--- jsr166/src/test/tck/AtomicReferenceTest.java	2003/09/14 20:42:40	1.3
+++ jsr166/src/test/tck/AtomicReferenceTest.java	2010/08/25 00:07:03	1.16
@@ -1,8 +1,9 @@
 /*
- * 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.*;
@@ -10,78 +11,135 @@ import java.util.concurrent.atomic.*;
 import java.io.*;
 
 public class AtomicReferenceTest extends JSR166TestCase {
-    public static void main (String[] args) {
-        junit.textui.TestRunner.run (suite());
+    public static void main(String[] args) {
+        junit.textui.TestRunner.run(suite());
     }
     public static Test suite() {
         return new TestSuite(AtomicReferenceTest.class);
     }
 
-    public void testConstructor(){
+    /**
+     * constructor initializes to given value
+     */
+    public void testConstructor() {
         AtomicReference ai = new AtomicReference(one);
-	assertEquals(one,ai.get());
+        assertSame(one,ai.get());
     }
 
-    public void testConstructor2(){
+    /**
+     * default constructed initializes to null
+     */
+    public void testConstructor2() {
         AtomicReference ai = new AtomicReference();
-	assertNull(ai.get());
+        assertNull(ai.get());
     }
 
-    public void testGetSet(){
+    /**
+     * get returns the last value set
+     */
+    public void testGetSet() {
         AtomicReference ai = new AtomicReference(one);
-	assertEquals(one,ai.get());
-	ai.set(two);
-	assertEquals(two,ai.get());
-	ai.set(m3);
-	assertEquals(m3,ai.get());
-	
+        assertSame(one,ai.get());
+        ai.set(two);
+        assertSame(two,ai.get());
+        ai.set(m3);
+        assertSame(m3,ai.get());
     }
-    public void testCompareAndSet(){
+
+    /**
+     * get returns the last value lazySet in same thread
+     */
+    public void testGetLazySet() {
         AtomicReference ai = new AtomicReference(one);
-	assertTrue(ai.compareAndSet(one,two));
-	assertTrue(ai.compareAndSet(two,m4));
-	assertEquals(m4,ai.get());
-	assertFalse(ai.compareAndSet(m5,seven));
-	assertFalse((seven.equals(ai.get())));
-	assertTrue(ai.compareAndSet(m4,seven));
-	assertEquals(seven,ai.get());
+        assertSame(one,ai.get());
+        ai.lazySet(two);
+        assertSame(two,ai.get());
+        ai.lazySet(m3);
+        assertSame(m3,ai.get());
     }
 
-    public void testWeakCompareAndSet(){
+    /**
+     * compareAndSet succeeds in changing value if equal to expected else fails
+     */
+    public void testCompareAndSet() {
+        AtomicReference ai = new AtomicReference(one);
+        assertTrue(ai.compareAndSet(one,two));
+        assertTrue(ai.compareAndSet(two,m4));
+        assertSame(m4,ai.get());
+        assertFalse(ai.compareAndSet(m5,seven));
+        assertSame(m4,ai.get());
+        assertTrue(ai.compareAndSet(m4,seven));
+        assertSame(seven,ai.get());
+    }
+
+    /**
+     * compareAndSet in one thread enables another waiting for value
+     * to succeed
+     */
+    public void testCompareAndSetInMultipleThreads() throws Exception {
+        final AtomicReference ai = new AtomicReference(one);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() {
+                while (!ai.compareAndSet(two, three))
+                    Thread.yield();
+            }});
+
+        t.start();
+        assertTrue(ai.compareAndSet(one, two));
+        t.join(LONG_DELAY_MS);
+        assertFalse(t.isAlive());
+        assertSame(ai.get(), three);
+    }
+
+    /**
+     * repeated weakCompareAndSet succeeds in changing value when equal
+     * to expected
+     */
+    public void testWeakCompareAndSet() {
         AtomicReference ai = new AtomicReference(one);
-	while(!ai.weakCompareAndSet(one,two));
-	while(!ai.weakCompareAndSet(two,m4));
-	assertEquals(m4,ai.get());
-        while(!ai.weakCompareAndSet(m4,seven));
-	assertEquals(seven,ai.get());
+        while (!ai.weakCompareAndSet(one,two));
+        while (!ai.weakCompareAndSet(two,m4));
+        assertSame(m4,ai.get());
+        while (!ai.weakCompareAndSet(m4,seven));
+        assertSame(seven,ai.get());
     }
 
-    public void testGetAndSet(){
+    /**
+     * getAndSet returns previous value and sets to given value
+     */
+    public void testGetAndSet() {
         AtomicReference ai = new AtomicReference(one);
-	assertEquals(one,ai.getAndSet(zero));
-	assertEquals(zero,ai.getAndSet(m10));
-	assertEquals(m10,ai.getAndSet(one));
+        assertSame(one,ai.getAndSet(zero));
+        assertSame(zero,ai.getAndSet(m10));
+        assertSame(m10,ai.getAndSet(one));
     }
 
-    public void testSerialization() {
+    /**
+     * a deserialized serialized atomic holds same value
+     */
+    public void testSerialization() throws Exception {
         AtomicReference l = new AtomicReference();
 
-        try {
-            l.set(one);
-            ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
-            ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
-            out.writeObject(l);
-            out.close();
-
-            ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
-            ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
-            AtomicReference r = (AtomicReference) in.readObject();
-            assertEquals(l.get(), r.get());
-        } catch(Exception e){
-            e.printStackTrace();
-            fail("unexpected exception");
-        }
+        l.set(one);
+        ByteArrayOutputStream bout = new ByteArrayOutputStream(10000);
+        ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout));
+        out.writeObject(l);
+        out.close();
+
+        ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray());
+        ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin));
+        AtomicReference r = (AtomicReference) in.readObject();
+        assertEquals(l.get(), r.get());
+    }
+
+    /**
+     * toString returns current value.
+     */
+    public void testToString() {
+        AtomicReference<Integer> ai = new AtomicReference<Integer>(one);
+        assertEquals(ai.toString(), one.toString());
+        ai.set(two);
+        assertEquals(ai.toString(), two.toString());
     }
 
 }
-