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Re: Strange EPOLLOUT|EPOLLET behaviour (spurious events)

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Christof Meerwald <NOSPAM-seeMySig+upk5+@usenet.cmeerw.org> writes:
> On Wed, 25 Apr 2012 23:11:51 +0100, Rainer Weikusat wrote:
>> Christof Meerwald <NOSPAM-seeMySig+uyk5+@usenet.cmeerw.org> writes:
>>> But as I am using EPOLLET, I wouldn't expect to get any EPOLLOUT
>>> events on that socket as send never returns EAGAIN (and there isn't
>>> any state transition).
>> That's expected behaviour: You get EPOLLOUT as soon as 'a send
>> operation' completed.
>
> Well, that's what appears to be happening, but is it documented
> anywhere?
>
>
> Looking at http://linux.die.net/man/7/epoll I see:
>
> "The suggested way to use epoll as an edge-triggered (EPOLLET)
> interface is as follows: with nonblocking file descriptors; and by
> waiting for an event only after read(2) or write(2) return EAGAIN."
>
> and
>
> "Do I need to continuously read/write a file descriptor until EAGAIN
> when using the EPOLLET flag (edge-triggered behavior)? Receiving an
> event from epoll_wait(2) should suggest to you that such file
> descriptor is ready for the requested I/O operation. You must consider
> it ready until the next (nonblocking) read/write yields EAGAIN."
>
> Nothing there suggests that I should get an EPOLLOUT as soon as "a
> send operation" completed.

I'm seriously sorry that the technology you are fumbling around with
doesn't work like you believe it should and apologize for assuming
that your misdirected complaint about the contents of some Linux
manpage was actually a question. I'm going to take suitable technical
measures for ensuring that this never happens again.

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Strange EPOLLOUT|EPOLLET behaviour (spurious events) Christof Meerwald <NOSPAM-seeMySig+uyk5+@usenet.cmeerw.org> - 2012-04-25 20:38 +0000
  Re: Strange EPOLLOUT|EPOLLET behaviour (spurious events) Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-04-25 23:11 +0100
    Re: Strange EPOLLOUT|EPOLLET behaviour (spurious events) Christof Meerwald <NOSPAM-seeMySig+upk5+@usenet.cmeerw.org> - 2012-04-26 06:01 +0000
      Re: Strange EPOLLOUT|EPOLLET behaviour (spurious events) Rainer Weikusat <rweikusat@mssgmbh.com> - 2012-04-26 15:14 +0100
      Re: Strange EPOLLOUT|EPOLLET behaviour (spurious events) Christof Meerwald <NOSPAM-seeMySig+u0k5+@usenet.cmeerw.org> - 2012-04-26 21:11 +0000

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