QUERY · ISSUE
non-blocking socket blocks and raises EAGAIN
port-esp8266
from https://github.com/pfalcon/micropython/issues/30
Problem: a non-blocking socket seems to block and raises EAGAIN (was EWOULDBLOCK some time ago)
paste mode; Ctrl-C to cancel, Ctrl-D to finish
=== import socket as _socket
=== ai = _socket.getaddrinfo("127.0.0.1", 85, 0, _socket.SOCK_STREAM)
=== ai = ai[0]
=== s = _socket.socket(ai[0], ai[1], ai[2])
=== s.setblocking(False)
=== s.setsockopt(_socket.SOL_SOCKET, _socket.SO_REUSEADDR, 1)
=== s.bind(ai[-1])
=== s.listen(0)
===
>>> s2, client_addr = s.accept()
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
OSError: [Errno 11] EAGAIN
This problem only appears, when AP mode is disabled. Connecting to a WiFi does not help.
See https://github.com/pfalcon/micropython/issues/30#issuecomment-497322149
Catching EAGAIN works but this only circumvents that bug...
paste mode; Ctrl-C to cancel, Ctrl-D to finish
=== import socket as _socket
=== ai = _socket.getaddrinfo("127.0.0.1", 85, 0, _socket.SOCK_STREAM)
=== ai = ai[0]
=== s = _socket.socket(ai[0], ai[1], ai[2])
=== s.setblocking(False)
=== s.setsockopt(_socket.SOL_SOCKET, _socket.SO_REUSEADDR, 1)
=== s.bind(ai[-1])
=== s.listen(0)
===
>>> try:
>>> s2, client_addr = s.accept()
>>> except OSError as e:
>>> if e.args[0] == uerrno.EAGAIN:
>>> continue
>>>
CANDIDATE · ISSUE
esp8266: in non-blocking mode, socket.accept raises ETIMEDOUT instead of EAGAIN
bug
Test code:
import socket
s = socket.socket()
s.bind(socket.getaddrinfo("0.0.0.0", 8000)[0][-1])
s.setblocking(False)
s.listen(1)
s.accept()
On CPy and uPy unix the accept raises EAGAIN. On esp8266 it raises ETIMEDOUT.
Note that if the socket is in a blocking mode with a finite timeout (eg s.settimeout(1)) then ETIMEDOUT is the correct error code to raise (matches CPy's socket.timeout exception for this case).