forked from joejulian/gio
083d407b47
After 34f10d9cbb, the display link callback
will never block. However, if the main thread is blocked for another reason,
say a bug in the user program, callback requests will pile up as blocked
goroutines.
This change ensures that a redraw request is queued only if no other request
is pending.
References: https://todo.sr.ht/~eliasnaur/gio/370
Signed-off-by: Elias Naur <mail@eliasnaur.com>