Window.driverRun is designed to run functions on the driver event
goroutine, to avoid race conditions with internal driver state and,
more importantly, to run on the designated main or UI thread for
platforms that require that.
However, driverRun runs functions during the processing of a driver
event, so if a function in turn triggers another driver event,
deadlock occurs.
This change introduces Window.driverDefer for functions that don't need
to block event processing. Functions passed to driverDefer may
themselves trigger new events.
A few callers of driverRun remain; they need the result of their
functions but are guaranteed not to trigger new events.
Fixes gio#263
Signed-off-by: Elias Naur <mail@eliasnaur.com>
Elias Naur
1796f24a38