Re: Memory problems with gdk_pixbuf

[Tristan Van Berkom <tvb gnome org>]

John Coppens wrote:
> Hello people.
>
> A few weeks ago I posted a message about memory leaking. I haven't solved
> the problem yet (thanks for a few privately received suggestions though).
>
> The example below is taken largely from the GGAD manual, but, if the
> segment is called repeatedly, allocates large chunks of memory, until a
> certain point, where things break ('process killed')
>
> --------------
> global variable    GnomeCanvasItem *img_item = NULL;
> --------------
>   pxb = gdk_pixbuf_new_from_file(path, &err);
>
> // Check if the image was previously allocated. If so, destroy it
> // Note that this relies on the pxb being destroyed too. It seems
> // this does _not_ happen (Valgrind indicate this)
>
>   if (img_item)
>     gtk_object_destroy(GTK_OBJECT(img_item));
>
>   img_item = gnome_canvas_item_new(root,
>                 gnome_canvas_pixbuf_get_type(),
>                 "pixbuf", pxb,
>                 "x", 0.0, "y", 0.0,
>                 "width", pxb_w, "height", pxb_h,
>                 NULL);
>   gdk_pixbuf_unref(pxb);
> --------------
> My question is, what is the mechanism to destroy canvas items so that all
> resources are freed too. (The above is derived from example in the GGAD, I
> believe). Do I have to free the pxb manually?

You could try:

(gdb) watch ((GObject *)pxb)->ref_count

and see if you can find a reference leek, maybe the
canvas item isn't releasing its reference when it gets
destroyed ? maybe there is a reference leek somewhere else ?

Cheers,
                      -Tristan