[Python知识库]python threading中停止socket.recv

为无法停止threading的坑做一次记录

在用PyQt5界面库写socket局域网通信时,发现窗口关闭后程序仍在运行,认真检查后是线程中的socket的recv函数出了问题，在socket关闭后(socket.close())，socket.recv()仍会堵塞，导致线程无法释放，现找到了三种做法

修改前服务器部分代码如下

threading.Thread(target=self.connect).start()

def connect(self, server=None):
    # 等待用户连接
    if not server:
        server = self.server  # socket
    # 服务器要一直运行所以使用死循环
    while True:
        # 接受所连接的客户端的信息
        try:
            connect, addrss = server.accept()
        except OSError:
            break  # 服务器关闭
        # 每连接一个客户端就开启一个线程
        t = threading.Thread(target=self.member_receive, args=(connect, addrss))
        t.start()
        self.receive_thread.append(t)

def member_receive(self, connect, addrss):
    while True:
        try:
            rData = connect.recv(1024)
        except Exception as error:
            print(error)
            break

?然后member_receive中的connect.recv(1024)会一直堵塞运行

修改方法来自?如何从Python中的另一个线程中止socket.recv（）

使用超时的解决方案。这将中断recv（实际上在超时之前），这很好：

链接中的代码:

# Echo server program
import socket
from threading import Thread
import time


class ClientThread(Thread):
    def __init__(self, clientSocke):
        Thread.__init__(self)
        self.clientSocket = clientSocket

    def run(self):
        while 1:
            try:
                data = self.clientSocket.recv(1024)
                print "Got data: ", data
                self.clientSocket.send(data)
            except socket.timeout: 
                # If it was a timeout, we want to continue with recv
                continue
            except:
                break

        self.clientSocket.close()

HOST = ''
PORT = 6000
serverSocket = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
serverSocket.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
serverSocket.bind((HOST, PORT))
serverSocket.listen(1)

clientSocket, addr = serverSocket.accept()
clientSocket.settimeout(5)

print 'Got a new connection from: ', addr
clientThread = ClientThread(clientSocket)
clientThread.start()

# Close it down immediatly 
clientSocket.close()

先设置超时的时间为5秒

socket.settimeout(5)

即1秒内如果没有接收到就会报出socket.timeout，然后跳到下一次循环，从而避免程序堵塞、线程无法释放

修改后服务器代码如下

self.server.settimeout(5)
threading.Thread(target=self.connect).start()

def connect(self, server=None):
    # 等待用户连接
    if not server:
        server = self.server  # socket
    # 服务器要一直运行所以使用死循环
    while True:
        # 接受所连接的客户端的信息
        try:
            connect, addrss = server.accept()
        except OSError:
            break  # 服务器关闭
        # 每连接一个客户端就开启一个线程
        t = threading.Thread(target=self.member_receive, args=(connect, addrss))
        t.start()
        self.receive_thread.append(t)

def member_receive(self, connect, addrss):
    while True:
        try:
            rData = connect.recv(1024)
        except socket.timeout:
            break
        except Exception as error:
            print(error)
            break

当然，你得确保你的超时时间足够使recv函数接收完所有的数据才行。