I’ve done thorough benchmarking of Rc and Arc. Rc is cheap to the point of free unless it frees - it’s literally just an addition or subtraction with no data d

I’ve done thorough benchmarking of Rc and Arc. Rc is cheap to the point of free unless it frees - it’s literally just an addition or subtraction with no data dependency in the path. Your CPU can do > 6 billion of these per second on a 6Ghz CPU (if I recall correctly you could do 3 per clock cycle in a micro benchmark due to out-of-order but at a minimum you should be able to do 1 per cycle). Arc is quite expensive, particularly on x86 because of its memory model. You can maybe do a few million of them per second. But as you said, you shouldn’t be incrementing ownership once you’ve sent it to a new thread and instead using references directly or using something Rc-like to track the lifetime (i.e. when the current thread’s Rc count hits 0, release your Arc reference).