Python中的loop.run_in_executor基本用法

loop.run_in_executor(executor, func, *args)

import asyncio
import time
def blocking_func(name):
    print(f"开始阻塞任务 {name}")
    time.sleep(3)
    print(f"结束阻塞任务 {name}")
    return f"{name} done"
async def main():
    loop = asyncio.get_running_loop()
    # 把阻塞函数丢进默认线程池
    result = await loop.run_in_executor(None, blocking_func, "任务A")
    print(result)
asyncio.run(main())

from concurrent.futures import ProcessPoolExecutor
def compute(n):
    return sum(i * i for i in range(n))
async def main():
    loop = asyncio.get_running_loop()
    with ProcessPoolExecutor() as executor:
        result = await loop.run_in_executor(executor, compute, 10_000_000)
        print(result)
asyncio.run(main())

import asyncio
import time
async def wrong():
    time.sleep(2)  # 阻塞整个事件循环！
    print("完成")
asyncio.run(wrong())

async def correct():
    loop = asyncio.get_running_loop()
    await loop.run_in_executor(None, time.sleep, 2)
    print("完成")

import asyncio
import time
def task(name, duration):
    print(f"开始 {name}")
    time.sleep(duration)
    print(f"结束 {name}")
    return name
async def main():
    loop = asyncio.get_running_loop()
    tasks = [
        loop.run_in_executor(None, task, 'A', 2),
        loop.run_in_executor(None, task, 'B', 3),
        loop.run_in_executor(None, task, 'C', 1),
    ]
    results = await asyncio.gather(*tasks)
    print("全部完成：", results)
asyncio.run(main())

def read_file(path):
    with open(path, 'r') as f:
        return f.read()
data = await loop.run_in_executor(None, read_file, "bigfile.txt")

import requests
def fetch(url):
    response = requests.get(url)
    return response.text
html = await loop.run_in_executor(None, fetch, "https://example.com")

import asyncio
from typing import Callable, Any
from functools import partial
async def to_thread(func: Callable, *args, **kwargs) -> Any:
    loop = asyncio.get_running_loop()
    return await loop.run_in_executor(None, partial(func, *args, **kwargs))
# 使用方式
result = await to_thread(my_blocking_function, arg1, arg2)

import asyncio
def blocking_func():
    ...
await asyncio.to_thread(blocking_func)

await loop.run_in_executor(None, blocking_func)