Verify that when receiving the first of two synchronization callback
events, destroying the second one doesn't cause any errors even if the
delete_id event is handled out of order.
Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Using signals in the previous way could potentially lead to dead locks
if the SIGCONT was signalled before a listener was registered.
Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
Check that after a callback removes a proxy that most likely will have
several events queued up with the same target proxy, no more callbacks
are invoked.
Signed-off-by: Jonas Ådahl <jadahl@gmail.com>
