Message-ID: <37B7D9CA.A39F8814@algroup.co.uk>
Date: Mon, 16 Aug 1999 10:28:42 +0100
From: Ben Laurie <ben@algroup.co.uk>
Organization: A.L. Group plc
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To: new-httpd@apache.org
Subject: Re: IOL and send_fb
References: <Pine.LNX.3.96dg4.990815153309.32109b-100000@twinlark.arctic.org>
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Dean Gaudet wrote:
> 
> On Sun, 15 Aug 1999, Ben Laurie wrote:
> 
> > BTW, this although we've managed to slide past it this time, I do have
> > this feeling of impending doom wrt to poll/select and IOL.
> 
> anything which relies on poll/select isn't portable... we just barely
> squeak by as it is on NT don't we?  for async stuff we want some other
> abstraction i think -- one which works for completion ports on NT and for
> poll/select on unix (or /dev/poll on solaris, or io signals on linux, or
> even async i/o on VMS :).
> 
> one possibility is eventlib, which comes with bind (i used it ages ago for
> one of my prototypes)... but the ISC guys say to wait a bit -- they're
> working on a portable library (with NT and unix ports) which will do this
> sort of stuff, and support SMP/multithreading.  i'll probably do the first
> crack of the async stuff using eventlib though, because i don't want to
> wait for the new library (and it doesn't sound hard to switch later).
> 
> oh the other problem with poll/select on IOL is that you can't ask an
> arbitrary layer for a selectable object and hope to get something which
> always works... at best you need to ask a layer for a set of poll masks
> which it is interested in.  whereas with something like eventlib, the
> layer can register its own events...

Err, yeah, that's the feeling of impending doom I had! That is, I
suspect we are going to need the facility, but it ain't portable. If you
are thinking of having a full-blown event handling library (which is
probably a damn good idea) then I have two comments:

a) Shouldn't it be part of APR?

b) Event libraries tend to end up being pretty pervasive (in their use),
so we'd better get cracking.

The downside is that a portable event library is pretty tricky stuff.
Especially if you want to support older 'nix - which have a tendency to
be picky about what you can select on and the like. Where do I find out
more about the ISC stuff?

Cheers,

Ben.

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

"My grandfather once told me that there are two kinds of people: those
who work and those who take the credit. He told me to try to be in the
first group; there was less competition there."
     - Indira Gandhi