uselect seems broken: polling for read seems to hang forever until data is written

[reivilibre]

>>> pr = uselect.poll()
>>> pr.register(sock, uselect.POLLIN)
>>> pr.poll()
[(<socket>, 1)]
>>> sock.read(1)
b'\n'
>>> pr.poll()

Note that I sent some more bytes to the socket from the remote end afterwards, but they are not received and poll hangs.

This causes issues with umqtt.simple2 and probably other networking libraries.

I'm using MicroPython v1.10-282-g6a9b3cb-dirty on 2019-09-17; WinnerMicro module with W600

In my experience with umqtt.simple2, when you write data to the socket, then the poll status has a chance to update.

[rkompass]

@reivilibre
Perhaps a bit late, but this should be solved now with the last PR on Robert Hammelraths site:

I just tested it:

# On the linux host do a
#
# nc -l -p 2000
#
# in order to receive the message "Hello from Micropython!\n".
#
# Then type a few words. As soon as you type '\n', the characters are received and displayed.

import socket, select

s = socket.socket()
s.connect(('192.168.178.46', 2000))  # My laptops ip address (got it with "ip addr")
s.send("Hello from Micropython!\n")  #     this will appear on the laptops terminal.

poll = select.poll()
poll.register(s, select.POLLIN)
while True:
    events = poll.poll()
    print('events =', events)
    for stream in events:         # Poll event is a tuple, first element is the stream,
        if stream[0] == s         #      here: the registered socket.
            ch = s.read(1)
            print('Got ', ch)

Do you still use the w600? In case yes, could you test umqtt.simple2 again?

[reivilibre]

Afraid I don't use the W600 anymore, it was a fairly one-off hack I was trying to do but the device I hacked blew itself up (maybe a result of shoddy electrical hacking skills, who knows :)).
Very grateful for you letting me know though!