如何使用aiohttp实现SIGTERM和SIGINT信号的回调

import asyncio
import signal
from aiohttp import web

app = web.Application()

async def cleanup(app):
    # 在这里执行一些清理操作，如关闭数据库连接、关闭文件等
    await asyncio.sleep(1)  # 模拟清理过程

async def shutdown(signal, loop):
    # 终止事件循环，停止服务器
    tasks = [task for task in asyncio.Task.all_tasks() if task is not
             asyncio.tasks.Task.current_task()]
    for task in tasks:
        task.cancel()
    await asyncio.gather(*tasks, return_exceptions=True)
    loop.stop()

app.on_cleanup.append(cleanup)
loop = asyncio.get_event_loop()
for signame in ('SIGINT', 'SIGTERM'):
    loop.add_signal_handler(getattr(signal, signame), lambda: asyncio.ensure_future(shutdown(signame, loop)))

web.run_app(app)