Demonstrates issue discussed over at https://nullprogram.com/blog/2020/05/24/

latency_pure_asyncio.py

import asyncio
import time


async def heartbeat():
    while True:
        start = time.time()
        await asyncio.sleep(1)
        delay = time.time() - start - 1
        print(f'heartbeat delay = {delay:.3f}s')


JOB_DURATION = 0.01  # 10ms


async def process():
    time.sleep(JOB_DURATION)  # simulate CPU time


JOB_COUNT = 200


async def main():
    asyncio.create_task(heartbeat())

    await asyncio.sleep(2.5)

    print('begin processing')
    count = JOB_COUNT
    for _ in range(JOB_COUNT):
        asyncio.create_task(process())

    await asyncio.sleep(5)


if __name__ == '__main__':
    asyncio.run(main())