Tornado graceful shutdown from a thread

tornado-thread.py

import threading
import tornado.ioloop
import tornado.web
import time
import asyncio
import logging
import requests

g_ioloop = None
g_server = None

class MainHandler(tornado.web.RequestHandler):
    def get(self):
        current = tornado.ioloop.IOLoop.current()
        print(f"[tornado] current(): {current}")
        self.write("Hello, world!\n")

def start_tornado(*args, **kwargs):
    # Create a new event loop for the thread
    # https://github.com/tornadoweb/tornado/issues/2308#issuecomment-372582005
    loop = asyncio.new_event_loop()
    loop.set_debug(False)
    loop._MY_THREAD = True
    logging.getLogger("asyncio").setLevel(logging.CRITICAL)  # Remove some debug spam
    asyncio.set_event_loop(loop)

    print(f"thread loop: {loop}")

    global g_ioloop, g_server
    application = tornado.web.Application([
        (r"/", MainHandler),
    ])
    g_server = application.listen(8888)
    print("Starting Torando")
    g_ioloop = tornado.ioloop.IOLoop.current()
    g_ioloop.start()
    print("Tornado finished")

def stop_tornado():
    global g_ioloop
    current = tornado.ioloop.IOLoop.current()
    print(f"[tornado] g_ioloop: {g_ioloop}\n[main] current(): {current}")
    g_ioloop.add_callback(g_server.stop)
    g_ioloop.add_callback(g_server.close_all_connections)
    g_ioloop.add_callback(g_ioloop.stop)
    print("Asked Tornado to exit")

def main():
    """
    # Create a new event loop for the main thread (not necessary)
    # https://github.com/tornadoweb/tornado/issues/2308#issuecomment-372582005
    loop = asyncio.new_event_loop()
    loop.set_debug(False)
    loop._MY_MAIN = True
    logging.getLogger("asyncio").setLevel(logging.CRITICAL)  # Remove some debug spam
    asyncio.set_event_loop(loop)
    """

    asyncio.get_event_loop()._MY_MAIN = True

    current = tornado.ioloop.IOLoop.current()
    print(f"[main] current(): {current}")

    t = threading.Thread(target=start_tornado)
    t.start()

    time.sleep(0.2)

    r = requests.get("http://localhost:8888")
    print(r.text)

    time.sleep(1)

    stop_tornado()
    t.join()

if __name__ == "__main__":
    main()