[adwn]

That's not entirely correct, or at least misleading. Rust will provide the same guarantees for variables in memory shared between processes as for variables in memory shared between threads. But you have to make sure that any locking datastructures you're using (like mutexes or read-write-locks) are able to work across processes.

(There are limits, though: if you map the same physical addresses to different virtual addresses, Rust can't help you. However, that is independent of threads/processes, because you can also do that in single-threaded programs.)

[pjmlp]

Which is a different story that just asserting fearless concurrency no matter what, also misleading.

Hence why I try to make a point that comes with a footnote.

Rust is after all supposed to target all kinds of system programming scenarios.

[adwn]

> Which is a different story that just asserting fearless concurrency no matter what, also misleading.

Frankly, you're being a bit disingenious. Nobody claimed that Rust can or will solve all conceivable concurrency problems. "Fearless concurrency" is generally understood to mean "...within a single program", not "...across different processes/machines/networks". By the time you understand what interprocess shared memory is, you're well able to correctly interpret Rust's "fearless concurrency" slogan.

[pjmlp]

Understood by most on the Rust community, not by others.

Most outside of the community aren't aware that nomicon points out exactly this.

By the way, there are also ways to cause havoc within a single program, example using a file as backing store being accessed by multiple threads concurrently, or accessing database data without transactions.

My goal is not to bash Rust, rather to trigger discussions around these kind of problems.

[noctune]

Both those situations are race conditions, but neither are data races. Rust only prevents data races, which is a specific kind of race condition, but it does not prevent race conditions in general.

[pjmlp]

It is the "in general" I care about and think it gets too little discussion on the community, because just like some RIR threads, the details get lost in the discussion.