Thanks for explanation David. If it's purely about interruption of a local thread, I'd prefer the option D without introducing a new subclass exceptions. I'm not sure it's cluttering but it will be very convenient for the API users though. Personally I chose interruptable one as default: http://mina.apache.org/report/trunk/xref/org/apache/mina/common/IoFuture.... As you pointed out, a user can know explicitly that the interruption status flag is set from the fact that he or she caught the InterruptedException by oneself. We will need more documentation if we deal it with any other exception classes (i.e. RemotingException subclasses). View the original post : http://www.jboss.com/index.html?module=bb&op=viewtopic&p=4085829#... Reply to the post : http://www.jboss.com/index.html?module=bb&op=posting&mode=reply&a...