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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 junit.framework.*; |
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import java.util.concurrent.atomic.*; |
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import java.io.*; |
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import java.util.*; |
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|
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public class AtomicLongArrayTest 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(AtomicLongArrayTest.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 zero |
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*/ |
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public void testConstructor() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) |
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assertEquals(0,ai.get(i)); |
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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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long[] a = null; |
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AtomicLongArray ai = new AtomicLongArray(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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long[] a = { 17L, 3L, -42L, 99L, -7L}; |
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AtomicLongArray ai = new AtomicLongArray(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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AtomicLongArray ai = new AtomicLongArray(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, 0); |
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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, 0); |
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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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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(1,ai.get(i)); |
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ai.set(i, 2); |
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assertEquals(2,ai.get(i)); |
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ai.set(i, -3); |
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assertEquals(-3,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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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.lazySet(i, 1); |
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assertEquals(1,ai.get(i)); |
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ai.lazySet(i, 2); |
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assertEquals(2,ai.get(i)); |
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ai.lazySet(i, -3); |
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assertEquals(-3,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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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertTrue(ai.compareAndSet(i, 1,2)); |
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assertTrue(ai.compareAndSet(i, 2,-4)); |
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assertEquals(-4,ai.get(i)); |
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assertFalse(ai.compareAndSet(i, -5,7)); |
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assertFalse((7 == ai.get(i))); |
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assertTrue(ai.compareAndSet(i, -4,7)); |
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assertEquals(7,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 AtomicLongArray a = new AtomicLongArray(1); |
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a.set(0, 1); |
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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, 2, 3)) |
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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, 1, 2)); |
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t.join(LONG_DELAY_MS); |
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assertFalse(t.isAlive()); |
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assertEquals(a.get(0), 3); |
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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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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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while (!ai.weakCompareAndSet(i, 1,2)); |
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while (!ai.weakCompareAndSet(i, 2,-4)); |
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assertEquals(-4,ai.get(i)); |
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while (!ai.weakCompareAndSet(i, -4,7)); |
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assertEquals(7,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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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(1,ai.getAndSet(i,0)); |
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assertEquals(0,ai.getAndSet(i,-10)); |
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assertEquals(-10,ai.getAndSet(i,1)); |
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} |
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} |
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|
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/** |
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* getAndAdd returns previous value and adds given value |
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*/ |
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public void testGetAndAdd() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(1,ai.getAndAdd(i,2)); |
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assertEquals(3,ai.get(i)); |
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assertEquals(3,ai.getAndAdd(i,-4)); |
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assertEquals(-1,ai.get(i)); |
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} |
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} |
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|
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/** |
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* getAndDecrement returns previous value and decrements |
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*/ |
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public void testGetAndDecrement() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(1,ai.getAndDecrement(i)); |
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assertEquals(0,ai.getAndDecrement(i)); |
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assertEquals(-1,ai.getAndDecrement(i)); |
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} |
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} |
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|
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/** |
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* getAndIncrement returns previous value and increments |
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*/ |
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public void testGetAndIncrement() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(1,ai.getAndIncrement(i)); |
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assertEquals(2,ai.get(i)); |
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ai.set(i,-2); |
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assertEquals(-2,ai.getAndIncrement(i)); |
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assertEquals(-1,ai.getAndIncrement(i)); |
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assertEquals(0,ai.getAndIncrement(i)); |
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assertEquals(1,ai.get(i)); |
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} |
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} |
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|
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/** |
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* addAndGet adds given value to current, and returns current value |
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*/ |
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public void testAddAndGet() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(3,ai.addAndGet(i,2)); |
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assertEquals(3,ai.get(i)); |
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assertEquals(-1,ai.addAndGet(i,-4)); |
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assertEquals(-1,ai.get(i)); |
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} |
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} |
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|
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/** |
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* decrementAndGet decrements and returns current value |
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*/ |
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public void testDecrementAndGet() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(0,ai.decrementAndGet(i)); |
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assertEquals(-1,ai.decrementAndGet(i)); |
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assertEquals(-2,ai.decrementAndGet(i)); |
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assertEquals(-2,ai.get(i)); |
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} |
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} |
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|
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/** |
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* incrementAndGet increments and returns current value |
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*/ |
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public void testIncrementAndGet() { |
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AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) { |
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ai.set(i, 1); |
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assertEquals(2,ai.incrementAndGet(i)); |
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assertEquals(2,ai.get(i)); |
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ai.set(i, -2); |
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assertEquals(-1,ai.incrementAndGet(i)); |
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assertEquals(0,ai.incrementAndGet(i)); |
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assertEquals(1,ai.incrementAndGet(i)); |
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assertEquals(1,ai.get(i)); |
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} |
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} |
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|
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static final long COUNTDOWN = 100000; |
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|
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class Counter implements Runnable { |
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final AtomicLongArray ai; |
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volatile long counts; |
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Counter(AtomicLongArray a) { ai = a; } |
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public void run() { |
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for (;;) { |
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boolean done = true; |
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for (int i = 0; i < ai.length(); ++i) { |
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long v = ai.get(i); |
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threadAssertTrue(v >= 0); |
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if (v != 0) { |
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done = false; |
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if (ai.compareAndSet(i, v, v-1)) |
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++counts; |
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} |
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} |
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if (done) |
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break; |
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} |
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} |
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} |
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|
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/** |
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* Multiple threads using same array of counters successfully |
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* update a number of times equal to total count |
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*/ |
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public void testCountingInMultipleThreads() throws InterruptedException { |
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final AtomicLongArray ai = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) |
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ai.set(i, COUNTDOWN); |
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Counter c1 = new Counter(ai); |
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Counter c2 = new Counter(ai); |
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Thread t1 = new Thread(c1); |
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Thread t2 = new Thread(c2); |
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t1.start(); |
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t2.start(); |
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t1.join(); |
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t2.join(); |
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assertEquals(c1.counts+c2.counts, SIZE * COUNTDOWN); |
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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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AtomicLongArray l = new AtomicLongArray(SIZE); |
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for (int i = 0; i < SIZE; ++i) |
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l.set(i, -i); |
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|
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ByteArrayOutputStream bout = new ByteArrayOutputStream(10000); |
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ObjectOutputStream out = new ObjectOutputStream(new BufferedOutputStream(bout)); |
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out.writeObject(l); |
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out.close(); |
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|
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ByteArrayInputStream bin = new ByteArrayInputStream(bout.toByteArray()); |
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ObjectInputStream in = new ObjectInputStream(new BufferedInputStream(bin)); |
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AtomicLongArray r = (AtomicLongArray) in.readObject(); |
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for (int i = 0; i < SIZE; ++i) { |
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assertEquals(l.get(i), r.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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long[] a = { 17, 3, -42, 99, -7}; |
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AtomicLongArray ai = new AtomicLongArray(a); |
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assertEquals(Arrays.toString(a), ai.toString()); |
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} |
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|
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|
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} |
