LB litmus test adapted to loom crate

relaxed.rs

use std::sync::atomic::Ordering;

use loom::{
    sync::{atomic::AtomicU32, Arc},
    thread,
};

#[test]
fn relaxed() {
    loom::model(|| {
        let x = Arc::new(AtomicU32::new(0));
        let y = Arc::new(AtomicU32::new(0));
        let th0 = {
            let x = x.clone();
            let y = y.clone();
            thread::spawn(move || {
                let r0 = x.load(Ordering::Relaxed);
                y.store(1, Ordering::Relaxed);
                r0
            })
        };
        let th1 = thread::spawn(move || {
            let r0 = y.load(Ordering::Relaxed);
            x.store(1, Ordering::Relaxed);
            r0
        });
        let th0_r0 = th0.join().unwrap();
        let th1_r0 = th1.join().unwrap();
        assert!(th0_r0 == 0 || th1_r0 == 0);
    });
}

relaxed.test

// Test that can be run in Vulkan memory model
// Place in alloy/tests subdir of
// https://github.com/KhronosGroup/Vulkan-MemoryModel
// then run "make" under alloy subdir

NEWWG
NEWSG
NEWTHREAD
ld.atom.scopedev.sc0 x = 1
st.atom.scopedev.sc0 y = 2
NEWWG
NEWSG
NEWTHREAD
ld.atom.scopedev.sc0 y = 2
st.atom.scopedev.sc0 x = 1
SOLUTION consistent[X]