Async IO on sockets: good news and bad news

[Martin Wilck]

Hi,

The good news is: I have the basic mechanism for async IO on sockets
running. Requests can be scheduled and waited for, just like for regular
files.

The bad news is: This is not enough for sockets.

Problems occur especially when sockets are closed, because the signalling
of socket events uses a completely independent mechanism.

This leads to all sorts of strange behaviour, mostly to data loss
because "FD_CLOSE" is signalled prematurely.

Sadly, this means for me:
- The whole event signalling mechanism needs to be reworked so that it
  is consistent with overlapped IO.
- Probably the async IO mechanism, too.
  It seems that it would be good to have a single IO queue where all
  events are handled, rather than several ones.
  Unlike now, also things like "peer closed socket" would be scheduled
  in that queue.

Well I need to think more.
Currently, I am not even sure how exactly it _should_ work.

Martin
-- 
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