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Comparing jsr166/src/test/tck/SplittableRandomTest.java (file contents):
Revision 1.3 by jsr166, Fri Jul 12 01:14:30 2013 UTC vs.
Revision 1.25 by jsr166, Fri Feb 22 19:27:47 2019 UTC

#	Line 3 | Line 3
3		* Expert Group and released to the public domain, as explained at
4		* http://creativecommons.org/publicdomain/zero/1.0/
5		*/
6	<	import junit.framework.*;
7	<	import java.util.*;
6	>
7	>	import java.util.Arrays;
8	>	import java.util.List;
9		import java.util.SplittableRandom;
10		import java.util.concurrent.atomic.AtomicInteger;
10	–	import java.util.concurrent.atomic.AtomicLong;
11		import java.util.concurrent.atomic.LongAdder;
12	+	import java.lang.reflect.Method;
13	+	import java.util.function.Predicate;
14	+	import java.util.stream.Collectors;
15	+
16	+	import junit.framework.Test;
17	+	import junit.framework.TestSuite;
18
19		public class SplittableRandomTest extends JSR166TestCase {
20
21		public static void main(String[] args) {
22	<	junit.textui.TestRunner.run(suite());
22	>	main(suite(), args);
23		}
24		public static Test suite() {
25		return new TestSuite(SplittableRandomTest.class);
#	Line 22 | Line 28 | public class SplittableRandomTest extend
28		/*
29		* Testing coverage notes:
30		*
31	<	* 1. Many of the test methods are adapted from ThreadLocalRandomTest
31	>	* 1. Many of the test methods are adapted from ThreadLocalRandomTest.
32		*
33	<	* 2. This set of tests do not check for random number generator
34	<	* quality. But we check for minimal API compliance by requiring
35	<	* that repeated calls to nextX methods, up to NCALLS tries,
36	<	* produce at least one different result. (In some possible
37	<	* universe, a "correct" implementation might fail, but the odds
38	<	* are vastly less than that of encountering a hardware failure
39	<	* while running the test.) For bounded nextX methods, we sample
40	<	* various intervals across multiples of primes. In other tests,
41	<	* we repeat under REPS different values.
33	>	* 2. These tests do not check for random number generator quality.
34	>	* But we check for minimal API compliance by requiring that
35	>	* repeated calls to nextX methods, up to NCALLS tries, produce at
36	>	* least two distinct results. (In some possible universe, a
37	>	* "correct" implementation might fail, but the odds are vastly
38	>	* less than that of encountering a hardware failure while running
39	>	* the test.) For bounded nextX methods, we sample various
40	>	* intervals across multiples of primes. In other tests, we repeat
41	>	* under REPS different values.
42		*/
43
44		// max numbers of calls to detect getting stuck on one value
45		static final int NCALLS = 10000;
46
47		// max sampled int bound
48	<	static final int MAX_INT_BOUND = (1 << 28);
48	>	static final int MAX_INT_BOUND = (1 << 26);
49
50	<	// Max sampled long bound
51	<	static final long MAX_LONG_BOUND = (1L << 42);
50	>	// max sampled long bound
51	>	static final long MAX_LONG_BOUND = (1L << 40);
52
53		// Number of replications for other checks
54	<	static final int REPS = 20;
54	>	static final int REPS =
55	>	Integer.getInteger("SplittableRandomTest.reps", 4);
56
57		/**
58	<	* Repeated calls to nextInt produce at least one different result
58	>	* Repeated calls to nextInt produce at least two distinct results
59		*/
60		public void testNextInt() {
61		SplittableRandom sr = new SplittableRandom();
#	Line 60 | Line 67 | public class SplittableRandomTest extend
67		}
68
69		/**
70	<	* Repeated calls to nextLong produce at least one different result
70	>	* Repeated calls to nextLong produce at least two distinct results
71		*/
72		public void testNextLong() {
73		SplittableRandom sr = new SplittableRandom();
#	Line 72 | Line 79 | public class SplittableRandomTest extend
79		}
80
81		/**
82	<	* Repeated calls to nextDouble produce at least one different result
82	>	* Repeated calls to nextDouble produce at least two distinct results
83		*/
84		public void testNextDouble() {
85		SplittableRandom sr = new SplittableRandom();
86		double f = sr.nextDouble();
87	<	double i = 0;
87	>	int i = 0;
88		while (i < NCALLS && sr.nextDouble() == f)
89		++i;
90		assertTrue(i < NCALLS);
#	Line 88 | Line 95 | public class SplittableRandomTest extend
95		* same values for nextLong.
96		*/
97		public void testSeedConstructor() {
98	<	for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863)  {
98	>	for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) {
99		SplittableRandom sr1 = new SplittableRandom(seed);
100		SplittableRandom sr2 = new SplittableRandom(seed);
101		for (int i = 0; i < REPS; ++i)
#	Line 127 | Line 134 | public class SplittableRandomTest extend
134		}
135
136		/**
137	<	* nextInt(negative) throws IllegalArgumentException;
137	>	* nextInt(non-positive) throws IllegalArgumentException
138		*/
139	<	public void testNextIntBoundedNeg() {
139	>	public void testNextIntBoundNonPositive() {
140		SplittableRandom sr = new SplittableRandom();
141	<	try {
142	<	int f = sr.nextInt(-17);
143	<	shouldThrow();
144	<	} catch (IllegalArgumentException success) {}
141	>	assertThrows(
142	>	IllegalArgumentException.class,
143	>	() -> sr.nextInt(-17),
144	>	() -> sr.nextInt(0),
145	>	() -> sr.nextInt(Integer.MIN_VALUE));
146		}
147
148		/**
149	<	* nextInt(least >= bound) throws IllegalArgumentException;
149	>	* nextInt(least >= bound) throws IllegalArgumentException
150		*/
151		public void testNextIntBadBounds() {
152		SplittableRandom sr = new SplittableRandom();
153	<	try {
154	<	int f = sr.nextInt(17, 2);
155	<	shouldThrow();
156	<	} catch (IllegalArgumentException success) {}
153	>	assertThrows(
154	>	IllegalArgumentException.class,
155	>	() -> sr.nextInt(17, 2),
156	>	() -> sr.nextInt(-42, -42),
157	>	() -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE));
158		}
159
160		/**
161		* nextInt(bound) returns 0 <= value < bound;
162	<	* repeated calls produce at least one different result
162	>	* repeated calls produce at least two distinct results
163		*/
164		public void testNextIntBounded() {
165		SplittableRandom sr = new SplittableRandom();
166	+	for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1));
167		// sample bound space across prime number increments
168		for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) {
169		int f = sr.nextInt(bound);
#	Line 171 | Line 181 | public class SplittableRandomTest extend
181
182		/**
183		* nextInt(least, bound) returns least <= value < bound;
184	<	* repeated calls produce at least one different result
184	>	* repeated calls produce at least two distinct results
185		*/
186		public void testNextIntBounded2() {
187		SplittableRandom sr = new SplittableRandom();
#	Line 192 | Line 202 | public class SplittableRandomTest extend
202		}
203
204		/**
205	<	* nextLong(negative) throws IllegalArgumentException;
205	>	* nextLong(non-positive) throws IllegalArgumentException
206		*/
207	<	public void testNextLongBoundedNeg() {
207	>	public void testNextLongBoundNonPositive() {
208		SplittableRandom sr = new SplittableRandom();
209	<	try {
210	<	long f = sr.nextLong(-17);
211	<	shouldThrow();
212	<	} catch (IllegalArgumentException success) {}
209	>	assertThrows(
210	>	IllegalArgumentException.class,
211	>	() -> sr.nextLong(-17L),
212	>	() -> sr.nextLong(0L),
213	>	() -> sr.nextLong(Long.MIN_VALUE));
214		}
215
216		/**
217	<	* nextLong(least >= bound) throws IllegalArgumentException;
217	>	* nextLong(least >= bound) throws IllegalArgumentException
218		*/
219		public void testNextLongBadBounds() {
220		SplittableRandom sr = new SplittableRandom();
221	<	try {
222	<	long f = sr.nextLong(17, 2);
223	<	shouldThrow();
224	<	} catch (IllegalArgumentException success) {}
221	>	assertThrows(
222	>	IllegalArgumentException.class,
223	>	() -> sr.nextLong(17L, 2L),
224	>	() -> sr.nextLong(-42L, -42L),
225	>	() -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE));
226		}
227
228		/**
229		* nextLong(bound) returns 0 <= value < bound;
230	<	* repeated calls produce at least one different result
230	>	* repeated calls produce at least two distinct results
231		*/
232		public void testNextLongBounded() {
233		SplittableRandom sr = new SplittableRandom();
234	+	for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L));
235		for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) {
236		long f = sr.nextLong(bound);
237		assertTrue(0 <= f && f < bound);
#	Line 235 | Line 248 | public class SplittableRandomTest extend
248
249		/**
250		* nextLong(least, bound) returns least <= value < bound;
251	<	* repeated calls produce at least one different result
251	>	* repeated calls produce at least two distinct results
252		*/
253		public void testNextLongBounded2() {
254		SplittableRandom sr = new SplittableRandom();
#	Line 256 | Line 269 | public class SplittableRandomTest extend
269		}
270
271		/**
272	+	* nextDouble(non-positive) throws IllegalArgumentException
273	+	*/
274	+	public void testNextDoubleBoundNonPositive() {
275	+	SplittableRandom sr = new SplittableRandom();
276	+	assertThrows(
277	+	IllegalArgumentException.class,
278	+	() -> sr.nextDouble(-17.0d),
279	+	() -> sr.nextDouble(0.0d),
280	+	() -> sr.nextDouble(-Double.MIN_VALUE),
281	+	() -> sr.nextDouble(Double.NEGATIVE_INFINITY),
282	+	() -> sr.nextDouble(Double.NaN));
283	+	}
284	+
285	+	/**
286	+	* nextDouble(! (least < bound)) throws IllegalArgumentException
287	+	*/
288	+	public void testNextDoubleBadBounds() {
289	+	SplittableRandom sr = new SplittableRandom();
290	+	assertThrows(
291	+	IllegalArgumentException.class,
292	+	() -> sr.nextDouble(17.0d, 2.0d),
293	+	() -> sr.nextDouble(-42.0d, -42.0d),
294	+	() -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE),
295	+	() -> sr.nextDouble(Double.NaN, 0.0d),
296	+	() -> sr.nextDouble(0.0d, Double.NaN));
297	+	}
298	+
299	+	// TODO: Test infinite bounds!
300	+	//() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d),
301	+	//() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY),
302	+
303	+	/**
304		* nextDouble(least, bound) returns least <= value < bound;
305	<	* repeated calls produce at least one different result
305	>	* repeated calls produce at least two distinct results
306		*/
307		public void testNextDoubleBounded2() {
308		SplittableRandom sr = new SplittableRandom();
#	Line 283 | Line 328 | public class SplittableRandomTest extend
328		*/
329		public void testBadStreamSize() {
330		SplittableRandom r = new SplittableRandom();
331	<	try {
332	<	java.util.stream.IntStream x = r.ints(-1L);
333	<	shouldThrow();
334	<	} catch (IllegalArgumentException ok) {
335	<	}
336	<	try {
337	<	java.util.stream.LongStream x = r.longs(-1L);
338	<	shouldThrow();
294	<	} catch (IllegalArgumentException ok) {
295	<	}
296	<	try {
297	<	java.util.stream.DoubleStream x = r.doubles(-1L);
298	<	shouldThrow();
299	<	} catch (IllegalArgumentException ok) {
300	<	}
331	>	assertThrows(
332	>	IllegalArgumentException.class,
333	>	() -> { java.util.stream.IntStream x = r.ints(-1L); },
334	>	() -> { java.util.stream.IntStream x = r.ints(-1L, 2, 3); },
335	>	() -> { java.util.stream.LongStream x = r.longs(-1L); },
336	>	() -> { java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); },
337	>	() -> { java.util.stream.DoubleStream x = r.doubles(-1L); },
338	>	() -> { java.util.stream.DoubleStream x = r.doubles(-1L, .5, .6); });
339		}
340
341		/**
#	Line 306 | Line 344 | public class SplittableRandomTest extend
344		*/
345		public void testBadStreamBounds() {
346		SplittableRandom r = new SplittableRandom();
347	<	try {
348	<	java.util.stream.IntStream x = r.ints(2, 1);
349	<	shouldThrow();
350	<	} catch (IllegalArgumentException ok) {
351	<	}
352	<	try {
353	<	java.util.stream.LongStream x = r.longs(1, -2);
354	<	shouldThrow();
317	<	} catch (IllegalArgumentException ok) {
318	<	}
319	<	try {
320	<	java.util.stream.DoubleStream x = r.doubles(0, 0);
321	<	shouldThrow();
322	<	} catch (IllegalArgumentException ok) {
323	<	}
347	>	assertThrows(
348	>	IllegalArgumentException.class,
349	>	() -> { java.util.stream.IntStream x = r.ints(2, 1); },
350	>	() -> { java.util.stream.IntStream x = r.ints(10, 42, 42); },
351	>	() -> { java.util.stream.LongStream x = r.longs(-1L, -1L); },
352	>	() -> { java.util.stream.LongStream x = r.longs(10, 1L, -2L); },
353	>	() -> { java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); },
354	>	() -> { java.util.stream.DoubleStream x = r.doubles(10, .5, .4); });
355		}
356
357		/**
#	Line 332 | Line 363 | public class SplittableRandomTest extend
363		long size = 0;
364		for (int reps = 0; reps < REPS; ++reps) {
365		counter.reset();
366	<	r.ints(size).parallel().forEach(x -> {counter.increment();});
367	<	assertEquals(counter.sum(), size);
366	>	r.ints(size).parallel().forEach(x -> counter.increment());
367	>	assertEquals(size, counter.sum());
368		size += 524959;
369		}
370		}
#	Line 347 | Line 378 | public class SplittableRandomTest extend
378		long size = 0;
379		for (int reps = 0; reps < REPS; ++reps) {
380		counter.reset();
381	<	r.longs(size).parallel().forEach(x -> {counter.increment();});
382	<	assertEquals(counter.sum(), size);
381	>	r.longs(size).parallel().forEach(x -> counter.increment());
382	>	assertEquals(size, counter.sum());
383		size += 524959;
384		}
385		}
#	Line 362 | Line 393 | public class SplittableRandomTest extend
393		long size = 0;
394		for (int reps = 0; reps < REPS; ++reps) {
395		counter.reset();
396	<	r.doubles(size).parallel().forEach(x -> {counter.increment();});
397	<	assertEquals(counter.sum(), size);
396	>	r.doubles(size).parallel().forEach(x -> counter.increment());
397	>	assertEquals(size, counter.sum());
398		size += 524959;
399		}
400		}
401
371	–
402		/**
403		* Each of a parallel sized stream of bounded ints is within bounds
404		*/
#	Line 379 | Line 409 | public class SplittableRandomTest extend
409		for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) {
410		for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) {
411		final int lo = least, hi = bound;
412	<	r.ints(size, lo, hi).parallel().
413	<	forEach(x -> {if (x < lo || x >= hi)
414	<	fails.getAndIncrement(); });
412	>	r.ints(size, lo, hi).parallel().forEach(
413	>	x -> {
414	>	if (x < lo || x >= hi)
415	>	fails.getAndIncrement(); });
416		}
417		}
418	<	assertEquals(fails.get(), 0);
418	>	assertEquals(0, fails.get());
419		}
420
421		/**
#	Line 397 | Line 428 | public class SplittableRandomTest extend
428		for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) {
429		for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) {
430		final long lo = least, hi = bound;
431	<	r.longs(size, lo, hi).parallel().
432	<	forEach(x -> {if (x < lo || x >= hi)
433	<	fails.getAndIncrement(); });
431	>	r.longs(size, lo, hi).parallel().forEach(
432	>	x -> {
433	>	if (x < lo || x >= hi)
434	>	fails.getAndIncrement(); });
435		}
436		}
437	<	assertEquals(fails.get(), 0);
437	>	assertEquals(0, fails.get());
438		}
439
440		/**
#	Line 415 | Line 447 | public class SplittableRandomTest extend
447		for (double least = 0.00011; least < 1.0e20; least *= 9) {
448		for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) {
449		final double lo = least, hi = bound;
450	<	r.doubles(size, lo, hi).parallel().
451	<	forEach(x -> {if (x < lo || x >= hi)
452	<	fails.getAndIncrement(); });
450	>	r.doubles(size, lo, hi).parallel().forEach(
451	>	x -> {
452	>	if (x < lo || x >= hi)
453	>	fails.getAndIncrement(); });
454		}
455		}
456	<	assertEquals(fails.get(), 0);
456	>	assertEquals(0, fails.get());
457		}
458
459		/**
#	Line 430 | Line 463 | public class SplittableRandomTest extend
463		LongAdder counter = new LongAdder();
464		SplittableRandom r = new SplittableRandom();
465		long size = 100;
466	<	r.ints().limit(size).parallel().forEach(x -> {counter.increment();});
467	<	assertEquals(counter.sum(), size);
466	>	r.ints().limit(size).parallel().forEach(x -> counter.increment());
467	>	assertEquals(size, counter.sum());
468		}
469
470		/**
#	Line 441 | Line 474 | public class SplittableRandomTest extend
474		LongAdder counter = new LongAdder();
475		SplittableRandom r = new SplittableRandom();
476		long size = 100;
477	<	r.longs().limit(size).parallel().forEach(x -> {counter.increment();});
478	<	assertEquals(counter.sum(), size);
477	>	r.longs().limit(size).parallel().forEach(x -> counter.increment());
478	>	assertEquals(size, counter.sum());
479		}
480
448	–
481		/**
482		* A parallel unsized stream of doubles generates at least 100 values
483		*/
#	Line 453 | Line 485 | public class SplittableRandomTest extend
485		LongAdder counter = new LongAdder();
486		SplittableRandom r = new SplittableRandom();
487		long size = 100;
488	<	r.doubles().limit(size).parallel().forEach(x -> {counter.increment();});
489	<	assertEquals(counter.sum(), size);
488	>	r.doubles().limit(size).parallel().forEach(x -> counter.increment());
489	>	assertEquals(size, counter.sum());
490		}
491
492		/**
#	Line 464 | Line 496 | public class SplittableRandomTest extend
496		LongAdder counter = new LongAdder();
497		SplittableRandom r = new SplittableRandom();
498		long size = 100;
499	<	r.ints().limit(size).forEach(x -> {counter.increment();});
500	<	assertEquals(counter.sum(), size);
499	>	r.ints().limit(size).forEach(x -> counter.increment());
500	>	assertEquals(size, counter.sum());
501		}
502
503		/**
#	Line 475 | Line 507 | public class SplittableRandomTest extend
507		LongAdder counter = new LongAdder();
508		SplittableRandom r = new SplittableRandom();
509		long size = 100;
510	<	r.longs().limit(size).forEach(x -> {counter.increment();});
511	<	assertEquals(counter.sum(), size);
510	>	r.longs().limit(size).forEach(x -> counter.increment());
511	>	assertEquals(size, counter.sum());
512		}
513
482	–
514		/**
515		* A sequential unsized stream of doubles generates at least 100 values
516		*/
#	Line 487 | Line 518 | public class SplittableRandomTest extend
518		LongAdder counter = new LongAdder();
519		SplittableRandom r = new SplittableRandom();
520		long size = 100;
521	<	r.doubles().limit(size).forEach(x -> {counter.increment();});
522	<	assertEquals(counter.sum(), size);
521	>	r.doubles().limit(size).forEach(x -> counter.increment());
522	>	assertEquals(size, counter.sum());
523	>	}
524	>
525	>	/**
526	>	* SplittableRandom should implement most of Random's public methods
527	>	*/
528	>	public void testShouldImplementMostRandomMethods() throws Throwable {
529	>	Predicate<Method> wasForgotten = method -> {
530	>	String name = method.getName();
531	>	// some methods deliberately not implemented
532	>	if (name.equals("setSeed")) return false;
533	>	if (name.equals("nextFloat")) return false;
534	>	if (name.equals("nextGaussian")) return false;
535	>	try {
536	>	SplittableRandom.class.getMethod(
537	>	method.getName(), method.getParameterTypes());
538	>	} catch (ReflectiveOperationException ex) {
539	>	return true;
540	>	}
541	>	return false;
542	>	};
543	>	List<Method> forgotten =
544	>	Arrays.stream(java.util.Random.class.getMethods())
545	>	.filter(wasForgotten)
546	>	.collect(Collectors.toList());
547	>	if (!forgotten.isEmpty())
548	>	throw new AssertionError("Please implement: " + forgotten);
549	>	}
550	>
551	>	/**
552	>	* Repeated calls to nextBytes produce at least values of different signs for every byte
553	>	*/
554	>	public void testNextBytes() {
555	>	SplittableRandom sr = new SplittableRandom();
556	>	int n = sr.nextInt(1, 20);
557	>	byte[] bytes = new byte[n];
558	>	outer:
559	>	for (int i = 0; i < n; i++) {
560	>	for (int tries = NCALLS; tries-->0; ) {
561	>	byte before = bytes[i];
562	>	sr.nextBytes(bytes);
563	>	byte after = bytes[i];
564	>	if (after * before < 0)
565	>	continue outer;
566	>	}
567	>	fail("not enough variation in random bytes");
568	>	}
569		}
570
571	+	/**
572	+	* Filling an empty array with random bytes succeeds without effect.
573	+	*/
574	+	public void testNextBytes_emptyArray() {
575	+	new SplittableRandom().nextBytes(new byte[0]);
576	+	}
577	+
578	+	public void testNextBytes_nullArray() {
579	+	try {
580	+	new SplittableRandom().nextBytes(null);
581	+	shouldThrow();
582	+	} catch (NullPointerException success) {}
583	+	}
584
585		}

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