Python + Shoutpy + Twisted Locks

[Michel Albert]

On Oct 6, 4:21 am, "Gabriel Genellina" <gagsl-... at yahoo.com.ar> wrote:
> En Fri, 05 Oct 2007 04:55:55 -0300, exhuma.twn <exh... at gmail.com> escribi?:
>
> > [...] What I found
> > is that "libshout" is blocking, which should be fine as the whole
> > thing runs in it's separate thread. But the application hangs
> > nevertheless while streaming. This effectively blocks out the other
> > thread that checks the player status, which then fails to append new
> > songs to the queue. So only one song is played when streaming.
>
> > The other threads in my application run fine and don't block the rest
> > of the app. So I guess, that the main problem is that blocking occurs
> > "outside" the python world and "inside" the libshout world.
>
> Only one thread at a time may be executing Python code; the Global
> Interpreter Lock (GIL) ensures the mutual exclusion. Extension modules
> (written in C) may use the macros
> Py_BEGIN_ALLOW_THREADS/Py_END_ALLOW_THREADS to release/acquire the GIL
> before/after an external blocking call.
> I don't know libshout, or how you are doing the binding python-libshout,
> but if your analysis is correct it means that the code is not releasing
> the GIL at the appropiate points.
>
> --
> Gabriel Genellina

Hmmm... ok. I suppose rewriting the whole thing using twisted's
deferreds could then solve the problem. Which are basically nothing
more than callbacks with a weird name ;) Unfortunately this means that
I have to re-think a lot. But in the end I suppose it will pay off.

Thanks for taking the time and reading my little essay Gabriel ;)