Re: [PATCH] /dev/epoll update ...

Dan Kegel (dank@kegel.com)
Tue, 25 Sep 2001 11:34:25 -0700


Jonathan Lemon wrote:
>
> In article <local.mail.linux-kernel/3BB03C6A.7D1DD7B3@kegel.com> you write:
> >Right, and kqueue() can't even represent the 'level triggered' style --
> >or at least it isn't clear from the paper that it can!
>
> Yes it does - kqueue() is 'level-triggered' by default.

Apologies for the line noise. I've corrected
http://www.kegel.com/c10k.html to show kqueue as both edge- and level- triggered.
Further corrections welcome...

> As Christopher pointed out, any event can be converted into an
> edge-triggered style notification simply by setting EV_CLEAR. However,
> this is not usually a popular model from a programmer's point of view,
> as it increases the complexity of their app. (This is what I've seen, YMMV)

Agreed; the poll()-like semantics of level-triggering are particularly
forgiving.

- Dan
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