[Python-Dev] multiple interpreters and extension modules

[Jeremy Kloth]

On Friday 22 December 2006 7:16 pm, Guido van Rossum wrote:
> I think you understand exactly what is happening. It is happening for
> good reasons. Rather than asking for a change in semantics, I
> recommend that you deal with it, either in your Python code, or in
> your extension. It's not likely to change.

I don't believe I was asking for a change in semantics, rather an additional, 
optional interface for extension module writers.

> > 2) would it be worthwhile to have an extension loading function similar
> > to DllMain() for Windows' DLLs which is called multiple times with a flag
> > stating the reason for the call? For reference, see:
> > http://msdn.microsoft.com/library/default.asp?url=/library/en-us/dllproc/
> >base/dllmain.asp I envision the reasons as: 'module init', 'module fini',
> > 'interpreter init', 'interpreter fini'. I see no current need for special
> > treatment of threads as they share the same interpreter space.
> >
> > As to question 2, I'm in the process of prototyping that approach to see
> > if it is feasible in our code and if so, (and people find it useful) I'll
> > attempt to write a PEP for that feature.

I'll add here that it has been brought up here before that extension module 
finalization is a feature that would be appreciated.  With that, it is not 
that far to add support for initialization/finalization for each interpreter. 
That is, of course, using a DllMain-like solution.

> > My current thoughts on that are instead of the current init<module name>
> > entry point in C modules, a new entry point is defined, and if found,
> > used in its place. That way, this proposal would be optional for
> > extension writers and existing modules would continue to work without
> > change.

With that approach in mind, I will be making changes so 4Suite will work in a 
production mod_python deployment (where the aforementioned error occurred). 
When that works, I'll come back with a proper PEP *and* patches against 
Python SVN to support its use. I hope no one was thinking I wanted someone 
else to do the work.

-- 
Jeremy Kloth
http://4suite.org/