virtualchannelselector.java

这是一个基于java编写的torrent的P2P源码

    }
    else {
      selector_impl.pauseSelects( channel );
    }
  }
  

  
  /**
   * Resume selection operations for the given channel
   * @param channel to resume
   */
  public void resumeSelects( AbstractSelectableChannel channel ) {
    if( SAFE_SELECTOR_MODE_ENABLED ) {
      try{  selectors_mon.enter();
      	//System.out.println( "resume - " + channel.hashCode() + " - " + Debug.getCompressedStackTrace());
        for( Iterator it = selectors.entrySet().iterator(); it.hasNext(); ) {
          Map.Entry entry = (Map.Entry)it.next();          
          VirtualChannelSelectorImpl sel = (VirtualChannelSelectorImpl)entry.getKey();
          ArrayList channels = (ArrayList)entry.getValue();
          
          if( channels.contains( channel ) ) {
            sel.resumeSelects( channel );
            return;
          }
        }
        
        System.out.println( "resumeSelects():: channel not found!" );
      }
      finally{ selectors_mon.exit();  }
    }
    else {
      selector_impl.resumeSelects( channel );
    }
  }
  
  

  /**
   * Cancel the selection operations for the given channel.
   * @param channel channel originally registered
   */
  public void cancel( AbstractSelectableChannel channel ) {
    if( SAFE_SELECTOR_MODE_ENABLED ) {
      try{  selectors_mon.enter();
      	//System.out.println( "cancel - " + channel.hashCode()  + " - " + Debug.getCompressedStackTrace());
        for( Iterator it = selectors.entrySet().iterator(); it.hasNext(); ) {
          Map.Entry entry = (Map.Entry)it.next();          
          VirtualChannelSelectorImpl sel = (VirtualChannelSelectorImpl)entry.getKey();
          ArrayList channels = (ArrayList)entry.getValue();
          
          if( channels.remove( channel ) ) {
            sel.cancel( channel );
            return;
          }
        }
      }
      finally{ selectors_mon.exit();  }
    }
    else {
      if( selector_impl != null )  selector_impl.cancel( channel );
    }
  }

  
  
  /**
   * Run a virtual select() operation, with the given selection timeout value;
   * (1) cancellations are processed (2) the select operation is performed; (3)
   * listener notification of completed selects (4) new registrations are processed
   * @param timeout in ms; if zero, block indefinitely
   * @return number of sockets selected
   */
  public int select(long timeout) {
    if( SAFE_SELECTOR_MODE_ENABLED ) {
      boolean	was_destroyed = destroyed;
      
      try{	
	      int count = 0;
	      
	      for( Iterator it = selectors_keyset_cow.iterator(); it.hasNext(); ){
	    	  
	        VirtualChannelSelectorImpl sel = (VirtualChannelSelectorImpl)it.next();
	        
	        count += sel.select( timeout );
	      }
	      
	      return count;
	      
      }finally{
    	  
    	  if ( was_destroyed ){
    		  
    		  // destruction process requires select op after destroy...
    		  
   			 try{  
   				 selectors_mon.enter();

	 		     selectors.clear();
			     selectors_keyset_cow = new HashSet();
			     
   			 }finally{
   				 selectors_mon.exit();
   			 }
    	  }
      }
    }
   
    return selector_impl.select( timeout );
  }

  public void destroy()
  {
	  destroyed	= true;
	  
	  if ( SAFE_SELECTOR_MODE_ENABLED ){
				      
	     for( Iterator it = selectors_keyset_cow.iterator(); it.hasNext(); ) {
	    	 
	        VirtualChannelSelectorImpl sel = (VirtualChannelSelectorImpl)it.next();
	        
	        sel.destroy();
	     }
	  }else{
		  selector_impl.destroy();
	  }
  }
  
  public boolean
  isDestroyed()
  {
	  return( destroyed );
  }
  
  public boolean isSafeSelectionModeEnabled() {  return SAFE_SELECTOR_MODE_ENABLED;  }
  
  public void enableSafeSelectionMode() {
    if( !SAFE_SELECTOR_MODE_ENABLED ) {
      SAFE_SELECTOR_MODE_ENABLED = true;
      COConfigurationManager.setParameter( "network.tcp.enable_safe_selector_mode", true );
      initSafeMode();
    }
  }
  
  public boolean
  selectSuccess(
	VirtualAbstractSelectorListener		listener,
	AbstractSelectableChannel 			sc, 
	Object 								attachment )
  {
	  if ( op == OP_ACCEPT ){
		  
		  return(((VirtualAcceptSelectorListener)listener).selectSuccess( VirtualChannelSelector.this, (ServerSocketChannel)sc, attachment ));
	  }else{
		
		  return(((VirtualSelectorListener)listener).selectSuccess( VirtualChannelSelector.this, (SocketChannel)sc, attachment ));
	  }
  }
  
  public void
  selectFailure(
	VirtualAbstractSelectorListener		listener,
	AbstractSelectableChannel 			sc, 
	Object 								attachment, 
	Throwable							msg)
  {
	  if ( op == OP_ACCEPT ){
		  
		  ((VirtualAcceptSelectorListener)listener).selectFailure( VirtualChannelSelector.this, (ServerSocketChannel)sc, attachment, msg );
	  }else{
		
		  ((VirtualSelectorListener)listener).selectFailure( VirtualChannelSelector.this, (SocketChannel)sc, attachment, msg );

	  }
  }

  public interface
  VirtualAbstractSelectorListener
  {
  }
  
  /**
   * Listener for notification upon socket channel selection.
   */
  public interface VirtualSelectorListener extends VirtualAbstractSelectorListener{
    /**
     * Called when a channel is successfully selected for readyness.
     * @param attachment originally given with the channel's registration
     * @return indicator of whether or not any 'progress' was made due to this select
     * 			null -> progress made, String -> location of non progress
     *         e.g. read-select -> read >0 bytes, write-select -> wrote > 0 bytes
     */
    public boolean selectSuccess(VirtualChannelSelector selector, SocketChannel sc, Object attachment);

    /**
     * Called when a channel selection fails.
     * @param msg  failure message
     */
    public void selectFailure(VirtualChannelSelector selector, SocketChannel sc, Object attachment, Throwable msg);
  }

  public interface VirtualAcceptSelectorListener extends VirtualAbstractSelectorListener{
    /**
     * Called when a channel is successfully selected for readyness.
     * @param attachment originally given with the channel's registration
     * @return indicator of whether or not any 'progress' was made due to this select
     *         e.g. read-select -> read >0 bytes, write-select -> wrote > 0 bytes
     */
    public boolean selectSuccess(VirtualChannelSelector selector, ServerSocketChannel sc, Object attachment);

    /**
     * Called when a channel selection fails.
     * @param msg  failure message
     */
    public void selectFailure(VirtualChannelSelector selector, ServerSocketChannel sc, Object attachment, Throwable msg);
  }

}