如何在Python SocketServer中创建连接超时

Question

大家好！我写了一个简单的服务器：

class SingleTCPHandler(SocketServer.BaseRequestHandler):

    def handle(self):
        data = self.request.recv(1024) 
        self.request.close()

class SimpleServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):

    daemon_threads = True

    allow_reuse_address = True

    def __init__(self, server_address, RequestHandlerClass):
        SocketServer.TCPServer.__init__(self, server_address, RequestHandlerClass)


def running():
    server = SimpleServer((settings.host, settings.port), SingleTCPHandler)
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        sys.exit(0)

我想设置一个连接超时。如果客户端在30秒内没有发送数据或者没有活动，服务器就会关闭这个连接。

附注：抱歉我的英语不好。

更新

#!/usr/bin/env python
# -*- coding: utf8 -*-

import sys
import time

import SocketServer
import datetime
import settings
import os
from signal import SIGTERM, SIGCHLD, signal, alarm
import socket
import subprocess
from threading import Thread
import MySQLdb
import re

class SingleTCPHandler(SocketServer.BaseRequestHandler):
    "One instance per connection.  Override handle(self) to customize action."
    def handle(self):
        alarm(30)
        data = self.request.recv(1024) 
        # Some code
        self.request.close()


class SimpleServer(SocketServer.ForkingMixIn, SocketServer.TCPServer):

    daemon_threads = True
    allow_reuse_address = True


    def __init__(self, server_address, RequestHandlerClass):
        SocketServer.TCPServer.__init__(self, server_address, RequestHandlerClass)




def running():
    server = SimpleServer((settings.host, settings.port), SingleTCPHandler)
    try:
        server.serve_forever()
    except KeyboardInterrupt:
        sys.exit(0)


def deamonize(stdout='/dev/null', stderr=None, stdin='/dev/null', pidfile=None, startmsg='started with pid %s'):
    try:
        pid = os.fork()
        if (pid > 0):
            sys.exit(0)
    except OSError, e:
        sys.stderr.write("fork #1 failed: (%d) %s\n" % (e.errno, e.strerror))
        sys.exit(1)

    os.chdir(settings.place)
    os.umask(0)
    os.setsid()

    try:
        pid = os.fork()
        if (pid > 0):
            sys.exit(0) 
    except OSError, e:
        sys.stderr.write("fork #2 failed: (%d) %s\n" % (e.errno, e.strerror))
        sys.exit(1)

    if (not stderr):
        stderr = stdout

        print stdin, stdout, stderr
        si = file(stdin, 'r')
        so = file(stdout, 'a+')
        se = file(stderr, 'a+', 0)
        pid = str(os.getpid())
        sys.stderr.write("\n%s\n" % startmsg % pid)
        sys.stderr.flush()
    if pidfile: file(pidfile, 'w+').write("%s\n" % pid)

    os.dup2(si.fileno(), sys.stdin.fileno())
    os.dup2(so.fileno(), sys.stdout.fileno())
    os.dup2(se.fileno(), sys.stderr.fileno())

def startstop(stdout='/dev/null', stderr=None, stdin='/dev/null', pidfile='pid.txt', startmsg='started with pid %s'):
    if len(sys.argv) > 1:
        action = sys.argv[1]
        try:
            pf = open(pidfile)
            pid = int(pf.read().strip())
            pf.close()
        except IOError:
            pid = None
        if ((action == 'stop') or (action == 'restart')):
            if (not pid):
                mess = "Не могу остановить, pid файл '%s' отсутствует.\n"
                sys.stderr.write(mess % pidfile)
                sys.exit(1)
            try:
                while 1:
                    os.kill(pid, SIGTERM)
                    time.sleep(1)
            except OSError, err:
                err = str(err)
                if err.find("No such process") > 0:
                    os.remove(pidfile)
                    if 'stop' == action:
                        sys.exit(0)
                    action = 'start'
                    pid = None
                else:
                    print str(err)
                    sys.exit(1)
        if ('start' == action):
            if (pid):
                mess = "Старт отменен — pid файл '%s' существует.\n"
                sys.stderr.write(mess % pidfile)
                sys.exit(1)
            deamonize(stdout, stderr, stdin, pidfile, startmsg)
            return
    print "Синтакс запуска: %s start|stop|restart" % sys.argv[0]
    sys.exit(2)

if (__name__ == "__main__"):
    startstop(stdout=settings.log, pidfile=settings.pid)
    running()

Answer 1

请看这个：

import sys
import SocketServer

class SingleTCPHandler(SocketServer.BaseRequestHandler):
    def handle(self):
        data = self.request.recv(1024)
        self.request.close()

class SimpleServer(SocketServer.ThreadingMixIn, SocketServer.TCPServer):

    timeout = 30

    daemon_threads = True
    allow_reuse_address = True

    def __init__(self, server_address, RequestHandlerClass):
        SocketServer.TCPServer.__init__(self, server_address, RequestHandlerClass)

    def handle_timeout(self):
        print 'Timeout!'


def running():
    server = SimpleServer(('localhost', 6666), SingleTCPHandler)
    try:
        #server.serve_forever()
        server.handle_request()
    except KeyboardInterrupt:
        sys.exit(0)

if __name__ == '__main__':
    running()

# vim: filetype=python syntax=python expandtab shiftwidth=4 softtabstop=4 encoding=utf8

如果你想处理多个请求，你需要再次执行 server.handle_request()。

Answer 2

如果你用的是StreamRequestHandler而不是BaseRequestHandler，那么你只需要在里面覆盖一下timeout这个变量，它就会被设置好。如果你想自己学怎么做，可以看看SocketServer.py这个文件。

这里有个例子，这段代码会在5秒内结束任何没有完成的连接：

#!/usr/bin/env python
import SocketServer

class myHandler(SocketServer.StreamRequestHandler):
    timeout = 5
    def handle(self):
        recvdata = ""
        while True:
            tmp = self.request.recv(16384)
            recvdata = recvdata + tmp.strip()
            if (len(tmp) < 16384):
                break;
        self.request.send("Received: {0}".format(recvdata))

class myApp(SocketServer.TCPServer):

    def __init__(self):
        SocketServer.TCPServer.__init__(self, ("localhost", 5555), myHandler)
        print self.server_address
        try:
            self.serve_forever()
        except KeyboardInterrupt:
            print "Got keyboard interrupt, shutting down"
            self.shutdown()

if __name__ == "__main__":
    app = myApp()

这段代码使用了Python的socket的settimeout()方法。

我觉得你的alarm()解决方案在使用线程或分叉时可能不太管用。