Hands-On Concurrency with Rust

Memory and caches

The memory storage of a CPU, alluded to in the last section, is fairly minimal. It is limited to the handful of words in general-purpose registers, plus the special-purpose registers in some limited cases. Registers are very fast, owing to their construction and on-die location, but they are not suited for storage. Modern machines connect CPUs over a bus or buses to the main memory, a very large block of randomly addressable bytes. This random addressability is important as it means that, unlike other kinds of storage, the cost to retrieve the 0^th byte from RAM is not distinct from retrieving the 1,000,000,000^th byte. We programmers don't have to do any goofy trickery to ensure that our structures appear in the front of ...