Add tests for Java built-in schedulers (#70)

Author: mperor

JavaReleases/src/test/java/pl/mperor/lab/java/Java3.java

@@ -10,7 +10,11 @@
 import javax.sound.sampled.*;
 import java.io.File;
 import java.io.IOException;
+import java.util.Timer;
+import java.util.TimerTask;
 import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.atomic.AtomicInteger;
 
 /**
  * Java 1.3 (May 2000)
@@ -36,19 +40,43 @@ public void testJavaNamingAndDirectoryInterfaceAkaJNDILookup() throws NamingExce
 
     @Test
     public void testJavaSoundAPI() throws UnsupportedAudioFileException, IOException, LineUnavailableException, InterruptedException {
-        if (AudioSystem.getMixerInfo().length != 0)
-            try (AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(new File("src/test/resources/beep.wav"))) {
-                Clip clip = AudioSystem.getClip();
-                clip.open(audioInputStream);
-                CountDownLatch latch = new CountDownLatch(1);
-                clip.addLineListener(event -> {
-                    if (event.getType() == LineEvent.Type.STOP) {
-                        clip.close();
-                        latch.countDown();
-                    }
-                });
-                clip.start();
-                latch.await();
+        if (AudioSystem.getMixerInfo().length == 0) {
+            return;
+        }
+
+        try (AudioInputStream audioInputStream = AudioSystem.getAudioInputStream(new File("src/test/resources/beep.wav"))) {
+            Clip clip = AudioSystem.getClip();
+            clip.open(audioInputStream);
+            CountDownLatch latch = new CountDownLatch(1);
+            clip.addLineListener(event -> {
+                if (event.getType() == LineEvent.Type.STOP) {
+                    clip.close();
+                    latch.countDown();
+                }
+            });
+            clip.start();
+            latch.await();
+        }
+    }
+
+    @Test
+    public void testScheduledTask() throws InterruptedException {
+        var schedulerCounter = new AtomicInteger(0);
+        var latch = new CountDownLatch(2);
+
+        var scheduler = new TimerTask() {
+            @Override
+            public void run() {
+                schedulerCounter.getAndIncrement();
+                latch.countDown();
             }
+        };
+        var timer = new Timer();
+        timer.scheduleAtFixedRate(scheduler, 0, 100);
+
+        boolean completed = latch.await(300, TimeUnit.MILLISECONDS);
+        Assertions.assertTrue(completed, "Scheduler did not run twice in time");
+        Assertions.assertEquals(2, schedulerCounter.get());
+        timer.cancel();
     }
 }

JavaReleases/src/test/java/pl/mperor/lab/java/Java5.java

@@ -9,8 +9,8 @@
 import java.lang.reflect.Method;
 import java.util.Arrays;
 import java.util.List;
-import java.util.concurrent.ExecutorService;
-import java.util.concurrent.Executors;
+import java.util.concurrent.*;
+import java.util.concurrent.atomic.AtomicInteger;
 import java.util.stream.IntStream;
 
 import static java.lang.Math.max;
@@ -113,6 +113,25 @@ public void testConcurrencyAPI() {
         TestUtils.resetSystemOut();
     }
 
+    @Test
+    public void testScheduledExecutor() throws InterruptedException {
+        var counter = new AtomicInteger(0);
+        var latch = new CountDownLatch(2);
+
+        ScheduledExecutorService executor = Executors.newSingleThreadScheduledExecutor();
+        ScheduledFuture<?> future = executor.scheduleAtFixedRate(() -> {
+            counter.getAndIncrement();
+            latch.countDown();
+        }, 0, 100, TimeUnit.MILLISECONDS);
+
+        boolean completed = latch.await(300, TimeUnit.MILLISECONDS);
+        Assertions.assertTrue(completed, "Task did not execute twice in time");
+        Assertions.assertEquals(2, counter.get());
+
+        future.cancel(true);
+        executor.shutdownNow();
+    }
+
     @Test
     public void testStaticImports() {
         Assertions.assertEquals(4, sqrt(16));   // Math.sqrt(16);