Re: CFT: patch for process shared pthread objects

On Mon, Nov 29, 2010 at 9:48 PM, David Xu <davidxu_at_freebsd.org> wrote:
> Hi,
>
> I finally have worked out first patch to make our pthread library
> support process shared pthread objects:
>
> http://people.freebsd.org/~davidxu/pshared/patch1.diff
>
> Many changes are related to redesigned pthread condition variable,
> these changes try to eliminate extra context switch when
> pthread_cond_signal is called which could reduce performance.
> There are two parts in the condition variable implementation.
> A pure usermode condition variable and kernel-based condition
> variable. All priority protected, inherited mutexs and process
> shared mutex will use kernel base condition variable, for a
> normal mutex, the usermode condition variable is used.
> Both user-mode and kernel-based try to migrate a thread from
> condition variable wait queue to mutex wait queue.
>
> Another added feature is robust mutex support,
> http://www.opengroup.org/onlinepubs/9699919799/functions/pthread_mutexattr_setrobust.html
> Which I think is mostly used for process-shared mutex.
>
> In the patch, if mutex attribute is robust, the thread library
> also uses kernel base condition variable which does not have
> internal lock in userland.

Doesn't build :/...:

===> lib/libthr (obj,depend,all,install)
make: don't know how to make thr_sleepq.c. Stop
*** Error code 2

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.
*** Error code 1

Stop in /usr/src.

Thanks,
-Garrett