We're seeing UI deadlocks occasionally and this is possibly due to the
use of a daemonic thread in the UI event queue processing. This thread
could terminate holding a threading Lock() which would cause issues
for the process when exitting.
Change the shutdown process to handle this more cleanly.
(Bitbake rev: f5ad8349a5dbff9824a89f5708cfd011d61888c9)
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
ce592bc9ac