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); |
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(); |
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(); |
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); |
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) |
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); |
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(); |
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); |
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(); |
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(); |
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 |
|
/** |
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 |
|
/** |
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 |
|
} |
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 |
|
} |
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 |
|
*/ |
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 |
|
/** |
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 |
|
/** |
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 |
|
/** |
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 |
|
/** |
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 |
|
*/ |
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 |
|
/** |
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 |
|
/** |
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 |
|
*/ |
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 |
|
} |