[Python-Dev] Find out whether PyEval_InitThreads has been called?

[Gustavo J. A. M. Carneiro]

A Seg, 2004-08-16 às 11:35, Gustavo J. A. M. Carneiro escreveu:
> Short version:
> 
>   Can I add a variable to python to indicate whether PyEval_InitThreads
> has been called?  Something like:
> 
> 	extern int PyEval_ThreadsInitialized;
> 
> Motivation:
> 
>   I have discovered that, in pygtk, performance decreases a lot (50-90%
> higher exectution time) when we use python locking.  We have an internal
> boolean flag in pygtk to indicate whether pygtk threading was enabled or
> not, thus avoiding the GIL locking functions in single threaded
> programs.
> 
>   The problem is that this flag is local to pygtk.  If another module
> activates threading in python, we would like to know it in order to
> start acquiring the GIL.
> 
>   This should be a very simple patch, with zero impact in python core,
> but it will help tremendously.  Is likely to be accepted for python 2.4?

  Forget it.  Why not go one step further and make all locking
operations in python no-ops if PyEval_InitThreads has never been
called?  Currently, we risk python crashing if we call such functions
without calling PyEval_InitThreads.  This is also trivial to implement.

  Regards.

-- 
Gustavo J. A. M. Carneiro
<gjc at inescporto.pt> <gustavo at users.sourceforge.net>
The universe is always one step beyond logic