test: loom won't simulate data races in current test

[OliverNChalk]

Not sure if the current test is runnable but with BUF_LEN > ELEMENTS the ring buffer will never loop and thus the writer will never write the same cell twice. This means you don't test the contention resolution algorithm (i.e. readers never spin).

Furthermore, I'm pretty sure loom will just report the data race and then panic. So I'm not entirely sure seqlocks can be proven sound with loom alone.

Referenced code:

const BUF_LEN: usize = 2_usize.pow(7);
const PAYLOAD: [u8; 8] = [0, 0, 0, 0, 0, 0, 0, 0];
const THREADS: [usize; 3] = [1, 2, 4];
const ELEMENTS: usize = 10;

// Snip

        for _ in 0..ELEMENTS {
            writer.push_back(PAYLOAD);
            std::thread::yield_now();
        }