From owner-freebsd-hackers  Sun Nov 29 09:14:40 1998
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	Sun, 29 Nov 1998 12:14:11 -0500 (EST)
Date: Sun, 29 Nov 1998 12:14:11 -0500 (EST)
From: Daniel Eischen <eischen@vigrid.com>
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To: eischen@vigrid.com, eivind@yes.no
Subject: Re: Thread locking (was Re: cvs commit: src/include pthread.h src/lib/libc_r/uthread uthread_mattr_kind_np.c uthread_mutex.c)
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Eivind Eklund wrote:
> On Sun, Nov 29, 1998 at 09:31:18AM -0500, Daniel Eischen wrote:
> > The threads library is not fully POSIX compliant yet and has to
> > change if it wants to achieve that.  POSIX says that we return
> > EDEADLK if we detect this condition (which we can and already do).
> > Do we care more about backwards compatibility or more about POSIX
> > compliance?  I vote for strong and strict POSIX compliance (if my
> > vote counts at all ;-).
>
> I'm in two minds about it.  I don't like breaking compatibility, and I
> don't like not being conformant, and it really comes down to each
> individual case.  The behaviour we have now seems to be conformant to
> SS2, at least, which IMO is more important than POSIX.

What does the P in Pthreads mean?  Isn't SS2 based off an earlier rev
(draft) of the POSIX spec?  I would prefer POSIX compatibility over
SS2 compatibility, but I think we can do both if we are smart about
it.  At least in this instance we can since SS2 allows us to map
PTHREAD_MUTEX_DEFAULT to any other mutex type and PTHREAD_MUTEX_ERRORCHECK
happens to be POSIX compliant.

> I'm not the
> maintainer, anyway, so I don't consider it within my authority to
> break backwards compatibility.

Good point.

> When I think about it, it probably wouldn't create more problems, as
> it will only create problems if somebody is checking the return value
> (otherwise it will work as it already does).  I still consider the
> decision to be in John Birrells camp, however,

OK

Dan Eischen
eischen@vigrid.com

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