OSError: [WinError 10038]

[bitsgalore]

From time to time the following error occurs:

starting connection to ('127.0.0.1', 65432)
Traceback (most recent call last):
File "f:\johan\pythonCode\socketclient\client-launch.py", line 8, in <module>
    main()
File "f:\johan\pythonCode\socketclient\socketclient\client\client.py", line 10
7, in main
    myClient.send_request(host, port, fieldName, value)
File "f:\johan\pythonCode\socketclient\socketclient\client\client.py", line 52
, in send_request
    events = self.sel.select(timeout=1)
File "c:\Python36\lib\selectors.py", line 323, in select
    r, w, _ = self._select(self._readers, self._writers, [], timeout)
File "c:\Python36\lib\selectors.py", line 314, in _select
    r, w, x = select.select(r, w, w, timeout)
OSError: [WinError 10038] An operation was attempted on something that is not a
socket

Not clears what triggers it, seems to happen pretty randomly and unrelated to the input used.

[bitsgalore]

Could be a bug in Python:

https://bugs.python.org/issue34795

This looks similar:

Rapptz/discord.py#1819

[bitsgalore]

Also closing sock directly using this modification:

def start_connection(self, host, port, request):
addr = (host, port)
print("starting connection to", addr)
self.sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
self.sock.setblocking(False)
self.sock.connect_ex(addr)
events = selectors.EVENT_READ | selectors.EVENT_WRITE
message = libclient.Message(self.sel, self.sock, addr, request)
self.sel.register(self.sock, events, data=message)

def send_request(self, host, port, fieldName, value):
    request = self.create_request(fieldName, value)
    self.start_connection(host, port, request)

    try:
        while True:
            events = self.sel.select(timeout=1)
            for key, mask in events:
                message = key.data
                try:
                    message.process_events(mask)
                except Exception:
                    print(
                        "main: error: exception for",
                        f"{message.addr}:\n{traceback.format_exc()}",
                    )
                    #message.close()
                    self.sock.close()
            # Check for a socket being monitored to continue.
            if not self.sel.get_map():
                break
    except KeyboardInterrupt:
        print("caught keyboard interrupt, exiting")
    finally:
        self.sel.close()

But this makes no difference.

[bitsgalore]

Replacing the existing socket code by the much simpler code adapted from here appears to solve this issue:

74333c5