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/* |
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* Written by Doug Lea with assistance from members of JCP JSR-166 |
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* Expert Group and released to the public domain, as explained at |
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* http://creativecommons.org/licenses/publicdomain |
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* Other contributors include Andrew Wright, Jeffrey Hayes, |
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* Pat Fisher, Mike Judd. |
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*/ |
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|
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import java.util.concurrent.atomic.*; |
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import junit.framework.*; |
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import java.util.*; |
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|
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public class AtomicReferenceFieldUpdaterTest extends JSR166TestCase{ |
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volatile Integer x = null; |
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Object z; |
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Integer w; |
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|
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public static void main(String[] args){ |
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junit.textui.TestRunner.run(suite()); |
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} |
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public static Test suite() { |
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return new TestSuite(AtomicReferenceFieldUpdaterTest.class); |
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} |
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|
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/** |
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* Contruction with non-existent field throws RuntimeException |
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*/ |
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public void testConstructor(){ |
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try{ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> |
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a = AtomicReferenceFieldUpdater.newUpdater |
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(AtomicReferenceFieldUpdaterTest.class, Integer.class, "y"); |
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shouldThrow(); |
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} |
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catch (RuntimeException rt) {} |
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} |
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|
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|
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/** |
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* construction with field not of given type throws RuntimeException |
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*/ |
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public void testConstructor2(){ |
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try{ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> |
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a = AtomicReferenceFieldUpdater.newUpdater |
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(AtomicReferenceFieldUpdaterTest.class, Integer.class, "z"); |
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shouldThrow(); |
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} |
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catch (RuntimeException rt) {} |
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} |
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|
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/** |
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* Constructor with non-volatile field throws exception |
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*/ |
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public void testConstructor3(){ |
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try{ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer> |
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a = AtomicReferenceFieldUpdater.newUpdater |
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(AtomicReferenceFieldUpdaterTest.class, Integer.class, "w"); |
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shouldThrow(); |
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} |
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catch (RuntimeException rt) {} |
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} |
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|
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/** |
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* get returns the last value set or assigned |
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*/ |
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public void testGetSet(){ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a = AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdaterTest.class, Integer.class, "x"); |
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x = one; |
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assertEquals(one,a.get(this)); |
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a.set(this,two); |
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assertEquals(two,a.get(this)); |
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a.set(this,-3); |
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assertEquals(-3,a.get(this)); |
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|
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} |
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/** |
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* compareAndSet succeeds in changing value if equal to expected else fails |
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*/ |
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public void testCompareAndSet(){ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a = AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdaterTest.class, Integer.class, "x"); |
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x = one; |
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assertTrue(a.compareAndSet(this,one,two)); |
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assertTrue(a.compareAndSet(this,two,m4)); |
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assertEquals(m4,a.get(this)); |
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assertFalse(a.compareAndSet(this,m5,seven)); |
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assertFalse((seven == a.get(this))); |
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assertTrue(a.compareAndSet(this,m4,seven)); |
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assertEquals(seven,a.get(this)); |
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} |
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|
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/** |
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* compareAndSet in one thread enables another waiting for value |
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* to succeed |
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*/ |
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public void testCompareAndSetInMultipleThreads() { |
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x = one; |
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final AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a = AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdaterTest.class, Integer.class, "x"); |
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|
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Thread t = new Thread(new Runnable() { |
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public void run() { |
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while(!a.compareAndSet(AtomicReferenceFieldUpdaterTest.this, two, three)) Thread.yield(); |
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}}); |
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try { |
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t.start(); |
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assertTrue(a.compareAndSet(this, one, two)); |
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t.join(LONG_DELAY_MS); |
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assertFalse(t.isAlive()); |
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assertEquals(a.get(this), three); |
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} |
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catch(Exception e) { |
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unexpectedException(); |
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} |
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} |
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|
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/** |
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* repeated weakCompareAndSet succeeds in changing value when equal |
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* to expected |
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*/ |
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public void testWeakCompareAndSet(){ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a = AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdaterTest.class, Integer.class, "x"); |
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x = one; |
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while(!a.weakCompareAndSet(this,one,two)); |
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while(!a.weakCompareAndSet(this,two,m4)); |
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assertEquals(m4,a.get(this)); |
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while(!a.weakCompareAndSet(this,m4,seven)); |
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assertEquals(seven,a.get(this)); |
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} |
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|
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/** |
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* getAndSet returns previous value and sets to given value |
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*/ |
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public void testGetAndSet(){ |
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AtomicReferenceFieldUpdater<AtomicReferenceFieldUpdaterTest, Integer>a = AtomicReferenceFieldUpdater.newUpdater(AtomicReferenceFieldUpdaterTest.class, Integer.class, "x"); |
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x = one; |
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assertEquals(one,a.getAndSet(this, zero)); |
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assertEquals(zero,a.getAndSet(this,m10)); |
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assertEquals(m10,a.getAndSet(this,1)); |
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} |
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|
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} |