Re: gobject reference question

[Matthias Clasen <mclasen redhat com>]

On Mon, 2005-08-15 at 12:42 -0700, Wallace Owen wrote:
> On Mon, 2005-08-15 at 16:29 -0400, Tristan Van Berkom wrote:
> > Wallace Owen wrote:
> > > How can I see what the current reference count is, so I can be sure I'm
> > > using g_object_ref() and g_object_unref() correctly?
> >
> > You can check G_OBJECT (object)->ref_count, note that it is
> > fundementally wrong to do any conditional code based on this
> > (for the same reason you cant check if any free'd memory is
> > actually free'd) but it may help you debug.
>
> Yow!  I guess I was going to use it incorrectly.  I had searched through
> the demos for code that called g_object_unref(), and searched the API
> docs installed on my machine, and searched the tutorials on the GTK site
> for clues about when to bump the reference count and when to decrement
> it.  What I did not see was documentation telling me which gtk library
> functions would increment the count.
>
> I assumed, after my search, that putting a widget into a container would
> increment it's reference count.  But no, adding code to show the
> refcount after adding the widget to the container, that doesn't seem to
> be the case.  Putting a table into a dialog didn't seem to increase the
> table's refcount, and adding labels to the table didn't increase the
> refcnt of either the table or the labels.

You probably want to read up on the concept of "floating" references,
which are what you are seeing here. When a widget is created, it has an 
initial "floating" reference. When you add it to a container while it is
still floating, the container takes over the floating reference instead
of adding a new one.