Re: [Qemu-devel] [PATCH 2/3] Always use nonblocking mode for qemu_chr_open_fd.

[Gerd Hoffmann]

Jamie Lokier wrote:
> I'm surprised it works.  You shouldn't be able to get any more
> information out of epoll() than poll() - they're supposed to be
> exactly equivalent informationally, except for details and performance.

I was thinking just the same ...

poll/epoll says the file handle is readable.  It does that in two cases:

  (1) there is data to read
  (2) pty is unconnected and read() wants to give you an -EIO.

And I think you can't keep those two cases apart using only the
information given by poll/epoll ...

cheers,
  Gerd

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