Launcher won't launch on Windows with python 3.9

[piraz]

I don't recall this errors with previous python versions and this is the error:

Traceback (most recent call last):
  File "C:\venvs\ntunnelenv\Lib\site-packages\firenado\bin\firenado-cli.py", line 21, in <module>
    run_from_command_line()
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\management.py", line 61, in run_from_command_line
    run_command(namespace.command, sys.argv[command_index-1:])
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\management.py", line 114, in run_command
    existing_command.run(args)
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\management.py", line 176, in run
    subcommand.run(unresolved_args)
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\management.py", line 180, in run
    self.run_tasks(args)
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\management.py", line 203, in run_tasks
    task.run(namespace)
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\management\tasks.py", line 143, in run
    launcher.launch()
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\launcher.py", line 212, in launch
    if self.add_sockets(self.port, address):
  File "C:\venvs\ntunnelenv\lib\site-packages\firenado\launcher.py", line 264, in add_sockets
    self.http_server.add_sockets(sockets)
  File "C:\venvs\ntunnelenv\lib\site-packages\tornado\tcpserver.py", line 165, in add_sockets
    self._handlers[sock.fileno()] = add_accept_handler(
  File "C:\venvs\ntunnelenv\lib\site-packages\tornado\netutil.py", line 279, in add_accept_handler
    io_loop.add_handler(sock, accept_handler, IOLoop.READ)
  File "C:\venvs\ntunnelenv\lib\site-packages\tornado\platform\asyncio.py", line 100, in add_handler
    self.asyncio_loop.add_reader(fd, self._handle_events, fd, IOLoop.READ)
  File "C:\AppData\Local\Programs\Python\Python39\lib\asyncio\events.py", line 504, in add_reader
    raise NotImplementedError
NotImplementedError

Maybe will need to disable that part of the launcher entirely on Windows.

[piraz]

I can run without issues in python 3.7.

[piraz]

The issue is being tracked by tornado at tornadoweb/tornado#2608.

It was introduced with python 3.8 and was fixed on tornado 6.1.

This should be handled updating tornado.

[piraz]

The fix here is to patch asyncio to force it to use the event loop from windows "proactor" instead of the current from tornado "selector".

Here is the patch:

import asyncio
asyncio.set_event_loop_policy(asyncio.WindowsSelectorEventLoopPolicy())

Should be used at the launcher or we must use tornado 6.1.