Re: python > 3.5: Issue with unix domain sockets

[Marco Atzeri <marco.atzeri@gmail.com>]

On 03.05.2021 14:57, Maximilian.Blenk--- via Cygwin wrote:
> Hello everyone,
> 
> I noticed that latest Cygwin release (3.2.0-1) has an issue with python and unix domain sockets, although I’m not a 100% sure about the root cause. My best guess is that something is wrong with the unix domain dockets implementation. I would like to attach the cygcheck.out but it seems to exceed the 180kb limit mentioned on the website (even zipped)
> 
> Simple Reproducer:
> I tried to get the example shown at https://pymotw.com/3/socket/uds.html working. It works if I execute it with python3.5 (both client and server), but it doesn’t if I use python3.6 or newer (actually tested 3.6 and 3.7 on Windows 10):
> 
> Correct Behavior:
> Server:
> $ python3.5 server.py
> starting up on ./uds_socket
> waiting for a connection
> connection from
> received b'This is the mess'
> sending data back to the client
> received b'age.  It will be'
> sending data back to the client
> received b' repeated.'
> sending data back to the client
> received b''
> no data from
> waiting for a connection
> …
> 
> Client:
> $ python3.5 client.py
> connecting to ./uds_socket
> sending b'This is the message.  It will be repeated.'
> received b'This is the mess'
> received b'age.  It will be'
> received b' repeated.'
> closing socket
> 
> Incorrect Behavior:
> Server:
> $ python3.7 server.py
> starting up on ./uds_socket
> waiting for a connection
> Traceback (most recent call last):
>    File "server.py", line 27, in <module>
>      connection, client_address = sock.accept()
>    File "/usr/lib/python3.7/socket.py", line 214, in accept
>      sock = socket(self.family, self.type, self.proto, fileno=fd)
>    File "/usr/lib/python3.7/socket.py", line 151, in __init__
>      _socket.socket.__init__(self, family, type, proto, fileno)
> SystemError: <slot wrapper '__init__' of '_socket.socket' objects> returned NULL without setting an error
> 
> Client:
> $ python3.7 client.py
> connecting to ./uds_socket
> sending b'This is the message.  It will be repeated.'
> closing socket
> Traceback (most recent call last):
>    File "client.py", line 27, in <module>
>      data = sock.recv(16)
> ConnectionResetError: [Errno 104] Connection reset by peer
> 
> 
> Am I missing something?
> 
> BR Max
> 

Hi Max,
thanks for the example.

Mark Geisert provided me a solution and it passes your
test case on python3.8 and it seems to not add other problem
at list in my tests.

give me some time to update all packages (3.6, 3.7, 3.8) for
both architecture in the coming days

Regards
Marco