apr-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From Ben Laurie <...@algroup.co.uk>
Subject Re: cvs commit: apr/memory/unix apr_sms.c
Date Mon, 11 Jun 2001 08:22:59 GMT
Luke Kenneth Casson Leighton wrote:
> 
> 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.

You can emulate regions with global locks and shared memory, of course.
And still tell people which you support natively.

Don't know whether its worth it - does anyone have any views?

Cheers,

Ben.

--
http://www.apache-ssl.org/ben.html

"There is no limit to what a man can do or how far he can go if he
doesn't mind who gets the credit." - Robert Woodruff

Mime
View raw message