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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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*/ |
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import junit.framework.*; |
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import java.util.concurrent.*; |
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import java.util.*; |
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|
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|
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public class ThreadLocalRandomTest extends JSR166TestCase { |
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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(ThreadLocalRandomTest.class); |
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} |
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|
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/** |
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* Testing coverage notes: |
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* |
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* We don't test randomness properties, but only that repeated |
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* calls, up to NCALLS tries, produce at least one different |
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* result. For bounded versions, we sample various intervals |
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* across multiples of primes. |
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*/ |
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|
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// |
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static final int NCALLS = 10000; |
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|
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// max sampled int bound |
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static final int MAX_INT_BOUND = (1 << 28); |
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|
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// Max sampled long bound |
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static final long MAX_LONG_BOUND = (1L << 42); |
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|
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/** |
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* setSeed throws UnsupportedOperationException |
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*/ |
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public void testSetSeed() { |
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try { |
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ThreadLocalRandom.current().setSeed(17); |
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shouldThrow(); |
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} catch (UnsupportedOperationException success) {} |
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} |
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|
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/** |
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* Repeated calls to nextInt produce at least one different result |
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*/ |
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public void testNextInt() { |
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int f = ThreadLocalRandom.current().nextInt(); |
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int i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextInt() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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/** |
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* Repeated calls to nextLong produce at least one different result |
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*/ |
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public void testNextLong() { |
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long f = ThreadLocalRandom.current().nextLong(); |
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int i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextLong() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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|
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/** |
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* Repeated calls to nextBoolean produce at least one different result |
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*/ |
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public void testNextBoolean() { |
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boolean f = ThreadLocalRandom.current().nextBoolean(); |
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int i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextBoolean() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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/** |
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* Repeated calls to nextFloat produce at least one different result |
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*/ |
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public void testNextFloat() { |
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float f = ThreadLocalRandom.current().nextFloat(); |
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int i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextFloat() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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/** |
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* Repeated calls to nextDouble produce at least one different result |
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*/ |
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public void testNextDouble() { |
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double f = ThreadLocalRandom.current().nextDouble(); |
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double i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextDouble() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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/** |
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* Repeated calls to nextGaussian produce at least one different result |
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*/ |
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public void testNextGaussian() { |
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double f = ThreadLocalRandom.current().nextGaussian(); |
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int i = 0; |
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while (i < NCALLS && ThreadLocalRandom.current().nextGaussian() == f) |
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++i; |
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assertTrue(i < NCALLS); |
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} |
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|
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|
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/** |
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* nextInt(negative) throws IllegalArgumentException; |
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*/ |
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public void testNextIntBoundedNeg() { |
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try { |
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int f = ThreadLocalRandom.current().nextInt(-17); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/** |
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* nextInt(least >= bound) throws IllegalArgumentException; |
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*/ |
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public void testNextIntBadBounds() { |
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try { |
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int f = ThreadLocalRandom.current().nextInt(17, 2); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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|
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/** |
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* nextInt(bound) returns 0 <= value < bound; |
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* repeated calls produce at least one different result |
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*/ |
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public void testNextIntBounded() { |
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// sample bound space across prime number increments |
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for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) { |
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int f = ThreadLocalRandom.current().nextInt(bound); |
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assertTrue(0 <= f && f < bound); |
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int i = 0; |
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int j; |
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while (i < NCALLS && |
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(j = ThreadLocalRandom.current().nextInt(bound)) == f) { |
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assertTrue(0 <= j && j < bound); |
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++i; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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|
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|
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/** |
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* nextInt(least, bound) returns least <= value < bound; |
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* repeated calls produce at least one different result |
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*/ |
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public void testNextIntBounded2() { |
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for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) { |
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for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) { |
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int f = ThreadLocalRandom.current().nextInt(least, bound); |
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assertTrue(least <= f && f < bound); |
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int i = 0; |
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int j; |
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while (i < NCALLS && |
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(j = ThreadLocalRandom.current().nextInt(least, bound)) == f) { |
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assertTrue(least <= j && j < bound); |
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++i; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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} |
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|
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/** |
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* nextLong(negative) throws IllegalArgumentException; |
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*/ |
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public void testNextLongBoundedNeg() { |
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try { |
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long f = ThreadLocalRandom.current().nextLong(-17); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/** |
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* nextLong(least >= bound) throws IllegalArgumentException; |
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*/ |
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public void testNextLongBadBounds() { |
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try { |
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long f = ThreadLocalRandom.current().nextLong(17, 2); |
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shouldThrow(); |
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} catch (IllegalArgumentException success) {} |
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} |
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|
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/** |
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* nextLong(bound) returns 0 <= value < bound; |
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* repeated calls produce at least one different result |
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*/ |
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public void testNextLongBounded() { |
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for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) { |
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long f = ThreadLocalRandom.current().nextLong(bound); |
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assertTrue(0 <= f && f < bound); |
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int i = 0; |
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long j; |
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while (i < NCALLS && |
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(j = ThreadLocalRandom.current().nextLong(bound)) == f) { |
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assertTrue(0 <= j && j < bound); |
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++i; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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|
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/** |
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* nextLong(least, bound) returns least <= value < bound; |
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* repeated calls produce at least one different result |
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*/ |
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public void testNextLongBounded2() { |
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for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) { |
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for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) { |
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long f = ThreadLocalRandom.current().nextLong(least, bound); |
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assertTrue(least <= f && f < bound); |
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int i = 0; |
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long j; |
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while (i < NCALLS && |
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(j = ThreadLocalRandom.current().nextLong(least, bound)) == f) { |
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assertTrue(least <= j && j < bound); |
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++i; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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} |
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|
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|
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/** |
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* nextDouble(least, bound) returns least <= value < bound; |
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* repeated calls produce at least one different result |
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*/ |
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public void testNextDoubleBounded2() { |
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for (double least = 0.0001; least < 1.0e20; least *= 8) { |
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for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) { |
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double f = ThreadLocalRandom.current().nextDouble(least, bound); |
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assertTrue(least <= f && f < bound); |
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int i = 0; |
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double j; |
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while (i < NCALLS && |
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(j = ThreadLocalRandom.current().nextDouble(least, bound)) == f) { |
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assertTrue(least <= j && j < bound); |
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++i; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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} |
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|
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|
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} |