Add assignments 12 and 13

src/assignments/assignment12_grade.rs

@@ -0,0 +1,44 @@
+#[cfg(test)]
+mod test {
+    use super::super::assignment12::*;
+
+    use std::sync::mpsc::channel;
+    use std::thread;
+
+    #[test]
+    fn test_ping_pong() {
+        let (tx1, mut rx1) = channel();
+        let (mut tx2, rx2) = channel();
+
+        let thread_ping = thread::spawn(move || {
+            for i in 0..100 {
+                tx1.send(i).unwrap();
+                let x = rx2.recv().unwrap();
+                assert_eq!(x, i + 1);
+            }
+        });
+
+        let thread_pong = thread::spawn(move || while pong(&mut rx1, &mut tx2) {});
+
+        thread_ping.join().unwrap();
+        thread_pong.join().unwrap();
+    }
+
+    #[test]
+    fn test_scoped_thread() {
+        for i in 0..100 {
+            let v = (0..i).collect::<Vec<u32>>();
+
+            thread::scope(|s| {
+                let (r1, r2) = use_scoped_thread(
+                    s,
+                    || v.iter().sum::<u32>(),
+                    || v.windows(2).map(|x| x[0] * x[1]).sum::<u32>(),
+                );
+
+                assert_eq!(r1, v.iter().sum());
+                assert_eq!(r2, v.windows(2).map(|x| x[0] * x[1]).sum());
+            });
+        }
+    }
+}