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Comparing jsr166/src/main/java/util/SplittableRandom.java (file contents):
Revision 1.4 by dl, Thu Jul 11 13:40:42 2013 UTC vs.
Revision 1.12 by dl, Sun Jul 21 14:02:23 2013 UTC

#	Line 25 | Line 25
25
26		package java.util;
27
28	+	import java.security.SecureRandom;
29		import java.util.concurrent.atomic.AtomicLong;
30		import java.util.Spliterator;
31		import java.util.function.IntConsumer;
#	Line 35 | Line 36 | import java.util.stream.IntStream;
36		import java.util.stream.LongStream;
37		import java.util.stream.DoubleStream;
38
38	–
39		/**
40		* A generator of uniform pseudorandom values applicable for use in
41		* (among other contexts) isolated parallel computations that may
42		* generate subtasks. Class SplittableRandom supports methods for
43		* producing pseudorandom numbers of type {@code int}, {@code long},
44		* and {@code double} with similar usages as for class
45	<	* {@link java.util.Random} but differs in the following ways: <ul>
45	>	* {@link java.util.Random} but differs in the following ways:
46	>	*
47	>	* <ul>
48		*
49		* <li>Series of generated values pass the DieHarder suite testing
50		* independence and uniformity properties of random number generators.
#	Line 50 | Line 52 | import java.util.stream.DoubleStream;
52		* href="http://www.phy.duke.edu/~rgb/General/dieharder.php"> version
53		* 3.31.1</a>.) These tests validate only the methods for certain
54		* types and ranges, but similar properties are expected to hold, at
55	<	* least approximately, for others as well.  </li>
55	>	* least approximately, for others as well. The <em>period</em>
56	>	* (length of any series of generated values before it repeats) is at
57	>	* least 2<sup>64</sup>. </li>
58		*
59		* <li> Method {@link #split} constructs and returns a new
60		* SplittableRandom instance that shares no mutable state with the
61	<	* current instance. However, with very high probability, the set of
62	<	* values collectively generated by the two objects has the same
61	>	* current instance. However, with very high probability, the
62	>	* values collectively generated by the two objects have the same
63		* statistical properties as if the same quantity of values were
64		* generated by a single thread using a single {@code
65		* SplittableRandom} object.  </li>
#	Line 97 | Line 101 | public class SplittableRandom {
101		* Random-Number Generation for Dynamic-Multithreading Platforms",
102		* PPoPP 2012, but improves and extends it in several ways.
103		*
104	<	* The primary update step is simply to add a constant ("gamma")
105	<	* to the current seed, modulo a prime ("George"). However, the
106	<	* nextLong and nextInt methods do not return this value, but
107	<	* instead the results of bit-mixing transformations that produce
108	<	* more uniformly distributed sequences.
104	>	* The primary update step (see method nextSeed()) is simply to
105	>	* add a constant ("gamma") to the current seed, modulo a prime
106	>	* ("George"). However, the nextLong and nextInt methods do not
107	>	* return this value, but instead the results of bit-mixing
108	>	* transformations that produce more uniformly distributed
109	>	* sequences.
110		*
111		* "George" is the otherwise nameless (because it cannot be
112		* represented) prime number 2^64+13. Using a prime number larger
#	Line 117 | Line 122 | public class SplittableRandom {
122		* this generator as nextSplit, and uses mix64(nextSplit) as its
123		* own gamma value. Computations of gammas themselves use a fixed
124		* constant as the second argument to the addGammaModGeorge
125	<	* function, GAMMA_GAMMA, a "genuinely random" number from a
126	<	* radioactive decay reading (obtained from
127	<	* http://www.fourmilab.ch/hotbits/) meeting the above range
128	<	* constraint. Using a fixed constant maintains the invariant that
124	<	* the value of gamma is the same for every instance that is at
125	<	* the same split-distance from their common root. (Note: there is
126	<	* nothing especially magic about obtaining this constant from a
127	<	* "truly random" physical source rather than just choosing one
128	<	* arbitrarily; using "hotbits" was merely an aesthetically pleasing
129	<	* choice.  In either case, good statistical behavior of the
130	<	* algorithm should be, and was, verified by using the DieHarder
131	<	* test suite.)
125	>	* function, GAMMA_GAMMA. The value of GAMMA_GAMMA is arbitrary
126	>	* (except must be at least 13), but because it serves as the base
127	>	* of split sequences, should be subject to validation of
128	>	* consequent random number quality metrics.
129		*
130		* The mix64 bit-mixing function called by nextLong and other
131		* methods computes the same value as the "64-bit finalizer"
#	Line 154 | Line 151 | public class SplittableRandom {
151		* SplittableRandom. Unlike other cases, this split must be
152		* performed in a thread-safe manner. We use
153		* AtomicLong.compareAndSet as the (typically) most efficient
154	<	* mechanism. To bootstrap, we start off using System.nanotime(),
155	<	* and update using another "genuinely random" constant
154	>	* mechanism. To bootstrap, we start off using a SecureRandom
155	>	* initial default seed, and update using a fixed
156		* DEFAULT_SEED_GAMMA. The default constructor uses GAMMA_GAMMA,
157		* not 0, for its splitSeed argument (addGammaModGeorge(0,
158		* GAMMA_GAMMA) == GAMMA_GAMMA) to reflect that each is split from
#	Line 164 | Line 161 | public class SplittableRandom {
161		*/
162
163		/**
164	<	* The "genuinely random" value for producing new gamma values.
165	<	* The value is arbitrary, subject to the requirement that it be
166	<	* greater or equal to 13.
164	>	* The value for producing new gamma values. Must be greater or
165	>	* equal to 13. Otherwise, the value is arbitrary subject to
166	>	* validation of the resulting statistical quality of splits.
167		*/
168		private static final long GAMMA_GAMMA = 0xF2281E2DBA6606F3L;
169
170		/**
171	<	* The "genuinely random" seed update value for default constructors.
172	<	* The value is arbitrary, subject to the requirement that it be
176	<	* greater or equal to 13.
171	>	* The seed update value for default constructors.  Must be
172	>	* greater or equal to 13. Otherwise, the value is arbitrary.
173		*/
174		private static final long DEFAULT_SEED_GAMMA = 0xBD24B73A95FB84D9L;
175
176		/**
177	+	* The value 13 with 64bit sign bit set. Used in the signed
178	+	* comparison in addGammaModGeorge.
179	+	*/
180	+	private static final long BOTTOM13 = 0x800000000000000DL;
181	+
182	+	/**
183	+	* The least non-zero value returned by nextDouble(). This value
184	+	* is scaled by a random value of 53 bits to produce a result.
185	+	*/
186	+	private static final double DOUBLE_UNIT = 1.0 / (1L << 53);
187	+
188	+	/**
189		* The next seed for default constructors.
190		*/
191		private static final AtomicLong defaultSeedGenerator =
192	<	new AtomicLong(System.nanoTime());
192	>	new AtomicLong(getInitialDefaultSeed());
193
194		/**
195		* The seed, updated only via method nextSeed.
#	Line 200 | Line 208 | public class SplittableRandom {
208		private final long nextSplit;
209
210		/**
203	–	* Internal constructor used by all other constructors and by
204	–	* method split. Establishes the initial seed for this instance,
205	–	* and uses the given splitSeed to establish gamma, as well as the
206	–	* nextSplit to use by this instance.
207	–	*/
208	–	private SplittableRandom(long seed, long splitSeed) {
209	–	this.seed = seed;
210	–	long s = splitSeed, g;
211	–	do { // ensure gamma >= 13, considered as an unsigned integer
212	–	s = addGammaModGeorge(s, GAMMA_GAMMA);
213	–	g = mix64(s);
214	–	} while (Long.compareUnsigned(g, 13L) < 0);
215	–	this.gamma = g;
216	–	this.nextSplit = s;
217	–	}
218	–
219	–	/**
211		* Adds the given gamma value, g, to the given seed value s, mod
212		* George (2^64+13). We regard s and g as unsigned values
213		* (ranging from 0 to 2^64-1). We add g to s either once or twice
#	Line 226 | Line 217 | public class SplittableRandom {
217		* George < 2^64; thus we need only a conditional, not a loop,
218		* to be sure of getting a representable value.
219		*
220	<	* @param s a seed value
220	>	* Because Java comparison operators are signed, we implement this
221	>	* by conceptually offsetting seed values downwards by 2^63, so
222	>	* 0..13 is represented as Long.MIN_VALUE..BOTTOM13.
223	>	*
224	>	* @param s a seed value, viewed as a signed long
225		* @param g a gamma value, 13 <= g (as unsigned)
226		*/
227		private static long addGammaModGeorge(long s, long g) {
228		long p = s + g;
229	<	if (Long.compareUnsigned(p, g) >= 0)
235	<	return p;
236	<	long q = p - 13L;
237	<	return (Long.compareUnsigned(p, 13L) >= 0) ? q : (q + g);
238	<	}
239	<
240	<	/**
241	<	* Updates in-place and returns seed.
242	<	* See above for explanation.
243	<	*/
244	<	private long nextSeed() {
245	<	return seed = addGammaModGeorge(seed, gamma);
229	>	return (p >= s) ? p : ((p >= BOTTOM13) ? p  : p + g) - 13L;
230		}
231
232		/**
#	Line 269 | Line 253 | public class SplittableRandom {
253		}
254
255		/**
256	<	* Atomically updates and returns next seed for default constructor
256	>	* Internal constructor used by all other constructors and by
257	>	* method split. Establishes the initial seed for this instance,
258	>	* and uses the given splitSeed to establish gamma, as well as the
259	>	* nextSplit to use by this instance. The loop to skip ineligible
260	>	* gammas very rarely iterates, and does so at most 13 times.
261	>	*/
262	>	private SplittableRandom(long seed, long splitSeed) {
263	>	this.seed = seed;
264	>	long s = splitSeed, g;
265	>	do { // ensure gamma >= 13, considered as an unsigned integer
266	>	s = addGammaModGeorge(s, GAMMA_GAMMA);
267	>	g = mix64(s);
268	>	} while (g >= 0L && g < 13L);
269	>	this.gamma = g;
270	>	this.nextSplit = s;
271	>	}
272	>
273	>	/**
274	>	* Updates in-place and returns seed.
275	>	* See above for explanation.
276	>	*/
277	>	private long nextSeed() {
278	>	return seed = addGammaModGeorge(seed, gamma);
279	>	}
280	>
281	>	/**
282	>	* Atomically updates and returns next seed for default constructor.
283		*/
284		private static long nextDefaultSeed() {
285		long oldSeed, newSeed;
#	Line 280 | Line 290 | public class SplittableRandom {
290		return mix64(newSeed);
291		}
292
293	+	/**
294	+	* Returns an initial default seed.
295	+	*/
296	+	private static long getInitialDefaultSeed() {
297	+	byte[] seedBytes = java.security.SecureRandom.getSeed(8);
298	+	long s = (long)(seedBytes[0]) & 0xffL;
299	+	for (int i = 1; i < 8; ++i)
300	+	s = (s << 8) | ((long)(seedBytes[i]) & 0xffL);
301	+	return s;
302	+	}
303	+
304		/*
305		* Internal versions of nextX methods used by streams, as well as
306		* the public nextX(origin, bound) methods.  These exist mainly to
#	Line 326 | Line 347 | public class SplittableRandom {
347		long r = mix64(nextSeed());
348		if (origin < bound) {
349		long n = bound - origin, m = n - 1;
350	<	if ((n & m) == 0L) // power of two
350	>	if ((n & m) == 0L)  // power of two
351		r = (r & m) + origin;
352	<	else if (n > 0) { // reject over-represented candidates
352	>	else if (n > 0L) {  // reject over-represented candidates
353		for (long u = r >>> 1;            // ensure nonnegative
354	<	u + m - (r = u % n) < 0L;    // reject
354	>	u + m - (r = u % n) < 0L;    // rejection check
355		u = mix64(nextSeed()) >>> 1) // retry
356		;
357		r += origin;
358		}
359	<	else {             // range not representable as long
359	>	else {              // range not representable as long
360		while (r < origin || r >= bound)
361		r = mix64(nextSeed());
362		}
#	Line 359 | Line 380 | public class SplittableRandom {
380		r = (r & m) + origin;
381		else if (n > 0) {
382		for (int u = r >>> 1;
383	<	u + m - (r = u % n) < 0L;
383	>	u + m - (r = u % n) < 0;
384		u = mix32(nextSeed()) >>> 1)
385		;
386		r += origin;
#	Line 380 | Line 401 | public class SplittableRandom {
401		* @return a pseudorandom value
402		*/
403		final double internalNextDouble(double origin, double bound) {
404	<	long bits = (1023L << 52) | (nextLong() >>> 12);
384	<	double r = Double.longBitsToDouble(bits) - 1.0;
404	>	double r = (nextLong() >>> 11) * DOUBLE_UNIT;
405		if (origin < bound) {
406		r = r * (bound - origin) + origin;
407	<	if (r == bound) // correct for rounding
407	>	if (r >= bound) // correct for rounding
408		r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
409		}
410		return r;
#	Line 393 | Line 413 | public class SplittableRandom {
413		/* ---------------- public methods ---------------- */
414
415		/**
416	<	* Creates a new SplittableRandom instance using the given initial
417	<	* seed. Two SplittableRandom instances created with the same seed
418	<	* generate identical sequences of values.
416	>	* Creates a new SplittableRandom instance using the specified
417	>	* initial seed. SplittableRandom instances created with the same
418	>	* seed in the same program generate identical sequences of values.
419		*
420		* @param seed the initial seed
421		*/
#	Line 434 | Line 454 | public class SplittableRandom {
454		/**
455		* Returns a pseudorandom {@code int} value.
456		*
457	<	* @return a pseudorandom value
457	>	* @return a pseudorandom {@code int} value
458		*/
459		public int nextInt() {
460		return mix32(nextSeed());
461		}
462
463		/**
464	<	* Returns a pseudorandom {@code int} value between 0 (inclusive)
464	>	* Returns a pseudorandom {@code int} value between zero (inclusive)
465		* and the specified bound (exclusive).
466		*
467		* @param bound the bound on the random number to be returned.  Must be
468		*        positive.
469	<	* @return a pseudorandom {@code int} value between {@code 0}
470	<	*         (inclusive) and the bound (exclusive).
471	<	* @exception IllegalArgumentException if the bound is not positive
469	>	* @return a pseudorandom {@code int} value between zero
470	>	*         (inclusive) and the bound (exclusive)
471	>	* @throws IllegalArgumentException if the bound is less than zero
472		*/
473		public int nextInt(int bound) {
474		if (bound <= 0)
#	Line 460 | Line 480 | public class SplittableRandom {
480		r &= m;
481		else { // reject over-represented candidates
482		for (int u = r >>> 1;
483	<	u + m - (r = u % bound) < 0L;
483	>	u + m - (r = u % bound) < 0;
484		u = mix32(nextSeed()) >>> 1)
485		;
486		}
#	Line 474 | Line 494 | public class SplittableRandom {
494		* @param origin the least value returned
495		* @param bound the upper bound (exclusive)
496		* @return a pseudorandom {@code int} value between the origin
497	<	*         (inclusive) and the bound (exclusive).
498	<	* @exception IllegalArgumentException if {@code origin} is greater than
497	>	*         (inclusive) and the bound (exclusive)
498	>	* @throws IllegalArgumentException if {@code origin} is greater than
499		*         or equal to {@code bound}
500		*/
501		public int nextInt(int origin, int bound) {
#	Line 487 | Line 507 | public class SplittableRandom {
507		/**
508		* Returns a pseudorandom {@code long} value.
509		*
510	<	* @return a pseudorandom value
510	>	* @return a pseudorandom {@code long} value
511		*/
512		public long nextLong() {
513		return mix64(nextSeed());
514		}
515
516		/**
517	<	* Returns a pseudorandom {@code long} value between 0 (inclusive)
517	>	* Returns a pseudorandom {@code long} value between zero (inclusive)
518		* and the specified bound (exclusive).
519		*
520		* @param bound the bound on the random number to be returned.  Must be
521		*        positive.
522	<	* @return a pseudorandom {@code long} value between {@code 0}
523	<	*         (inclusive) and the bound (exclusive).
524	<	* @exception IllegalArgumentException if the bound is not positive
522	>	* @return a pseudorandom {@code long} value between zero
523	>	*         (inclusive) and the bound (exclusive)
524	>	* @throws IllegalArgumentException if {@code bound} is less than zero
525		*/
526		public long nextLong(long bound) {
527		if (bound <= 0)
#	Line 527 | Line 547 | public class SplittableRandom {
547		* @param origin the least value returned
548		* @param bound the upper bound (exclusive)
549		* @return a pseudorandom {@code long} value between the origin
550	<	*         (inclusive) and the bound (exclusive).
551	<	* @exception IllegalArgumentException if {@code origin} is greater than
550	>	*         (inclusive) and the bound (exclusive)
551	>	* @throws IllegalArgumentException if {@code origin} is greater than
552		*         or equal to {@code bound}
553		*/
554		public long nextLong(long origin, long bound) {
#	Line 538 | Line 558 | public class SplittableRandom {
558		}
559
560		/**
561	<	* Returns a pseudorandom {@code double} value between {@code 0.0}
562	<	* (inclusive) and {@code 1.0} (exclusive).
561	>	* Returns a pseudorandom {@code double} value between zero
562	>	* (inclusive) and one (exclusive).
563		*
564	<	* @return a pseudorandom value between {@code 0.0}
565	<	* (inclusive) and {@code 1.0} (exclusive)
564	>	* @return a pseudorandom {@code double} value between zero
565	>	* (inclusive) and one (exclusive)
566		*/
567		public double nextDouble() {
568	<	long bits = (1023L << 52) | (nextLong() >>> 12);
549	<	return Double.longBitsToDouble(bits) - 1.0;
568	>	return (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT;
569		}
570
571		/**
#	Line 555 | Line 574 | public class SplittableRandom {
574		*
575		* @param bound the bound on the random number to be returned.  Must be
576		*        positive.
577	<	* @return a pseudorandom {@code double} value between {@code 0.0}
578	<	*         (inclusive) and the bound (exclusive).
579	<	* @throws IllegalArgumentException if {@code bound} is not positive
577	>	* @return a pseudorandom {@code double} value between zero
578	>	*         (inclusive) and the bound (exclusive)
579	>	* @throws IllegalArgumentException if {@code bound} is less than zero
580		*/
581		public double nextDouble(double bound) {
582	<	if (bound <= 0.0)
582	>	if (!(bound > 0.0))
583		throw new IllegalArgumentException("bound must be positive");
584	<	double result = nextDouble() * bound;
584	>	double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound;
585		return (result < bound) ?  result : // correct for rounding
586		Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
587		}
588
589		/**
590	<	* Returns a pseudorandom {@code double} value between the given
590	>	* Returns a pseudorandom {@code double} value between the specified
591		* origin (inclusive) and bound (exclusive).
592		*
593		* @param origin the least value returned
594		* @param bound the upper bound
595		* @return a pseudorandom {@code double} value between the origin
596	<	*         (inclusive) and the bound (exclusive).
596	>	*         (inclusive) and the bound (exclusive)
597		* @throws IllegalArgumentException if {@code origin} is greater than
598		*         or equal to {@code bound}
599		*/
600		public double nextDouble(double origin, double bound) {
601	<	if (origin >= bound)
601	>	if (!(origin < bound))
602		throw new IllegalArgumentException("bound must be greater than origin");
603		return internalNextDouble(origin, bound);
604		}
605
606	+	/**
607	+	* Returns a pseudorandom {@code boolean} value.
608	+	*
609	+	* @return a pseudorandom {@code boolean} value
610	+	*/
611	+	public boolean nextBoolean() {
612	+	return mix32(nextSeed()) < 0;
613	+	}
614	+
615		// stream methods, coded in a way intended to better isolate for
616		// maintenance purposes the small differences across forms.
617
618		/**
619	<	* Returns a stream with the given {@code streamSize} number of
619	>	* Returns a stream producing the given {@code streamSize} number of
620		* pseudorandom {@code int} values.
621		*
622		* @param streamSize the number of values to generate
623		* @return a stream of pseudorandom {@code int} values
624		* @throws IllegalArgumentException if {@code streamSize} is
625	<	* less than zero
625	>	*         less than zero
626		*/
627		public IntStream ints(long streamSize) {
628		if (streamSize < 0L)
#	Line 607 | Line 635 | public class SplittableRandom {
635
636		/**
637		* Returns an effectively unlimited stream of pseudorandom {@code int}
638	<	* values
638	>	* values.
639		*
640		* @implNote This method is implemented to be equivalent to {@code
641		* ints(Long.MAX_VALUE)}.
#	Line 622 | Line 650 | public class SplittableRandom {
650		}
651
652		/**
653	<	* Returns a stream with the given {@code streamSize} number of
653	>	* Returns a stream producing the given {@code streamSize} number of
654		* pseudorandom {@code int} values, each conforming to the given
655		* origin and bound.
656		*
#	Line 630 | Line 658 | public class SplittableRandom {
658		* @param randomNumberOrigin the origin of each random value
659		* @param randomNumberBound the bound of each random value
660		* @return a stream of pseudorandom {@code int} values,
661	<	* each with the given origin and bound.
661	>	*         each with the given origin and bound
662		* @throws IllegalArgumentException if {@code streamSize} is
663	<	* less than zero.
636	<	* @throws IllegalArgumentException if {@code randomNumberOrigin}
663	>	*         less than zero, or {@code randomNumberOrigin}
664		*         is greater than or equal to {@code randomNumberBound}
665		*/
666		public IntStream ints(long streamSize, int randomNumberOrigin,
#	Line 658 | Line 685 | public class SplittableRandom {
685		* @param randomNumberOrigin the origin of each random value
686		* @param randomNumberBound the bound of each random value
687		* @return a stream of pseudorandom {@code int} values,
688	<	* each with the given origin and bound.
688	>	*         each with the given origin and bound
689		* @throws IllegalArgumentException if {@code randomNumberOrigin}
690		*         is greater than or equal to {@code randomNumberBound}
691		*/
#	Line 672 | Line 699 | public class SplittableRandom {
699		}
700
701		/**
702	<	* Returns a stream with the given {@code streamSize} number of
702	>	* Returns a stream producing the given {@code streamSize} number of
703		* pseudorandom {@code long} values.
704		*
705		* @param streamSize the number of values to generate
706	<	* @return a stream of {@code long} values
706	>	* @return a stream of pseudorandom {@code long} values
707		* @throws IllegalArgumentException if {@code streamSize} is
708	<	* less than zero
708	>	*         less than zero
709		*/
710		public LongStream longs(long streamSize) {
711		if (streamSize < 0L)
#	Line 706 | Line 733 | public class SplittableRandom {
733		}
734
735		/**
736	<	* Returns a stream with the given {@code streamSize} number of
736	>	* Returns a stream producing the given {@code streamSize} number of
737		* pseudorandom {@code long} values, each conforming to the
738		* given origin and bound.
739		*
#	Line 714 | Line 741 | public class SplittableRandom {
741		* @param randomNumberOrigin the origin of each random value
742		* @param randomNumberBound the bound of each random value
743		* @return a stream of pseudorandom {@code long} values,
744	<	* each with the given origin and bound.
744	>	*         each with the given origin and bound
745		* @throws IllegalArgumentException if {@code streamSize} is
746	<	* less than zero.
720	<	* @throws IllegalArgumentException if {@code randomNumberOrigin}
746	>	*         less than zero, or {@code randomNumberOrigin}
747		*         is greater than or equal to {@code randomNumberBound}
748		*/
749		public LongStream longs(long streamSize, long randomNumberOrigin,
#	Line 742 | Line 768 | public class SplittableRandom {
768		* @param randomNumberOrigin the origin of each random value
769		* @param randomNumberBound the bound of each random value
770		* @return a stream of pseudorandom {@code long} values,
771	<	* each with the given origin and bound.
771	>	*         each with the given origin and bound
772		* @throws IllegalArgumentException if {@code randomNumberOrigin}
773		*         is greater than or equal to {@code randomNumberBound}
774		*/
#	Line 756 | Line 782 | public class SplittableRandom {
782		}
783
784		/**
785	<	* Returns a stream with the given {@code streamSize} number of
786	<	* pseudorandom {@code double} values, each between {@code 0.0}
787	<	* (inclusive) and {@code 1.0} (exclusive).
785	>	* Returns a stream producing the given {@code streamSize} number of
786	>	* pseudorandom {@code double} values, each between zero
787	>	* (inclusive) and one (exclusive).
788		*
789		* @param streamSize the number of values to generate
790		* @return a stream of {@code double} values
791		* @throws IllegalArgumentException if {@code streamSize} is
792	<	* less than zero
792	>	*         less than zero
793		*/
794		public DoubleStream doubles(long streamSize) {
795		if (streamSize < 0L)
#	Line 776 | Line 802 | public class SplittableRandom {
802
803		/**
804		* Returns an effectively unlimited stream of pseudorandom {@code
805	<	* double} values, each between {@code 0.0} (inclusive) and {@code
806	<	* 1.0} (exclusive).
805	>	* double} values, each between zero (inclusive) and one
806	>	* (exclusive).
807		*
808		* @implNote This method is implemented to be equivalent to {@code
809		* doubles(Long.MAX_VALUE)}.
#	Line 792 | Line 818 | public class SplittableRandom {
818		}
819
820		/**
821	<	* Returns a stream with the given {@code streamSize} number of
821	>	* Returns a stream producing the given {@code streamSize} number of
822		* pseudorandom {@code double} values, each conforming to the
823		* given origin and bound.
824		*
#	Line 800 | Line 826 | public class SplittableRandom {
826		* @param randomNumberOrigin the origin of each random value
827		* @param randomNumberBound the bound of each random value
828		* @return a stream of pseudorandom {@code double} values,
829	<	* each with the given origin and bound.
829	>	* each with the given origin and bound
830		* @throws IllegalArgumentException if {@code streamSize} is
831	<	* less than zero.
831	>	* less than zero
832		* @throws IllegalArgumentException if {@code randomNumberOrigin}
833		*         is greater than or equal to {@code randomNumberBound}
834		*/
#	Line 810 | Line 836 | public class SplittableRandom {
836		double randomNumberBound) {
837		if (streamSize < 0L)
838		throw new IllegalArgumentException("negative Stream size");
839	<	if (randomNumberOrigin >= randomNumberBound)
839	>	if (!(randomNumberOrigin < randomNumberBound))
840		throw new IllegalArgumentException("bound must be greater than origin");
841		return StreamSupport.doubleStream
842		(new RandomDoublesSpliterator
#	Line 828 | Line 854 | public class SplittableRandom {
854		* @param randomNumberOrigin the origin of each random value
855		* @param randomNumberBound the bound of each random value
856		* @return a stream of pseudorandom {@code double} values,
857	<	* each with the given origin and bound.
857	>	* each with the given origin and bound
858		* @throws IllegalArgumentException if {@code randomNumberOrigin}
859		*         is greater than or equal to {@code randomNumberBound}
860		*/
861		public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
862	<	if (randomNumberOrigin >= randomNumberBound)
862	>	if (!(randomNumberOrigin < randomNumberBound))
863		throw new IllegalArgumentException("bound must be greater than origin");
864		return StreamSupport.doubleStream
865		(new RandomDoublesSpliterator
#	Line 843 | Line 869 | public class SplittableRandom {
869
870		/**
871		* Spliterator for int streams.  We multiplex the four int
872	<	* versions into one class by treating and bound < origin as
872	>	* versions into one class by treating a bound less than origin as
873		* unbounded, and also by treating "infinite" as equivalent to
874		* Long.MAX_VALUE. For splits, it uses the standard divide-by-two
875		* approach. The long and double versions of this class are
876		* identical except for types.
877		*/
878	<	static class RandomIntsSpliterator implements Spliterator.OfInt {
878	>	static final class RandomIntsSpliterator implements Spliterator.OfInt {
879		final SplittableRandom rng;
880		long index;
881		final long fence;
#	Line 903 | Line 929 | public class SplittableRandom {
929		/**
930		* Spliterator for long streams.
931		*/
932	<	static class RandomLongsSpliterator implements Spliterator.OfLong {
932	>	static final class RandomLongsSpliterator implements Spliterator.OfLong {
933		final SplittableRandom rng;
934		long index;
935		final long fence;
#	Line 958 | Line 984 | public class SplittableRandom {
984		/**
985		* Spliterator for double streams.
986		*/
987	<	static class RandomDoublesSpliterator implements Spliterator.OfDouble {
987	>	static final class RandomDoublesSpliterator implements Spliterator.OfDouble {
988		final SplittableRandom rng;
989		long index;
990		final long fence;
#	Line 1010 | Line 1036 | public class SplittableRandom {
1036		}
1037
1038		}
1013	–

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