Shared memory space, not necessarily shared memory. I referenced Erlang & Pony after all so it's not like I'm unaware of the issues here. You don't need a full OS process boundary to separate things; it is a very crude and blunt instrument and there are much better options available. Separation is nice but paying to cross OS boundaries with every message kills performance dead. A full OS process boundary between all concurrently-running threads would be insane overkill for a Rust, Erlang or Pony program, and in practice, with best practices and the use of some tooling, even for Go, even if it is just old-fashioned shared-memory at its core.
"Memory space" is usually called "address space". And I think you're confused - context switching is expensive but there's no context switching involved when you're running in parallel across N cores. We're talking about parallelism, not concurrency.
No, we're talking about what I'm talking about. I've started the whole thread and participated all the way down to here. I also find myself wondering if you understand what we're talking about. I know what I'm saying about terminology is a bit controversial, but the nature of what existing run time systems are doing is not. They've been doing it for decades.
