Additional in-order queue test for router

src/wireguard/router/queue.rs

@@ -97,12 +97,82 @@ impl<J: SequentialJob> Queue<J> {
 mod tests {
     use super::*;
 
-    use std::sync::Arc;
     use std::thread;
 
+    use std::sync::Arc;
+    use std::time::Duration;
+
     use rand::thread_rng;
     use rand::Rng;
 
+    #[test]
+    fn test_consume_queue() {
+        struct TestJob {
+            cnt: Arc<AtomicUsize>,
+            wait_sequential: Duration,
+        }
+
+        impl SequentialJob for TestJob {
+            fn is_ready(&self) -> bool {
+                true
+            }
+
+            fn sequential_work(self) {
+                thread::sleep(self.wait_sequential);
+                self.cnt.fetch_add(1, Ordering::SeqCst);
+            }
+        }
+
+        fn hammer(queue: &Arc<Queue<TestJob>>, cnt: Arc<AtomicUsize>) -> usize {
+            let mut jobs = 0;
+            let mut rng = thread_rng();
+            for _ in 0..10_000 {
+                if rng.gen() {
+                    let wait_sequential: u64 = rng.gen();
+                    let wait_sequential = wait_sequential % 1000;
+
+                    let wait_parallel: u64 = rng.gen();
+                    let wait_parallel = wait_parallel % 1000;
+
+                    thread::sleep(Duration::from_micros(wait_parallel));
+
+                    queue.push(TestJob {
+                        cnt: cnt.clone(),
+                        wait_sequential: Duration::from_micros(wait_sequential),
+                    });
+                    jobs += 1;
+                } else {
+                    queue.consume();
+                }
+            }
+            queue.consume();
+            jobs
+        }
+
+        let queue = Arc::new(Queue::new());
+        let counter = Arc::new(AtomicUsize::new(0));
+
+        // repeatedly apply operations randomly from concurrent threads
+        let other = {
+            let queue = queue.clone();
+            let counter = counter.clone();
+            thread::spawn(move || hammer(&queue, counter))
+        };
+        let mut jobs = hammer(&queue, counter.clone());
+
+        // wait, consume and check empty
+        jobs += other.join().unwrap();
+        assert_eq!(queue.queue.lock().len(), 0, "elements left in queue");
+        assert_eq!(
+            jobs,
+            counter.load(Ordering::Acquire),
+            "did not consume every job"
+        );
+    }
+
+    /* Fuzz the Queue */
+    #[test]
+    fn test_fuzz_queue() {
         struct TestJob {}
 
         impl SequentialJob for TestJob {
@@ -113,9 +183,6 @@ mod tests {
             fn sequential_work(self) {}
         }
 
-    /* Fuzz the Queue */
-    #[test]
-    fn test_queue() {
         fn hammer(queue: &Arc<Queue<TestJob>>) {
             let mut rng = thread_rng();
             for _ in 0..1_000_000 {