[issue8184] multiprocessing.managers will not fail if listening ocket already in use

[Antoine Pitrou]

Antoine Pitrou <pitrou at free.fr> added the comment:

> Actually, it seems that even though the documentation doesn't mention
> sockets in TIME_WAIT state, SO_REUSEADDR is actually required on
> Windows:
> http://twistedmatrix.com/trac/ticket/1151#comment:18

According to that message, we would only need (or desire)
SO_EXCLUSIVEADDRUSE.

Note however what the MSDN doc says: “Conversely, a socket with the
SO_EXCLUSIVEADDRUSE set cannot necessarily be reused immediately after
socket closure. For example, if a listening socket with
SO_EXCLUSIVEADDRUSE set accepts a connection and is then subsequently
closed, another socket (also with SO_EXCLUSIVEADDRUSE) cannot bind to
the same port as the first socket until the original connection becomes
inactive.”

... and goes on to discuss the virtues of shutdown() etc.

So I still think we need no option at all under Windows, and
SO_EXCLUSIVEADDR actually prevents the behaviour we are trying to avoid.

> So the proper solution is the one adopted by support.bind_port(),
> SO_REUSEADDR + SO_EXCLUSIVEADDRUSE.

I think you read it wrong. bind_port() only uses SO_EXCLUSIVEADDRUSE and
forbids SO_REUSEADDR.
Not surprising considering the commentor above, Trent, is the same that
wrote the bind_port() code :)

----------

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue8184>
_______________________________________