t_name);
      }
    }

    protected static void addObject(JacobObject o)
    {
      String t_name = Thread.currentThread().getName();
      //System.out.println(t_name + "  add:"+o+"->"+o.getClass().getName());
      Vector v = (Vector)rot.get(t_name);
      if (v == null)
      {
        // this thread has not been initialized as a COM thread
        // so make it part of MTA for backwards compatibility
        ComThread.InitMTA(false);
        addThread();
        v = (Vector)rot.get(t_name);
      }
      if (v != null)
      {
        v.addElement(o);
      }
    }

    static {
      System.loadLibrary("jacob");
    }
}