Vendor things

third-party/vendor/loom/tests/litmus.rs

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+#![deny(warnings, rust_2018_idioms)]
+
+use loom::sync::atomic::AtomicUsize;
+use loom::thread;
+
+use std::collections::HashSet;
+use std::sync::atomic::Ordering::Relaxed;
+use std::sync::{Arc, Mutex};
+
+// Loom currently does not support load buffering.
+#[test]
+#[ignore]
+fn load_buffering() {
+    let values = Arc::new(Mutex::new(HashSet::new()));
+    let values_ = values.clone();
+    loom::model(move || {
+        let x = Arc::new(AtomicUsize::new(0));
+        let y = Arc::new(AtomicUsize::new(0));
+
+        let th = {
+            let (x, y) = (x.clone(), y.clone());
+            thread::spawn(move || {
+                x.store(y.load(Relaxed), Relaxed);
+            })
+        };
+
+        let a = x.load(Relaxed);
+        y.store(1, Relaxed);
+
+        th.join().unwrap();
+        values.lock().unwrap().insert(a);
+    });
+    assert!(values_.lock().unwrap().contains(&1));
+}
+
+#[test]
+fn store_buffering() {
+    let values = Arc::new(Mutex::new(HashSet::new()));
+    let values_ = values.clone();
+    loom::model(move || {
+        let x = Arc::new(AtomicUsize::new(0));
+        let y = Arc::new(AtomicUsize::new(0));
+
+        let a = {
+            let (x, y) = (x.clone(), y.clone());
+            thread::spawn(move || {
+                x.store(1, Relaxed);
+                y.load(Relaxed)
+            })
+        };
+
+        y.store(1, Relaxed);
+        let b = x.load(Relaxed);
+
+        let a = a.join().unwrap();
+        values.lock().unwrap().insert((a, b));
+    });
+    assert!(values_.lock().unwrap().contains(&(0, 0)));
+}