为什么这个套接字连接只允许1个发送和接收？

Question

背景
我有一个简单的套接字服务器设置,我试图允许同时连接和回显数据.客户端启动多个线程,每个线程都与服务器建立自己的连接.这适用于socket.send()调用,但所有后续调用都会导致"由对等方重置连接"或"断开管道".请注意,我没有找到切换重置和损坏管道的更改.我在这里寻找解决方案,但恐怕我可能不知道该搜索什么.

我是以错误的方式解决这个问题,还是我在设置中忽略了什么？

服务器

import SocketServer

class MyTCPHandler(SocketServer.BaseRequestHandler):
    def handle(self):
        self.data = self.request.recv(1024).strip()
        print "{} wrote: {}\n".format(self.client_address[0], self.data)
        self.request.send(self.data.upper())

if __name__ == "__main__":
    HOST, PORT = "localhost", 9999
    server = SocketServer.TCPServer((HOST, PORT), MyTCPHandler)
    server.serve_forever()

客户

import socket
import sys
import threading
import time

HOST, PORT = "localhost", 9999
def create_client():
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    try:
        cur_thread = threading.current_thread()
        sock.connect((HOST, PORT))
        for x in range(55):
            msg = "{}: {}\n".format(cur_thread.name, str(x))
            # Connect to server and send data
            print cur_thread.name + ": sending message\n"
            sock.send(msg)
            # Receive data from the server and shut down
            received = sock.recv(2048)
            print "RX:" + received
    finally:
        cur_thread = threading.current_thread()
        response = "{}: Closing!\n".format(cur_thread.name)
        print response
        sock.close()

if __name__ == "__main__":
    print "testing single thread"
    #create_client()
    print "starting threads"
    client_1 = threading.Thread(target=create_client)
    client_1.daemon = True
    client_1.start()
    client_2 = threading.Thread(target=create_client)
    client_2.daemon = True
    client_2.start()

    time.sleep(20)

Answer 1

从handle套接字返回时关闭.使用while循环并handle仅在何时返回self.data == ''.recv客户端关闭连接时返回零字节.strip()在测试返回值之后也不要得到结果,否则你可能会得到错误的结果.最后,使用ThreadingTCPServer或服务器一次只能处理一个连接.

例:

import SocketServer

class MyTCPHandler(SocketServer.BaseRequestHandler):
    def handle(self):
        while True:
            self.data = self.request.recv(1024)
            if self.data == '':
                break
            self.data = self.data.strip()
            print "{} wrote: {}\n".format(self.client_address[0], self.data)
            self.request.send(self.data.upper())

if __name__ == "__main__":
    HOST, PORT = "localhost", 9999
    server = SocketServer.ThreadingTCPServer((HOST, PORT), MyTCPHandler)
    server.serve_forever()

另请注意,send()不保证发送所有字节的消息,因此请使用sendall()或检查返回值. recv()也可能很棘手.TCP/IP是一种流协议,没有消息边界的概念,因此您需要实现一个协议来检查您是否收到了完整的消息.可以发送10000个字节并接收少于该字节,需要多个接收才能获得整个消息.也可以在一个接收中发送和接收两个,或者甚至发送一个发送和接收另一个发送.对于您的示例,只需缓冲所有接收,直到\n消息中有a表示简单协议.