_run.py 文件源码

def _might_change_effective_deadline(self):
        try:
            yield
        finally:
            old = self._effective_deadline
            if self.cancel_called or not self._tasks:
                new = inf
            else:
                new = self._deadline
            if old != new:
                self._effective_deadline = new
                runner = GLOBAL_RUN_CONTEXT.runner
                if old != inf:
                    del runner.deadlines[old, id(self)]
                if new != inf:
                    runner.deadlines[new, id(self)] = self