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Message-ID: <00b101c101b4$1cbcc980$6501a8c0@apache>
From: "Bill Stoddard" <bill@wstoddard.com>
To: <dev@apr.apache.org>
References: <Pine.LNX.4.30.0106301407300.2496-100000@koj.rkbloom.net>
Subject: Re: [PATCH] Allow pthread_mutex_t to be a cross-process lock
Date: Sat, 30 Jun 2001 18:29:14 -0400
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> On Sat, 30 Jun 2001, Bill Stoddard wrote:
>
> >
> > > On Sat, 30 Jun 2001, Justin Erenkrantz wrote:
> > >
> > > > Can someone enlighten me as to why we have --with-pthread-cross and we
> > > > aren't telling anyone?  If we have pthread.h, PTHREAD_PROCESS_SHARED,
> > > > and pthread_mutexattr_setpshared, it seems reasonable enough to
> > > > define USE_PROC_PTHREAD_SERIALIZE to 1.  Or, are pthread_mutex_t not
> > > > suitable for cross-process locks for some other reason that we have to
> > > > have a manual override?
> > > >
> > > > Unless someone says otherwise, I'll commit this tonight/tomorrow.
> > >
> > > In general, most platforms don't really support cross process pthread
> > > mutex's.  Even those that have PTHREAD_PROCESS_SHARED tend to not work
> > > properly.  For example, AIX has that defined, but they don't really
> > > support pthread mutex's cross processes.
> >
> > PTHREAD_PROCESS_SHARED works for me on AIX 4.3.2 and later. And you will see this is the default
for
> > Apache 1.3 for AIX.
> >
> > Are you seeing actual failures or going from memory of conversations past?
>
> Memories of conversations with Manoj.  AIX may have it working, but I
> definately remember that there are platforms with PTHREAD_PROCESS_SHARED
> defined even though it doesn't work.
>
> Ryan

AIX 4.2.1 implements pthreads draft 7 and it defines PTHREAD_PROCESS_SHARED but does not implement
it. That's probably what your thinking of.

Bill