为什么线程中的python套接字无法始终正确关闭（即，如果我连续多次运行该程序）

Question

我有以下代码（可能带有调试消息）。 如果我连续运行几次（彼此之间几秒钟之内），我经常会收到一个地址使用错误。 并非每次都发生。

socket.error: [Errno 98] Address already in use

当我没有收到错误时，输出为：

 trying to recv ('127.0.0.1', 38041)
 recved
 from client -->  None genuine without this seal!
 shutting down con
 closing con
 done closing con
 shutting down
 running server shutdown
 running server close
 done closing
 done shutting down

以下是我的代码：

import socket
from threading import Thread
from time import sleep
from subprocess import Popen, PIPE, STDOUT


def shutdown_thread(t):
    print "shutting down"
    t.shutdown()
    while t.isAlive():
        sleep(.1)
    print "done shutting down"


def send_with_netcat(msg):
    nc = Popen(
        ['nc', '127.0.0.1', '8000'],
        stdin=PIPE,
        stdout=PIPE,
        stderr=STDOUT)

    result = nc.communicate(msg)
    return result


class Server(Thread):
    is_shutdown = False

    def __init__(self):
        super(Server, self).__init__()
        self.start_server()

    def start_server(self):
        self.server = socket.socket(
            socket.AF_INET,
            socket.SOCK_STREAM)

        # "A socket is a 5 tuple (proto, local addr, local port,
        # remote addr, remote port).  SO_REUSEADDR just says that you
        # can reuse local addresses.  The 5 tuple still must be
        # unique!"
        self.server.setsockopt(
            socket.SOL_SOCKET,
            socket.SO_REUSEADDR,
            1)

        self.server = socket.socket(
            socket.AF_INET,
            socket.SOCK_STREAM)

        # bind the socket
        # ERROR HAPPENS HERE, HOW TO DEAL DEAL WITH OR AVOID?
        self.server.bind(('127.0.0.1', 8000))
        self.server.listen(5)

    def shutdown(self):
        self.is_shutdown = True

    def run(self):
        while not self.is_shutdown:
            con, addr = self.server.accept()
            print "trying to recv", addr
            buf = con.recv(128)
            print "recved"
            if len(buf) > 0:
                print "from client --> ", buf

            print "shutting down con"
            con.shutdown(socket.SHUT_RDWR)
            print "closing con"
            con.close()
            print "done closing con"
            sleep(.1)

        print "running server shutdown"
        self.server.shutdown(socket.SHUT_RDWR)
        print "running server close"
        self.server.close()
        print "done closing"

if __name__ == '__main__':
    s = Server()
    s.start()
    send_with_netcat("None genuine without this seal!")
    shutdown_thread(s)
    sleep(5)

如果您发现github更具可读性，则可以在此处看到相同的代码

奇怪的是，当我尝试发布此帖子时，可能需要花费更多的时间。 可能是因为我的计算机上发生了更多连接以随机化客户端nc连接吗？

感谢您对此问题的任何澄清。

Answer 1

在start_server()方法中，您将在self.server打开一个套接字，然后在此套接字上设置SO_REUSEADDR ，然后再次调用socket.socket() ，这将删除您的setsockopt()调用。 尝试删除第二个socket.socket()调用。 这应该使SO_REUSEADDR标志生效。