author | dl |
Sat, 10 Feb 2018 09:23:41 -0800 | |
changeset 48843 | 21efc1774302 |
parent 48541 | 946e34c2dec9 |
permissions | -rw-r--r-- |
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/* |
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
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* |
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* This code is free software; you can redistribute it and/or modify it |
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* under the terms of the GNU General Public License version 2 only, as |
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* published by the Free Software Foundation. |
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* |
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* This code is distributed in the hope that it will be useful, but WITHOUT |
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
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* version 2 for more details (a copy is included in the LICENSE file that |
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* accompanied this code). |
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* |
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* You should have received a copy of the GNU General Public License version |
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* 2 along with this work; if not, write to the Free Software Foundation, |
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
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* |
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
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* or visit www.oracle.com if you need additional information or have any |
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* questions. |
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*/ |
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/* |
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* This file is available under and governed by the GNU General Public |
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* License version 2 only, as published by the Free Software Foundation. |
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* However, the following notice accompanied the original version of this |
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* file: |
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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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*/ |
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import java.util.concurrent.ThreadLocalRandom; |
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import java.util.concurrent.atomic.AtomicLong; |
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import java.util.concurrent.atomic.AtomicReference; |
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
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public class ThreadLocalRandomTest extends JSR166TestCase { |
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public static void main(String[] args) { |
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main(suite(), args); |
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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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* 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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// max numbers of calls to detect getting stuck on one value |
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static final int NCALLS = 10000; |
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// max sampled int bound |
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static final int MAX_INT_BOUND = (1 << 28); |
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// max sampled long bound |
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static final long MAX_LONG_BOUND = (1L << 42); |
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// Number of replications for other checks |
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static final int REPS = 20; |
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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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* Repeated calls to next (only accessible via reflection) produce |
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* at least two distinct results, and repeated calls produce all |
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* possible values. |
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*/ |
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public void testNext() throws ReflectiveOperationException { |
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// Inhibit "An illegal reflective access operation has occurred" |
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if (!testImplementationDetails) return; |
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ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
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final java.lang.reflect.Method m; |
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try { |
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m = ThreadLocalRandom.class.getDeclaredMethod("next", int.class); |
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m.setAccessible(true); |
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} catch (SecurityException acceptable) { |
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// Security manager may deny access |
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return; |
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} catch (Exception ex) { |
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// jdk9 module system may deny access |
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if (ex.getClass().getSimpleName() |
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.equals("InaccessibleObjectException")) |
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return; |
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throw ex; |
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} |
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int i; |
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{ |
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int val = new java.util.Random().nextInt(4); |
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for (i = 0; i < NCALLS; i++) { |
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int q = (int) m.invoke(rnd, new Object[] { 2 }); |
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if (val == q) break; |
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} |
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assertTrue(i < NCALLS); |
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} |
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{ |
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int r = (int) m.invoke(rnd, new Object[] { 3 }); |
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for (i = 0; i < NCALLS; i++) { |
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int q = (int) m.invoke(rnd, new Object[] { 3 }); |
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assertTrue(q < (1<<3)); |
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if (r != q) break; |
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} |
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assertTrue(i < NCALLS); |
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} |
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} |
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/** |
35394 | 128 |
* Repeated calls to nextInt produce at least two distinct results |
129 |
*/ |
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130 |
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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* Repeated calls to nextLong produce at least two distinct results |
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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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* Repeated calls to nextBoolean produce at least two distinct results |
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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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161 |
* Repeated calls to nextFloat produce at least two distinct results |
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*/ |
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163 |
public void testNextFloat() { |
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164 |
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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168 |
assertTrue(i < NCALLS); |
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} |
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/** |
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172 |
* Repeated calls to nextDouble produce at least two distinct results |
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*/ |
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public void testNextDouble() { |
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175 |
double f = ThreadLocalRandom.current().nextDouble(); |
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176 |
int i = 0; |
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177 |
while (i < NCALLS && ThreadLocalRandom.current().nextDouble() == f) |
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++i; |
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179 |
assertTrue(i < NCALLS); |
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} |
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/** |
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183 |
* Repeated calls to nextGaussian produce at least two distinct results |
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184 |
*/ |
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185 |
public void testNextGaussian() { |
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186 |
double f = ThreadLocalRandom.current().nextGaussian(); |
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int i = 0; |
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188 |
while (i < NCALLS && ThreadLocalRandom.current().nextGaussian() == f) |
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189 |
++i; |
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190 |
assertTrue(i < NCALLS); |
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} |
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/** |
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194 |
* nextInt(non-positive) throws IllegalArgumentException |
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195 |
*/ |
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196 |
public void testNextIntBoundNonPositive() { |
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197 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
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198 |
for (int bound : new int[] { 0, -17, Integer.MIN_VALUE }) { |
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199 |
try { |
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200 |
rnd.nextInt(bound); |
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201 |
shouldThrow(); |
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202 |
} catch (IllegalArgumentException success) {} |
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203 |
} |
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204 |
} |
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205 |
||
206 |
/** |
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207 |
* nextInt(least >= bound) throws IllegalArgumentException |
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*/ |
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209 |
public void testNextIntBadBounds() { |
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210 |
int[][] badBoundss = { |
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{ 17, 2 }, |
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{ -42, -42 }, |
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{ Integer.MAX_VALUE, Integer.MIN_VALUE }, |
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214 |
}; |
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215 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
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216 |
for (int[] badBounds : badBoundss) { |
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217 |
try { |
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218 |
rnd.nextInt(badBounds[0], badBounds[1]); |
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219 |
shouldThrow(); |
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220 |
} catch (IllegalArgumentException success) {} |
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221 |
} |
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222 |
} |
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223 |
||
224 |
/** |
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225 |
* nextInt(bound) returns 0 <= value < bound; |
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226 |
* repeated calls produce at least two distinct results |
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227 |
*/ |
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228 |
public void testNextIntBounded() { |
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229 |
// sample bound space across prime number increments |
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230 |
for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) { |
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231 |
int f = ThreadLocalRandom.current().nextInt(bound); |
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232 |
assertTrue(0 <= f && f < bound); |
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233 |
int i = 0; |
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234 |
int j; |
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235 |
while (i < NCALLS && |
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236 |
(j = ThreadLocalRandom.current().nextInt(bound)) == f) { |
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237 |
assertTrue(0 <= j && j < bound); |
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238 |
++i; |
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239 |
} |
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240 |
assertTrue(i < NCALLS); |
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241 |
} |
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242 |
} |
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243 |
||
244 |
/** |
|
245 |
* nextInt(least, bound) returns least <= value < bound; |
|
246 |
* repeated calls produce at least two distinct results |
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247 |
*/ |
|
248 |
public void testNextIntBounded2() { |
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249 |
for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) { |
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250 |
for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) { |
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251 |
int f = ThreadLocalRandom.current().nextInt(least, bound); |
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252 |
assertTrue(least <= f && f < bound); |
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253 |
int i = 0; |
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254 |
int j; |
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255 |
while (i < NCALLS && |
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256 |
(j = ThreadLocalRandom.current().nextInt(least, bound)) == f) { |
|
257 |
assertTrue(least <= j && j < bound); |
|
258 |
++i; |
|
259 |
} |
|
260 |
assertTrue(i < NCALLS); |
|
261 |
} |
|
262 |
} |
|
263 |
} |
|
264 |
||
265 |
/** |
|
266 |
* nextLong(non-positive) throws IllegalArgumentException |
|
267 |
*/ |
|
268 |
public void testNextLongBoundNonPositive() { |
|
269 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
|
270 |
for (long bound : new long[] { 0L, -17L, Long.MIN_VALUE }) { |
|
271 |
try { |
|
272 |
rnd.nextLong(bound); |
|
273 |
shouldThrow(); |
|
274 |
} catch (IllegalArgumentException success) {} |
|
275 |
} |
|
276 |
} |
|
277 |
||
278 |
/** |
|
279 |
* nextLong(least >= bound) throws IllegalArgumentException |
|
280 |
*/ |
|
281 |
public void testNextLongBadBounds() { |
|
282 |
long[][] badBoundss = { |
|
283 |
{ 17L, 2L }, |
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284 |
{ -42L, -42L }, |
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285 |
{ Long.MAX_VALUE, Long.MIN_VALUE }, |
|
286 |
}; |
|
287 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
|
288 |
for (long[] badBounds : badBoundss) { |
|
289 |
try { |
|
290 |
rnd.nextLong(badBounds[0], badBounds[1]); |
|
291 |
shouldThrow(); |
|
292 |
} catch (IllegalArgumentException success) {} |
|
293 |
} |
|
294 |
} |
|
295 |
||
296 |
/** |
|
297 |
* nextLong(bound) returns 0 <= value < bound; |
|
298 |
* repeated calls produce at least two distinct results |
|
299 |
*/ |
|
300 |
public void testNextLongBounded() { |
|
301 |
for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) { |
|
302 |
long f = ThreadLocalRandom.current().nextLong(bound); |
|
303 |
assertTrue(0 <= f && f < bound); |
|
304 |
int i = 0; |
|
305 |
long j; |
|
306 |
while (i < NCALLS && |
|
307 |
(j = ThreadLocalRandom.current().nextLong(bound)) == f) { |
|
308 |
assertTrue(0 <= j && j < bound); |
|
309 |
++i; |
|
310 |
} |
|
311 |
assertTrue(i < NCALLS); |
|
312 |
} |
|
313 |
} |
|
314 |
||
315 |
/** |
|
316 |
* nextLong(least, bound) returns least <= value < bound; |
|
317 |
* repeated calls produce at least two distinct results |
|
318 |
*/ |
|
319 |
public void testNextLongBounded2() { |
|
320 |
for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) { |
|
321 |
for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) { |
|
322 |
long f = ThreadLocalRandom.current().nextLong(least, bound); |
|
323 |
assertTrue(least <= f && f < bound); |
|
324 |
int i = 0; |
|
325 |
long j; |
|
326 |
while (i < NCALLS && |
|
327 |
(j = ThreadLocalRandom.current().nextLong(least, bound)) == f) { |
|
328 |
assertTrue(least <= j && j < bound); |
|
329 |
++i; |
|
330 |
} |
|
331 |
assertTrue(i < NCALLS); |
|
332 |
} |
|
333 |
} |
|
334 |
} |
|
335 |
||
336 |
/** |
|
337 |
* nextDouble(non-positive) throws IllegalArgumentException |
|
338 |
*/ |
|
339 |
public void testNextDoubleBoundNonPositive() { |
|
340 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
|
341 |
double[] badBounds = { |
|
342 |
0.0d, |
|
343 |
-17.0d, |
|
344 |
-Double.MIN_VALUE, |
|
345 |
Double.NEGATIVE_INFINITY, |
|
346 |
Double.NaN, |
|
347 |
}; |
|
348 |
for (double bound : badBounds) { |
|
349 |
try { |
|
350 |
rnd.nextDouble(bound); |
|
351 |
shouldThrow(); |
|
352 |
} catch (IllegalArgumentException success) {} |
|
353 |
} |
|
354 |
} |
|
355 |
||
356 |
/** |
|
357 |
* nextDouble(least, bound) returns least <= value < bound; |
|
358 |
* repeated calls produce at least two distinct results |
|
359 |
*/ |
|
360 |
public void testNextDoubleBounded2() { |
|
361 |
for (double least = 0.0001; least < 1.0e20; least *= 8) { |
|
362 |
for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) { |
|
363 |
double f = ThreadLocalRandom.current().nextDouble(least, bound); |
|
364 |
assertTrue(least <= f && f < bound); |
|
365 |
int i = 0; |
|
366 |
double j; |
|
367 |
while (i < NCALLS && |
|
368 |
(j = ThreadLocalRandom.current().nextDouble(least, bound)) == f) { |
|
369 |
assertTrue(least <= j && j < bound); |
|
370 |
++i; |
|
371 |
} |
|
372 |
assertTrue(i < NCALLS); |
|
373 |
} |
|
374 |
} |
|
375 |
} |
|
376 |
||
377 |
/** |
|
378 |
* Different threads produce different pseudo-random sequences |
|
379 |
*/ |
|
380 |
public void testDifferentSequences() { |
|
381 |
// Don't use main thread's ThreadLocalRandom - it is likely to |
|
382 |
// be polluted by previous tests. |
|
383 |
final AtomicReference<ThreadLocalRandom> threadLocalRandom = |
|
48541
946e34c2dec9
8193300: Miscellaneous changes imported from jsr166 CVS 2018-01
dl
parents:
47342
diff
changeset
|
384 |
new AtomicReference<>(); |
35394 | 385 |
final AtomicLong rand = new AtomicLong(); |
386 |
||
387 |
long firstRand = 0; |
|
388 |
ThreadLocalRandom firstThreadLocalRandom = null; |
|
389 |
||
390 |
Runnable getRandomState = new CheckedRunnable() { |
|
391 |
public void realRun() { |
|
392 |
ThreadLocalRandom current = ThreadLocalRandom.current(); |
|
393 |
assertSame(current, ThreadLocalRandom.current()); |
|
394 |
// test bug: the following is not guaranteed and not true in JDK8 |
|
395 |
// assertNotSame(current, threadLocalRandom.get()); |
|
396 |
rand.set(current.nextLong()); |
|
397 |
threadLocalRandom.set(current); |
|
398 |
}}; |
|
399 |
||
400 |
Thread first = newStartedThread(getRandomState); |
|
401 |
awaitTermination(first); |
|
402 |
firstRand = rand.get(); |
|
403 |
firstThreadLocalRandom = threadLocalRandom.get(); |
|
404 |
||
405 |
for (int i = 0; i < NCALLS; i++) { |
|
406 |
Thread t = newStartedThread(getRandomState); |
|
407 |
awaitTermination(t); |
|
408 |
if (firstRand != rand.get()) |
|
409 |
return; |
|
410 |
} |
|
411 |
fail("all threads generate the same pseudo-random sequence"); |
|
412 |
} |
|
413 |
||
47342 | 414 |
/** |
415 |
* Repeated calls to nextBytes produce at least values of different signs for every byte |
|
416 |
*/ |
|
417 |
public void testNextBytes() { |
|
418 |
ThreadLocalRandom rnd = ThreadLocalRandom.current(); |
|
419 |
int n = rnd.nextInt(1, 20); |
|
420 |
byte[] bytes = new byte[n]; |
|
421 |
outer: |
|
422 |
for (int i = 0; i < n; i++) { |
|
423 |
for (int tries = NCALLS; tries-->0; ) { |
|
424 |
byte before = bytes[i]; |
|
425 |
rnd.nextBytes(bytes); |
|
426 |
byte after = bytes[i]; |
|
427 |
if (after * before < 0) |
|
428 |
continue outer; |
|
429 |
} |
|
430 |
fail("not enough variation in random bytes"); |
|
431 |
} |
|
432 |
} |
|
433 |
||
434 |
/** |
|
435 |
* Filling an empty array with random bytes succeeds without effect. |
|
436 |
*/ |
|
437 |
public void testNextBytes_emptyArray() { |
|
438 |
ThreadLocalRandom.current().nextBytes(new byte[0]); |
|
439 |
} |
|
440 |
||
441 |
public void testNextBytes_nullArray() { |
|
442 |
try { |
|
443 |
ThreadLocalRandom.current().nextBytes(null); |
|
444 |
shouldThrow(); |
|
445 |
} catch (NullPointerException success) {} |
|
446 |
} |
|
447 |
||
35394 | 448 |
} |