[Xcb] xcb 1.1 dead lock

Todd Goyen tgoyen at swri.org
Sat Dec 15 22:00:47 PST 2007

I think I can produce a test case of it that can be released to the public. Give me a day or two.

Thanks for the repsonse.


PS See Below

On Sat, 15 Dec 2007 21:39:03 -0800
Jamey Sharp <jamey at minilop.net> wrote:

> Hash: SHA1
> On 12/13/07, Todd Goyen <tgoyen at swri.org> wrote:
> > Hello All,
> Hi Todd!
> > I am using Debian Unstable with XCB 1.1 from experimental.
> I assume you mean libX11 from experimental, and libxcb 1.1 from
> unstable? If you're still running libxcb 1.0, please make sure you can
> reproduce this bug with libxcb 1.1. We did fix a deadlock in that
> release, but I think not this deadlock.

You assume correctly and it is version 1.1 from unstable.

> > I have seen a dead lock with the following backtraces. The program
> > uses QT-4.3.3 and calls XInitThreads before anything else is
> > performed. The threads are used with the nVidia driver to  separate
> > OpenGL contexts and keep them synced to VBlank. In this case there
> > were 24 threads 11 of which are OpenGL rendering threads, 1 is the
> > GUI, and 12 are timers. It appears as though XTranslateCoordinates in
> > the main GUI thread caused the deadlock. Any ideas would be helpful.
> Augh. I believe I've seen this same deadlock using `ico -threads 3` or
> higher, but I haven't been able to work out the cause, let alone a fix.
> Since an application that matters is encountering it, I guess we'd
> better hurry up and fix it, eh? sigh. If you have experience debugging
> deadlocks, I believe the problem is mostly confined to process_responses
> in xcb_io.c, and any insight you can provide would be appreciated.
> Thanks for the complete backtrace. We'll let you know when there's a fix
> you can test; in the meantime, is this application one that we can get a
> copy of?
> Jamey
> Version: GnuPG v1.4.6 (GNU/Linux)
> iD8DBQFHZLnup1aplQ4I9mURAgsvAJ9DmvZbaGFmsJhg7GXLvsFGbKXtEACdGwmq
> ak2UYvBhYcKYY9MmI8fHUWQ=
> =zaZU

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