tornado异步和同步交叉使用

1 同步代码异步执行

from concurrent.futures.thread import ThreadPoolExecutor

class AsyncClient(object):
    __instance = None
    """
        这里做成了单例以便于使用相同线程池来处理所有这种情况
    """
    
    def __new__(cls, *args, **kwargs):
        if cls.__instance is None:
            cls.__instance = super(
                AsyncClient, cls).__new__(cls, *args, **kwargs)
        return cls.__instance

    def __init__(self):
        self.executor = ThreadPoolExecutor()
        self.io_loop = ioloop.IOLoop.current()

    @concurrent.run_on_executor
    def methods(self, syncfunc, args):
        return syncfunc(args)

class AsyncRequestHandle(tornado.web.RequestHandler):
    async def get(self):
        client = AsyncClient()
        res = await client.methods(requests.get,"https://www.baidu.com")
        print(res.status_code)
        self.write('ok')
        await self.finish()

2 同步代码中引入异步代码时

alt_ioloop_fut = concurrent.futures.Future()
def run_alt_loop():
    asyncio.set_event_loop(asyncio.SelectorEventLoop())
    ioloop = IOLoop()
    alt_ioloop_fut.set_result(ioloop)
    ioloop.start()
alt_thread = threading.Thread(target=run_alt_loop)
alt_thread.daemon = True
alt_thread.start()
alt_ioloop = alt_ioloop_fut.result()

def run_coro_on_other_thread(f, *args, **kw):
    fut = concurrent.futures.Future()
    async def wrapper():
        try:
            res = await f(*args, **kw)
            fut.set_result(res)
        except Exception as e:
            fut.set_exception(e)
    alt_ioloop.add_callback(wrapper)
    return fut.result()

async def func():
    async_client = httpclient.AsyncHTTPClient()
    res = await async_client.fetch('https://www.baidu.com')
    return res

class Handler(tornado.web.RequestHandler):
    def get(self):
        res = run_coro_on_other_thread(func)
        print(res.body)
        self.write('ok')