Tornado asyncio tcp服务器抛出AttributeError：'_UnixSelectorEventLoop'

Question

我想构建一个使用Tornado和Asyncio的tcp服务器。在龙卷风的documentation他们说，await和async应该为tornado.gen.coroutine装饰更换工作，但我在开始本服务器有问题。我在这里做错了什么？

from tornado.ioloop import IOLoop 
from tornado.tcpserver import TCPServer 
from tornado.iostream import StreamClosedError 
from tornado.platform.asyncio import to_asyncio_future 

class Server(TCPServer): 

    async def handle_stream(self, stream, address): 
     """Called when new IOStream object is ready for usage""" 
     print('Incoming connection from %r', address) 
     while True: 
      try: 
       message = await to_asyncio_future(stream.read_until('\n'.encode('utf8'))) 
       print("Message: ", message) 
      except StreamClosedError: 
       print("Good bye!!") 
       break 


if __name__ == "__main__": 
    IOLoop.configure('tornado.platform.asyncio.AsyncIOLoop') 
    server = Server(io_loop=IOLoop.current().asyncio_loop) 
    server.listen(7000) 
    IOLoop.current().start() 

这是错误：

Traceback (most recent call last): 
    File "tornadoasyncioserver.py", line 41, in <module> 
    server.listen(7000) 
    File "/Users/user/tornadotcp/venv/lib/python3.5/site-packages/tornado/tcpserver.py", line 127, in listen 
    self.add_sockets(sockets) 
    File "/Users/user/tornadotcp/venv/lib/python3.5/site-packages/tornado/tcpserver.py", line 144, in add_sockets 
    io_loop=self.io_loop) 
    File "/Users/user/tornadotcp/venv/lib/python3.5/site-packages/tornado/netutil.py", line 275, in add_accept_handler 
    io_loop.add_handler(sock, accept_handler, IOLoop.READ) 
AttributeError: '_UnixSelectorEventLoop' object has no attribute 'add_handler' 

Answer 1

变化Server(io_loop=IOLoop.current().asyncio_loop)到Server(io_loop=IOLoop.current())因为服务器等待IOLoop，而不是ASYNCIO循环本身。