Java NIO and SSL

Question

I'm writing a server using java NIO, and I have a few questions that I can't find answers to.

First, regarding SSLEngine, how to handle NEED_TASK properly in separated thread? When I invoke tasks in separate thread they complete, but I have no idea how to go back to perform another handshake operation. One option would be to call that operation from a thread that was performing delegated task, but I guess that's not the way to do it.

Another question is about calling interestOps() from different thread then selector thread. I need to change key interests after an attempt to write to channel hadn't written all data. I thought about using some sort of Queue of changes like in ROX NIO tutorial, but I have read in another thread here that it is not the best way.

Answer 1

first regarding SSLEngine, how to handle NEED_TASK properly in separated thread. When I invoke tasks in separate thread they complete, but I have no idea how to go back to perform another handshake operations.

While the engine is in NEED_TASK state it can't do anything else. When the task completes you should then repeat the operation that originally returned NEED_TASK and let the engine tell you what to do next. You need to block or disable use of that engine by other threads until the task completes, i.e. don't select on that channel.

Another question is about calling interestOps() from different thread then selector thread. I need to change key interests after an attempt to write to channel hadn't written all data. I thought about using some sort of Queue of changes like in ROX NIO tutorial, but I have read in another thread here that it is not the best way.

That would have been me. I hate those queues. I just wakeup() the selector and change the interestOps, never seen a problem with that. The selector thread has to cope correctly with zero keys being ready, but it already needs to do that.