1 files changed, 203 insertions, 0 deletions
diff --git a/third_party/rust/ringbuf/src/tests/single.rs b/third_party/rust/ringbuf/src/tests/single.rs
new file mode 100644
index 0000000000..16f8af6455
--- /dev/null
+++ b/third_party/rust/ringbuf/src/tests/single.rs
@@ -0,0 +1,203 @@
+use crate::RingBuffer;
+use core::sync::atomic::Ordering;
+#[cfg(feature = "std")]
+use std::thread;
+
+fn head_tail<T>(rb: &RingBuffer<T>) -> (usize, usize) {
+    (
+        rb.head.load(Ordering::Acquire),
+        rb.tail.load(Ordering::Acquire),
+    )
+}
+
+#[test]
+fn capacity() {
+    let cap = 13;
+    let buf = RingBuffer::<i32>::new(cap);
+    assert_eq!(buf.capacity(), cap);
+}
+#[test]
+fn split_capacity() {
+    let cap = 13;
+    let buf = RingBuffer::<i32>::new(cap);
+    let (prod, cons) = buf.split();
+
+    assert_eq!(prod.capacity(), cap);
+    assert_eq!(cons.capacity(), cap);
+}
+
+#[cfg(feature = "std")]
+#[test]
+fn split_threads() {
+    let buf = RingBuffer::<i32>::new(10);
+    let (prod, cons) = buf.split();
+
+    let pjh = thread::spawn(move || {
+        let _ = prod;
+    });
+
+    let cjh = thread::spawn(move || {
+        let _ = cons;
+    });
+
+    pjh.join().unwrap();
+    cjh.join().unwrap();
+}
+
+#[test]
+fn push() {
+    let cap = 2;
+    let buf = RingBuffer::<i32>::new(cap);
+    let (mut prod, _) = buf.split();
+
+    assert_eq!(head_tail(&prod.rb), (0, 0));
+
+    assert_eq!(prod.push(123), Ok(()));
+    assert_eq!(head_tail(&prod.rb), (0, 1));
+
+    assert_eq!(prod.push(234), Ok(()));
+    assert_eq!(head_tail(&prod.rb), (0, 2));
+
+    assert_eq!(prod.push(345), Err(345));
+    assert_eq!(head_tail(&prod.rb), (0, 2));
+}
+
+#[test]
+fn pop_empty() {
+    let cap = 2;
+    let buf = RingBuffer::<i32>::new(cap);
+    let (_, mut cons) = buf.split();
+
+    assert_eq!(head_tail(&cons.rb), (0, 0));
+
+    assert_eq!(cons.pop(), None);
+    assert_eq!(head_tail(&cons.rb), (0, 0));
+}
+
+#[test]
+fn push_pop_one() {
+    let cap = 2;
+    let buf = RingBuffer::<i32>::new(cap);
+    let (mut prod, mut cons) = buf.split();
+
+    let vcap = cap + 1;
+    let values = [12, 34, 56, 78, 90];
+    assert_eq!(head_tail(&cons.rb), (0, 0));
+
+    for (i, v) in values.iter().enumerate() {
+        assert_eq!(prod.push(*v), Ok(()));
+        assert_eq!(head_tail(&cons.rb), (i % vcap, (i + 1) % vcap));
+
+        assert_eq!(cons.pop().unwrap(), *v);
+        assert_eq!(head_tail(&cons.rb), ((i + 1) % vcap, (i + 1) % vcap));
+
+        assert_eq!(cons.pop(), None);
+        assert_eq!(head_tail(&cons.rb), ((i + 1) % vcap, (i + 1) % vcap));
+    }
+}
+
+#[test]
+fn push_pop_all() {
+    let cap = 2;
+    let buf = RingBuffer::<i32>::new(cap);
+    let (mut prod, mut cons) = buf.split();
+
+    let vcap = cap + 1;
+    let values = [(12, 34, 13), (56, 78, 57), (90, 10, 91)];
+    assert_eq!(head_tail(&cons.rb), (0, 0));
+
+    for (i, v) in values.iter().enumerate() {
+        assert_eq!(prod.push(v.0), Ok(()));
+        assert_eq!(head_tail(&cons.rb), (cap * i % vcap, (cap * i + 1) % vcap));
+
+        assert_eq!(prod.push(v.1), Ok(()));
+        assert_eq!(head_tail(&cons.rb), (cap * i % vcap, (cap * i + 2) % vcap));
+
+        assert_eq!(prod.push(v.2).unwrap_err(), v.2);
+        assert_eq!(head_tail(&cons.rb), (cap * i % vcap, (cap * i + 2) % vcap));
+
+        assert_eq!(cons.pop().unwrap(), v.0);
+        assert_eq!(
+            head_tail(&cons.rb),
+            ((cap * i + 1) % vcap, (cap * i + 2) % vcap)
+        );
+
+        assert_eq!(cons.pop().unwrap(), v.1);
+        assert_eq!(
+            head_tail(&cons.rb),
+            ((cap * i + 2) % vcap, (cap * i + 2) % vcap)
+        );
+
+        assert_eq!(cons.pop(), None);
+        assert_eq!(
+            head_tail(&cons.rb),
+            ((cap * i + 2) % vcap, (cap * i + 2) % vcap)
+        );
+    }
+}
+
+#[test]
+fn empty_full() {
+    let buf = RingBuffer::<i32>::new(1);
+    let (mut prod, cons) = buf.split();
+
+    assert!(prod.is_empty());
+    assert!(cons.is_empty());
+    assert!(!prod.is_full());
+    assert!(!cons.is_full());
+
+    assert_eq!(prod.push(123), Ok(()));
+
+    assert!(!prod.is_empty());
+    assert!(!cons.is_empty());
+    assert!(prod.is_full());
+    assert!(cons.is_full());
+}
+
+#[test]
+fn len_remaining() {
+    let buf = RingBuffer::<i32>::new(2);
+    let (mut prod, mut cons) = buf.split();
+
+    assert_eq!(prod.len(), 0);
+    assert_eq!(cons.len(), 0);
+    assert_eq!(prod.remaining(), 2);
+    assert_eq!(cons.remaining(), 2);
+
+    assert_eq!(prod.push(123), Ok(()));
+
+    assert_eq!(prod.len(), 1);
+    assert_eq!(cons.len(), 1);
+    assert_eq!(prod.remaining(), 1);
+    assert_eq!(cons.remaining(), 1);
+
+    assert_eq!(prod.push(456), Ok(()));
+
+    assert_eq!(prod.len(), 2);
+    assert_eq!(cons.len(), 2);
+    assert_eq!(prod.remaining(), 0);
+    assert_eq!(cons.remaining(), 0);
+
+    assert_eq!(cons.pop(), Some(123));
+
+    assert_eq!(prod.len(), 1);
+    assert_eq!(cons.len(), 1);
+    assert_eq!(prod.remaining(), 1);
+    assert_eq!(cons.remaining(), 1);
+
+    assert_eq!(cons.pop(), Some(456));
+
+    assert_eq!(prod.len(), 0);
+    assert_eq!(cons.len(), 0);
+    assert_eq!(prod.remaining(), 2);
+    assert_eq!(cons.remaining(), 2);
+
+    // now head is at 2, so tail will be at 0. This caught an overflow error
+    // when tail+1 < head because of the substraction of usize.
+    assert_eq!(prod.push(789), Ok(()));
+
+    assert_eq!(prod.len(), 1);
+    assert_eq!(cons.len(), 1);
+    assert_eq!(prod.remaining(), 1);
+    assert_eq!(cons.remaining(), 1);
+}