Question

我正在学习Python中的套接字，并且一直在使用着名的echo服务器。我正在尝试将asyncore库用于异步IO，但我从客户端套接字中得到了这种奇怪的行为。

这是我写的代码：

import socket
import asyncore

class Handler(asyncore.dispatcher):
    '''
    Class to handle connected clients and send them messages.
    '''
    def __init__(self, sock, server):
        asyncore.dispatcher.__init__(self, sock)
        self.server = server
        self.buffer = 'Connection accepted'

    def writable(self):
        return len(self.buffer) > 0

    def handle_read(self):
        '''
        Read from the buffer.
        '''
        data = self.recv(2)

        if not data:
            raise RuntimeError('Lost connection to client.')

        print 'Handler received: %s' % data

    def handle_write(self):
        sent = self.send(self.buffer)

        print 'sent %d bytes' % sent
        self.buffer = self.buffer[sent:]

class Server(asyncore.dispatcher):
    def __init__(self, host, port):
        asyncore.dispatcher.__init__(self)
        self.create_socket(socket.AF_INET, socket.SOCK_STREAM)
        self.bind((host, port))
        self.listen(1)

    def handle_accept(self):
        self.client, _ = self.accept()
        self.handler = Handler(client, self)


if __name__ == '__main__':
    port = 5655

    server = Server('', port)
    client = socket.socket()
    client.connect(('localhost', port))

    asyncore.loop(0.1, count=5)

    client.send('hi')
    print 'Client received: %s' % client.recv(19)

    asyncore.loop(1, count=1)

当我尝试将客户端套接字连接到服务器时，它根本无法与处理程序进行通信。这是发生的事情：

Traceback (most recent call last):
  File "test.py", line 57, in <module>
    print 'Client received: %s' % server.client.recv(19)
socket.error: [Errno 10035] A non-blocking socket operation could not be completed immediately

但是，如果我使用服务器的accept方法而不是原始客户端套接字返回的客户端套接字，它会按预期工作：

if __name__ == '__main__':
    port = 5655

    server = Server('', port)
    client = socket.socket()
    client.connect(('localhost', port))

    asyncore.loop(0.1, count=5)

    server.client.send('hi')
    print 'Client received: %s' % server.client.recv(19)

    asyncore.loop(1, count=1)

输出：

sent 19 bytes
Client received: Connection accepted
Handler received: hi

我做错了什么，还是预期的行为？如果后者是真的，我真的需要提高对套接字的理解。

客户端套接字不与Python中的处理程序通信

0 个答案: