This patch was motivated by the need to fix the use-after-free in
dri2ClientWake, but in doing so removes an arbitrary restriction that
limits DRI2 to only blocking the first client on each drawable. In order
to fix the use-after-free, we need to avoid touching our privates in the
ClientSleep callback and so we want to only use that external list as
our means of controlling sleeps and wakeups. We thus have a list of
sleeping clients at our disposal and can manage multiple events and
sources.
Reviewed-by: Adam Jackson <ajax@redhat.com>
Signed-off-by: Chris Wilson <chris@chris-wilson.co.uk>