1 |
/* |
2 |
* Written by Doug Lea with assistance from members of JCP JSR-166 |
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.*; |
8 |
import java.util.SplittableRandom; |
9 |
import java.util.concurrent.atomic.AtomicInteger; |
10 |
import java.util.concurrent.atomic.LongAdder; |
11 |
|
12 |
public class SplittableRandomTest extends JSR166TestCase { |
13 |
|
14 |
public static void main(String[] args) { |
15 |
junit.textui.TestRunner.run(suite()); |
16 |
} |
17 |
public static Test suite() { |
18 |
return new TestSuite(SplittableRandomTest.class); |
19 |
} |
20 |
|
21 |
/* |
22 |
* Testing coverage notes: |
23 |
* |
24 |
* 1. Many of the test methods are adapted from ThreadLocalRandomTest. |
25 |
* |
26 |
* 2. These tests do not check for random number generator quality. |
27 |
* But we check for minimal API compliance by requiring that |
28 |
* repeated calls to nextX methods, up to NCALLS tries, produce at |
29 |
* least two distinct results. (In some possible universe, a |
30 |
* "correct" implementation might fail, but the odds are vastly |
31 |
* less than that of encountering a hardware failure while running |
32 |
* the test.) For bounded nextX methods, we sample various |
33 |
* intervals across multiples of primes. In other tests, we repeat |
34 |
* under REPS different values. |
35 |
*/ |
36 |
|
37 |
// max numbers of calls to detect getting stuck on one value |
38 |
static final int NCALLS = 10000; |
39 |
|
40 |
// max sampled int bound |
41 |
static final int MAX_INT_BOUND = (1 << 26); |
42 |
|
43 |
// max sampled long bound |
44 |
static final long MAX_LONG_BOUND = (1L << 40); |
45 |
|
46 |
// Number of replications for other checks |
47 |
static final int REPS = |
48 |
Integer.getInteger("SplittableRandomTest.reps", 4); |
49 |
|
50 |
/** |
51 |
* Repeated calls to nextInt produce at least two distinct results |
52 |
*/ |
53 |
public void testNextInt() { |
54 |
SplittableRandom sr = new SplittableRandom(); |
55 |
int f = sr.nextInt(); |
56 |
int i = 0; |
57 |
while (i < NCALLS && sr.nextInt() == f) |
58 |
++i; |
59 |
assertTrue(i < NCALLS); |
60 |
} |
61 |
|
62 |
/** |
63 |
* Repeated calls to nextLong produce at least two distinct results |
64 |
*/ |
65 |
public void testNextLong() { |
66 |
SplittableRandom sr = new SplittableRandom(); |
67 |
long f = sr.nextLong(); |
68 |
int i = 0; |
69 |
while (i < NCALLS && sr.nextLong() == f) |
70 |
++i; |
71 |
assertTrue(i < NCALLS); |
72 |
} |
73 |
|
74 |
/** |
75 |
* Repeated calls to nextDouble produce at least two distinct results |
76 |
*/ |
77 |
public void testNextDouble() { |
78 |
SplittableRandom sr = new SplittableRandom(); |
79 |
double f = sr.nextDouble(); |
80 |
int i = 0; |
81 |
while (i < NCALLS && sr.nextDouble() == f) |
82 |
++i; |
83 |
assertTrue(i < NCALLS); |
84 |
} |
85 |
|
86 |
/** |
87 |
* Two SplittableRandoms created with the same seed produce the |
88 |
* same values for nextLong. |
89 |
*/ |
90 |
public void testSeedConstructor() { |
91 |
for (long seed = 2; seed < MAX_LONG_BOUND; seed += 15485863) { |
92 |
SplittableRandom sr1 = new SplittableRandom(seed); |
93 |
SplittableRandom sr2 = new SplittableRandom(seed); |
94 |
for (int i = 0; i < REPS; ++i) |
95 |
assertEquals(sr1.nextLong(), sr2.nextLong()); |
96 |
} |
97 |
} |
98 |
|
99 |
/** |
100 |
* A SplittableRandom produced by split() of a default-constructed |
101 |
* SplittableRandom generates a different sequence |
102 |
*/ |
103 |
public void testSplit1() { |
104 |
SplittableRandom sr = new SplittableRandom(); |
105 |
for (int reps = 0; reps < REPS; ++reps) { |
106 |
SplittableRandom sc = sr.split(); |
107 |
int i = 0; |
108 |
while (i < NCALLS && sr.nextLong() == sc.nextLong()) |
109 |
++i; |
110 |
assertTrue(i < NCALLS); |
111 |
} |
112 |
} |
113 |
|
114 |
/** |
115 |
* A SplittableRandom produced by split() of a seeded-constructed |
116 |
* SplittableRandom generates a different sequence |
117 |
*/ |
118 |
public void testSplit2() { |
119 |
SplittableRandom sr = new SplittableRandom(12345); |
120 |
for (int reps = 0; reps < REPS; ++reps) { |
121 |
SplittableRandom sc = sr.split(); |
122 |
int i = 0; |
123 |
while (i < NCALLS && sr.nextLong() == sc.nextLong()) |
124 |
++i; |
125 |
assertTrue(i < NCALLS); |
126 |
} |
127 |
} |
128 |
|
129 |
/** |
130 |
* nextInt(non-positive) throws IllegalArgumentException |
131 |
*/ |
132 |
public void testNextIntBoundNonPositive() { |
133 |
SplittableRandom sr = new SplittableRandom(); |
134 |
Runnable[] throwingActions = { |
135 |
() -> sr.nextInt(-17), |
136 |
() -> sr.nextInt(0), |
137 |
() -> sr.nextInt(Integer.MIN_VALUE), |
138 |
}; |
139 |
assertThrows(IllegalArgumentException.class, throwingActions); |
140 |
} |
141 |
|
142 |
/** |
143 |
* nextInt(least >= bound) throws IllegalArgumentException |
144 |
*/ |
145 |
public void testNextIntBadBounds() { |
146 |
SplittableRandom sr = new SplittableRandom(); |
147 |
Runnable[] throwingActions = { |
148 |
() -> sr.nextInt(17, 2), |
149 |
() -> sr.nextInt(-42, -42), |
150 |
() -> sr.nextInt(Integer.MAX_VALUE, Integer.MIN_VALUE), |
151 |
}; |
152 |
assertThrows(IllegalArgumentException.class, throwingActions); |
153 |
} |
154 |
|
155 |
/** |
156 |
* nextInt(bound) returns 0 <= value < bound; |
157 |
* repeated calls produce at least two distinct results |
158 |
*/ |
159 |
public void testNextIntBounded() { |
160 |
SplittableRandom sr = new SplittableRandom(); |
161 |
// sample bound space across prime number increments |
162 |
for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) { |
163 |
int f = sr.nextInt(bound); |
164 |
assertTrue(0 <= f && f < bound); |
165 |
int i = 0; |
166 |
int j; |
167 |
while (i < NCALLS && |
168 |
(j = sr.nextInt(bound)) == f) { |
169 |
assertTrue(0 <= j && j < bound); |
170 |
++i; |
171 |
} |
172 |
assertTrue(i < NCALLS); |
173 |
} |
174 |
} |
175 |
|
176 |
/** |
177 |
* nextInt(least, bound) returns least <= value < bound; |
178 |
* repeated calls produce at least two distinct results |
179 |
*/ |
180 |
public void testNextIntBounded2() { |
181 |
SplittableRandom sr = new SplittableRandom(); |
182 |
for (int least = -15485863; least < MAX_INT_BOUND; least += 524959) { |
183 |
for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 49979687) { |
184 |
int f = sr.nextInt(least, bound); |
185 |
assertTrue(least <= f && f < bound); |
186 |
int i = 0; |
187 |
int j; |
188 |
while (i < NCALLS && |
189 |
(j = sr.nextInt(least, bound)) == f) { |
190 |
assertTrue(least <= j && j < bound); |
191 |
++i; |
192 |
} |
193 |
assertTrue(i < NCALLS); |
194 |
} |
195 |
} |
196 |
} |
197 |
|
198 |
/** |
199 |
* nextLong(non-positive) throws IllegalArgumentException |
200 |
*/ |
201 |
public void testNextLongBoundNonPositive() { |
202 |
SplittableRandom sr = new SplittableRandom(); |
203 |
Runnable[] throwingActions = { |
204 |
() -> sr.nextLong(-17L), |
205 |
() -> sr.nextLong(0L), |
206 |
() -> sr.nextLong(Long.MIN_VALUE), |
207 |
}; |
208 |
assertThrows(IllegalArgumentException.class, throwingActions); |
209 |
} |
210 |
|
211 |
/** |
212 |
* nextLong(least >= bound) throws IllegalArgumentException |
213 |
*/ |
214 |
public void testNextLongBadBounds() { |
215 |
SplittableRandom sr = new SplittableRandom(); |
216 |
Runnable[] throwingActions = { |
217 |
() -> sr.nextLong(17L, 2L), |
218 |
() -> sr.nextLong(-42L, -42L), |
219 |
() -> sr.nextLong(Long.MAX_VALUE, Long.MIN_VALUE), |
220 |
}; |
221 |
assertThrows(IllegalArgumentException.class, throwingActions); |
222 |
} |
223 |
|
224 |
/** |
225 |
* nextLong(bound) returns 0 <= value < bound; |
226 |
* repeated calls produce at least two distinct results |
227 |
*/ |
228 |
public void testNextLongBounded() { |
229 |
SplittableRandom sr = new SplittableRandom(); |
230 |
for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) { |
231 |
long f = sr.nextLong(bound); |
232 |
assertTrue(0 <= f && f < bound); |
233 |
int i = 0; |
234 |
long j; |
235 |
while (i < NCALLS && |
236 |
(j = sr.nextLong(bound)) == f) { |
237 |
assertTrue(0 <= j && j < bound); |
238 |
++i; |
239 |
} |
240 |
assertTrue(i < NCALLS); |
241 |
} |
242 |
} |
243 |
|
244 |
/** |
245 |
* nextLong(least, bound) returns least <= value < bound; |
246 |
* repeated calls produce at least two distinct results |
247 |
*/ |
248 |
public void testNextLongBounded2() { |
249 |
SplittableRandom sr = new SplittableRandom(); |
250 |
for (long least = -86028121; least < MAX_LONG_BOUND; least += 982451653L) { |
251 |
for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) { |
252 |
long f = sr.nextLong(least, bound); |
253 |
assertTrue(least <= f && f < bound); |
254 |
int i = 0; |
255 |
long j; |
256 |
while (i < NCALLS && |
257 |
(j = sr.nextLong(least, bound)) == f) { |
258 |
assertTrue(least <= j && j < bound); |
259 |
++i; |
260 |
} |
261 |
assertTrue(i < NCALLS); |
262 |
} |
263 |
} |
264 |
} |
265 |
|
266 |
/** |
267 |
* nextDouble(non-positive) throws IllegalArgumentException |
268 |
*/ |
269 |
public void testNextDoubleBoundNonPositive() { |
270 |
SplittableRandom sr = new SplittableRandom(); |
271 |
Runnable[] throwingActions = { |
272 |
() -> sr.nextDouble(-17.0d), |
273 |
() -> sr.nextDouble(0.0d), |
274 |
() -> sr.nextDouble(-Double.MIN_VALUE), |
275 |
() -> sr.nextDouble(Double.NEGATIVE_INFINITY), |
276 |
() -> sr.nextDouble(Double.NaN), |
277 |
}; |
278 |
assertThrows(IllegalArgumentException.class, throwingActions); |
279 |
} |
280 |
|
281 |
/** |
282 |
* nextDouble(! (least < bound)) throws IllegalArgumentException |
283 |
*/ |
284 |
public void testNextDoubleBadBounds() { |
285 |
SplittableRandom sr = new SplittableRandom(); |
286 |
Runnable[] throwingActions = { |
287 |
() -> sr.nextDouble(17.0d, 2.0d), |
288 |
() -> sr.nextDouble(-42.0d, -42.0d), |
289 |
() -> sr.nextDouble(Double.MAX_VALUE, Double.MIN_VALUE), |
290 |
() -> sr.nextDouble(Double.NaN, 0.0d), |
291 |
() -> sr.nextDouble(0.0d, Double.NaN), |
292 |
}; |
293 |
assertThrows(IllegalArgumentException.class, throwingActions); |
294 |
} |
295 |
|
296 |
// TODO: Test infinite bounds! |
297 |
//() -> sr.nextDouble(Double.NEGATIVE_INFINITY, 0.0d), |
298 |
//() -> sr.nextDouble(0.0d, Double.POSITIVE_INFINITY), |
299 |
|
300 |
/** |
301 |
* nextDouble(least, bound) returns least <= value < bound; |
302 |
* repeated calls produce at least two distinct results |
303 |
*/ |
304 |
public void testNextDoubleBounded2() { |
305 |
SplittableRandom sr = new SplittableRandom(); |
306 |
for (double least = 0.0001; least < 1.0e20; least *= 8) { |
307 |
for (double bound = least * 1.001; bound < 1.0e20; bound *= 16) { |
308 |
double f = sr.nextDouble(least, bound); |
309 |
assertTrue(least <= f && f < bound); |
310 |
int i = 0; |
311 |
double j; |
312 |
while (i < NCALLS && |
313 |
(j = sr.nextDouble(least, bound)) == f) { |
314 |
assertTrue(least <= j && j < bound); |
315 |
++i; |
316 |
} |
317 |
assertTrue(i < NCALLS); |
318 |
} |
319 |
} |
320 |
} |
321 |
|
322 |
/** |
323 |
* Invoking sized ints, long, doubles, with negative sizes throws |
324 |
* IllegalArgumentException |
325 |
*/ |
326 |
public void testBadStreamSize() { |
327 |
SplittableRandom r = new SplittableRandom(); |
328 |
Runnable[] throwingActions = { |
329 |
() -> { java.util.stream.IntStream x = r.ints(-1L); }, |
330 |
() -> { java.util.stream.IntStream x = r.ints(-1L, 2, 3); }, |
331 |
() -> { java.util.stream.LongStream x = r.longs(-1L); }, |
332 |
() -> { java.util.stream.LongStream x = r.longs(-1L, -1L, 1L); }, |
333 |
() -> { java.util.stream.DoubleStream x = r.doubles(-1L); }, |
334 |
() -> { java.util.stream.DoubleStream x = r.doubles(-1L, .5, .6); }, |
335 |
}; |
336 |
assertThrows(IllegalArgumentException.class, throwingActions); |
337 |
} |
338 |
|
339 |
/** |
340 |
* Invoking bounded ints, long, doubles, with illegal bounds throws |
341 |
* IllegalArgumentException |
342 |
*/ |
343 |
public void testBadStreamBounds() { |
344 |
SplittableRandom r = new SplittableRandom(); |
345 |
Runnable[] throwingActions = { |
346 |
() -> { java.util.stream.IntStream x = r.ints(2, 1); }, |
347 |
() -> { java.util.stream.IntStream x = r.ints(10, 42, 42); }, |
348 |
() -> { java.util.stream.LongStream x = r.longs(-1L, -1L); }, |
349 |
() -> { java.util.stream.LongStream x = r.longs(10, 1L, -2L); }, |
350 |
() -> { java.util.stream.DoubleStream x = r.doubles(0.0, 0.0); }, |
351 |
() -> { java.util.stream.DoubleStream x = r.doubles(10, .5, .4); }, |
352 |
}; |
353 |
assertThrows(IllegalArgumentException.class, throwingActions); |
354 |
} |
355 |
|
356 |
/** |
357 |
* A parallel sized stream of ints generates the given number of values |
358 |
*/ |
359 |
public void testIntsCount() { |
360 |
LongAdder counter = new LongAdder(); |
361 |
SplittableRandom r = new SplittableRandom(); |
362 |
long size = 0; |
363 |
for (int reps = 0; reps < REPS; ++reps) { |
364 |
counter.reset(); |
365 |
r.ints(size).parallel().forEach(x -> counter.increment()); |
366 |
assertEquals(size, counter.sum()); |
367 |
size += 524959; |
368 |
} |
369 |
} |
370 |
|
371 |
/** |
372 |
* A parallel sized stream of longs generates the given number of values |
373 |
*/ |
374 |
public void testLongsCount() { |
375 |
LongAdder counter = new LongAdder(); |
376 |
SplittableRandom r = new SplittableRandom(); |
377 |
long size = 0; |
378 |
for (int reps = 0; reps < REPS; ++reps) { |
379 |
counter.reset(); |
380 |
r.longs(size).parallel().forEach(x -> counter.increment()); |
381 |
assertEquals(size, counter.sum()); |
382 |
size += 524959; |
383 |
} |
384 |
} |
385 |
|
386 |
/** |
387 |
* A parallel sized stream of doubles generates the given number of values |
388 |
*/ |
389 |
public void testDoublesCount() { |
390 |
LongAdder counter = new LongAdder(); |
391 |
SplittableRandom r = new SplittableRandom(); |
392 |
long size = 0; |
393 |
for (int reps = 0; reps < REPS; ++reps) { |
394 |
counter.reset(); |
395 |
r.doubles(size).parallel().forEach(x -> counter.increment()); |
396 |
assertEquals(size, counter.sum()); |
397 |
size += 524959; |
398 |
} |
399 |
} |
400 |
|
401 |
/** |
402 |
* Each of a parallel sized stream of bounded ints is within bounds |
403 |
*/ |
404 |
public void testBoundedInts() { |
405 |
AtomicInteger fails = new AtomicInteger(0); |
406 |
SplittableRandom r = new SplittableRandom(); |
407 |
long size = 12345L; |
408 |
for (int least = -15485867; least < MAX_INT_BOUND; least += 524959) { |
409 |
for (int bound = least + 2; bound > least && bound < MAX_INT_BOUND; bound += 67867967) { |
410 |
final int lo = least, hi = bound; |
411 |
r.ints(size, lo, hi).parallel(). |
412 |
forEach(x -> {if (x < lo || x >= hi) |
413 |
fails.getAndIncrement(); }); |
414 |
} |
415 |
} |
416 |
assertEquals(0, fails.get()); |
417 |
} |
418 |
|
419 |
/** |
420 |
* Each of a parallel sized stream of bounded longs is within bounds |
421 |
*/ |
422 |
public void testBoundedLongs() { |
423 |
AtomicInteger fails = new AtomicInteger(0); |
424 |
SplittableRandom r = new SplittableRandom(); |
425 |
long size = 123L; |
426 |
for (long least = -86028121; least < MAX_LONG_BOUND; least += 1982451653L) { |
427 |
for (long bound = least + 2; bound > least && bound < MAX_LONG_BOUND; bound += Math.abs(bound * 7919)) { |
428 |
final long lo = least, hi = bound; |
429 |
r.longs(size, lo, hi).parallel(). |
430 |
forEach(x -> {if (x < lo || x >= hi) |
431 |
fails.getAndIncrement(); }); |
432 |
} |
433 |
} |
434 |
assertEquals(0, fails.get()); |
435 |
} |
436 |
|
437 |
/** |
438 |
* Each of a parallel sized stream of bounded doubles is within bounds |
439 |
*/ |
440 |
public void testBoundedDoubles() { |
441 |
AtomicInteger fails = new AtomicInteger(0); |
442 |
SplittableRandom r = new SplittableRandom(); |
443 |
long size = 456; |
444 |
for (double least = 0.00011; least < 1.0e20; least *= 9) { |
445 |
for (double bound = least * 1.0011; bound < 1.0e20; bound *= 17) { |
446 |
final double lo = least, hi = bound; |
447 |
r.doubles(size, lo, hi).parallel(). |
448 |
forEach(x -> {if (x < lo || x >= hi) |
449 |
fails.getAndIncrement(); }); |
450 |
} |
451 |
} |
452 |
assertEquals(0, fails.get()); |
453 |
} |
454 |
|
455 |
/** |
456 |
* A parallel unsized stream of ints generates at least 100 values |
457 |
*/ |
458 |
public void testUnsizedIntsCount() { |
459 |
LongAdder counter = new LongAdder(); |
460 |
SplittableRandom r = new SplittableRandom(); |
461 |
long size = 100; |
462 |
r.ints().limit(size).parallel().forEach(x -> counter.increment()); |
463 |
assertEquals(size, counter.sum()); |
464 |
} |
465 |
|
466 |
/** |
467 |
* A parallel unsized stream of longs generates at least 100 values |
468 |
*/ |
469 |
public void testUnsizedLongsCount() { |
470 |
LongAdder counter = new LongAdder(); |
471 |
SplittableRandom r = new SplittableRandom(); |
472 |
long size = 100; |
473 |
r.longs().limit(size).parallel().forEach(x -> counter.increment()); |
474 |
assertEquals(size, counter.sum()); |
475 |
} |
476 |
|
477 |
/** |
478 |
* A parallel unsized stream of doubles generates at least 100 values |
479 |
*/ |
480 |
public void testUnsizedDoublesCount() { |
481 |
LongAdder counter = new LongAdder(); |
482 |
SplittableRandom r = new SplittableRandom(); |
483 |
long size = 100; |
484 |
r.doubles().limit(size).parallel().forEach(x -> counter.increment()); |
485 |
assertEquals(size, counter.sum()); |
486 |
} |
487 |
|
488 |
/** |
489 |
* A sequential unsized stream of ints generates at least 100 values |
490 |
*/ |
491 |
public void testUnsizedIntsCountSeq() { |
492 |
LongAdder counter = new LongAdder(); |
493 |
SplittableRandom r = new SplittableRandom(); |
494 |
long size = 100; |
495 |
r.ints().limit(size).forEach(x -> counter.increment()); |
496 |
assertEquals(size, counter.sum()); |
497 |
} |
498 |
|
499 |
/** |
500 |
* A sequential unsized stream of longs generates at least 100 values |
501 |
*/ |
502 |
public void testUnsizedLongsCountSeq() { |
503 |
LongAdder counter = new LongAdder(); |
504 |
SplittableRandom r = new SplittableRandom(); |
505 |
long size = 100; |
506 |
r.longs().limit(size).forEach(x -> counter.increment()); |
507 |
assertEquals(size, counter.sum()); |
508 |
} |
509 |
|
510 |
/** |
511 |
* A sequential unsized stream of doubles generates at least 100 values |
512 |
*/ |
513 |
public void testUnsizedDoublesCountSeq() { |
514 |
LongAdder counter = new LongAdder(); |
515 |
SplittableRandom r = new SplittableRandom(); |
516 |
long size = 100; |
517 |
r.doubles().limit(size).forEach(x -> counter.increment()); |
518 |
assertEquals(size, counter.sum()); |
519 |
} |
520 |
|
521 |
} |