RE: qdata callback not called

[Murray Cumming Comneon com]

> From: Owen Taylor [mailto:otaylor redhat com] 
> 
> On Thu, 2003-06-26 at 02:54, Murray Cumming Comneon com wrote:
> > I believe that the callback given to g_object_set_qdata_full()
> > should be called when the GObject is destroyed, but it 
> doesn't seem to work
> > in this simple test case:
> > http://bugzilla.gnome.org/showattachment.cgi?attach_id=17788
> > 
> > Have I made a simple mistake in that test code, or am I 
> misunderstanding
> > something?
> > 
> > We use this in the internals of gtkmm and I'm sure it works 
> most of the
> > time, so I am confused. We can of course just connect to 
> the "destroy"
> > signal if we can't get this to work consistently.
> 
> qdata is freed on finalize, not on destroy. Your example leaks
> the button, so the qdata will never be freed.

I thought it might be something like this. I guess we'll watch for destroy
rather than finalize.
 
> The reason that it leaks is probably most apparent if you 
> understand why it is *not* leaked in the normal case:
> 
>  create button: reference count 1, floating
>  add button to container: container adopts button, reference count 1,
>   not floating
>  destroy button: button is removed from parent, reference
>   count drops to 0, finalized
> 
> But if you destroy a floating button, nothing will happen to
> the reference count.

OK, thanks. Out of interest, can we explicitly finalize the button, or do we
have to add it to a container, then destroy it, in order to avoid the leak.

Murray Cumming
murrayc usa net
www.murrayc.com