--- jsr166/src/test/tck/AtomicStampedReferenceTest.java	2003/08/31 19:24:53	1.1
+++ jsr166/src/test/tck/AtomicStampedReferenceTest.java	2010/08/25 00:07:03	1.15
@@ -1,99 +1,151 @@
 /*
- * Written by members of JCP JSR-166 Expert Group and released to the
- * public domain. Use, modify, and redistribute this code in any way
- * without acknowledgement. Other contributors include Andrew Wright,
- * Jeffrey Hayes, Pat Fischer, Mike Judd.
+ * Written by Doug Lea with assistance from members of JCP JSR-166
+ * Expert Group and released to the public domain, as explained at
+ * http://creativecommons.org/licenses/publicdomain
+ * Other contributors include Andrew Wright, Jeffrey Hayes,
+ * Pat Fisher, Mike Judd.
  */
 
 import junit.framework.*;
 import java.util.concurrent.atomic.*;
 
-public class AtomicStampedReferenceTest extends TestCase{
-    public static void main (String[] args) {
-        junit.textui.TestRunner.run (suite());
+public class AtomicStampedReferenceTest extends JSR166TestCase {
+    public static void main(String[] args) {
+        junit.textui.TestRunner.run(suite());
     }
     public static Test suite() {
         return new TestSuite(AtomicStampedReferenceTest.class);
     }
-    
-    static final Integer zero = new Integer(0);
-    static final Integer one = new Integer(1);
-    static final Integer two = new Integer(2);
-    static final Integer m3  = new Integer(-3);
 
-    public void testConstructor(){
+    /**
+     * constructor initializes to given reference and stamp
+     */
+    public void testConstructor() {
         AtomicStampedReference ai = new AtomicStampedReference(one, 0);
-	assertEquals(one,ai.getReference());
-	assertEquals(0, ai.getStamp());
+        assertSame(one,ai.getReference());
+        assertEquals(0, ai.getStamp());
         AtomicStampedReference a2 = new AtomicStampedReference(null, 1);
-	assertNull(a2.getReference());
-	assertEquals(1, a2.getStamp());
-
+        assertNull(a2.getReference());
+        assertEquals(1, a2.getStamp());
     }
 
-    public void testGetSet(){
+    /**
+     *  get returns the last values of reference and stamp set
+     */
+    public void testGetSet() {
         int[] mark = new int[1];
         AtomicStampedReference ai = new AtomicStampedReference(one, 0);
-	assertEquals(one,ai.getReference());
-	assertEquals(0, ai.getStamp());
-        assertEquals(one, ai.get(mark));
-        assertEquals(0, mark[0]);
-	ai.set(two, 0);
-	assertEquals(two,ai.getReference());
-	assertEquals(0, ai.getStamp());
-        assertEquals(two, ai.get(mark));
-        assertEquals(0, mark[0]);
-	ai.set(one, 1);
-	assertEquals(one,ai.getReference());
-	assertEquals(1, ai.getStamp());
-        assertEquals(one, ai.get(mark));
+        assertSame(one,ai.getReference());
+        assertEquals(0, ai.getStamp());
+        assertSame(one, ai.get(mark));
+        assertEquals(0, mark[0]);
+        ai.set(two, 0);
+        assertSame(two,ai.getReference());
+        assertEquals(0, ai.getStamp());
+        assertSame(two, ai.get(mark));
+        assertEquals(0, mark[0]);
+        ai.set(one, 1);
+        assertSame(one,ai.getReference());
+        assertEquals(1, ai.getStamp());
+        assertSame(one, ai.get(mark));
         assertEquals(1,mark[0]);
     }
 
-    public void testAttemptStamp(){
+    /**
+     *  attemptStamp succeeds in single thread
+     */
+    public void testAttemptStamp() {
         int[] mark = new int[1];
         AtomicStampedReference ai = new AtomicStampedReference(one, 0);
         assertEquals(0, ai.getStamp());
         assertTrue(ai.attemptStamp(one, 1));
-	assertEquals(1, ai.getStamp());
-        assertEquals(one, ai.get(mark));
+        assertEquals(1, ai.getStamp());
+        assertSame(one, ai.get(mark));
         assertEquals(1, mark[0]);
     }
 
-    public void testCompareAndSet(){
+    /**
+     * compareAndSet succeeds in changing values if equal to expected reference
+     * and stamp else fails
+     */
+    public void testCompareAndSet() {
         int[] mark = new int[1];
         AtomicStampedReference ai = new AtomicStampedReference(one, 0);
-	assertEquals(one, ai.get(mark));
+        assertSame(one, ai.get(mark));
         assertEquals(0, ai.getStamp());
-	assertEquals(0, mark[0]);
+        assertEquals(0, mark[0]);
 
         assertTrue(ai.compareAndSet(one, two, 0, 0));
-	assertEquals(two, ai.get(mark));
-	assertEquals(0, mark[0]);
+        assertSame(two, ai.get(mark));
+        assertEquals(0, mark[0]);
 
         assertTrue(ai.compareAndSet(two, m3, 0, 1));
-	assertEquals(m3, ai.get(mark));
-	assertEquals(1, mark[0]);
+        assertSame(m3, ai.get(mark));
+        assertEquals(1, mark[0]);
 
         assertFalse(ai.compareAndSet(two, m3, 1, 1));
-	assertEquals(m3, ai.get(mark));
-	assertEquals(1, mark[0]);
+        assertSame(m3, ai.get(mark));
+        assertEquals(1, mark[0]);
     }
 
-    public void testWeakCompareAndSet(){
+    /**
+     * compareAndSet in one thread enables another waiting for reference value
+     * to succeed
+     */
+    public void testCompareAndSetInMultipleThreads() throws Exception {
+        final AtomicStampedReference ai = new AtomicStampedReference(one, 0);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() {
+                while (!ai.compareAndSet(two, three, 0, 0))
+                    Thread.yield();
+            }});
+
+        t.start();
+        assertTrue(ai.compareAndSet(one, two, 0, 0));
+        t.join(LONG_DELAY_MS);
+        assertFalse(t.isAlive());
+        assertSame(ai.getReference(), three);
+        assertEquals(ai.getStamp(), 0);
+    }
+
+    /**
+     * compareAndSet in one thread enables another waiting for stamp value
+     * to succeed
+     */
+    public void testCompareAndSetInMultipleThreads2() throws Exception {
+        final AtomicStampedReference ai = new AtomicStampedReference(one, 0);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() {
+                while (!ai.compareAndSet(one, one, 1, 2))
+                    Thread.yield();
+            }});
+
+        t.start();
+        assertTrue(ai.compareAndSet(one, one, 0, 1));
+        t.join(LONG_DELAY_MS);
+        assertFalse(t.isAlive());
+        assertSame(ai.getReference(), one);
+        assertEquals(ai.getStamp(), 2);
+    }
+
+    /**
+     * repeated weakCompareAndSet succeeds in changing values when equal
+     * to expected
+     */
+    public void testWeakCompareAndSet() {
         int[] mark = new int[1];
         AtomicStampedReference ai = new AtomicStampedReference(one, 0);
-	assertEquals(one, ai.get(mark));
-        assertEquals(0, ai.getStamp ());
-	assertEquals(0, mark[0]);
-
-        while(!ai.weakCompareAndSet(one, two, 0, 0));
-	assertEquals(two, ai.get(mark));
-	assertEquals(0, mark[0]);
-
-        while(!ai.weakCompareAndSet(two, m3, 0, 1));
-	assertEquals(m3, ai.get(mark));
-	assertEquals(1, mark[0]);
+        assertSame(one, ai.get(mark));
+        assertEquals(0, ai.getStamp());
+        assertEquals(0, mark[0]);
+
+        while (!ai.weakCompareAndSet(one, two, 0, 0));
+        assertSame(two, ai.get(mark));
+        assertEquals(0, mark[0]);
+
+        while (!ai.weakCompareAndSet(two, m3, 0, 1));
+        assertSame(m3, ai.get(mark));
+        assertEquals(1, mark[0]);
     }
 
 }