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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/publicdomain/zero/1.0/ |
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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 junit.framework.*; |
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import java.util.Arrays; |
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import java.util.concurrent.atomic.AtomicReferenceArray; |
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|
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public class AtomicReferenceArrayTest extends JSR166TestCase { |
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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(AtomicReferenceArrayTest.class); |
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} |
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|
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/** |
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* constructor creates array of given size with all elements null |
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*/ |
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public void testConstructor() { |
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AtomicReferenceArray<Integer> ai = new AtomicReferenceArray<Integer>(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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assertNull(ai.get(i)); |
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} |
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} |
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|
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/** |
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* constructor with null array throws NPE |
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*/ |
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public void testConstructor2NPE() { |
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try { |
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Integer[] a = null; |
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AtomicReferenceArray<Integer> ai = new AtomicReferenceArray<Integer>(a); |
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shouldThrow(); |
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} catch (NullPointerException success) {} |
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} |
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|
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/** |
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* constructor with array is of same size and has all elements |
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*/ |
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public void testConstructor2() { |
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Integer[] a = { two, one, three, four, seven}; |
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AtomicReferenceArray<Integer> ai = new AtomicReferenceArray<Integer>(a); |
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assertEquals(a.length, ai.length()); |
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for (int i = 0; i < a.length; ++i) |
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assertEquals(a[i], ai.get(i)); |
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} |
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|
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/** |
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* get and set for out of bound indices throw IndexOutOfBoundsException |
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*/ |
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public void testIndexing() { |
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AtomicReferenceArray<Integer> ai = new AtomicReferenceArray<Integer>(SIZE); |
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try { |
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ai.get(SIZE); |
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shouldThrow(); |
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} catch (IndexOutOfBoundsException success) { |
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} |
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try { |
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ai.get(-1); |
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shouldThrow(); |
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} catch (IndexOutOfBoundsException success) { |
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} |
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try { |
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ai.set(SIZE, null); |
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shouldThrow(); |
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} catch (IndexOutOfBoundsException success) { |
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} |
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try { |
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ai.set(-1, null); |
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shouldThrow(); |
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} catch (IndexOutOfBoundsException success) { |
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} |
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} |
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|
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/** |
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* get returns the last value set at index |
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*/ |
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public void testGetSet() { |
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AtomicReferenceArray ai = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, one); |
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assertSame(one,ai.get(i)); |
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ai.set(i, two); |
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assertSame(two,ai.get(i)); |
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ai.set(i, m3); |
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assertSame(m3,ai.get(i)); |
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} |
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} |
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|
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/** |
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* get returns the last value lazySet at index by same thread |
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*/ |
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public void testGetLazySet() { |
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AtomicReferenceArray ai = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.lazySet(i, one); |
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assertSame(one,ai.get(i)); |
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ai.lazySet(i, two); |
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assertSame(two,ai.get(i)); |
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ai.lazySet(i, m3); |
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assertSame(m3,ai.get(i)); |
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} |
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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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AtomicReferenceArray ai = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, one); |
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assertTrue(ai.compareAndSet(i, one,two)); |
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assertTrue(ai.compareAndSet(i, two,m4)); |
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assertSame(m4,ai.get(i)); |
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assertFalse(ai.compareAndSet(i, m5,seven)); |
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assertSame(m4,ai.get(i)); |
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assertTrue(ai.compareAndSet(i, m4,seven)); |
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assertSame(seven,ai.get(i)); |
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} |
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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() throws InterruptedException { |
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final AtomicReferenceArray a = new AtomicReferenceArray(1); |
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a.set(0, one); |
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Thread t = new Thread(new CheckedRunnable() { |
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public void realRun() { |
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while (!a.compareAndSet(0, two, three)) |
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Thread.yield(); |
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}}); |
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|
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t.start(); |
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assertTrue(a.compareAndSet(0, one, two)); |
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t.join(LONG_DELAY_MS); |
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assertFalse(t.isAlive()); |
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assertSame(a.get(0), three); |
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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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AtomicReferenceArray ai = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, one); |
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while (!ai.weakCompareAndSet(i, one,two)); |
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while (!ai.weakCompareAndSet(i, two,m4)); |
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assertSame(m4,ai.get(i)); |
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while (!ai.weakCompareAndSet(i, m4,seven)); |
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assertSame(seven,ai.get(i)); |
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} |
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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 at given index |
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*/ |
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public void testGetAndSet() { |
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AtomicReferenceArray ai = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, one); |
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assertSame(one,ai.getAndSet(i,zero)); |
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assertSame(zero,ai.getAndSet(i,m10)); |
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assertSame(m10,ai.getAndSet(i,one)); |
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} |
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} |
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|
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/** |
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* a deserialized serialized array holds same values |
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*/ |
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public void testSerialization() throws Exception { |
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AtomicReferenceArray x = new AtomicReferenceArray(SIZE); |
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for (int i = 0; i < SIZE; i++) { |
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x.set(i, new Integer(-i)); |
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} |
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AtomicReferenceArray y = serialClone(x); |
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assertTrue(x != y); |
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assertEquals(x.length(), y.length()); |
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for (int i = 0; i < SIZE; i++) { |
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assertEquals(x.get(i), y.get(i)); |
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} |
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} |
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|
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/** |
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* toString returns current value. |
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*/ |
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public void testToString() { |
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Integer[] a = { two, one, three, four, seven}; |
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AtomicReferenceArray<Integer> ai = new AtomicReferenceArray<Integer>(a); |
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assertEquals(Arrays.toString(a), ai.toString()); |
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} |
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} |