Re: Help needed with an a11y related Cheese bug

[Filippo Argiolas <fargiolas gnome org>]

On Thu, Mar 5, 2009 at 9:28 AM, Li Yuan <Li Yuan sun com> wrote:
> Hi Filippo,

Hi Li,

> I reproduced the bug. I think cheese is hanging. From the trace, I found 10
> threads in cheese, but I don't find any accessibility code involved. I am

Cheese should spawn at most 3 threads (main, camera setup, thumbnail
generation) (well, probably more when generating several thumbnails
but it's not a common case and surely not this one). The other ones
should come from gstreamer.

> not familiar with cheese's code so I don't know why there is a hang. But
> note that, when accessibility is enabled, a thread could lost the gdk lock
> when it emit a GUI signal, like show a window.
>
> There is such code in atk-bridge:
>
> bridge_threads_leave ();
> Accessibility_Registry_notifyEvent(...);
> bridge_threads_enter ();
>
> bridge_threads_leave is equal to GDK_THREADS_LEAVE and bridge_threads_enter
> is equal to GDK_THREADS_ENTER.
>
> Maybe this has something to do with the hang.

Yes, this seems reasonable, but what should I do to prevent this sort
of lock stealing?
See also my reply to Michael.
Thanks,

Filippo