Re: [Discuss-gnuradio] Threading in python?

[Ilia Mirkin]

Quoting Michael Ford <address@hidden>:

> Up until now, all of my networking projects have been in C/C++, and I'd like
> to think that I'm pretty good with threading in those languages. As with the
> previous projects, I feel like threading will be a must. It's true that with
> wireless nodes, I won't be sending/receiving simultaneously with the same
> node. I figure that I'll have the node receiving unless the user inputs a
> file to be sent, so I'll need a thread that does nothing but receive (and
> that sendswhen it needs to), and a thread that constantly looks for user
> input. Should I be implementing the threading on the python level, or can I
> get away with doing this as a C++ file?
>
> -Michael Ford-

A somewhat more generic answer than Eric's:

Python and threads don't mix easily. There's one python interpreter/state, and
if it's interpreting in one thread, and you try to get it to do something else
from another thread, things will go bad (trying to access state, running
functions, etc may all do Bad Things (tm)). Python 2.4 and up has the concept
of a GIL (Global Interpreter Lock), which you must acquire before doing
anything else with the interpreter in a thread context. Alternatively you can
dedicate one thread to synchronize access to the python interpreter. To my
knowledge neither SWIG nor Boost.Python are aware of the GIL, so you must
acquire/release it for them.

Additionally, python does user threads (cooperative), though they are probably
not what you're looking for.

 -Ilia