[Bug libgomp/40362] openmp: some libgomp functions trigger data races

[pinskia at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40362

--- Comment #13 from Andrew Pinski <pinskia at gcc dot gnu.org> 2012-12-29 21:32:06 UTC ---
(In reply to comment #12)
>   ws = gomp_ptrlock_get (&ws->next_ws);

This is really just:
 ws = gomp_ptrlock_get (ws+offsetof(next_ws));

So there are no loads there.  This is a race condition only if we go from
non-null to null which cannot happen here.  TSAN cannot detect that as it does
not understand that case which is a complex case to understand

Also does TSAN understand futex's which might the other thing throwing it off
just as Hellgrtind and drd was thrown off by it.