Learning Python Network Programming

Client and Server Applications

def handle_client_send(sock, q, addr):

""" Monitor queue for new messages, send them to client as

they arrive """

while True:

msg = q.get()

if msg == None: break

try:

tincanchat.send_msg(sock, msg)

except (ConnectionError, BrokenPipe):

handle_disconnect(sock, addr)

break

def broadcast_msg(msg):

""" Add message to each connected client's send queue """

for q in send_queues.values():

q.put(msg)

def handle_disconnect(sock, addr):

""" Ensure queue is cleaned up and socket closed when a client

disconnects """

fd = sock.fileno()

# Get send queue for this client

q = send_queues.get(fd, None)

# If we find a queue then this disconnect has not yet

# been handled

if q:

q.put(None)

del send_queues[fd]

addr = sock.getpeername()

print('Client {} disconnected'.format(addr))

sock.close()

if __name__ == '__main__':

server = eventlet.listen((HOST, PORT))

addr = server.getsockname()

print('Listening on {}'.format(addr))

while True:

client_sock,addr = server.accept()

q = queue.Queue()

send_queues[client_sock.fileno()] = q

eventlet.spawn_n(handle_client_recv,

client_sock,

addr)