| 4 |
|
* http://creativecommons.org/publicdomain/zero/1.0/ |
| 5 |
|
*/ |
| 6 |
|
|
| 7 |
+ |
import java.util.Arrays; |
| 8 |
+ |
import java.util.ArrayList; |
| 9 |
+ |
import java.util.List; |
| 10 |
|
import java.util.SplittableRandom; |
| 11 |
|
import java.util.concurrent.atomic.AtomicInteger; |
| 12 |
|
import java.util.concurrent.atomic.LongAdder; |
| 13 |
+ |
import java.lang.reflect.Method; |
| 14 |
+ |
import java.util.function.Predicate; |
| 15 |
+ |
import java.util.stream.Collectors; |
| 16 |
|
|
| 17 |
|
import junit.framework.Test; |
| 18 |
|
import junit.framework.TestSuite; |
| 166 |
|
*/ |
| 167 |
|
public void testNextIntBounded() { |
| 168 |
|
SplittableRandom sr = new SplittableRandom(); |
| 169 |
+ |
for (int i = 0; i < 2; i++) assertEquals(0, sr.nextInt(1)); |
| 170 |
|
// sample bound space across prime number increments |
| 171 |
|
for (int bound = 2; bound < MAX_INT_BOUND; bound += 524959) { |
| 172 |
|
int f = sr.nextInt(bound); |
| 236 |
|
*/ |
| 237 |
|
public void testNextLongBounded() { |
| 238 |
|
SplittableRandom sr = new SplittableRandom(); |
| 239 |
+ |
for (int i = 0; i < 2; i++) assertEquals(0L, sr.nextLong(1L)); |
| 240 |
|
for (long bound = 2; bound < MAX_LONG_BOUND; bound += 15485863) { |
| 241 |
|
long f = sr.nextLong(bound); |
| 242 |
|
assertTrue(0 <= f && f < bound); |
| 531 |
|
assertEquals(size, counter.sum()); |
| 532 |
|
} |
| 533 |
|
|
| 534 |
+ |
/** |
| 535 |
+ |
* SplittableRandom should implement most of Random's public methods |
| 536 |
+ |
*/ |
| 537 |
+ |
public void testShouldImplementMostRandomMethods() throws Throwable { |
| 538 |
+ |
Predicate<Method> wasForgotten = method -> { |
| 539 |
+ |
String name = method.getName(); |
| 540 |
+ |
// some methods deliberately not implemented |
| 541 |
+ |
if (name.equals("setSeed")) return false; |
| 542 |
+ |
if (name.equals("nextFloat")) return false; |
| 543 |
+ |
if (name.equals("nextGaussian")) return false; |
| 544 |
+ |
try { |
| 545 |
+ |
SplittableRandom.class.getMethod( |
| 546 |
+ |
method.getName(), method.getParameterTypes()); |
| 547 |
+ |
} catch (ReflectiveOperationException ex) { |
| 548 |
+ |
return true; |
| 549 |
+ |
} |
| 550 |
+ |
return false; |
| 551 |
+ |
}; |
| 552 |
+ |
List<Method> forgotten = |
| 553 |
+ |
Arrays.stream(java.util.Random.class.getMethods()) |
| 554 |
+ |
.filter(wasForgotten) |
| 555 |
+ |
.collect(Collectors.toList()); |
| 556 |
+ |
if (!forgotten.isEmpty()) |
| 557 |
+ |
throw new AssertionError("Please implement: " + forgotten); |
| 558 |
+ |
} |
| 559 |
+ |
|
| 560 |
+ |
/** |
| 561 |
+ |
* Repeated calls to nextBytes produce at least values of different signs for every byte |
| 562 |
+ |
*/ |
| 563 |
+ |
public void testNextBytes() { |
| 564 |
+ |
SplittableRandom sr = new SplittableRandom(); |
| 565 |
+ |
int n = sr.nextInt(1, 20); |
| 566 |
+ |
byte[] bytes = new byte[n]; |
| 567 |
+ |
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 |
+ |
if (after * before < 0) |
| 574 |
+ |
continue outer; |
| 575 |
+ |
} |
| 576 |
+ |
fail("not enough variation in random bytes"); |
| 577 |
+ |
} |
| 578 |
+ |
} |
| 579 |
+ |
|
| 580 |
+ |
/** |
| 581 |
+ |
* Filling an empty array with random bytes succeeds without effect. |
| 582 |
+ |
*/ |
| 583 |
+ |
public void testNextBytes_emptyArray() { |
| 584 |
+ |
new SplittableRandom().nextBytes(new byte[0]); |
| 585 |
+ |
} |
| 586 |
+ |
|
| 587 |
+ |
public void testNextBytes_nullArray() { |
| 588 |
+ |
try { |
| 589 |
+ |
new SplittableRandom().nextBytes(null); |
| 590 |
+ |
shouldThrow(); |
| 591 |
+ |
} catch (NullPointerException success) {} |
| 592 |
+ |
} |
| 593 |
+ |
|
| 594 |
|
} |
