void g_closure_add_marshal_guards ( GClosure* closure, gpointer pre_marshal_data, GClosureNotify pre_marshal_notify, gpointer post_marshal_data, GClosureNotify post_marshal_notify )
Adds a pair of notifiers which get invoked before and after the closure callback, respectively.
This is typically used to protect the extra arguments for the
duration of the callback. See
g_object_watch_closure() for an
example of marshal guards.