public synchronized void addPvChangeListener(PvChangeListener l,int eventMask){
  ensurePvChangeListeners();
  PvChangeListeners.put(l,new Integer(eventMask));
  allowEvents=true;
  log.trace("+PvListener:" + toString() + "->"+ String.valueOf(l));
}

public synchronized void addPvChangeListener ( PvChangeListener l , int eventMask ) { ensurePvChangeListeners ( ) ; PvChangeListeners . put ( l , new Integer ( eventMask ) ) ; allowEvents = true ; log . trace ( "+PvListener:" + toString ( ) + "->" + String . valueOf ( l ) ) ; }
add listener for pv changes with specified change events
