<html> <head> <base href="https://bugs.freedesktop.org/"> </head> <body> <div> <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Some Unity games fail assertion on startup in glXCreateContextAttribsARB" href="https://bugs.freedesktop.org/show_bug.cgi?id=99781#c22">Comment # 22</a> on <a class="bz_bug_link bz_status_REOPENED " title="REOPENED - Some Unity games fail assertion on startup in glXCreateContextAttribsARB" href="https://bugs.freedesktop.org/show_bug.cgi?id=99781">bug 99781</a> from <a class="email" href="mailto:zegentzy@protonmail.com" title="Hal Gentz <zegentzy@protonmail.com>"> Hal Gentz</a> <pre>Created <a href="attachment.cgi?id=144685" name="attach_144685" title="Requested patch (does not work)">attachment 144685</a> <a href="attachment.cgi?id=144685&action=edit" title="Requested patch (does not work)">[details]</a> <a href='page.cgi?id=splinter.html&bug=99781&attachment=144685'>[review]</a> Requested patch (does not work) I tried implementing your suggested patch, Uli, but it did not work. XSync also tried to call LockDisplay, which for some reason blocks with our call to LockDisplay. This behavior, I think, contradicts what the XLockDisplay docs say: > Nested calls to XLockDisplay work correctly; the display will not actually be unlocked until XUnlockDisplay has been called the same number of times as XLockDisplay. This behavior really suprized me, so I'm not sure what's up. My only suspician is that the mutex not being made with a call to pthread_mutex_init w/ the PTHREAD_MUTEX_RECURSIVE attribute. I tried grepping for `pthread_mutex_init`, `PTHREAD_MUTEX_RECURSIVE`, `pthread` and `RECURSIVE` in the libx11 codebase to no avail. The only file I found was `UIThrStubs.c`, which if I understand correctly, is only used when multi-threading support is disabled at compile time. I found a call to some `xmutex_init` function in locking.c, however, this function only receives one parameter, unlike the two required by `pthread_mutex_init`. gdb shows (I had to use `si` instead of `s`) that calls to `xmutex_init` actually result in `pthread_mutex_init` getting called, however, I'm not sure if that's because `xmutex_init` is some clever macro, or if `-O3` inlined it. Nevertheless, I could not find any definition for `xmutex_init` beyond the one in `UIThrStubs.c`. I think we could possibly move the call to XSync after the call to UnlockDisplay, however, I'm concerned that this might lead to some sort of race condition if some other thread locking the display between our call to UnlockDisplay and XSync's call to LockDisplay.</pre> </div> <hr> You are receiving this mail because: <ul> <li>You are the QA Contact for the bug.</li> </ul> </body> </html>