Python 多处理/套接字 - 错误的文件描述符

Question

我正在用Python编写一个服务器，客户端将发送命令(通过命令行arg)“BYE”。此时客户端/服务器之间的连接应终止。 (我认为 socket.close() 会终止连接，但我不完全确定这是否正确)

我编写了一个改编的回显服务器，其中clientsocket.close()位于服务器迭代的末尾。我希望只有在收到 BYE 时才会发生这种情况。

我不确定我的服务器程序的结构是否导致了问题(我还没有使用 getopt - 因为我仍然需要弄清楚)

服务器:

from multiprocessing import Process
import socket
import os

def handler(clientsocket, clientaddr):
    print "Accepted connection from: ", clientaddr
    while 1:
        data = clientsocket.recv(1024)
        if data:
            if data == "BYE":
                print "recvd BYE"
                clientsocket.send("BYE")
                clientsocket.close()
#                p.join()
            elif data == "DIR":
                print "recvd DIR"
                DIR = os.getcwd()
                clientsocket.send(DIR)

            print "data recieved:"
            print data
            msg = "You sent me: %s" % data
            clientsocket.send(msg)
            clientsocket.close()
            return

if __name__ == "__main__":

    TCP_IP = '127.0.0.1'
    TCP_PORT = 5004
    BUFFER_SIZE = 1024

    print 'socket()'
    s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)

    print 'bind()'
    s.bind((TCP_IP, TCP_PORT))

#    f = open('recv.txt', 'wb')

    print 'listen()'
    s.listen(5)

    workerProcesses =[]

    while 1:
        print "Server is listening for connections\n"
        clientsocket, clientaddr = s.accept()
        p = Process(target=handler, args = (clientsocket, clientaddr))
        p.start()
#        p.join()
        workerProcesses.append(p)

    serversocket.close()

当我将clientsocket.close()放入if“BYE”语句中时，我收到错误:错误的套接字描述符。服务器的输出是:

data recieved:
BYE
Process Process-1:
Traceback (most recent call last):
  File "/usr/lib64/python2.6/multiprocessing/process.py", line 232, in _bootstrap
    self.run()
  File "/usr/lib64/python2.6/multiprocessing/process.py", line 88, in run
    self._target(*self._args, **self._kwargs)
  File "pyServ.py", line 26, in handler
    clientsocket.send(msg)
  File "/usr/lib64/python2.6/socket.py", line 167, in _dummy
    raise error(EBADF, 'Bad file descriptor')
error: [Errno 9] Bad file descriptor

有什么关于为什么会发生这种情况的想法吗？

Answer 1

在你的 handler() 函数中你有这个:

       if data == "BYE":
            print "recvd BYE"
            clientsocket.send("BYE")
            clientsocket.close()
            #p.join()
        elif data == "DIR":
            print "recvd DIR"
            DIR = os.getcwd()
            clientsocket.send(DIR)

        print "data recieved:"
        print data
        msg = "You sent me: %s" % data
        clientsocket.send(msg)
        clientsocket.close()
        return

if data == "BYE" 然后你发送“BYE”并关闭你的套接字...然后你打印“data receive”(打字错误):)

然后在 if 语句中调用 close() 。一旦超出 if 语句，您就尝试在刚刚关闭的套接字上再次 send() 数据。一旦关闭套接字，文件句柄就不再有效。您需要修改代码，以便不在关闭的套接字上发送...我认为有两种明显的方法。

应该

        if data == "BYE":
            print "recvd BYE"
            clientsocket.send("BYE")
            clientsocket.close()
            #p.join()
        elif data == "DIR":
            print "recvd DIR"
            DIR = os.getcwd()
            clientsocket.send(DIR)

        print "data recieved:"
        print data
        return

或

在 if 语句中删除对clientsocket.close() 的调用