Protocol for thread communication

[Michael Torrie]

Does anyone have any recommended ideas/ways of implementing a proper
control and status protocol for communicating with threads?  I have a
program that spawns a few worker threads, and I'd like a good, clean way
of communicating the status of these threads back to the main thread.
Each thread (wrapped in a very simple class) has only a few states, and
progress levels in those states.  And sometimes they can error out,
although if the main thread knew about it, it could ask the thread to
retry (start over).  How would any of you do this?  A callback method
that the thread can call (synchronizing one-way variables isn't a
problem)?  A queue?  How would the main thread check these things?
Currently the main thread is polling some simple status variables.  This
works, and polling will likely continue to be the simplest and easiest
way, but simple status variables are very limited.  Are there any
pythonic patterns people have developed for this.

thanks.

Michael