时间：2022-03-09 09:34:52 | 栏目：Python代码 | 点击：次
在使用aiohttp结合apscheduler的AsyncIOScheduler模拟定点并发的时候遇到两个问题
- 在调度器scheduler.start()后，程序直接退出（在Jupiter中任务可以正常启动）
- 如何在指定时间调用scheduler.shutdown()? (因为程序直接退出了）
原调试代码如下：
from datetime import datetime, timedelta
import aiohttp
from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
async def get(session):
url = 'https://httpbin.org/get?a=1'
async with session.get(url) as res:
print('get', res.status)
return await res.text()
async def post(session):
url = 'https://httpbin.org/post?b=2'
async with session.post(url) as res:
print('post', res.status)
return await res.text()
async def main():
async with aiohttp.ClientSession() as session:
await get(session)
await post(session)
if __name__ == '__main__':
jobstores = {'default': SQLAlchemyJobStore(url='sqlite:///jobs.sqlite')}
scheduler = AsyncIOScheduler(jobstores=jobstores)
for i in range(10): # 添加10个任务
job = scheduler.add_job(main, 'date', run_date=datetime.now() + timedelta(seconds=10))
scheduler.start()
Google后发现AsyncIOScheduler的使用需要在scheduler启动后，需要自己调用asyncio.get_event_loop().run_forever()来启动协程任务。
但是一旦run_forever()则就会阻塞至死。除非有KeyboardInterrupt, SystemExit等异常或者强杀来停止其运行。
此时想到使用Python的signal来定时发送信号，修改后程序如下，可以正常延迟停止（感觉有点像模拟Go的defer)。
# -*- coding: utf-8 -*-
"""
@Time ： 2021/7/23
@Auth ： hanzhichao
@Desc：
"""
from datetime import datetime, timedelta
import signal
import asyncio
import aiohttp
from apscheduler.schedulers.asyncio import AsyncIOScheduler
from apscheduler.jobstores.sqlalchemy import SQLAlchemyJobStore
async def get(session):
url = 'https://httpbin.org/get?a=1'
async with session.get(url) as res:
print('get', res.status)
return await res.text()
async def post(session):
url = 'https://httpbin.org/post?b=2'
async with session.post(url) as res:
print('post', res.status)
return await res.text()
async def main():
async with aiohttp.ClientSession() as session:
await get(session)
await post(session)
if __name__ == '__main__':
jobstores = {'default': SQLAlchemyJobStore(url='sqlite:///jobs.sqlite')}
scheduler = AsyncIOScheduler(jobstores=jobstores)
for i in range(10): # 添加10个任务
job = scheduler.add_job(main, 'date', run_date=datetime.now() + timedelta(seconds=10))
scheduler.start()
signal.alarm(20) # 20秒后终止程序
asyncio.get_event_loop().run_forever() # 永远运行