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Date: Mon, 11 Jun 2001 00:31:53 +0200
From: Luke Kenneth Casson Leighton <lkcl@samba-tng.org>
To: Ben Laurie <ben@algroup.co.uk>
Cc: Cliff Woolley <cliffwoolley@yahoo.com>, dev@apr.apache.org
Subject: Re: cvs commit: apr/memory/unix apr_sms.c
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	Cliff Woolley <cliffwoolley@yahoo.com>, dev@apr.apache.org
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In-Reply-To: <3B225E1D.B5F26BB6@algroup.co.uk>;
 from ben@algroup.co.uk on Sat, Jun 09, 2001 at 06:34:21PM +0100

On Sat, Jun 09, 2001 at 06:34:21PM +0100, Ben Laurie wrote:
> Luke Kenneth Casson Leighton wrote:
> > 
> > uh... i thought i should point out: the original proposal
> > i recommended for the sms locking routine should pass
> > in the area of memory to be locked and its length,
> > and ditto for the unlocking.
> 
> +1.
> 
> > in this way, let's say you do mmap on a file, you can
> > use posix locking as the implementation of the locking
> > on the memory.
> > 
> > [or can you?  i dunno, for sure :) ]
> 
> I believe so.
> 
> > and, if the argument is NULL, it means ' do a Global Lock'.
> > 
> > if the unlock() argument is NULL, it means 'do a Global
> > Unlock - i.e. free all locks'.
> 
> And if the locking mechanism doesn't support regions? (This is
> particularly important if you allow unlocking of subregions). The
> obvious answer being that we implement them in APR, of course.

well, that is what made me think that perhaps a separate
lock and lock_region be done, such that one or other
cold be supported.

or, you mandate providing locking, emulating regions by
... errr.... providing ref-counting on a global lock (yuck!)

hm, that don't work.  nope: have to do the lock and
lock_region, then have a means for Users to detect
that a lock_region function is available / supported.

you know, this is all tending to suggest having a
'apr_sms_get_features()' fn, returning a bitfield
of supported features.

... ?

luke