[PATCH xcb] Fix hanging issue in _XReply
Jose Alarcon
jose.alarcon at ge.com
Fri Aug 11 11:46:31 UTC 2017
From: Tatu Frisk <tatu.frisk at ge.com>
Assume event queue is empty if another thread is blocking waiting for event.
If one thread was blocking waiting for an event and another thread sent a
reply to the X server, both threads got blocked until an event was
received.
Signed-off-by: Tatu Frisk <tatu.frisk at ge.com>
Signed-off-by: Jose Alarcon <jose.alarcon at ge.com>
---
src/xcb_io.c | 19 +++++++------------
1 file changed, 7 insertions(+), 12 deletions(-)
diff --git a/src/xcb_io.c b/src/xcb_io.c
index bd26a62..a3ed025 100644
--- a/src/xcb_io.c
+++ b/src/xcb_io.c
@@ -603,22 +603,17 @@ Status _XReply(Display *dpy, xReply *rep, int extra, Bool discard)
* letting anyone else process this sequence number, we
* need to process any events that should have come
* earlier. */
-
if(dpy->xcb->event_owner == XlibOwnsEventQueue)
{
xcb_generic_reply_t *event;
- /* If some thread is already waiting for events,
- * it will get the first one. That thread must
- * process that event before we can continue. */
- /* FIXME: That event might be after this reply,
- * and might never even come--or there might be
- * multiple threads trying to get events. */
- while(dpy->xcb->event_waiter)
- { /* need braces around ConditionWait */
- ConditionWait(dpy, dpy->xcb->event_notify);
+
+ /* Assume event queue is empty if another thread is blocking
+ * waiting for event. */
+ if(!dpy->xcb->event_waiter)
+ {
+ while((event = poll_for_response(dpy)))
+ handle_response(dpy, event, True);
}
- while((event = poll_for_event(dpy)))
- handle_response(dpy, event, True);
}
req->reply_waiter = 0;
--
2.10.1
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