具有多线程的 Python 套接字编程

Question

我正在尝试在 python 中使用套接字。现在，我正试图让它在任何客户端发送任何消息时都被所有客户端接收。但是我得到了非常奇怪的结果。我认为这是因为我正在使用多个线程。每次运行程序时，程序的输出都会发生变化。这是线程问题还是其他问题？

import socket
import sys
from thread import *
from server import Server
from client import Client

s = Server()
start_new_thread(s.acceptConnection,())


m = Client("m")
k = Client("k")
start_new_thread(m.recieveData,())
start_new_thread(k.recieveData,())
k.sendData("Hey!")
print "*"*100
print repr(k.data()), repr(m.data())
print "*"*100
m.sendData("okay okay")
print "*"*100
print repr(k.data()), repr(m.data())
print "*"*100
m.client.close()
k.client.close()
s.s.close()

服务器类：

import socket
import sys
from thread import *

class Server(object):
    def __init__(self,port = 5555):
        self.host = 'localhost'  # '' means connect to all hosts
        self.port = port
        self.text = ""        
        self.s = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
        self.s.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
        try:
            self.s.bind((self.host, self.port))
        except socket.error as e:
            print(str(e))
        self.s.listen(2)
        print "Waiting for a connection.\n"
        self.connections = []

    def threaded_client(self,conn):
        # conn.send("Connected to server\n")
        while True:
            try:
                data = conn.recv(2048)
            except:
                data = ""
            if(not data):
                break
            # conn.sendall(reply)
            for c,a in self.connections:
                try:
                    c.sendall(data + "\n")
                except:
                    print "connection lost\n"
                    self.connections.remove((c,a))
        conn.close()

    def acceptConnection(self):
        while True:
            conn, addr = self.s.accept()
            self.connections += [(conn,addr)]
            start_new_thread(self.threaded_client,(conn,))

客户端类：

import socket
import sys
from thread import *

class Client(object):
    def __init__(self,name):
        self.host = 'localhost'
        self.port = 5555
        self.name = name
        self.client= socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
        self.client.connect((self.host,self.port))
        self.text = ""

    def sendData(self,data):
        self.client.send(data)

    def recieveData(self):
        while True:
            try:
                data = self.client.recv(2048)
            except:
                break
            if data:
                self.text = data
        self.client.close()

    def data(self):
        return self.text

    def closeClient(self):
        self.client.close()

Answer 1

无论如何，当您尝试打印数据时，您无法保证数据已经返回给客户。您应该介绍一些Conditions 并使用wait() 和notifyAll() 来确保数据到达....要检查我的猜测是否正确，请在您的测试中添加一些sleep()：

import time
k.sendData("Hey!")
print "*"*100
time.sleep(200)
print repr(k.data()), repr(m.data())
print "*"*100
m.sendData("okay okay")
print "*"*100
time.sleep(200)
print repr(k.data()), repr(m.data())
print "*"*100

如果可行，您应该使用条件并通知进行测试。

此外，您必须通过Lock() 保护data 访问。

def recieveData(self):

    while True:
        try:
            data = self.client.recv(2048)
        except:
            break
        if data:
            self.l.acquire()
            self.text = data
            self.l.release()
    self.client.close()

def data(self):
    self.l.acquire()
    ret = self.text
    self.l.release()
    return ret

其中客户端的属性l在__init__中定义

self.l=threading.Lock()