Attachment 44625 Details for Bug 30450 – Wake up _XReadEvents when _XReply might need a turn.

[patch] Wake up _XReadEvents when _XReply might need a turn.

0001-Wake-up-_XReadEvents-when-_XReply-might-need-a-turn.patch (text/plain), 2.83 KB, created by Jamey Sharp on 2011-03-19 16:29:03 UTC

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Creator: Jamey Sharp

Created: 2011-03-19 16:29:03 UTC

Size: 2.83 KB

patch

obsolete

>From 02ba27f37ffde181536f4f76097c3b95ead88680 Mon Sep 17 00:00:00 2001
>From: Jamey Sharp <jamey@minilop.net>
>Date: Fri, 18 Mar 2011 22:00:10 -0700
>Subject: [PATCH] Wake up _XReadEvents when _XReply might need a turn.
>
>This fixes the remaining known multi-thread "gotcha" left over after
>commit 933aee1d5c53b0cc7d608011a29188b594c8d70b.
>
>Fixes: https://bugs.freedesktop.org/show_bug.cgi?id=30450
>
>Signed-off-by: Jamey Sharp <jamey@minilop.net>
>Reviewed-by: Josh Triplett <josh@freedesktop.org>
>---
> src/xcb_io.c |   27 +++++++++++++++++----------
> 1 files changed, 17 insertions(+), 10 deletions(-)
>
>diff --git a/src/xcb_io.c b/src/xcb_io.c
>index 8930736..ed66cd9 100644
>--- a/src/xcb_io.c
>+++ b/src/xcb_io.c
>@@ -337,9 +337,20 @@ void _XReadEvents(Display *dpy)
> 		if(!dpy->xcb->next_event)
> 		{
> 			xcb_generic_event_t *event;
>+			unsigned long next_reply;
>+			if(dpy->xcb->pending_requests)
>+				next_reply = dpy->xcb->pending_requests->sequence;
>+			else
>+			{
>+				/* Make sure the Display's sequence
>+				 * numbers are valid. */
>+				require_socket(dpy);
>+				next_reply = dpy->request;
>+			}
>+
> 			dpy->xcb->event_waiter = 1;
> 			UnlockDisplay(dpy);
>-			event = xcb_wait_for_event(dpy->xcb->connection);
>+			event = xcb_wait_for_event_until(dpy->xcb->connection, next_reply);
> 			/* It appears that classic Xlib respected user
> 			 * locks when waking up after waiting for
> 			 * events. However, if this thread did not have
>@@ -351,8 +362,6 @@ void _XReadEvents(Display *dpy)
> 			InternalLockDisplay(dpy, /* ignore user locks */ 1);
> 			dpy->xcb->event_waiter = 0;
> 			ConditionBroadcast(dpy, dpy->xcb->event_notify);
>-			if(!event)
>-				_XIOError(dpy);
> 			dpy->xcb->next_event = event;
> 		}
> 
>@@ -365,11 +374,11 @@ void _XReadEvents(Display *dpy)
> 		response = poll_for_response(dpy);
> 		if(response)
> 			handle_response(dpy, response, False);
>-		else if(dpy->xcb->pending_requests->reply_waiter)
>+		else if(dpy->xcb->pending_requests && dpy->xcb->pending_requests->reply_waiter)
> 		{ /* need braces around ConditionWait */
> 			ConditionWait(dpy, dpy->xcb->reply_notify);
> 		}
>-		else
>+		else if(xcb_connection_has_error(dpy->xcb->connection))
> 			_XIOError(dpy);
> 	}
> 
>@@ -553,11 +562,9 @@ Status _XReply(Display *dpy, xReply *rep, int extra, Bool discard)
> 		{
> 			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. */
>+			 * it will get the first one, if there are any
>+			 * before this reply. That thread must process
>+			 * that event before we can continue. */
> 			while(dpy->xcb->event_waiter)
> 			{ /* need braces around ConditionWait */
> 				ConditionWait(dpy, dpy->xcb->event_notify);
>-- 
>1.7.2.3
>

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Attachments on bug 30450: 39041 | 44609 | 44625 | 44715

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