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

[Dan Kegel <dank@kegel.com>]

Aaron Sethman wrote:
> 
> > 2. you need to wrap your read()/write() calls on the socket with code
> > that notices EWOULDBLOCK
> This is perhaps the part we it disagrees with our code.  I will
> investigate this part.  The way we normally do things is have callbacks
> per fd, that get called when our event occurs doing the read, or, write
> directly.  

That sounds totally fine; in fact, it's how my Poller library works.

> We do check for the EWOULDBLOCK stuff and re-register the
> event.

But do you remember that this fd is ready until EWOULDBLOCK?
i.e. if you're notified that an fd is ready, and then you
don't for whatever reason continue to do I/O on it until EWOULDBLOCK,
you'll never ever be notified that it's ready again.
If your code assumes that it will be notified again anyway,
as with poll(), it will be sorely disappointed.

> The thing we do not currently do is, attempt to read or write
> unless we've received notification first.  This is what I am assuming is
> breaking it.

Yeah, that would break it, too, I think.

- Dan