asyncio执行阻塞代码

在线程或者进程池中执行代码

#!/usr/bin/env python
# -*- coding: utf-8 -*-
# @time: 2021/12/31 2:41 下午
# https://docs.python.org/zh-cn/3/library/asyncio-eventloop.html#asyncio.loop.run_in_executor
import asyncio
import concurrent.futures


def blocking_io():
    # File operations (such as logging) can block the
    # event loop: run them in a thread pool.
    with open('/dev/urandom', 'rb') as f:
        return f.read(100)


def cpu_bound():
    # CPU-bound operations will block the event loop:
    # in general it is preferable to run them in a
    # process pool.
    return sum(i * i for i in range(10 ** 7))


async def main():
    loop = asyncio.get_running_loop()

    # 1. Run in the default loop's executor:
    result = await loop.run_in_executor(None, blocking_io)
    print('default thread pool', result)

    # 2. Run in a custom thread pool:
    with concurrent.futures.ThreadPoolExecutor() as pool:
        result = await loop.run_in_executor(pool, blocking_io)
        print('custom thread pool', result)

    # 3. Run in a custom process pool:
    with concurrent.futures.ProcessPoolExecutor() as pool:
        result = await loop.run_in_executor(pool, cpu_bound)
        print('custom process pool', result)


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