loop.py 文件源码

def tick(self):

        self.handle_exceptions()

        if not self.ready:
            # Don't let idle block the loop from exiting
            # There should be other handdles blocking exiting if
            # there is nothing ready
            self.unref_ticker()
            return
        coroutine_or_func, future = self.ready.popitem()

        if inspect.iscoroutine(coroutine_or_func):
            process_until_await(self, future, coroutine_or_func)
        else:
            coroutine_or_func()