3 ms·

I think the disconnect here is that some people want their data races (a) not to result in memory safety violations; some people want them to also (b) not resul

by amluto 2y ago

I think the disconnect here is that some people want their data races (a) not to result in memory safety violations; some people want them to also (b) not result in nonsensical control flow or code producing results that look impossible, and some people want (c) data races to simply not occur. You seem to like (a), Linus Torvalds seems to like (b), and Rust targets (c).

pizlonator 2y ago
Rust doesn’t target (c). That’s a hugely disingenuous claim. The truth is: Rust’s approach to memory safety only works if you also have no data races. This makes it a strictly inferior approach to memory safety, since programs sometimes do have to race (sometimes it’s just the best solution). So, Rust has data race prevention not because it’s a good idea but because the whole language falls apart without it.
- NobodyNada 2y ago
  > Rust has data race prevention not because it’s a good idea but because the whole language falls apart without it. In terms of the design goals and evolution of the Rust language, this is exactly backwards. Rust was originally conceived as a garbage-collected, green-threaded language designed for concurrent programming -- think something similar to Go but with a stronger type system and no data races. The ownership model was created, first as foremost, not for memory safety but to prevent data races; and, more broadly, to help programmers reason about the correctness of their code. Midway through development, as people started using the language & getting a feel for it, the language designers realized that the ownership model was powerful enough to express not just data race freedom but full memory safety without needing a GC (some writing from this stage in Rust's development: https://smallcultfollowing.com/babysteps/blog/2013/06/11/on-the-connection-between-memory-management-and-data-race-freedom/ https://smallcultfollowing.com/babysteps/blog/2013/06/11/on-..., https://pcwalton.github.io/_posts/2013-06-02-removing-garbage-collection-from-the-rust-language.html https://pcwalton.github.io/_posts/2013-06-02-removing-garbag...). So they removed the GC, and that decision positioned Rust where it is today: a nicer, memory-safe "C/C++ competitor", popular for systems code where the performance overhead or runtime complexity of a garbage collector is considered unacceptable.

by amluto 2y ago

pizlonator 2y ago

Rust doesn’t target (c). That’s a hugely disingenuous claim. The truth is: Rust’s approach to memory safety only works if you also have no data races. This makes it a strictly inferior approach to memory safety, since programs sometimes do have to race (sometimes it’s just the best solution). So, Rust has data race prevention not because it’s a good idea but because the whole language falls apart without it.

NobodyNada 2y ago
> Rust has data race prevention not because it’s a good idea but because the whole language falls apart without it. In terms of the design goals and evolution of the Rust language, this is exactly backwards. Rust was originally conceived as a garbage-collected, green-threaded language designed for concurrent programming -- think something similar to Go but with a stronger type system and no data races. The ownership model was created, first as foremost, not for memory safety but to prevent data races; and, more broadly, to help programmers reason about the correctness of their code. Midway through development, as people started using the language & getting a feel for it, the language designers realized that the ownership model was powerful enough to express not just data race freedom but full memory safety without needing a GC (some writing from this stage in Rust's development: https://smallcultfollowing.com/babysteps/blog/2013/06/11/on-the-connection-between-memory-management-and-data-race-freedom/ https://smallcultfollowing.com/babysteps/blog/2013/06/11/on-..., https://pcwalton.github.io/_posts/2013-06-02-removing-garbage-collection-from-the-rust-language.html https://pcwalton.github.io/_posts/2013-06-02-removing-garbag...). So they removed the GC, and that decision positioned Rust where it is today: a nicer, memory-safe "C/C++ competitor", popular for systems code where the performance overhead or runtime complexity of a garbage collector is considered unacceptable.