But also, maintain a bunch of memory and cpu state invisibly, and apply a bunch atomically or roll it back, and do this for multiple threads simultaneously. An

But also, maintain a bunch of memory and cpu state invisibly, and apply a bunch atomically or roll it back, and do this for multiple threads simultaneously. And then try debugging some seemingly unrelated issue at the memory/instruction level, and drop the assumption that everything below your level of abstraction works perfectly as you expect. And yes, this is very similar to mis-predicted branches and the speculative execution vulnerabilities. I have honestly tried to understand those at the instruction level, and felt like I did at one point, and then a few months later felt like I forgot some key details and couldn't put it together again... like I get the idea, but can't quite put together the assembly to demo the problem on my own, it's a bit of a mindfuck ...