Rename param in Barrier#get_after and add tests of MultiProducerBarrier.

src/barrier.rs

@@ -6,8 +6,9 @@ pub const NONE: Sequence = -1;
 #[doc(hidden)]
 pub trait Barrier: Send + Sync {
 	/// Gets the sequence number of the barrier with relaxed memory ordering.
+	/// `prev` must be the last sequence returned from this barrier.
 	///
 	/// Note, to establish proper happens-before relationships (and thus proper synchronization),
 	/// the caller must issue a [`std::sync::atomic::fence`] with [`Ordering::Acquire`].
-	fn get_after(&self, lower_bound: Sequence) -> Sequence;
+	fn get_after(&self, prev: Sequence) -> Sequence;
 }

src/producer/multi.rs

@@ -320,12 +320,57 @@ mod tests {
 	use super::*;
 
 	#[test]
-	fn test_log2() {
+	fn log2() {
 		assert_eq!(1, MultiProducerBarrier::log2(2));
 		assert_eq!(1, MultiProducerBarrier::log2(3));
 		assert_eq!(3, MultiProducerBarrier::log2(8));
 		assert_eq!(3, MultiProducerBarrier::log2(9));
 		assert_eq!(3, MultiProducerBarrier::log2(10));
 		assert_eq!(3, MultiProducerBarrier::log2(11));
 	}
+
+	#[test]
+	fn publication_of_single_event_for_small_barrier() {
+		let barrier = MultiProducerBarrier::new(64);
+
+		barrier.publish_range_relaxed(0, 1);
+		// Verify published:
+		assert_eq!(barrier.get_after(0), 0);
+	}
+
+	#[test]
+	fn publication_of_range_for_small_barrier() {
+		let barrier = MultiProducerBarrier::new(64);
+
+		barrier.publish_range_relaxed(0, 10);
+		// Verify published:
+		assert_eq!(barrier.get_after(0), 9);
+	}
+
+	#[test]
+	fn publication_of_range_wrapping_ringbuffer_for_small_barrier() {
+		let barrier = MultiProducerBarrier::new(64);
+
+		barrier.publish_range_relaxed(0, 50);
+		// Verify published:
+		assert_eq!(barrier.get_after(0), 49);
+
+		barrier.publish_range_relaxed(50, 50);
+		// Verify published:
+		assert_eq!(barrier.get_after(49), 99);
+	}
+
+	#[test]
+	fn publication_of_range_wrapping_ringbuffer_for_barrier() {
+		let barrier = MultiProducerBarrier::new(128);
+
+		barrier.publish_range_relaxed(0, 100);
+		// Verify published:
+		assert_eq!(barrier.get_after(0), 99);
+		// Verify not published:
+
+		barrier.publish_range_relaxed(100, 100);
+		// Verify published:
+		assert_eq!(barrier.get_after(99), 199);
+	}
 }

src/producer/single.rs

@@ -181,7 +181,7 @@ impl SingleProducerBarrier {
 impl Barrier for SingleProducerBarrier {
 	/// Gets the `Sequence` of the last published event.
 	#[inline]
-	fn get_after(&self, _lower_bound: Sequence) -> Sequence {
+	fn get_after(&self, _prev: Sequence) -> Sequence {
 		self.cursor.relaxed_value()
 	}
 }