tasks.py 文件源码

def _wakeup(self, future):
        try:
            future.result()
        except Exception as exc:
            # This may also be a cancellation.
            self._step(exc)
        else:
            # Don't pass the value of `future.result()` explicitly,
            # as `Future.__iter__` and `Future.__await__` don't need it.
            # If we call `_step(value, None)` instead of `_step()`,
            # Python eval loop would use `.send(value)` method call,
            # instead of `__next__()`, which is slower for futures
            # that return non-generator iterators from their `__iter__`.
            self._step()
        self = None  # Needed to break cycles when an exception occurs.


# wait() and as_completed() similar to those in PEP 3148.