[Xcb] Bug#463159: XCB-enabled libx11 causes hangs in various X clients

Michel Dänzer daenzer at debian.org
Wed Jan 30 02:01:01 PST 2008

On Tue, 2008-01-29 at 16:30 -0500, Joe Drew wrote:
> Package: libx11-6
> Version: 2:1.1.3-1
> Severity: critical
> This is only 'critical' because it causes unrelated software (e.g., Side
> Effects Software's Houdini) to break by causing hangs. Feel free to
> downgrade, but this is a very important bug to me, at least.
> This is also reported upstream:
> http://bugs.freedesktop.org/show_bug.cgi?id=9528
> Simply upgrading to a XCB-enabled libx11 build causes clients to start
> hanging inside _XReply. There is a bunch of analysis at
> http://lists.freedesktop.org/archives/xcb/2007-August/002961.html too.
> To reproduce, download a build of Houdini 9.0 from www.sidefx.com and
> run it. You will see various hangs almost immediately upon running
> 'houdini'.

As it seems threading related: Does XInitThreads() get called and finish
before any other libX11 function is called?

> I can help with all manner of debugging; I just don't understand X (and
> in particular, libx11 and XCB) enough to do this myself.

You can probably get better help on this on the upstream bug report or
mailing list.

Earthling Michel Dänzer           |          http://tungstengraphics.com
Libre software enthusiast         |          Debian, X and DRI developer

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