This can be used to query whether the task has completed, in the sense
that it has had a result set on it, and has already – or will soon –
invoke its callback function.
Notifications for this property are emitted immediately after the task’s
main callback, in the same main context as that callback. This allows
for multiple bits of code to listen for completion of the GTask, which
opens the door for blocking on cancellation of the GTask and improved
handling of ‘pending’ behaviour.
https://bugzilla.gnome.org/show_bug.cgi?id=743636
This allows compilation with clang without errors, even when
-Wformat-nonliteral is active (as long as there are no real cases of
non literal formatting).
https://bugzilla.gnome.org/show_bug.cgi?id=691608
GTask is a replacement for GSimpleAsyncResult and GIOScheduler, that
also allows for making cancellable wrappers around non-cancellable
functions (as in GThreadedResolver).
https://bugzilla.gnome.org/show_bug.cgi?id=661767
