Re:Next steps for Rust in the kernel
by tialaramex on Saturday September 24, 2022 @03:23PM
(#32965776)
I think what got confused here is just the nomenclature? In particular the use of "reference" to mean what we get when we borrow something in Rust, and its use to mean the address of something as part of a calling convention.
> are you promising to deallocate and otherwise clean up the object when you're done with it, versus are you promising that the caller can keep using it after you return.
Whether I ask for a Goose or a Box<Goose>, it's mine now. The caller no longer has it, it's not just that they shouldn't use it, they can't, the compiler won't let them. Since it's mine, it is now my responsibility as owner either clean up, give it to somebody else or explicitly leak() it.
Rust doesn't promise how exactly this is implemented, and it is likely to be different for an object of 4 bytes than for an object of 400 bytes.
> are you promising to deallocate and otherwise clean up the object when you're done with it, versus are you promising that the caller can keep using it after you return.
Whether I ask for a Goose or a Box<Goose>, it's mine now. The caller no longer has it, it's not just that they shouldn't use it, they can't, the compiler won't let them. Since it's mine, it is now my responsibility as owner either clean up, give it to somebody else or explicitly leak() it.
Rust doesn't promise how exactly this is implemented, and it is likely to be different for an object of 4 bytes than for an object of 400 bytes.