Doubt on what can I do from secondary threads

[Conscious User <conscioususer gmail com>]

Hi,

I am using a little bit of Python threading in my app and I know
that I'm supposed to either use the (soon-to-be-deprecated)
Gdk.threads_enter/Gdk.threads_leave pair or (preferably)
GLib.idle_add to call Gdk/Gtk methods from secondary threads.

I'm in doubt whether I can do two basic operations directly from
secondary threads:

1) Create new references to Gdk/Gtk objects. For example, if
"a" is a variable that references a Gdk/Gtk object, can I do
"b = a" in a secondary thread?

2) Call methods of a Gdk/Gtk object, but methods that I created
in a subclass and that do nothing directly related to Gdk/Gtk.
For example, if I have a class like

class MyButton(Gtk.Button):
    def my_method(self):
          a = 1 + 1

can I call my_method from a secondary thread?

Those doubts come from the fact that I don't know what
PyGObject does under the hood. For example, it obviously
does some GObject refcount updates in case (1), but I'm
in doubt whether this "touches" Gtk/Gdk somehow.

Thanks!