The simplest possible service-discovery with pyzmq?

Question

I'd like to be able to do something like this: Python service discovery: Advertise a service across a local network

But without the time.sleep() statements - everything should work out of the pyzmq event loop.

How could this be rewritten in the 0mq style?

EDIT0: This will need to run on Linux (Redhat + Ubuntu) and Windows. Possibly mac as well. Let's just say everything, including Raspberry pi.