""Magnus Hagander"" <mha@sollentuna.net> wrote
> Ok, I've coded up a patch that changes the code to use a mutex instead.

Are we asserting the problem is caused by the spinlock random wake-up order?
I am not sure why this would fix the problem. If my memory serves, a
critical section might be a problem if one process aborts unexpected while
it is inside. Other waiting processes can never have a chance to enter it
(also have no chance to handle SIGQUIT) -- so this patch may solve this.

There is another suspect in http://www.devisser-siderius.com/stack1.jpg,
i.e., process 3 does shmctl. I once filed a server core dump bug in win32 of
reporting WSAEWOULDBLOCK.
(http://archives.postgresql.org/pgsql.../msg00185.php). AFAICS, it
is actually an mistranslated EINTR. There seems some relation between these
issues, but I didn't come up with a complete theory of it.

Regards,
Qingqing