> There are a couple of interesting implications from this outcome, should it hold. The first of those is that, as Rust code reaches more deeply into the core kernel, its code for concurrent access to shared data will look significantly different from the equivalent C code, even though the code on both sides may be working with the same data. Understanding lockless data access is challenging enough when dealing with one API; developers may now have to understand two APIs, which will not make the task easier.
The thing is, it'll be far less challenging for the Rust code, which will actually define the ordering semantics explicitly. That's the point of rejecting the READ_ONCE/WRITE_ONCE approach - it's unclear what the goal is when using those, what guarantee you actually want.
I suspect that if Rust continues forward with this approach it will basically end up as the code where someone goes to read the actual semantics to determine what the C code should do.
The thing is, it'll be far less challenging for the Rust code, which will actually define the ordering semantics explicitly. That's the point of rejecting the READ_ONCE/WRITE_ONCE approach - it's unclear what the goal is when using those, what guarantee you actually want.
I suspect that if Rust continues forward with this approach it will basically end up as the code where someone goes to read the actual semantics to determine what the C code should do.