public synchronized void invalidateReader(int id_jvm) throws JvnException{
		if(reader_list.size() > 0){
			for(Integer i : reader_list){
				if(i.intValue() != id_jvm){
					coord.jvnInvalidateReader(id_jvn_object, i.intValue());
				}
			}
			reader_list.clear();
			writer = id_jvm;	
		}
	}