2013-11-19 10:40, John Emmas skrev:
On
18/11/2013 19:16, John Emmas wrote:
On 18/11/2013 18:32, Kjell Ahlstedt wrote:
Seems quite similar to the problem you described in
https://mail.gnome.org/archives/gtkmm-list/2013-November/msg00000.html
Have you got any further with the trouble-shooting after
https://mail.gnome.org/archives/gtkmm-list/2013-November/msg00024.html
?
You're right, it's exactly the same issue. [...] I'll resume
my trouble-shooting on that previous issue and report back what
I find.
Okay, it only took a few minutes to resume my trouble-shooting so
I've just added an update about what I found.
Getting back to the "MyDialog" example I supplied yesterday, this
is the sequence of function calls when closing MyDialog on my
system:-
1) Gtk::Widget::on_hide() // occurs on window closure (BEFORE the
call to delete). Therefore 'gobject_' is still valid
2) Window::_destroy_c_instance() // occurs during the call to
'delete' and subsequently calls....
3) Object::disconnect_cpp_wrapper() // invalidates 'gobject_'
(sets it to NULL)
4) Gtk::Widget::on_unrealize() // crashes because gobject_ ==
NULL
Kjell, if you can find some time today could you try building
MyDialog and verify if you see the same sequence? If you do,
we'll need to figure out why your gcc build is tolerant of
gobject_ being NULL whereas my MSVC build isn't. I feel as if
we're getting quite close to a solution though. Many thanks.
John
I have run your MyDialog program with gtkmm 2.24.4 on Linux. I can
verify that I do not see the same sequence.
Steps 1, 2, and 3 are the same, but Gtk::Widget::on_unrealize() is
not called. Widget_Class::unrealize_callback() is called, but
on_unrealize() is not called from there, because
Glib::ObjectBase::_get_current_wrapper((GObject*)self) returns 0,
and obj_base is 0.
_get_current_wrapper() returns 0, because
Gtk::Object::disconnect_cpp_wrapper() removed Glib::quark_.
You mentioned in
https://mail.gnome.org/archives/gtkmm-list/2013-November/msg00022.html
that you have "glibmm_Glib::quark_" in the list of GQuarks, when I
have "glibmm_Glib::quark_cpp_wrapper_deleted_". It's as if
g_object_steal_qdata((GObject*)gobj(), Glib::quark_);
g_object_set_qdata((GObject*)gobj(),
Glib::quark_cpp_wrapper_deleted_, (gpointer)true);
in Gtk::Object::disconnect_cpp_wrapper() don't do what they should.
Confusing!
In your example with Gtk::Dialog instead of MyDialog, the crash is
avoided because in Widget_Class::unrealize_callback()
obj_base->is_derived_() is false, and on_unrealize() is not
called even if obj_base != 0.
Kjell
|
