In the case of the original article, the reference count was being updated by all the threads so having an Arc-with-Rc-for-one-thread wouldn’t actually change things, I think. But maybe you just mean for ‘cheaper smart-pointers in general’?
The python thing is interesting. I thought there were other reasons for the GIL than ref counts but I guess everything must be addressed.
Yep in this case it might not have helped, but all this to say that some exploration of having multiple reference counts is a great idea. The balance becomes the overhead of coordinating multiple reference counts versus the gains from reduced atomic operations.
The python thing is interesting. I thought there were other reasons for the GIL than ref counts but I guess everything must be addressed.