Unclear behaviour of recv(timeout=0) for Server (threading) #1552
Description
I think the behavior of recv(timeout=0) for the Thread-based Server is unclear.
Due to the design of my application, I can't use the "for message in websocket" and have to resort to an update() function that I call frequently to check if messages were received:
def update(self) -> None:
"""
Check for received data with proper handling of timeouts and connection closure.
"""
while True:
try:
# Attempt to receive data with a timeout
data_rx = self.ws_client.recv(timeout=0)
except TimeoutError:
# No data received within the timeout period
break
except websockets.exceptions.ConnectionClosed as e:
# Handle connection closure
Log(f"Connection closed: {e}")
self._is_connected = False
break
except Exception as e:
# Handle any other exceptions
Log(f"Error occurred: {e}")
self._is_connected = False
break
# If no data received, exit the loop
if data_rx is None:
break
self.log(f"RX: {data_rx}")
I was expecting when I set timeout=0 that only when a message was received I get it otherwise TimeoutError is raised so it's not blocking.
the behavior I'm getting is that with very low values like timeout=0.001 (1ms) it works, but with 0 I don't receive any messages.
Have I understood timeout=0 incorrectly? In the documentation it says:
"Set timeout to 0 to check if a message was already received." see