[_huayra_]

> I didn't think in 2023 I would read that programmers are shocked that relaxed atomics can be reordered.

At my current and prior jobs, I've had to do the "C++ cleanup" job while porting some x86_64 code to ARM. The TSO model from x86 is just something I think a lot of people have assumed and haven't been hurt by (again because it's TSO). Most of the work I had to do is basically using all the SA and sanitizers I could, staring hard at the code to convince myself there wasn't some secret data dependency on some relaxed atomic.

"It's just a simple flag, so I'll use a relaxed atomic, nbd", meanwhile the same person is assuming another structure they've "published" (e.g. to a shared queue) will be visible is alarming.

[dataflow]

Isn't the problem elsewhere here? The fact that people are using an API whose entire purpose they don't understand? "I passed a flag without understanding at all what it's supposed to do" doesn't seem specific to atomics at all.

This feels exactly like crossing an intersection without looking around despite noticing a sign saying "blind intersection", then being surprised when you get hit, then blaming it on the sign being "tricky" to reason about. There was nothing tricky about the logic... you just ignored it.

[_huayra_]

Just to be clear, I'm agreeing with you. It's people using an API they don't understand but happens to work because of TSO. When you take away TSO (e.g. on ARM), those assumptions come back to haunt the code in very tricky race conditions.