How to recognize, what functions are filled in of the Python interpreter stack?

[AlekseyPython]

Thanks to all!
It turned out that the error was that the events were not reusable.

import asyncio, time

async def waiter(event, index_corrutine, start):
    print('start: ' + str(index_corrutine) + '\ttime=' + str(round(time.time()-start)))
    await event.wait()
    print('end: ' + str(index_corrutine) + '\ttime=' + str(round(time.time()-start)))

async def main():
    # Create an Event object.
    event = asyncio.Event()

    start = time.time()
    waiter_task1 = asyncio.create_task(waiter(event, 1, start))
    await asyncio.sleep(3)
    event.set()
    waiter_task2 = asyncio.create_task(waiter(event, 2, start))
    await asyncio.sleep(1)
    event.set()

    # Wait until the waiters of tasks is finished.
    await waiter_task1, waiter_task2

asyncio.run(main())
exit(1)

Output:
start: 1	time=0
end: 1	time=3
start: 2	time=3
end: 2	time=3

That is, after the event is set, it stops doing something, but does not throw an exception. Therefore, it seems that everything works correctly.