httpd-dev mailing list archives

Site index · List index
Message view « Date » · « Thread »
Top « Date » · « Thread »
From "Bill Stoddard" <>
Subject Re: [VOTE] ap_r* model.
Date Fri, 02 Mar 2001 14:09:28 GMT


> On Thu, Mar 01, 2001 at 02:17:34PM -0800, wrote:
> > On Thu, 1 Mar 2001, Greg Stein wrote:
> >...
> > > In ADDITION: There is a coupling across subsystems introduced by the
> > > mechanism. As a result, they will have ordering issues unless they
> > > pay attention to what other pieces are doing.
> >
> > This doesn't exist at all if the sub-systems use ap_r.
> Not all subsystems *are* going to use ap_r*. The whole point of "subsystem"
> means it is an independent unit. Coupling means that the subsystem is no
> longer independent -- it is "coupled" to what its callers/users do.
> If it was independent, it could choose to reimplement its output in terms of
> brigades for better performance. Maybe it keeps a whole bunch of them
> around, ready for delivery, and chooses one to shoot down the pipe.
> This cache of brigades is quite likely. Consider the mod_cache_file module.

Why cache brigades?  You want to cache the operations that take CPU cycles,
which is opening (and perhaps reading the file).  If you have an open fd or a
chunk of mmap storage, it is trivial to create the bucket/brigade and send it
down the pipe. I don't see the need to cache buckets/keep ref counts, etc.
It's making a simple concept complicated.


View raw message