Re: memory management with glibmm & giomm

[Armin Burgmeier <armin arbur net>]

On Tue, 2008-10-14 at 20:04 +0200, nico wrote:
> Hello,
> 
> One week ago, I sent an email about a leak of memory of a program that 
> list files of a directory (using giomm).
> My program was inspired by an official sample code (that we can get 
> here: 
> http://svn.gnome.org/viewvc/gtkmm-documentation/trunk/examples/book/giomm/directory_list/)
> 
> In fact, there is a bug in this sample program:
> 
> >  *Glib*::RefPtr<Gio::FileInfo> file_info = enumerator->next_file();
> >     *while*(file_info)
> >     {
> >       *std*::cout << *"file: "* << file_info->get_name() << std::endl;
> >       file_info = enumerator->next_file();
> >     }
> This piece of code create FileInfo objects and never unref them.
> The right code would have beeb:
> >  Glib::RefPtr<Gio::FileInfo> file_info = enumerator->next_file();
> >     while(file_info)
> >     {
> >       std::cout << "file: " << file_info->get_name() << std::endl;
> >       file_info = enumerator->next_file();
> >       file_info->unreference();
> >     }
> Or, an other variant :
> > while(Glib::RefPtr<Gio::FileInfo> file_info = enumerator->next_file()) {
> >     std::cout << "file: " << file_info->get_name() << std::endl;
> >     file_info->unreference();
> > }

You should never need to call unreference() yourself. If this fixes the
memory leak problem, then the problem is that
FileEnumerator::next_file() method does add an additional reference to
the return value, although it shouldn't.

> I'll try to report the bug,

Thanks.

> Regards,
> Nicolas

Armin