So what would you use instead of threads? How do you mean "maximizing locality"? My intuition is that the reason Java can be concurrent is that it uses a VM t

So what would you use instead of threads? How do you mean "maximizing locality"? My intuition is that the reason Java can be concurrent is that it uses a VM that incurs cache misses on all IO. So in practice you can't have both. In C you can try to use locks to achieve something but for a long time of development you will be in dead-lock and race condition hell.