[maemo-developers] python2.5 - unnecessary multiple processes forked

[From: Lauro Moura]

On 12/30/07, Jayesh Salvi <jayesh at altfrequency.com> wrote:
> Hi,
>
> I am porting a pygtk application to maemo. It works alright, but I noticed
> that it was consuming lot of memory, preventing me from opening other
> applications.
>
> When I investigated, I found that my python application was forking 4 more
> instances of itself, each one identical in memory footprint. Thus they
> consumed nearly 60-70% of my memory.
>
> So I ran my application using pdb and narrowed down to a code segment that
> was leading to multiple instances of the process. It turned out that when I
> call run() on hildon.fileChooserDialog object, the dialog opens and at that
> moment in the "top" I see 4 more instances being forked.
>
> I fail to understand this behavior. I replaced the hildon widgets by pure
> gtk widgets and I see similar behavior, except that 2 more instances get
> forked. Also when using gtk.FileChooserDialog, these new instances get
> created in the instantiation of the dialog object, rather than call to
> run(). (code included below)
>
> So to further explore the problem, I ran same application on my desktop with
> gtk widgets. But I verified that when fileChooserDialog's run is called,
> there are no additional instances of python.
>
> I am running this code on n770, with 2007 HE and python2.5 runtime. My
> application code is pure python and not using any additional libraries. In
> fact following would be a simpler version of it to reproduce the problem:
>
> ...
> Do you have any tips, as to what might be going wrong?
>

With the following C code[1] the same problem happens.

[1] http://pastebin.com/m2d7c9783

-- 
Lauro Moura
INdT - Instituto Nokia de Tecnologia