Currently, I am implementing an async interface for Ray. The implementation needs some kind of message polling methods like `get_next_notification`.
Unfortunately, I find `get_next_notification` in `https://github.com/apache/arrow/blob/master/python/pyarrow/_plasma.pyx` blocking, which is an impediment to implementing async utilities. Also, it's hard to check the status of the socket (it could be closed or break up). So I suggest export the notification socket so that there will be more flexibility.