Re: [rfc] epoll interface change and glibc bits ...

[Jamie Lokier <lk@tantalophile.demon.co.uk>]

Davide Libenzi wrote:
> > 1. Fwiw, I would really like to see epoll extended beyond fds, to a more
> > general edge-triggered event collector - signals, timers, aios.  I've
> > written about this before as you know (but been too busy lately to
> > pursue the idea).  I'm not going to say any more about this until I
> > have time to code something...
> 
> Anything that "exposes" a file* interface that support f_op->poll() is
> usable with epoll. File rocks !! :)

I agree, fds are pretty good, and it's nice that they work equally
well with poll/select/sigio as with epoll.

It's just that to write an ideal, general event loop, pollable fds
need to be created on the fly for futexes, signals, timers and aio
requests at least.  Currently this is already done for futexes.  In
addition, some kinds of event result need to return a few words of
data with each event (for example, SIGCHLD events).

Perhaps it's not a bad idea, but I do wonder whether fds created on
the fly for every requested event, and events than can only report
"readable" not anything richer than that are a good solution.

-- Jamie