Sv: AF_UNIX/AF_LOCAL

sten.kristian.ivarsson@gmail.com sten.kristian.ivarsson@gmail.com
Thu Jun 11 06:37:20 GMT 2020


> On Jun  2 14:46, Kristian Ivarsson via Cygwin wrote:
> > Hey folks (probably Corinna more specifically)
> >
> > As far as I know the "unix domain socket implementation" is not really
> > complete
> >
> > We tried it and it didn't work for our purposes (the symptoms were
> > UDP-like, i.e. it seemed that some messages were lost along the way
> > (or possibly ended up in the wrong order)
> 
> That shouldn't occur because the current AF_UNIX implementation is using
> AF_INET sockets under the hood, and it doesn't implement any packet
> caching overriding the OS buffers.

Maybe the symptoms were explained bad. The real observable symptoms are that
the endpoint doesn't get a message once in a while and it, depending on
testcase, just "hangs" in a reading block though the other side successfully
sends them and in other testcases (where we have a sequence number in the
message) msg number X+1 ends up before X (etc) (which is ok with
DGRAM-semantics but not generally with AF_UNIX (as far as I understand))

Maybe the description of that messages are lost were bad, but maybe they are
dropped (perhaps by the fact that the socket-buffer or such is full (just a
wild guess))

If we get some spare time, we will try to reproduce this in a more simple
manner (i.e. a small test-program)

Keep up the good work,
Kristian


[snip]

 
> Corinna
> 
> --
> Corinna Vinschen
> Cygwin Maintainer
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