Re: [Coder-Com] Re: PROBLEM: high system usage / poor SMPnetwork performance

From: Aaron Sethman (androsyn@ratbox.org)
Date: Sun Feb 03 2002 - 23:47:30 EST


On Sun, 3 Feb 2002, Dan Kegel wrote:

> Kev wrote:
> > If that's true, I confess I can't quite see your point even still. Once
> > the event is generated, ircd should read or write as much as it can, then
> > not pay any attention to the socket until readiness is again signaled by
> > the generation of an event. Sorry if I'm being dense here...
>
> If you actually do read or write *until an EWOULDBLOCK*, no problem.
> If your code has a path where it fails to do so, it will get stuck,
> as no further readiness events will be forthcoming. That's all.

It seems kind of odd, at first, but it does make sense in a inverted sort
of way. Basically you aren't going to get any signals from the kernel
until the EWOULDBLOCK state clears. Consider what would happen if you
received a signal every time you could, say send. Your process would be
flooded with signals, which of course wouldn't work. If you want to take
a look at the Hybrid-7 cvs tree, let me know and I can give you a copy of
it. I just got the sigio stuff working correctly in their.

Regards,

Aaron

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