Merge pull request junit-team#508 from Tibor17/junit.issues

Improved Test: ParallelMethodTest fails few times

src/test/java/org/junit/tests/experimental/parallel/ParallelMethodTest.java

@@ -1,44 +1,52 @@
 package org.junit.tests.experimental.parallel;
 
+import static org.hamcrest.core.Is.is;
+import static org.hamcrest.core.IsNot.not;
+import static org.junit.Assert.assertNotNull;
 import static org.junit.Assert.assertThat;
 import static org.junit.Assert.assertTrue;
-import org.hamcrest.Description;
-import org.hamcrest.Matcher;
-import org.hamcrest.TypeSafeMatcher;
 import org.junit.Test;
 import org.junit.experimental.ParallelComputer;
 import org.junit.runner.JUnitCore;
 import org.junit.runner.Result;
+import org.junit.Before;
+import org.junit.BeforeClass;
+import java.util.concurrent.CountDownLatch;
+import java.util.concurrent.TimeUnit;
 
 public class ParallelMethodTest {
+	private static final long TIMEOUT= 15;
+	private static volatile Thread fOne= null;
+	private static volatile Thread fTwo= null;
+
 	public static class Example {
+		private static volatile CountDownLatch fSynchronizer;
+
+		@BeforeClass public static void init() {
+			fSynchronizer= new CountDownLatch(2);
+		}
 		@Test public void one() throws InterruptedException {
-			Thread.sleep(1000);
+			fSynchronizer.countDown();
+			assertTrue(fSynchronizer.await(TIMEOUT, TimeUnit.SECONDS));
+			fOne= Thread.currentThread();
 		}
 		@Test public void two() throws InterruptedException {
-			Thread.sleep(1000);
+			fSynchronizer.countDown();
+			assertTrue(fSynchronizer.await(TIMEOUT, TimeUnit.SECONDS));
+			fTwo= Thread.currentThread();
 		}
 	}
 
+	@Before public void init() {
+		fOne= null;
+		fTwo= null;
+	}
+
 	@Test public void testsRunInParallel() {
-		long start= System.currentTimeMillis();
-		Result result= JUnitCore.runClasses(ParallelComputer.methods(),
-				Example.class);
+		Result result= JUnitCore.runClasses(ParallelComputer.methods(), Example.class);
 		assertTrue(result.wasSuccessful());
-		long end= System.currentTimeMillis();
-		assertThat(end - start, betweenInclusive(1000, 1900));
-	}
-
-	private Matcher<Long> betweenInclusive(final long min, final long max) {
-		return new TypeSafeMatcher<Long>() {
-			@Override
-			public boolean matchesSafely(Long item) {
-				return item >= min && item <= max;
-			}
-
-			public void describeTo(Description description) {
-				description.appendText("between " + min + " and " + max);
-			}
-		};
+		assertNotNull(fOne);
+		assertNotNull(fTwo);
+		assertThat(fOne, is(not(fTwo)));
 	}
 }