Python 套接字只允许一个连接，但在新连接时断开连接，而不是拒绝

Question

在python中，你可以通过listen()函数的参数来定义最大socket连接数...例如:

serversocket = socket.socket(
socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind((socket.gethostname(), 80))
serversocket.listen(1) // allow only 1 connection

但问题是，当第二个客户端想要连接时，连接被拒绝了。我想断开旧用户的连接并连接新用户。有人可以帮我吗？

可能是一个答案:

我发布它有问题，因为它是可能的答案(我没有时间检查它)

serversocket = socket.socket(
socket.AF_INET, socket.SOCK_STREAM)
serversocket.bind((socket.gethostname(), 80))
serversocket.listen(10) // allow 10 connections, but disconnect previous later
someone_connected = 0
while 1:
    (clientsocket, address) = serversocket.accept()
    if(someone_connected) someone_connected.close()
    someone_connected = clientsocket

Answer 1

我不确定我是否完全理解你的问题，但我认为下面的例子可以满足你的要求。服务器可以断开旧用户并为新用户提供服务。

服务器端:

#!/usr/bin/env python
import socket
import multiprocessing


HOST = '127.0.0.1'                
PORT = 50007      

# you can do your real staff in handler
def handler(conn, addr):
    try:
        print 'processing...'
        while 1:
            data = conn.recv(1024)
            if not data:
                break
            print data
            conn.sendall(data)
        conn.close()
        print 'processing done'
    except:
        pass

s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
s.setsockopt(socket.SOL_SOCKET,socket.SO_REUSEADDR, 1)
s.bind((HOST, PORT))
s.listen(5)
processes = []
while True:
    conn, addr = s.accept()
    print conn, addr

    [p.terminate() for p in processes] # to disconnect the old connection
    # start process newer connection and save it for next kill 
    p = multiprocessing.Process(target=handler, args=(conn, addr))
    processes = [p]
    p.start()

    newest_conn = conn # this is the newest connection object, if you need it

为了测试，客户端:

#!/usr/bin/env python

import socket
import time
import multiprocessing

HOST = '127.0.0.1'
PORT = 50007

def client():
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    s.connect((HOST, PORT))
    time.sleep(0.1)

    try:
        for n in range(20):
            s.send(str(n))
            data = s.recv(1024)
            print data
            time.sleep(0.5)
        s.send('')
        s.close()
    except:
        pass

if __name__ == "__main__":
    for i in range(5):
        print 'user %i connect' %i
        p = multiprocessing.Process(target=client)
        p.start() # simulate a new user start connect
        time.sleep(3)

试一试:-)