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* http://creativecommons.org/publicdomain/zero/1.0/ |
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*/ |
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|
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import java.util.Arrays; |
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import java.util.ArrayList; |
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import java.util.List; |
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import java.util.SplittableRandom; |
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import java.util.concurrent.atomic.AtomicInteger; |
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import java.util.concurrent.atomic.LongAdder; |
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import java.lang.reflect.Method; |
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import java.util.function.Predicate; |
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import java.util.stream.Collectors; |
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|
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import junit.framework.Test; |
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import junit.framework.TestSuite; |
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Integer.getInteger("SplittableRandomTest.reps", 4); |
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|
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/** |
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* Repeated calls to next (only accessible via reflection) produce |
54 |
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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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SplittableRandom rnd = new SplittableRandom(); |
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try { |
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java.lang.reflect.Method m |
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= SplittableRandom.class.getDeclaredMethod( |
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"next", new Class[] { int.class }); |
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m.setAccessible(true); |
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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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{ |
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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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} catch (SecurityException acceptable) {} |
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} |
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|
87 |
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/** |
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* Repeated calls to nextInt produce at least two distinct results |
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*/ |
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public void testNextInt() { |
531 |
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assertEquals(size, counter.sum()); |
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} |
533 |
|
|
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/** |
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* SplittableRandom should implement most of Random's public methods |
536 |
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*/ |
537 |
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public void testShouldImplementMostRandomMethods() throws Throwable { |
538 |
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Predicate<Method> wasForgotten = method -> { |
539 |
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String name = method.getName(); |
540 |
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// some methods deliberately not implemented |
541 |
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if (name.equals("setSeed")) return false; |
542 |
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if (name.equals("nextFloat")) return false; |
543 |
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if (name.equals("nextGaussian")) return false; |
544 |
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try { |
545 |
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SplittableRandom.class.getMethod( |
546 |
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method.getName(), method.getParameterTypes()); |
547 |
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} catch (ReflectiveOperationException ex) { |
548 |
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return true; |
549 |
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} |
550 |
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return false; |
551 |
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}; |
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List<Method> forgotten = |
553 |
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Arrays.stream(java.util.Random.class.getMethods()) |
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.filter(wasForgotten) |
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.collect(Collectors.toList()); |
556 |
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if (!forgotten.isEmpty()) |
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throw new AssertionError("Please implement: " + forgotten); |
558 |
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} |
559 |
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|
560 |
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/** |
561 |
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* Repeated calls to nextBytes produce at least values of different signs for every byte |
562 |
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*/ |
563 |
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public void testNextBytes() { |
564 |
+ |
SplittableRandom sr = new SplittableRandom(); |
565 |
+ |
int n = sr.nextInt(20); |
566 |
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byte[] bytes = new byte[n]; |
567 |
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outer: |
568 |
+ |
for (int i = 0; i < n; i++) { |
569 |
+ |
for (int tries = NCALLS; tries-->0; ) { |
570 |
+ |
byte before = bytes[i]; |
571 |
+ |
sr.nextBytes(bytes); |
572 |
+ |
byte after = bytes[i]; |
573 |
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if (after * before < 0) |
574 |
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continue outer; |
575 |
+ |
} |
576 |
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fail("not enough variation in random bytes"); |
577 |
+ |
} |
578 |
+ |
} |
579 |
+ |
|
580 |
|
} |