[troutwine]

This is a good question. Yes, it's exactly the same kind of problem. There is potentially a difference between Rust's memory model and what's actually present on any given target host. x64 has a "strong" memory model which that ordering will always be implicitly acquire/release. Compare this to ARM which is "weak" where your relaxed ordering will actually be relaxed. (There's actually quite a bit more nuance, discussed well here[0].) It's important to write code that is correct with regard to Rust's memory model so that it's portable, but if you don't have a weakly ordered machine to test on it's tricky. Loom[1] is helpful in this regard. This is true of any language that allows you to write atomic code where you specify the ordering.

[0] https://preshing.com/20120930/weak-vs-strong-memory-models/ [1] https://github.com/tokio-rs/loom