--- jsr166/src/test/tck/AtomicIntegerArrayTest.java	2003/09/07 20:39:11	1.2
+++ jsr166/src/test/tck/AtomicIntegerArrayTest.java	2010/09/16 00:52:49	1.18
@@ -1,34 +1,90 @@
 /*
- * 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.*;
 import java.io.*;
+import java.util.*;
 
-public class AtomicIntegerArrayTest extends TestCase 
-{
-    static final int N = 10;
+public class AtomicIntegerArrayTest 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(AtomicIntegerArrayTest.class);
     }
 
-    public void testConstructor(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N);
-        for (int i = 0; i < N; ++i) 
+
+    /**
+     * constructor creates array of given size with all elements zero
+     */
+    public void testConstructor() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i)
             assertEquals(0,ai.get(i));
     }
 
-    public void testGetSet(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * constructor with null array throws NPE
+     */
+    public void testConstructor2NPE() {
+        try {
+            int[] a = null;
+            AtomicIntegerArray ai = new AtomicIntegerArray(a);
+            shouldThrow();
+        } catch (NullPointerException success) {}
+    }
+
+    /**
+     * constructor with array is of same size and has all elements
+     */
+    public void testConstructor2() {
+        int[] a = { 17, 3, -42, 99, -7};
+        AtomicIntegerArray ai = new AtomicIntegerArray(a);
+        assertEquals(a.length, ai.length());
+        for (int i = 0; i < a.length; ++i)
+            assertEquals(a[i], ai.get(i));
+    }
+
+    /**
+     * get and set for out of bound indices throw IndexOutOfBoundsException
+     */
+    public void testIndexing() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        try {
+            ai.get(SIZE);
+            shouldThrow();
+        } catch (IndexOutOfBoundsException success) {
+        }
+        try {
+            ai.get(-1);
+            shouldThrow();
+        } catch (IndexOutOfBoundsException success) {
+        }
+        try {
+            ai.set(SIZE, 0);
+            shouldThrow();
+        } catch (IndexOutOfBoundsException success) {
+        }
+        try {
+            ai.set(-1, 0);
+            shouldThrow();
+        } catch (IndexOutOfBoundsException success) {
+        }
+    }
+
+    /**
+     * get returns the last value set at index
+     */
+    public void testGetSet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(1,ai.get(i));
             ai.set(i, 2);
@@ -38,35 +94,80 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testCompareAndSet(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * get returns the last value lazySet at index by same thread
+     */
+    public void testGetLazySet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
+            ai.lazySet(i, 1);
+            assertEquals(1,ai.get(i));
+            ai.lazySet(i, 2);
+            assertEquals(2,ai.get(i));
+            ai.lazySet(i, -3);
+            assertEquals(-3,ai.get(i));
+        }
+    }
+
+    /**
+     * compareAndSet succeeds in changing value if equal to expected else fails
+     */
+    public void testCompareAndSet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertTrue(ai.compareAndSet(i, 1,2));
             assertTrue(ai.compareAndSet(i, 2,-4));
             assertEquals(-4,ai.get(i));
             assertFalse(ai.compareAndSet(i, -5,7));
-            assertFalse((7 == ai.get(i)));
+            assertEquals(-4,ai.get(i));
             assertTrue(ai.compareAndSet(i, -4,7));
             assertEquals(7,ai.get(i));
         }
     }
 
-    public void testWeakCompareAndSet(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * compareAndSet in one thread enables another waiting for value
+     * to succeed
+     */
+    public void testCompareAndSetInMultipleThreads() throws Exception {
+        final AtomicIntegerArray a = new AtomicIntegerArray(1);
+        a.set(0, 1);
+        Thread t = new Thread(new CheckedRunnable() {
+            public void realRun() {
+                while (!a.compareAndSet(0, 2, 3))
+                    Thread.yield();
+            }});
+
+        t.start();
+        assertTrue(a.compareAndSet(0, 1, 2));
+        t.join(LONG_DELAY_MS);
+        assertFalse(t.isAlive());
+        assertEquals(a.get(0), 3);
+    }
+
+    /**
+     * repeated weakCompareAndSet succeeds in changing value when equal
+     * to expected
+     */
+    public void testWeakCompareAndSet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
-            while(!ai.weakCompareAndSet(i, 1,2));
-            while(!ai.weakCompareAndSet(i, 2,-4));
+            while (!ai.weakCompareAndSet(i, 1,2));
+            while (!ai.weakCompareAndSet(i, 2,-4));
             assertEquals(-4,ai.get(i));
-            while(!ai.weakCompareAndSet(i, -4,7));
+            while (!ai.weakCompareAndSet(i, -4,7));
             assertEquals(7,ai.get(i));
         }
     }
 
-    public void testGetAndSet(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     *  getAndSet returns previous value and sets to given value at given index
+     */
+    public void testGetAndSet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(1,ai.getAndSet(i,0));
             assertEquals(0,ai.getAndSet(i,-10));
@@ -74,9 +175,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testGetAndAdd(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     *  getAndAdd returns previous value and adds given value
+     */
+    public void testGetAndAdd() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(1,ai.getAndAdd(i,2));
             assertEquals(3,ai.get(i));
@@ -85,9 +189,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testGetAndDecrement(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * getAndDecrement returns previous value and decrements
+     */
+    public void testGetAndDecrement() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(1,ai.getAndDecrement(i));
             assertEquals(0,ai.getAndDecrement(i));
@@ -95,9 +202,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testGetAndIncrement(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * getAndIncrement returns previous value and increments
+     */
+    public void testGetAndIncrement() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(1,ai.getAndIncrement(i));
             assertEquals(2,ai.get(i));
@@ -109,9 +219,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
+    /**
+     *  addAndGet adds given value to current, and returns current value
+     */
     public void testAddAndGet() {
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(3,ai.addAndGet(i,2));
             assertEquals(3,ai.get(i));
@@ -120,9 +233,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testDecrementAndGet(){
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+    /**
+     * decrementAndGet decrements and returns current value
+     */
+    public void testDecrementAndGet() {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(0,ai.decrementAndGet(i));
             assertEquals(-1,ai.decrementAndGet(i));
@@ -131,9 +247,12 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
+    /**
+     *  incrementAndGet increments and returns current value
+     */
     public void testIncrementAndGet() {
-        AtomicIntegerArray ai = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) {
+        AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i) {
             ai.set(i, 1);
             assertEquals(2,ai.incrementAndGet(i));
             assertEquals(2,ai.get(i));
@@ -145,27 +264,79 @@ public class AtomicIntegerArrayTest exte
         }
     }
 
-    public void testSerialization() {
-        AtomicIntegerArray l = new AtomicIntegerArray(N); 
-        for (int i = 0; i < N; ++i) 
-            l.set(i, -i);
+    static final int COUNTDOWN = 100000;
 
-        try {
-            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));
-            AtomicIntegerArray r = (AtomicIntegerArray) in.readObject();
-            for (int i = 0; i < N; ++i) {
-                assertEquals(l.get(i), r.get(i));
+    class Counter extends CheckedRunnable {
+        final AtomicIntegerArray ai;
+        volatile int counts;
+        Counter(AtomicIntegerArray a) { ai = a; }
+        public void realRun() {
+            for (;;) {
+                boolean done = true;
+                for (int i = 0; i < ai.length(); ++i) {
+                    int v = ai.get(i);
+                    assertTrue(v >= 0);
+                    if (v != 0) {
+                        done = false;
+                        if (ai.compareAndSet(i, v, v-1))
+                            ++counts;
+                    }
+                }
+                if (done)
+                    break;
             }
-        } catch(Exception e){
-            e.printStackTrace();
-            fail("unexpected exception");
         }
     }
 
+    /**
+     * Multiple threads using same array of counters successfully
+     * update a number of times equal to total count
+     */
+    public void testCountingInMultipleThreads() throws InterruptedException {
+        final AtomicIntegerArray ai = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i)
+            ai.set(i, COUNTDOWN);
+        Counter c1 = new Counter(ai);
+        Counter c2 = new Counter(ai);
+        Thread t1 = new Thread(c1);
+        Thread t2 = new Thread(c2);
+        t1.start();
+        t2.start();
+        t1.join();
+        t2.join();
+        assertEquals(c1.counts+c2.counts, SIZE * COUNTDOWN);
+    }
+
+
+    /**
+     * a deserialized serialized array holds same values
+     */
+    public void testSerialization() throws Exception {
+        AtomicIntegerArray l = new AtomicIntegerArray(SIZE);
+        for (int i = 0; i < SIZE; ++i)
+            l.set(i, -i);
+
+        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));
+        AtomicIntegerArray r = (AtomicIntegerArray) in.readObject();
+        for (int i = 0; i < SIZE; ++i) {
+            assertEquals(l.get(i), r.get(i));
+        }
+    }
+
+
+    /**
+     * toString returns current value.
+     */
+    public void testToString() {
+        int[] a = { 17, 3, -42, 99, -7};
+        AtomicIntegerArray ai = new AtomicIntegerArray(a);
+        assertEquals(Arrays.toString(a), ai.toString());
+    }
+
 }