Problem with references

["Gabriele Greco" <gabriele greco darts it>]

After some headache with my gtk C++ classes I've found  with a small test
program this fact about the gobject references:

Window
Creation: 1 Sink: 2 End: 1
Label
Creation: 1 Sink: 1 End: 0

It seems that window derived widgets are created with a not floating
reference, so they should be handled differently, are window classes the
only GTK objects created with a strong reference or there are also other
widgets?

The strange thing is that both GtkWindow and GtkLabel derive from
GObjectInitiallyUnowned. And that if I use:

g_object_is_floating() to avoid the additional reference on the window
object when I unref it I get:

(<unknown>:29976): GLib-GObject-WARNING **: instance with invalid (NULL)
class pointer

(<unknown>:29976): GLib-GObject-CRITICAL **: g_signal_handlers_destroy:
assertion `G_TYPE_CHECK_INSTANCE (instance)' failed
End: -1


Here is the code (tested with GTK 2.12):

#include <gtk/gtk.h>

int main()
{
    gtk_init(NULL, NULL);

    GtkWindow *w = gtk_window_new(GTK_WINDOW_TOPLEVEL);
    GtkWidget *l = gtk_label_new("Test");

    printf("Window\nStart: %d ", G_OBJECT(w)->ref_count);
    g_object_ref_sink(G_OBJECT(w));
    printf("Sink: %d ", ((GObject *)w)->ref_count);
    g_object_unref(G_OBJECT(w));
    printf("End: %d\n", ((GObject *)w)->ref_count);

    printf("Label\nStart: %d ", G_OBJECT(l)->ref_count);
    g_object_ref_sink(G_OBJECT(l));
    printf("Sink: %d ", ((GObject *)l)->ref_count);
    g_object_unref(G_OBJECT(l));
    printf("End: %d\n", ((GObject *)l)->ref_count);
}

-- 
Ing. Gabriele Greco, DARTS Engineering
Tel: +39-0105761240  Fax: +39-0105760224
s-mail: Via G.T. Invrea 14 - 16129 GENOVA (ITALY)