python - transport.write() 从线程扭曲时出错

Question

我正在尝试制作这个简单的服务器脚本，其中多个客户端连接到它并存储在 factory.connected_clients 字典中。然后我想显示一个菜单，以便执行服务器的用户可以选择他想要使用的客户端以及他想要发送给它们的命令(就像在反向 shell 中一样)。这是代码:

class RshServer(protocol.Protocol):

    def __init__(self, factory, addr):
        self.addr = addr
        self.factory = factory

    def connectionMade(self):
        address = self.addr.host + ':' + str(self.addr.port)
        self.factory.connected_clients[address] = self
        print '[*] Connection made with ' + address

class RshFactory(Factory):

    def __init__(self):
        self.connected_clients = {}

    def buildProtocol(self, addr):
        return RshServer(self, addr)

def show_server_menu():
    print '1. Show connected clients'
    print '2. Open client interface'
    msg = raw_input('Select an option: ')
    return msg

def show_client_menu():
    print '1. Show all processes'
    msg = raw_input('Select an option: ')
    return msg

def server_interface():
    while 1:
        msg = show_server_menu()
        command = server_commands.get(msg, None)
        if command: command()

def client_interface():
    protocol_name = raw_input('Enter client address: ')
    protoc = rsh_factory.connected_clients.get(protocol_name, None)
    if protoc: 
        msg = show_client_menu()
        protoc.transport.write(msg) 


rsh_factory = RshFactory()

server_commands = {
    '1' : lambda: sys.stdout.write(str(rsh_factory.connected_clients)+'\n'),
    '2' : client_interface
}

reactor.listenTCP(8000, rsh_factory)
reactor.callInThread(server_interface)
reactor.run()

但是，当我选择一个客户端并执行客户端接口(interface)函数时，我得到了这个错误:

Unhandled Error
Traceback (most recent call last):
  File "rsh_twisted_serv.py", line 58, in <module>
    reactor.run()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/base.py", line 1192, in run
    self.mainLoop()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/base.py", line 1204, in mainLoop
    self.doIteration(t)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/epollreactor.py", line 396, in doPoll
    log.callWithLogger(selectable, _drdw, selectable, fd, event)
--- <exception caught here> ---
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 88, in callWithLogger
    return callWithContext({"system": lp}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/log.py", line 73, in callWithContext
    return context.call({ILogContext: newCtx}, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 118, in callWithContext
    return self.currentContext().callWithContext(ctx, func, *args, **kw)
  File "/usr/lib/python2.7/dist-packages/twisted/python/context.py", line 81, in callWithContext
    return func(*args,**kw)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/posixbase.py", line 627, in _doReadOrWrite
    self._disconnectSelectable(selectable, why, inRead)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/posixbase.py", line 257, in _disconnectSelectable
    selectable.readConnectionLost(f)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/tcp.py", line 279, in readConnectionLost
    self.connectionLost(reason)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/tcp.py", line 293, in connectionLost
    abstract.FileDescriptor.connectionLost(self, reason)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/abstract.py", line 207, in connectionLost
    self.stopWriting()
  File "/usr/lib/python2.7/dist-packages/twisted/internet/abstract.py", line 429, in stopWriting
    self.reactor.removeWriter(self)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/epollreactor.py", line 344, in removeWriter
    EPOLLOUT, EPOLLIN)
  File "/usr/lib/python2.7/dist-packages/twisted/internet/epollreactor.py", line 321, in _remove
    self._poller.unregister(fd)
exceptions.IOError: [Errno 2] No such file or directory

我认为这是错误，是因为从非 react 器线程调用了 transport.write()。我对吗？我该如何解决？

解决方案: 正如@Glyph 所述，问题确实是我从非 react 器线程调用 transport.write()(他的回答中有更多详细信息)。我通过将 protoc.transport.write() 更改为 reactor.callFromThread(lambda: protoc.transport.write(msg))

使用了他提出的解决方案

Answer 1

我认为您的意思是“从非 react 器线程调用”。除非明确指定，否则 Twisted 中的代码都不是线程安全的。查看threading documentation了解更多信息。使用 reactor.callFromThread从您的 stdio 读取线程调用 Twisted 方法，或使用 StandardIO告诉 Twisted 改为从标准输入读取。