I'm wanting to exit an UDP-server on KeyboardInterrupt, but this is not working immediately. when doing some research I stumbled on this question, where someone suggests that it is a issue with the GIL. Python processes calling into C APIs can block the Python interpreter from processing the interrupt. is there any way the unblock this in python?
the code I have is the following:
if __name__ == '__main__':
try:
main()
except KeyboardInterrupt: #works after new data is send to server
print('Interrupted', file=sys.stderr)
try:
sys.exit(0)
except SystemExit:
os._exit(0)
main:
def main():
s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
server_address = ('localhost', 2000)
s.bind(server_address)
running = True
print('Ready for connection')
while running:
try:
msg = ""
data, address = s.recvfrom(2000) #look for timeout and interrupt
msg = data.decode('utf-8')
if not data:
break
print(f'received {msg}')
if msg[:5] == "PING-":
print('sending PONG back to the client')
message = 'PONG-' + msg[5:len(msg)]
s.sendto(message.encode('utf-8'), address)
else:
print('bad format')
except socket.error as socketerror:
print(f'Error: {socketerror}', file=sys.stderr)
s.close()
When i'm not running the client and press ctrl-c nothing happens, the program just does nothing. When I start up the client and send a UDP message, the interrupt is perfectly handled when the server gets a UDP message from the client. The UDP message then is dropped and the client handles it as a timeout. After the timeout the client has a lost connection.
The goal is to get the server exit even without the client running and without using ctrl-break.
