1 files changed, 49 insertions, 5 deletions
diff --git a/tests/atomic_cell.rs b/tests/atomic_cell.rs
index da7a6e1..edb7a4b 100644
--- a/tests/atomic_cell.rs
+++ b/tests/atomic_cell.rs
@@ -35,11 +35,7 @@ fn is_lock_free() {
     // of `AtomicU64` is `8`, so `AtomicCell<u64>` is not lock-free.
     assert_eq!(
         AtomicCell::<u64>::is_lock_free(),
-        cfg!(not(crossbeam_no_atomic_64))
-            && cfg!(any(
-                target_pointer_width = "64",
-                target_pointer_width = "128"
-            ))
+        cfg!(not(crossbeam_no_atomic_64)) && std::mem::align_of::<u64>() == 8
     );
     assert_eq!(mem::size_of::<U64Align8>(), 8);
     assert_eq!(mem::align_of::<U64Align8>(), 8);
@@ -330,3 +326,51 @@ fn issue_748() {
     let x = AtomicCell::new(Test::FieldLess);
     assert_eq!(x.load(), Test::FieldLess);
 }
+
+// https://github.com/crossbeam-rs/crossbeam/issues/833
+#[rustversion::since(1.40)] // const_constructor requires Rust 1.40
+#[test]
+fn issue_833() {
+    use std::num::NonZeroU128;
+    use std::sync::atomic::{AtomicBool, Ordering};
+    use std::thread;
+
+    #[cfg(miri)]
+    const N: usize = 10_000;
+    #[cfg(not(miri))]
+    const N: usize = 1_000_000;
+
+    #[allow(dead_code)]
+    enum Enum {
+        NeverConstructed,
+        Cell(AtomicCell<NonZeroU128>),
+    }
+
+    static STATIC: Enum = Enum::Cell(AtomicCell::new(match NonZeroU128::new(1) {
+        Some(nonzero) => nonzero,
+        None => unreachable!(),
+    }));
+    static FINISHED: AtomicBool = AtomicBool::new(false);
+
+    let handle = thread::spawn(|| {
+        let cell = match &STATIC {
+            Enum::NeverConstructed => unreachable!(),
+            Enum::Cell(cell) => cell,
+        };
+        let x = NonZeroU128::new(0xFFFF_FFFF_FFFF_FFFF_0000_0000_0000_0000).unwrap();
+        let y = NonZeroU128::new(0x0000_0000_0000_0000_FFFF_FFFF_FFFF_FFFF).unwrap();
+        while !FINISHED.load(Ordering::Relaxed) {
+            cell.store(x);
+            cell.store(y);
+        }
+    });
+
+    for _ in 0..N {
+        if let Enum::NeverConstructed = STATIC {
+            unreachable!(":(");
+        }
+    }
+
+    FINISHED.store(true, Ordering::Relaxed);
+    handle.join().unwrap();
+}