code: /***************************************************************************
   *   Copyright (C) by Fabrizio Montesi                                     *
   *                                                                         *
   *   This program is free software; you can redistribute it and/or modify  *
   *   it under the terms of the GNU Library General Public License as       *
   *   published by the Free Software Foundation; either version 2 of the    *
   *   License, or (at your option) any later version.                       *
   *                                                                         *
   *   This program is distributed in the hope that it will be useful,       *
   *   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
   *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
   *   GNU General Public License for more details.                          *
   *                                                                         *
   *   You should have received a copy of the GNU Library General Public     *
   *   License along with this program; if not, write to the                 *
   *   Free Software Foundation, Inc.,                                       *
   *   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
   *                                                                         *
   *   For details about the authors of this software, see the AUTHORS file. *
   ***************************************************************************/
  
  
  package jolie.runtime;
  
  
  import java.util.LinkedList;
  import java.util.List;
  import jolie.ExecutionThread;
  import jolie.net.CommChannel;
  import jolie.net.CommMessage;
  import jolie.process.LinkInProcess;
  
  
  /** Internal synchronization link for parallel processes.
   * 
   * @author Fabrizio Montesi
   */
  public class InternalLink extends AbstractIdentifiableObject
  {
  	private final List< LinkInProcess.Execution > procsList =
  					new LinkedList< LinkInProcess.Execution > ();
  	private int signals = 0;
  	private final CommMessage linkMessage;
  	
  	public InternalLink( String id )
  	{
  		super( id );
  		linkMessage = new CommMessage( CommMessage.GENERIC_ID, id, "/", Value.UNDEFINED_VALUE, null );
  	}
  	
  	public synchronized void recvMessage( CommChannel channel, CommMessage message )
  	{
  		for( int i = 0; i < procsList.size(); i++ ) {
  			if ( procsList.get( i ).recvMessage( null, linkMessage ) ) {
  				procsList.remove( i );
  				return;
  			}
  		}
  		signals++;
  	}
  
  	public synchronized void signForMessage( LinkInProcess.Execution process )
  	{
  		if ( signals > 0 && process.recvMessage( null, linkMessage ) ) {
  			signals--;
  		} else {
  			procsList.add( process );
  		}
  	}
  	
  	public synchronized void cancelWaiting( LinkInProcess.Execution process )
  	{
  		procsList.remove( process );
  	}
  
  	public static InternalLink getById( String id )
  	{
  		return ExecutionThread.currentThread().state().getLink( id ); 
  	}
  }
  