| /* |
| * 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.*; |
| |
| public class AtomicReferenceTest extends JSR166TestCase { |
| public static void main (String[] args) { |
| junit.textui.TestRunner.run (suite()); |
| } |
| public static Test suite() { |
| return new TestSuite(AtomicReferenceTest.class); |
| } |
| |
| /** |
| * constructor initializes to given value |
| */ |
| public void testConstructor(){ |
| AtomicReference ai = new AtomicReference(one); |
| assertEquals(one,ai.get()); |
| } |
| |
| /** |
| * default constructed initializes to null |
| */ |
| public void testConstructor2(){ |
| AtomicReference ai = new AtomicReference(); |
| assertNull(ai.get()); |
| } |
| |
| /** |
| * 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()); |
| |
| } |
| /** |
| * 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)); |
| assertEquals(m4,ai.get()); |
| assertFalse(ai.compareAndSet(m5,seven)); |
| assertFalse((seven.equals(ai.get()))); |
| assertTrue(ai.compareAndSet(m4,seven)); |
| assertEquals(seven,ai.get()); |
| } |
| |
| /** |
| * compareAndSet in one thread enables another waiting for value |
| * to succeed |
| */ |
| public void testCompareAndSetInMultipleThreads() { |
| final AtomicReference ai = new AtomicReference(one); |
| Thread t = new Thread(new Runnable() { |
| public void run() { |
| while(!ai.compareAndSet(two, three)) Thread.yield(); |
| }}); |
| try { |
| t.start(); |
| assertTrue(ai.compareAndSet(one, two)); |
| t.join(LONG_DELAY_MS); |
| assertFalse(t.isAlive()); |
| assertEquals(ai.get(), three); |
| } |
| catch(Exception e) { |
| unexpectedException(); |
| } |
| } |
| |
| /** |
| * 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()); |
| } |
| |
| /** |
| * 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)); |
| } |
| |
| /** |
| * a deserialized serialized atomic holds same value |
| */ |
| public void testSerialization() { |
| 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){ |
| unexpectedException(); |
| } |
| } |
| |
| /** |
| * 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()); |
| } |
| |
| } |
| |