[Python] Python interpreter freezing while handling exceptions with asyncio.to_thread

This is an abstracted version of my code - I'm actually using socket.accept, not time.sleep (the same things happen though). It happens in Python 3.11.9 (Windows)

I want to use non-async function as async function, so I used asyncio.to_thread. But when an exception occured in non-async function (e.g. KeyboardInterrupt), the python interpreter just freezes and does not respond (and nothing was printed in console).

import asyncio
import time


async def func_1():
while True:
print('print something..')
await asyncio.sleep(0.5)

async def func_2():
print('start here')
# await asyncio.sleep(100)
await asyncio.to_thread(time.sleep, 100)
print('end here')

async def main():
asyncio.create_task(func_1())
await func_2()

try:
asyncio.run(main())
except BaseException:
print('exception has occured')


I wonder why this happens, and how to fix it concisely.

Continue reading...