cvs commit: src/lib/libpthread/thread thr_private.h thr_sig.c

Daniel Eischen deischen at
Tue Nov 2 15:40:51 PST 2004

On Wed, 3 Nov 2004, David Xu wrote:

> John Baldwin wrote:
> >On Monday 01 November 2004 06:04 pm, David Xu wrote:
> >
> >
> >>Not every important,  I think I have another very important history
> >>bug in hand,  did you get my "fix famous libpthread conditional
> >>variable race condition" mail ? :-)
> >>
> >>
> >
> >Oooo, can I test it please?  We are still having problems with mono on HEAD
> >here at work.  I tried merging the changes in uthread_cond.c 1.32 to
> >libpthread but that seemed to make it worse.  The problems seem to be that a
> >signal handler is being run when the SYNCQ sflag is set (but the thread is
> >not on a cv or a mutex queue), and the handler calls sem_post() which is
> >supposed to be signal safe.  sem_post() tries to lock a mutex and then bombs
> >with the assertion failure.
> >
> >
> >
> You can try:
> But it was not designed to fix the problem you have seen. :-)

I think if _kse_critical_leave() were replaced by _kcb_critical_leave()
at around line 676 in thr_kern.c, that should fix the problem, no?
There's no reason to do a yield check after leaving the scheduler,
and the check for signals and cancellation is done right after
that point before returning.

Dan Eischen

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