impl Sync for FixedRegisters?

[ChocolateLoverRaj]

AcpiPlatform, which contains FixedRegisters, is marked as Sync. So is it safe to also mark FixedRegisters as safe? My use case is storing a Arc<FixedRegisters> in a global variable.

[martin-hughes]

Not by itself, because of the embedded NonNull via PhysicalMapping. To be honest, I think AcpiPlatform probably shouldn't currently be marked Sync.

I think if PhysicalMapping is marked Sync appropriately then the thread-safety flows through MappedGas and the register-block structs to FixedRegisters

But at present PhysicalMapping isn't really thread-safe because of the pub virtual_start: NonNull<T> member. Implementing Deref and DerefMut takes it most of the way there, it just needs a bit more work.

Does that make sense?