Isn't it still possible for the stack to get corrupted even if it is the same size as before? Say if you replace the top two elements AB with AD, then the top element is the same and the size is also the same.

@victor the top element is the same and the size is the same, but the pop-count would be 2 greater if we added AD. The pop-count doesnt check the size of the stack, but checks the number of modifications.

I think what's really interesting about these lock-free implementations is that they all rely on spinning? So how is that supposed to be responsible use of the processors at all?

I am used to thread being taken off by the OS and put back when there's actually time for change