Python中的多线程TCP服务器

Question

我使用 python 的 threding 模块创建了一个简单的多线程 tcp 服务器。每次连接新客户端时，此服务器都会创建一个新线程。

#!/usr/bin/env python

import socket, threading

class ClientThread(threading.Thread):

    def __init__(self,ip,port):
        threading.Thread.__init__(self)
        self.ip = ip
        self.port = port
        print "[+] New thread started for "+ip+":"+str(port)


    def run(self):    
        print "Connection from : "+ip+":"+str(port)

        clientsock.send("\nWelcome to the server\n\n")

        data = "dummydata"

        while len(data):
            data = clientsock.recv(2048)
            print "Client sent : "+data
            clientsock.send("You sent me : "+data)

        print "Client disconnected..."

host = "0.0.0.0"
port = 9999

tcpsock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
tcpsock.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)

tcpsock.bind((host,port))
threads = []


while True:
    tcpsock.listen(4)
    print "\nListening for incoming connections..."
    (clientsock, (ip, port)) = tcpsock.accept()
    newthread = ClientThread(ip, port)
    newthread.start()
    threads.append(newthread)

for t in threads:
    t.join()

然后我打开两个新终端并使用netcat连接到服务器。然后，当我使用我连接的第一个终端键入并将我的第一个数据发送到服务器时，来自服务器的回复到达另一个终端并且第一个连接断开了。我猜到了原因，但我怀疑这是否会发生，因为 clientsock 变量被覆盖，因此它引用了第二个连接的套接字。我是否正确，然后如何避免这种情况？

除了使用套接字变量数量有限的数组并为每个连接使用每个变量之外，还有其他方法吗？

Answer 1

您应该像使用 ip 地址和端口一样将客户端 sock 传递给线程：

class ClientThread(threading.Thread):

    def __init__(self, ip, port, socket):
        threading.Thread.__init__(self)
        self.ip = ip
        self.port = port
        self.socket = socket
        print "[+] New thread started for "+ip+":"+str(port)

    def run(self):
        # use self.socket to send/receive

...
(clientsock, (ip, port)) = tcpsock.accept()
newthread = ClientThread(ip, port, clientsock)
...

Answer 2

我创建了一个你可以覆盖的好类

import socket
import thread

class SocketServer(socket.socket):
    clients = []

    def __init__(self):
        socket.socket.__init__(self)
        #To silence- address occupied!!
        self.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        self.bind(('0.0.0.0', 8080))
        self.listen(5)

    def run(self):
        print "Server started"
        try:
            self.accept_clients()
        except Exception as ex:
            print ex
        finally:
            print "Server closed"
            for client in self.clients:
                client.close()
            self.close()

    def accept_clients(self):
        while 1:
            (clientsocket, address) = self.accept()
            #Adding client to clients list
            self.clients.append(clientsocket)
            #Client Connected
            self.onopen(clientsocket)
            #Receiving data from client
            thread.start_new_thread(self.recieve, (clientsocket,))

    def recieve(self, client):
        while 1:
            data = client.recv(1024)
            if data == '':
                break
            #Message Received
            self.onmessage(client, data)
        #Removing client from clients list
        self.clients.remove(client)
        #Client Disconnected
        self.onclose(client)
        #Closing connection with client
        client.close()
        #Closing thread
        thread.exit()
        print self.clients

    def broadcast(self, message):
        #Sending message to all clients
        for client in self.clients:
            client.send(message)

    def onopen(self, client):
        pass

    def onmessage(self, client, message):
        pass

    def onclose(self, client):
        pass

这是一个例子：

class BasicChatServer(SocketServer):

    def __init__(self):
        SocketServer.__init__(self)

    def onmessage(self, client, message):
        print "Client Sent Message"
        #Sending message to all clients
        self.broadcast(message)

    def onopen(self, client):
        print "Client Connected"

    def onclose(self, client):
        print "Client Disconnected"

def main():
    server = BasicChatServer()
    server.run()

if __name__ == "__main__":
    main()

Answer 3

Python3 有 ThreadingTCPServer (and others) 可以为你做到这一点

注意这里的线程是每个 request 而不是每个 client - 这具有每个请求的线程结束时间小的缺点，但它的优点是随着客户数量的增加，可以更好地扩展。