Client/Server UDP Program debugging in Eclipse

I'm trying to debug my Client-Server UDP program to see what it is doing but when I get to the .receive() method (in either the client or the server code) the break point disappears and the step-into/step-over buttons turn gray. What I see next to the .receive() method call is a littl开发者_JAVA技巧e white arrow that says "debug call stack" when I hover over it. What exactly is happening?

Has it something to do with the fact that it's a blocking call? If so how do I get past beyond this point?

Your call is blocked on that line, waiting for a read.

You can place another breakpoint right after that specific line. It will break after the receive() is done.

The block is probably native, so you can't really debug it. However, if you never get to the second breakpoint, you know that there is problem ;-)