Messages in this thread |  | | Date | Wed, 19 Sep 2001 02:04:07 -0500 | From | "Christopher K. St. John" <> | Subject | Re: [PATCH] /dev/epoll update ... |
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Dan Kegel wrote: > > I'm getting ready to stress-test /dev/epoll finally. > In porting my Poller_devpoll.{cc,h} to support /dev/epoll, I noticed > the following issues: >
Another issue to throw into the mix:
The Banga, Mogul and Druschel[1] paper (which I understand was the inspiration for the Solaris /dev/poll which was the inspiration for /dev/epoll?) talks about having the poll return the current state of new descriptors. As far as I can tell, /dev/epoll only gives you events on state changes. So, for example, if you accept() a new socket and add it to the interest list, you (probably) won't get a POLLIN. That's not fatal, but it's awkward.
The BMD paper suggests making the behavior optional, but I didn't see anything about it in the Solaris /dev/poll manpage (and I don't have a copy of Solaris to try it out on).
My vote would be to always report the initial state, but that would make the driver a little more complicated.
What are the preferred semantics?
[1] http://citeseer.nj.nec.com/banga99scalable.html
-- Christopher St. John cks@distributopia.com DistribuTopia http://www.distributopia.com - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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