flask_and_asyncio

flask_and_asyncio.py

# -*- coding: utf-8 -*-
# 2021/9/9
# create by: snower

import threading
import asyncio
from flask import Flask

app = Flask(__name__)

_loop_thread = None
_loop = None

def get_loop():
    global _loop_thread, _loop
    if _loop:
        return _loop

    _loop = asyncio.new_event_loop()
    def run():
        asyncio.set_event_loop(_loop)
        _loop.run_forever()
    _loop_thread = threading.Thread(target=run)
    _loop_thread.setDaemon(True)
    _loop_thread.start()
    return _loop


@app.route("/")
def hello_world():
    event = threading.Event()
    def asyncio_run():
        print("This is running in asyncio")
        event.set()

    print("This is wait asyncio run")
    get_loop().call_soon_threadsafe(asyncio_run)
    event.wait()
    print("This is asyncio running finish")
    return "<p>Hello, World!</p>"