Python 高级编程和异步IO并发编程 --13_8 asyncio的同步和通信

import asyncio
from asyncio import Lock, Queue
cache = {}
lock = Lock()


async def get_stuff(url):
    # lock.acquire()是一个协程
    # await lock.acquire()
    # with await lock
    # Lock实现了__enter__和__exit__可以使用with语法
    async with lock:
        if url in cache:
            return cache[url]
        stuff = await aiohttp.request('GET', url)
        cache[url] = stuff
        return stuff


async def parse_stuff():
    stuff = await get_stuff()
    # do some parsing


async def use_stuff():
    stuff = await get_stuff()
    # use stuff to do something interesting


if __name__ == '__main__':
    tasks = [parse_stuff(), use_stuff()]
    loop = asyncio.get_event_loop()
    loop.run_until_complete(asyncio.wait(tasks))