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

[From: Martin Grimme]

Especially make use of gc.collect() after you have worked with
gdk.Pixbuf objects. They won't free their memory otherwise. It's a
good habit to free unused Pixbufs with del and run the garbage
collector afterwards.
And be aware that if a class overrides the __del__ method (some sort
of destructor), it won't be freed by the garbage collector at all.


Cheers,
Martin

2007/12/31, Alex Iliadis <alex at immunityinc.com>:
> I recommend using the garbage collector module manually to override the
> defaults. Python for some reason doesn't reclaim memory fast. So if you
> put in your code:
> import gc
> gc.collect()  (at the right spots, probably after the file chooser dialog
> and after some memory intensive tasks). You should notice a lot of memory
> being free'd up.
>
> -Alex
>
> On Sunday 30 December 2007 05:20:34 pm Jayesh Salvi 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:
> >
> > import gtk
> > import hildon
> >
> > #window = gtk.Window(gtk.WINDOW_TOPLEVEL)
> >
> > #fileChooser = gtk.FileChooserDialog(
> > #       title="Choose a photo to publish",
> > #       buttons=(gtk.STOCK_CANCEL, gtk.RESPONSE_CANCEL,
> > #       gtk.STOCK_OK, gtk.RESPONSE_OK))
> >
> > fileChooser = hildon.FileChooserDialog(
> >         window,gtk.FILE_CHOOSER_ACTION_OPEN)
> >
> >
> > result = fileChooser.run()
> >
> > if result == gtk.RESPONSE_OK:
> >         print fileChooser.get_filename()
> >
> > Do you have any tips, as to what might be going wrong?
> >
> > This problem is fatal at least on n770 - it will trigger low memory
> > message when other applications are used on the side.
> >
> > Any help will be useful.
> >
> > Thanks,
>
>
> _______________________________________________
> maemo-developers mailing list
> maemo-developers at maemo.org
> https://lists.maemo.org/mailman/listinfo/maemo-developers
>