싱글 스레드 소켓 멀티플렉싱을 통한 다중 접속 에코서버(selectors 사용)

client.py

import time
import random
import socket
from multiprocessing import Process

def run_client(word, port=5557):
    sock = socket.socket()
    sock.connect(('localhost', port))
    sock.sendall(word.encode())
    data = sock.recv(1024)
    print(data.decode())
    sock.close()


def main():
    words = 'apple hello world banana orange shuffle'.split()
    for _ in range(10):
        Process(target=run_client, args=(random.choices(words))).start()

if __name__ == '__main__':
    main()

echo_server.py

import selectors
import socket


def accept_handler(sock, mask):
    conn, addr = sock.accept()
    print(f'accepted: {conn} from {addr}')
    conn.setblocking(False)
    sel.register(conn, selectors.EVENT_READ, read_handler)

def read_handler(conn, mask):
    data = conn.recv(1000)
    if data:
        print(f'echoing: {repr(data)} to {conn}')
        conn.send(data)
    else:
        print('closing')
        sel.unregister(conn)
        conn.close()


sel = selectors.DefaultSelector()
sock = socket.socket()
sock.bind(('localhost', 5557))
sock.listen(100)
sock.setblocking(False)
sel.register(sock, selectors.EVENT_READ, accept_handler)

while True:
    events = sel.select()
    for key, mask in events:
        callback = key.data
        callback(key.fileobj, mask)