Python：同步线程之间的输入和输出

Question

目前，我正在尝试使用Python中的套接字（一种双用户聊天系统）做一个小型项目。

import socket 
import threading 

#Callback. Print doesn't work across threads 
def data_recieved(data): 
    print data 

#Thread class to gather input 
class socket_read(threading.Thread): 
    sock = object 
    def __init__(self, sock): 
     threading.Thread.__init__(self) 
     self.sock = sock 
    def run(self): 
     while True: 
      data = self.sock.recv(1000) 
      if (data == "\quitting\\"): 
       return 
      data_recieved(self.sock.recv(1000)) 

#################################################################################### 
server = False 
uname = input("What's your username: ") 
print "Now for the technical info..." 
port = input("What port do I connect to ['any' if first]: ") 
#This is the first client. Let it get an available port 
if (port == "any"): 
    server = True 
    port = 9999 
    err = True 
    while err == True: 
     try: 
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
      sock.bind(('', port)) 
      err = False 
     except: 
      err = True 
     sock.close() 

    print "Bound to port #" + str(port) 
    print "Waiting for client..." 

    sock.listen(1) 
    (channel, info) = sock.accept() 
else: 
    #This is the client. Just bind it tho a predisposed port 
    host = input("What's the IP of the other client: ") 
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
    sock.connect((host, int(port))) 

msg = "" 
if (server == True): 
    #Use the connection from accept 
    reader = socket_read(channel) 
else: 
    #Use the actual socket 
    reader = socket_read(sock) 
reader.start() 
while msg != 'quit': 
    #Get the message... 
    msg = uname + ": " + input("Message: ") 
    try: 
     #And send it 
     if (server == True): 
      #Use the connection from accept 
      channel.send(msg) 
     else: 
      #Use direct socket 
      sock.send(msg) 
    except: 
     break 
reader.join() 
channel.send("\quitting\\") 
sock.close() 

（我希望评论帮助）

总之，通过调用输入的同时，并获得对方套接字的消息时，我有一个小的同步化问题。我可以连接，但是当我收到消息时，它不会取消输入语句。

换句话说，当我收到一个消息，它说这个

Message: user: I got a message 
#Flashing cursor here 

因此，它不会取消输入语句。

此外，我只收到其他所有消息。

有什么建议吗？

Answer 1

你在这里所做的并不是一个同步问题，因为它是一个演示/ UI问题。我建议让你的生活更轻松，并选择一些UI工具包（curses，wxPython，pyqt）来处理与用户的交互。使用input（）对于快速而肮脏的一次性代码非常方便，但它并不十分复杂。

如果你这样做，你会看到你根本不需要使用线程（就像往常一样），你的问题就会像魔术一样消失！

Answer 2

好吧，对于我自己的问题，很抱歉这么快速回答，但使用线程时（至少在Linux的模型上），回调是神奇的。

总之，这样做：

import socket 
import threading 

def msg_loop(socket): 
    msg = "" 
    if (server == True): 
     reader = socket_read(channel) 
    else: 
     reader = socket_read(sock) 
    reader.start() 
    while msg != 'quit': 
     msg = uname + " said : " + input("Message: ") 
     print "" 
     try: 
      if (server == True): 
       channel.send('null') 
       channel.send(msg) 
      else: 
       sock.send('null') 
       sock.send(msg) 
     except: 
      break 

def data_recieved(data, socket): 
    print "Hold on...\n\n" + data + "\n" 
    msg_loop(socket) 

class socket_read(threading.Thread): 
    sock = object 
    def __init__(self, sock): 
     threading.Thread.__init__(self) 
     self.sock = sock 
    def run(self): 
     while True: 
      data = self.sock.recv(1000) 
      if (data == "\quitting\\" or data == ''): 
       return 
      data_recieved(self.sock.recv(1000), self.sock) 

#################################################################################### 
server = False 
uname = str(input("What's your username: ")) 
print "Now for the technical stuff..." 
port = input("What port do I connect to ['any' if first]: ") 
if (port == "any"): 
    server = True 
    port = 9999 
    err = True 
    while err == True: 
     try: 
      sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
      sock.bind(('', port)) 
      err = False 
     except: 
      print "Socket #" + str(port) + " failed" 
      err = True 
      sock.close() 
      port -= 1 

    print "Bound to port #" + str(port) 
    print "Waiting for client..." 

    sock.listen(1) 
    (channel, info) = sock.accept() 
else: 
    host = input("What's the IP of the other client: ") 
    sock = socket.socket(socket.AF_INET, socket.SOCK_STREAM) 
    sock.connect((host, int(port))) 

if (server == True): 
    msg_loop(channel) 
else: 
    msg_loop(sock) 

reader.join() 
channel.send("\quitting\\") 
sock.close() 

正如你所看到的，我加了消息循环作为回调。

另请注意，我发送空值，以规避“其他”问题。

那，我在data_recieved的打印结束处使用换行符来禁用换行符。

（如果你喜欢的代码，它不运行，以及在Windows上，这是因为，很显然，在那里Python的线程模型不作为instentaniously执行。尝试在您的本地Linux框）