One piece of friction that hurts here is that the C++/Rust and ARM memory models aren't the same, and the consequences of this are unintuitive - compilers and CPUs can both screw with execution ordering.
People who write in C++ should technically _only_ be concerned with the C++ memory model, but x86 has let them be very lax and undisciplined with std::memory_order_relaxed. ARM has some alluring constructs that don't quite fit with the C++ model, which can tempt you to mix and match memory models for performance. All of this means trouble with atomics.
People who write in C++ should technically _only_ be concerned with the C++ memory model, but x86 has let them be very lax and undisciplined with std::memory_order_relaxed. ARM has some alluring constructs that don't quite fit with the C++ model, which can tempt you to mix and match memory models for performance. All of this means trouble with atomics.