--- a/src/java.base/share/classes/java/security/SecureRandom.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/java/security/SecureRandom.java Thu Nov 14 12:39:49 2019 -0400
@@ -25,11 +25,11 @@
package java.security;
+import java.math.BigInteger;
import java.util.*;
+import java.util.random.RandomGenerator;
import java.util.regex.*;
-
import java.security.Provider.Service;
-
import sun.security.jca.*;
import sun.security.jca.GetInstance.Instance;
import sun.security.provider.SunEntries;
@@ -1031,6 +1031,16 @@
}
}
+ /**
+ * Returns the period of this random number generator.
+ *
+ * @return the period of this random number generator.
+ */
+ @Override
+ public BigInteger period() {
+ return RandomGenerator.HUGE_PERIOD;
+ }
+
// Declare serialVersionUID to be compatible with JDK1.1
@java.io.Serial
static final long serialVersionUID = 4940670005562187L;
--- a/src/java.base/share/classes/java/util/Random.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/java/util/Random.java Thu Nov 14 12:39:49 2019 -0400
@@ -24,11 +24,18 @@
*/
package java.util;
+
import java.io.*;
+import java.math.BigInteger;
+import java.util.Spliterator;
import java.util.concurrent.atomic.AtomicLong;
import java.util.function.DoubleConsumer;
import java.util.function.IntConsumer;
import java.util.function.LongConsumer;
+import java.util.random.RandomGenerator;
+import java.util.random.RandomSupport;
+import java.util.random.RandomSupport.AbstractSpliteratorGenerator;
+import java.util.random.RandomSupport.RandomSpliterator;
import java.util.stream.DoubleStream;
import java.util.stream.IntStream;
import java.util.stream.LongStream;
@@ -74,7 +81,7 @@
* @since 1.0
*/
public
-class Random implements java.io.Serializable {
+class Random extends AbstractSpliteratorGenerator implements java.io.Serializable {
/** use serialVersionUID from JDK 1.1 for interoperability */
@java.io.Serial
static final long serialVersionUID = 3905348978240129619L;
@@ -206,6 +213,20 @@
return (int)(nextseed >>> (48 - bits));
}
+ /*
+ * Period of Random is 2**48
+ */
+ private static final BigInteger PERIOD = BigInteger.valueOf(1L<<48);
+
+ /**
+ * Returns the period of this random number generator.
+ *
+ * @return the period of this random number generator.
+ */
+ public BigInteger period() {
+ return PERIOD;
+ }
+
/**
* Generates random bytes and places them into a user-supplied
* byte array. The number of random bytes produced is equal to
@@ -234,82 +255,6 @@
}
/**
- * The form of nextLong used by LongStream Spliterators. If
- * origin is greater than bound, acts as unbounded form of
- * nextLong, else as bounded form.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final long internalNextLong(long origin, long bound) {
- long r = nextLong();
- if (origin < bound) {
- long n = bound - origin, m = n - 1;
- if ((n & m) == 0L) // power of two
- r = (r & m) + origin;
- else if (n > 0L) { // reject over-represented candidates
- for (long u = r >>> 1; // ensure nonnegative
- u + m - (r = u % n) < 0L; // rejection check
- u = nextLong() >>> 1) // retry
- ;
- r += origin;
- }
- else { // range not representable as long
- while (r < origin || r >= bound)
- r = nextLong();
- }
- }
- return r;
- }
-
- /**
- * The form of nextInt used by IntStream Spliterators.
- * For the unbounded case: uses nextInt().
- * For the bounded case with representable range: uses nextInt(int bound)
- * For the bounded case with unrepresentable range: uses nextInt()
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final int internalNextInt(int origin, int bound) {
- if (origin < bound) {
- int n = bound - origin;
- if (n > 0) {
- return nextInt(n) + origin;
- }
- else { // range not representable as int
- int r;
- do {
- r = nextInt();
- } while (r < origin || r >= bound);
- return r;
- }
- }
- else {
- return nextInt();
- }
- }
-
- /**
- * The form of nextDouble used by DoubleStream Spliterators.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final double internalNextDouble(double origin, double bound) {
- double r = nextDouble();
- if (origin < bound) {
- r = r * (bound - origin) + origin;
- if (r >= bound) // correct for rounding
- r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
- }
- return r;
- }
-
- /**
* Returns the next pseudorandom, uniformly distributed {@code int}
* value from this random number generator's sequence. The general
* contract of {@code nextInt} is that one {@code int} value is
@@ -331,71 +276,26 @@
}
/**
- * Returns a pseudorandom, uniformly distributed {@code int} value
- * between 0 (inclusive) and the specified value (exclusive), drawn from
- * this random number generator's sequence. The general contract of
- * {@code nextInt} is that one {@code int} value in the specified range
- * is pseudorandomly generated and returned. All {@code bound} possible
- * {@code int} values are produced with (approximately) equal
- * probability. The method {@code nextInt(int bound)} is implemented by
- * class {@code Random} as if by:
- * <pre> {@code
- * public int nextInt(int bound) {
- * if (bound <= 0)
- * throw new IllegalArgumentException("bound must be positive");
- *
- * if ((bound & -bound) == bound) // i.e., bound is a power of 2
- * return (int)((bound * (long)next(31)) >> 31);
- *
- * int bits, val;
- * do {
- * bits = next(31);
- * val = bits % bound;
- * } while (bits - val + (bound-1) < 0);
- * return val;
- * }}</pre>
- *
- * <p>The hedge "approximately" is used in the foregoing description only
- * because the next method is only approximately an unbiased source of
- * independently chosen bits. If it were a perfect source of randomly
- * chosen bits, then the algorithm shown would choose {@code int}
- * values from the stated range with perfect uniformity.
- * <p>
- * The algorithm is slightly tricky. It rejects values that would result
- * in an uneven distribution (due to the fact that 2^31 is not divisible
- * by n). The probability of a value being rejected depends on n. The
- * worst case is n=2^30+1, for which the probability of a reject is 1/2,
- * and the expected number of iterations before the loop terminates is 2.
- * <p>
- * The algorithm treats the case where n is a power of two specially: it
- * returns the correct number of high-order bits from the underlying
- * pseudo-random number generator. In the absence of special treatment,
- * the correct number of <i>low-order</i> bits would be returned. Linear
- * congruential pseudo-random number generators such as the one
- * implemented by this class are known to have short periods in the
- * sequence of values of their low-order bits. Thus, this special case
- * greatly increases the length of the sequence of values returned by
- * successive calls to this method if n is a small power of two.
+ * Returns a pseudorandom {@code int} value between zero (inclusive)
+ * and the specified bound (exclusive).
*
* @param bound the upper bound (exclusive). Must be positive.
- * @return the next pseudorandom, uniformly distributed {@code int}
- * value between zero (inclusive) and {@code bound} (exclusive)
- * from this random number generator's sequence
- * @throws IllegalArgumentException if bound is not positive
- * @since 1.2
+ * @return a pseudorandom {@code int} value between zero
+ * (inclusive) and the bound (exclusive)
+ * @throws IllegalArgumentException if {@code bound} is not positive
*/
public int nextInt(int bound) {
if (bound <= 0)
throw new IllegalArgumentException(BadBound);
-
- int r = next(31);
+ // Specialize internalNextInt for origin 0
+ int r = nextInt();
int m = bound - 1;
- if ((bound & m) == 0) // i.e., bound is a power of 2
- r = (int)((bound * (long)r) >> 31);
- else {
- for (int u = r;
- u - (r = u % bound) + m < 0;
- u = next(31))
+ if ((bound & m) == 0) // power of two
+ r &= m;
+ else { // reject over-represented candidates
+ for (int u = r >>> 1;
+ u + m - (r = u % bound) < 0;
+ u = nextInt() >>> 1)
;
}
return r;
@@ -600,565 +500,6 @@
}
}
- // stream methods, coded in a way intended to better isolate for
- // maintenance purposes the small differences across forms.
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code int} values.
- *
- * <p>A pseudorandom {@code int} value is generated as if it's the result of
- * calling the method {@link #nextInt()}.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code int} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public IntStream ints(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, streamSize, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code int}
- * values.
- *
- * <p>A pseudorandom {@code int} value is generated as if it's the result of
- * calling the method {@link #nextInt()}.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code int} values
- * @since 1.8
- */
- public IntStream ints() {
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number
- * of pseudorandom {@code int} values, each conforming to the given
- * origin (inclusive) and bound (exclusive).
- *
- * <p>A pseudorandom {@code int} value is generated as if it's the result of
- * calling the following method with the origin and bound:
- * <pre> {@code
- * int nextInt(int origin, int bound) {
- * int n = bound - origin;
- * if (n > 0) {
- * return nextInt(n) + origin;
- * }
- * else { // range not representable as int
- * int r;
- * do {
- * r = nextInt();
- * } while (r < origin || r >= bound);
- * return r;
- * }
- * }}</pre>
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public IntStream ints(long streamSize, int randomNumberOrigin,
- int randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * int} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * <p>A pseudorandom {@code int} value is generated as if it's the result of
- * calling the following method with the origin and bound:
- * <pre> {@code
- * int nextInt(int origin, int bound) {
- * int n = bound - origin;
- * if (n > 0) {
- * return nextInt(n) + origin;
- * }
- * else { // range not representable as int
- * int r;
- * do {
- * r = nextInt();
- * } while (r < origin || r >= bound);
- * return r;
- * }
- * }}</pre>
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code long} values.
- *
- * <p>A pseudorandom {@code long} value is generated as if it's the result
- * of calling the method {@link #nextLong()}.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code long} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public LongStream longs(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, streamSize, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code long}
- * values.
- *
- * <p>A pseudorandom {@code long} value is generated as if it's the result
- * of calling the method {@link #nextLong()}.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code long} values
- * @since 1.8
- */
- public LongStream longs() {
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code long}, each conforming to the given origin
- * (inclusive) and bound (exclusive).
- *
- * <p>A pseudorandom {@code long} value is generated as if it's the result
- * of calling the following method with the origin and bound:
- * <pre> {@code
- * long nextLong(long origin, long bound) {
- * long r = nextLong();
- * long n = bound - origin, m = n - 1;
- * if ((n & m) == 0L) // power of two
- * r = (r & m) + origin;
- * else if (n > 0L) { // reject over-represented candidates
- * for (long u = r >>> 1; // ensure nonnegative
- * u + m - (r = u % n) < 0L; // rejection check
- * u = nextLong() >>> 1) // retry
- * ;
- * r += origin;
- * }
- * else { // range not representable as long
- * while (r < origin || r >= bound)
- * r = nextLong();
- * }
- * return r;
- * }}</pre>
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public LongStream longs(long streamSize, long randomNumberOrigin,
- long randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * long} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * <p>A pseudorandom {@code long} value is generated as if it's the result
- * of calling the following method with the origin and bound:
- * <pre> {@code
- * long nextLong(long origin, long bound) {
- * long r = nextLong();
- * long n = bound - origin, m = n - 1;
- * if ((n & m) == 0L) // power of two
- * r = (r & m) + origin;
- * else if (n > 0L) { // reject over-represented candidates
- * for (long u = r >>> 1; // ensure nonnegative
- * u + m - (r = u % n) < 0L; // rejection check
- * u = nextLong() >>> 1) // retry
- * ;
- * r += origin;
- * }
- * else { // range not representable as long
- * while (r < origin || r >= bound)
- * r = nextLong();
- * }
- * return r;
- * }}</pre>
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values, each between zero
- * (inclusive) and one (exclusive).
- *
- * <p>A pseudorandom {@code double} value is generated as if it's the result
- * of calling the method {@link #nextDouble()}.
- *
- * @param streamSize the number of values to generate
- * @return a stream of {@code double} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public DoubleStream doubles(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, streamSize, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values, each between zero (inclusive) and one
- * (exclusive).
- *
- * <p>A pseudorandom {@code double} value is generated as if it's the result
- * of calling the method {@link #nextDouble()}.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code double} values
- * @since 1.8
- */
- public DoubleStream doubles() {
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values, each conforming to the given origin
- * (inclusive) and bound (exclusive).
- *
- * <p>A pseudorandom {@code double} value is generated as if it's the result
- * of calling the following method with the origin and bound:
- * <pre> {@code
- * double nextDouble(double origin, double bound) {
- * double r = nextDouble();
- * r = r * (bound - origin) + origin;
- * if (r >= bound) // correct for rounding
- * r = Math.nextDown(bound);
- * return r;
- * }}</pre>
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public DoubleStream doubles(long streamSize, double randomNumberOrigin,
- double randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BadSize);
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * <p>A pseudorandom {@code double} value is generated as if it's the result
- * of calling the following method with the origin and bound:
- * <pre> {@code
- * double nextDouble(double origin, double bound) {
- * double r = nextDouble();
- * r = r * (bound - origin) + origin;
- * if (r >= bound) // correct for rounding
- * r = Math.nextDown(bound);
- * return r;
- * }}</pre>
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BadRange);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Spliterator for int streams. We multiplex the four int
- * versions into one class by treating a bound less than origin as
- * unbounded, and also by treating "infinite" as equivalent to
- * Long.MAX_VALUE. For splits, it uses the standard divide-by-two
- * approach. The long and double versions of this class are
- * identical except for types.
- */
- static final class RandomIntsSpliterator implements Spliterator.OfInt {
- final Random rng;
- long index;
- final long fence;
- final int origin;
- final int bound;
- RandomIntsSpliterator(Random rng, long index, long fence,
- int origin, int bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomIntsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomIntsSpliterator(rng, i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextInt(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- Random r = rng;
- int o = origin, b = bound;
- do {
- consumer.accept(r.internalNextInt(o, b));
- } while (++i < f);
- }
- }
- }
-
- /**
- * Spliterator for long streams.
- */
- static final class RandomLongsSpliterator implements Spliterator.OfLong {
- final Random rng;
- long index;
- final long fence;
- final long origin;
- final long bound;
- RandomLongsSpliterator(Random rng, long index, long fence,
- long origin, long bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomLongsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomLongsSpliterator(rng, i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextLong(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- Random r = rng;
- long o = origin, b = bound;
- do {
- consumer.accept(r.internalNextLong(o, b));
- } while (++i < f);
- }
- }
-
- }
-
- /**
- * Spliterator for double streams.
- */
- static final class RandomDoublesSpliterator implements Spliterator.OfDouble {
- final Random rng;
- long index;
- final long fence;
- final double origin;
- final double bound;
- RandomDoublesSpliterator(Random rng, long index, long fence,
- double origin, double bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomDoublesSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomDoublesSpliterator(rng, i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextDouble(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- Random r = rng;
- double o = origin, b = bound;
- do {
- consumer.accept(r.internalNextDouble(o, b));
- } while (++i < f);
- }
- }
- }
-
/**
* Serializable fields for Random.
*
@@ -1228,4 +569,164 @@
private void resetSeed(long seedVal) {
unsafe.putReferenceVolatile(this, seedOffset, new AtomicLong(seedVal));
}
+
+ // Methods required by class AbstractSpliteratorGenerator
+ public Spliterator.OfInt makeIntsSpliterator(long index, long fence, int origin, int bound) {
+ return new RandomIntsSpliterator(this, index, fence, origin, bound);
+ }
+ public Spliterator.OfLong makeLongsSpliterator(long index, long fence, long origin, long bound) {
+ return new RandomLongsSpliterator(this, index, fence, origin, bound);
+ }
+ public Spliterator.OfDouble makeDoublesSpliterator(long index, long fence, double origin, double bound) {
+ return new RandomDoublesSpliterator(this, index, fence, origin, bound);
+ }
+
+ /**
+ * Spliterators for producing streams. These are based on abstract spliterator classes provided
+ * by class AbstractSpliteratorGenerator. Each one needs to define only a constructor and two
+ * methods.
+ */
+ static class RandomIntsSpliterator extends RandomSupport.RandomSpliterator
+ implements Spliterator.OfInt {
+ final AbstractSpliteratorGenerator generatingGenerator;
+ final int origin;
+ final int bound;
+
+ RandomIntsSpliterator(AbstractSpliteratorGenerator generatingGenerator,
+ long index, long fence, int origin, int bound) {
+ super(index, fence);
+ this.generatingGenerator = generatingGenerator;
+ this.origin = origin; this.bound = bound;
+ }
+
+ public Spliterator.OfInt trySplit() {
+ long i = index, m = (i + fence) >>> 1;
+ if (m <= i) return null;
+ index = m;
+ // The same generatingGenerator is used, with no splitting or copying.
+ return new RandomIntsSpliterator(generatingGenerator, i, m, origin, bound);
+ }
+
+ public boolean tryAdvance(IntConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ consumer.accept(RandomSupport.boundedNextInt(generatingGenerator, origin, bound));
+ index = i + 1;
+ return true;
+ }
+ else return false;
+ }
+
+ public void forEachRemaining(IntConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ index = f;
+ RandomGenerator r = generatingGenerator;
+ int o = origin, b = bound;
+ do {
+ consumer.accept(RandomSupport.boundedNextInt(r, o, b));
+ } while (++i < f);
+ }
+ }
+ }
+
+ /**
+ * Spliterator for long streams.
+ */
+ static class RandomLongsSpliterator extends RandomSupport.RandomSpliterator
+ implements Spliterator.OfLong {
+ final AbstractSpliteratorGenerator generatingGenerator;
+ final long origin;
+ final long bound;
+
+ RandomLongsSpliterator(AbstractSpliteratorGenerator generatingGenerator,
+ long index, long fence, long origin, long bound) {
+ super(index, fence);
+ this.generatingGenerator = generatingGenerator;
+ this.origin = origin; this.bound = bound;
+ }
+
+ public Spliterator.OfLong trySplit() {
+ long i = index, m = (i + fence) >>> 1;
+ if (m <= i) return null;
+ index = m;
+ // The same generatingGenerator is used, with no splitting or copying.
+ return new RandomLongsSpliterator(generatingGenerator, i, m, origin, bound);
+ }
+
+ public boolean tryAdvance(LongConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ consumer.accept(RandomSupport.boundedNextLong(generatingGenerator, origin, bound));
+ index = i + 1;
+ return true;
+ }
+ else return false;
+ }
+
+ public void forEachRemaining(LongConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ index = f;
+ RandomGenerator r = generatingGenerator;
+ long o = origin, b = bound;
+ do {
+ consumer.accept(RandomSupport.boundedNextLong(r, o, b));
+ } while (++i < f);
+ }
+ }
+ }
+
+ /**
+ * Spliterator for double streams.
+ */
+ static class RandomDoublesSpliterator extends RandomSupport.RandomSpliterator
+ implements Spliterator.OfDouble {
+ final AbstractSpliteratorGenerator generatingGenerator;
+ final double origin;
+ final double bound;
+
+ RandomDoublesSpliterator(AbstractSpliteratorGenerator generatingGenerator,
+ long index, long fence, double origin, double bound) {
+ super(index, fence);
+ this.generatingGenerator = generatingGenerator;
+ this.origin = origin; this.bound = bound;
+ }
+
+ public Spliterator.OfDouble trySplit() {
+ long i = index, m = (i + fence) >>> 1;
+ if (m <= i) return null;
+ index = m;
+ // The same generatingGenerator is used, with no splitting or copying.
+ return new RandomDoublesSpliterator(generatingGenerator, i, m, origin, bound);
+ }
+
+ public boolean tryAdvance(DoubleConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ consumer.accept(RandomSupport.boundedNextDouble(generatingGenerator, origin, bound));
+ index = i + 1;
+ return true;
+ }
+ else return false;
+ }
+
+ public void forEachRemaining(DoubleConsumer consumer) {
+ if (consumer == null) throw new NullPointerException();
+ long i = index, f = fence;
+ if (i < f) {
+ index = f;
+ RandomGenerator r = generatingGenerator;
+ double o = origin, b = bound;
+ do {
+ consumer.accept(RandomSupport.boundedNextDouble(r, o, b));
+ } while (++i < f);
+ }
+ }
+ }
}
--- a/src/java.base/share/classes/java/util/SplittableRandom.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/java/util/SplittableRandom.java Thu Nov 14 12:39:49 2019 -0400
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2013, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2013, 2019, Oracle and/or its affiliates. All rights reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
@@ -22,17 +22,13 @@
* or visit www.oracle.com if you need additional information or have any
* questions.
*/
-
package java.util;
+import java.math.BigInteger;
import java.util.concurrent.atomic.AtomicLong;
-import java.util.function.DoubleConsumer;
-import java.util.function.IntConsumer;
-import java.util.function.LongConsumer;
-import java.util.stream.DoubleStream;
-import java.util.stream.IntStream;
-import java.util.stream.LongStream;
-import java.util.stream.StreamSupport;
+import java.util.random.RandomGenerator.SplittableGenerator;
+import java.util.random.RandomSupport;
+import java.util.random.RandomSupport.AbstractSplittableGenerator;
/**
* A generator of uniform pseudorandom values applicable for use in
@@ -52,15 +48,15 @@
* types and ranges, but similar properties are expected to hold, at
* least approximately, for others as well. The <em>period</em>
* (length of any series of generated values before it repeats) is at
- * least 2<sup>64</sup>.
+ * least 2<sup>64</sup>. </li>
*
- * <li>Method {@link #split} constructs and returns a new
+ * <li> Method {@link #split} constructs and returns a new
* SplittableRandom instance that shares no mutable state with the
* current instance. However, with very high probability, the
* values collectively generated by the two objects have the same
* statistical properties as if the same quantity of values were
* generated by a single thread using a single {@code
- * SplittableRandom} object.
+ * SplittableRandom} object. </li>
*
* <li>Instances of SplittableRandom are <em>not</em> thread-safe.
* They are designed to be split, not shared, across threads. For
@@ -71,7 +67,7 @@
*
* <li>This class provides additional methods for generating random
* streams, that employ the above techniques when used in {@code
- * stream.parallel()} mode.
+ * stream.parallel()} mode.</li>
*
* </ul>
*
@@ -80,13 +76,13 @@
* in security-sensitive applications. Additionally,
* default-constructed instances do not use a cryptographically random
* seed unless the {@linkplain System#getProperty system property}
- * {@systemProperty java.util.secureRandomSeed} is set to {@code true}.
+ * {@code java.util.secureRandomSeed} is set to {@code true}.
*
* @author Guy Steele
* @author Doug Lea
* @since 1.8
*/
-public final class SplittableRandom {
+public final class SplittableRandom extends AbstractSplittableGenerator {
/*
* Implementation Overview.
@@ -161,12 +157,6 @@
private static final long GOLDEN_GAMMA = 0x9e3779b97f4a7c15L;
/**
- * The least non-zero value returned by nextDouble(). This value
- * is scaled by a random value of 53 bits to produce a result.
- */
- private static final double DOUBLE_UNIT = 0x1.0p-53; // 1.0 / (1L << 53);
-
- /**
* The seed. Updated only via method nextSeed.
*/
private long seed;
@@ -186,6 +176,7 @@
/**
* Computes Stafford variant 13 of 64bit mix function.
+ * http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
*/
private static long mix64(long z) {
z = (z ^ (z >>> 30)) * 0xbf58476d1ce4e5b9L;
@@ -195,6 +186,7 @@
/**
* Returns the 32 high bits of Stafford variant 4 mix64 function as int.
+ * http://zimbry.blogspot.com/2011/09/better-bit-mixing-improving-on.html
*/
private static int mix32(long z) {
z = (z ^ (z >>> 33)) * 0x62a9d9ed799705f5L;
@@ -203,6 +195,8 @@
/**
* Returns the gamma value to use for a new split instance.
+ * Uses the 64bit mix function from MurmurHash3.
+ * https://github.com/aappleby/smhasher/wiki/MurmurHash3
*/
private static long mixGamma(long z) {
z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL; // MurmurHash3 mix constants
@@ -219,141 +213,10 @@
return seed += gamma;
}
- // IllegalArgumentException messages
- static final String BAD_BOUND = "bound must be positive";
- static final String BAD_RANGE = "bound must be greater than origin";
- static final String BAD_SIZE = "size must be non-negative";
-
/**
* The seed generator for default constructors.
*/
- private static final AtomicLong defaultGen
- = new AtomicLong(mix64(System.currentTimeMillis()) ^
- mix64(System.nanoTime()));
-
- // at end of <clinit> to survive static initialization circularity
- static {
- if (java.security.AccessController.doPrivileged(
- new java.security.PrivilegedAction<Boolean>() {
- public Boolean run() {
- return Boolean.getBoolean("java.util.secureRandomSeed");
- }})) {
- byte[] seedBytes = java.security.SecureRandom.getSeed(8);
- long s = (long)seedBytes[0] & 0xffL;
- for (int i = 1; i < 8; ++i)
- s = (s << 8) | ((long)seedBytes[i] & 0xffL);
- defaultGen.set(s);
- }
- }
-
- /*
- * Internal versions of nextX methods used by streams, as well as
- * the public nextX(origin, bound) methods. These exist mainly to
- * avoid the need for multiple versions of stream spliterators
- * across the different exported forms of streams.
- */
-
- /**
- * The form of nextLong used by LongStream Spliterators. If
- * origin is greater than bound, acts as unbounded form of
- * nextLong, else as bounded form.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final long internalNextLong(long origin, long bound) {
- /*
- * Four Cases:
- *
- * 1. If the arguments indicate unbounded form, act as
- * nextLong().
- *
- * 2. If the range is an exact power of two, apply the
- * associated bit mask.
- *
- * 3. If the range is positive, loop to avoid potential bias
- * when the implicit nextLong() bound (2<sup>64</sup>) is not
- * evenly divisible by the range. The loop rejects candidates
- * computed from otherwise over-represented values. The
- * expected number of iterations under an ideal generator
- * varies from 1 to 2, depending on the bound. The loop itself
- * takes an unlovable form. Because the first candidate is
- * already available, we need a break-in-the-middle
- * construction, which is concisely but cryptically performed
- * within the while-condition of a body-less for loop.
- *
- * 4. Otherwise, the range cannot be represented as a positive
- * long. The loop repeatedly generates unbounded longs until
- * obtaining a candidate meeting constraints (with an expected
- * number of iterations of less than two).
- */
-
- long r = mix64(nextSeed());
- if (origin < bound) {
- long n = bound - origin, m = n - 1;
- if ((n & m) == 0L) // power of two
- r = (r & m) + origin;
- else if (n > 0L) { // reject over-represented candidates
- for (long u = r >>> 1; // ensure nonnegative
- u + m - (r = u % n) < 0L; // rejection check
- u = mix64(nextSeed()) >>> 1) // retry
- ;
- r += origin;
- }
- else { // range not representable as long
- while (r < origin || r >= bound)
- r = mix64(nextSeed());
- }
- }
- return r;
- }
-
- /**
- * The form of nextInt used by IntStream Spliterators.
- * Exactly the same as long version, except for types.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final int internalNextInt(int origin, int bound) {
- int r = mix32(nextSeed());
- if (origin < bound) {
- int n = bound - origin, m = n - 1;
- if ((n & m) == 0)
- r = (r & m) + origin;
- else if (n > 0) {
- for (int u = r >>> 1;
- u + m - (r = u % n) < 0;
- u = mix32(nextSeed()) >>> 1)
- ;
- r += origin;
- }
- else {
- while (r < origin || r >= bound)
- r = mix32(nextSeed());
- }
- }
- return r;
- }
-
- /**
- * The form of nextDouble used by DoubleStream Spliterators.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final double internalNextDouble(double origin, double bound) {
- double r = (nextLong() >>> 11) * DOUBLE_UNIT;
- if (origin < bound) {
- r = r * (bound - origin) + origin;
- if (r >= bound) // correct for rounding
- r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
- }
- return r;
- }
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
/* ---------------- public methods ---------------- */
@@ -375,11 +238,13 @@
* may, and typically does, vary across program invocations.
*/
public SplittableRandom() { // emulate defaultGen.split()
- long s = defaultGen.getAndAdd(GOLDEN_GAMMA << 1);
+ long s = defaultGen.getAndAdd(2 * GOLDEN_GAMMA);
this.seed = mix64(s);
this.gamma = mixGamma(s + GOLDEN_GAMMA);
}
+ // public SplittableRandom copy() { return new SplittableRandom(seed, gamma); }
+
/**
* Constructs and returns a new SplittableRandom instance that
* shares no mutable state with this instance. However, with very
@@ -398,24 +263,8 @@
return new SplittableRandom(nextLong(), mixGamma(nextSeed()));
}
- /**
- * Fills a user-supplied byte array with generated pseudorandom bytes.
- *
- * @param bytes the byte array to fill with pseudorandom bytes
- * @throws NullPointerException if bytes is null
- * @since 10
- */
- public void nextBytes(byte[] bytes) {
- int i = 0;
- int len = bytes.length;
- for (int words = len >> 3; words--> 0; ) {
- long rnd = nextLong();
- for (int n = 8; n--> 0; rnd >>>= Byte.SIZE)
- bytes[i++] = (byte)rnd;
- }
- if (i < len)
- for (long rnd = nextLong(); i < len; rnd >>>= Byte.SIZE)
- bytes[i++] = (byte)rnd;
+ public SplittableRandom split(SplittableGenerator source) {
+ return new SplittableRandom(source.nextLong(), mixGamma(source.nextLong()));
}
/**
@@ -428,49 +277,6 @@
}
/**
- * Returns a pseudorandom {@code int} value between zero (inclusive)
- * and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code int} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public int nextInt(int bound) {
- if (bound <= 0)
- throw new IllegalArgumentException(BAD_BOUND);
- // Specialize internalNextInt for origin 0
- int r = mix32(nextSeed());
- int m = bound - 1;
- if ((bound & m) == 0) // power of two
- r &= m;
- else { // reject over-represented candidates
- for (int u = r >>> 1;
- u + m - (r = u % bound) < 0;
- u = mix32(nextSeed()) >>> 1)
- ;
- }
- return r;
- }
-
- /**
- * Returns a pseudorandom {@code int} value between the specified
- * origin (inclusive) and the specified bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code int} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public int nextInt(int origin, int bound) {
- if (origin >= bound)
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextInt(origin, bound);
- }
-
- /**
* Returns a pseudorandom {@code long} value.
*
* @return a pseudorandom {@code long} value
@@ -479,537 +285,10 @@
return mix64(nextSeed());
}
- /**
- * Returns a pseudorandom {@code long} value between zero (inclusive)
- * and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code long} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public long nextLong(long bound) {
- if (bound <= 0)
- throw new IllegalArgumentException(BAD_BOUND);
- // Specialize internalNextLong for origin 0
- long r = mix64(nextSeed());
- long m = bound - 1;
- if ((bound & m) == 0L) // power of two
- r &= m;
- else { // reject over-represented candidates
- for (long u = r >>> 1;
- u + m - (r = u % bound) < 0L;
- u = mix64(nextSeed()) >>> 1)
- ;
- }
- return r;
- }
-
- /**
- * Returns a pseudorandom {@code long} value between the specified
- * origin (inclusive) and the specified bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code long} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public long nextLong(long origin, long bound) {
- if (origin >= bound)
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextLong(origin, bound);
- }
-
- /**
- * Returns a pseudorandom {@code double} value between zero
- * (inclusive) and one (exclusive).
- *
- * @return a pseudorandom {@code double} value between zero
- * (inclusive) and one (exclusive)
- */
- public double nextDouble() {
- return (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT;
- }
-
- /**
- * Returns a pseudorandom {@code double} value between 0.0
- * (inclusive) and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code double} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public double nextDouble(double bound) {
- if (!(bound > 0.0))
- throw new IllegalArgumentException(BAD_BOUND);
- double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound;
- return (result < bound) ? result : // correct for rounding
- Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
- }
-
- /**
- * Returns a pseudorandom {@code double} value between the specified
- * origin (inclusive) and bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code double} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public double nextDouble(double origin, double bound) {
- if (!(origin < bound))
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextDouble(origin, bound);
- }
-
- /**
- * Returns a pseudorandom {@code boolean} value.
- *
- * @return a pseudorandom {@code boolean} value
- */
- public boolean nextBoolean() {
- return mix32(nextSeed()) < 0;
- }
-
- // stream methods, coded in a way intended to better isolate for
- // maintenance purposes the small differences across forms.
-
- /**
- * Returns a stream producing the given {@code streamSize} number
- * of pseudorandom {@code int} values from this generator and/or
- * one split from it.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code int} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- */
- public IntStream ints(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, streamSize, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code int}
- * values from this generator and/or one split from it.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code int} values
- */
- public IntStream ints() {
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number
- * of pseudorandom {@code int} values from this generator and/or one split
- * from it; each value conforms to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public IntStream ints(long streamSize, int randomNumberOrigin,
- int randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * int} values from this generator and/or one split from it; each value
- * conforms to the given origin (inclusive) and bound (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number
- * of pseudorandom {@code long} values from this generator and/or
- * one split from it.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code long} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- */
- public LongStream longs(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, streamSize, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * long} values from this generator and/or one split from it.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code long} values
- */
- public LongStream longs() {
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code long} values from this generator and/or one split
- * from it; each value conforms to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public LongStream longs(long streamSize, long randomNumberOrigin,
- long randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
+ static final BigInteger PERIOD = BigInteger.ONE.shiftLeft(64); // Period is 2**64
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * long} values from this generator and/or one split from it; each value
- * conforms to the given origin (inclusive) and bound (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values from this generator and/or one split
- * from it; each value is between zero (inclusive) and one (exclusive).
- *
- * @param streamSize the number of values to generate
- * @return a stream of {@code double} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- */
- public DoubleStream doubles(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, streamSize, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values from this generator and/or one split from it; each value
- * is between zero (inclusive) and one (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code double} values
- */
- public DoubleStream doubles() {
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values from this generator and/or one split
- * from it; each value conforms to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public DoubleStream doubles(long streamSize, double randomNumberOrigin,
- double randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values from this generator and/or one split from it; each value
- * conforms to the given origin (inclusive) and bound (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- */
- public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Spliterator for int streams. We multiplex the four int
- * versions into one class by treating a bound less than origin as
- * unbounded, and also by treating "infinite" as equivalent to
- * Long.MAX_VALUE. For splits, it uses the standard divide-by-two
- * approach. The long and double versions of this class are
- * identical except for types.
- */
- private static final class RandomIntsSpliterator
- implements Spliterator.OfInt {
- final SplittableRandom rng;
- long index;
- final long fence;
- final int origin;
- final int bound;
- RandomIntsSpliterator(SplittableRandom rng, long index, long fence,
- int origin, int bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomIntsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomIntsSpliterator(rng.split(), i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextInt(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- SplittableRandom r = rng;
- int o = origin, b = bound;
- do {
- consumer.accept(r.internalNextInt(o, b));
- } while (++i < f);
- }
- }
- }
-
- /**
- * Spliterator for long streams.
- */
- private static final class RandomLongsSpliterator
- implements Spliterator.OfLong {
- final SplittableRandom rng;
- long index;
- final long fence;
- final long origin;
- final long bound;
- RandomLongsSpliterator(SplittableRandom rng, long index, long fence,
- long origin, long bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomLongsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomLongsSpliterator(rng.split(), i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextLong(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- SplittableRandom r = rng;
- long o = origin, b = bound;
- do {
- consumer.accept(r.internalNextLong(o, b));
- } while (++i < f);
- }
- }
-
- }
-
- /**
- * Spliterator for double streams.
- */
- private static final class RandomDoublesSpliterator
- implements Spliterator.OfDouble {
- final SplittableRandom rng;
- long index;
- final long fence;
- final double origin;
- final double bound;
- RandomDoublesSpliterator(SplittableRandom rng, long index, long fence,
- double origin, double bound) {
- this.rng = rng; this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomDoublesSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomDoublesSpliterator(rng.split(), i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(rng.internalNextDouble(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- SplittableRandom r = rng;
- double o = origin, b = bound;
- do {
- consumer.accept(r.internalNextDouble(o, b));
- } while (++i < f);
- }
- }
+ public BigInteger period() {
+ return PERIOD;
}
}
--- a/src/java.base/share/classes/java/util/concurrent/ThreadLocalRandom.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/java/util/concurrent/ThreadLocalRandom.java Thu Nov 14 12:39:49 2019 -0400
@@ -31,6 +31,9 @@
* Written by Doug Lea with assistance from members of JCP JSR-166
* Expert Group and released to the public domain, as explained at
* http://creativecommons.org/publicdomain/zero/1.0/
+ *
+ * Additional modifications by Guy Steele in 2019 to refactor the code
+ * and to implement the {@link RandomGenerator} interface.
*/
package java.util.concurrent;
@@ -41,13 +44,7 @@
import java.util.Spliterator;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicLong;
-import java.util.function.DoubleConsumer;
-import java.util.function.IntConsumer;
-import java.util.function.LongConsumer;
-import java.util.stream.DoubleStream;
-import java.util.stream.IntStream;
-import java.util.stream.LongStream;
-import java.util.stream.StreamSupport;
+import java.util.random.RandomSupport;
import jdk.internal.misc.Unsafe;
import jdk.internal.misc.VM;
@@ -123,19 +120,12 @@
* SplittableRandom, that were in part derived from a previous
* version of this class.
*
- * The nextLocalGaussian ThreadLocal supports the very rarely used
- * nextGaussian method by providing a holder for the second of a
- * pair of them. As is true for the base class version of this
- * method, this time/space tradeoff is probably never worthwhile,
- * but we provide identical statistical properties.
+ * This implementation of ThreadLocalRandom overrides the
+ * definition of the nextGaussian() method in the class Random,
+ * and instead uses the ziggurat-based algorithm that is the
+ * default for the RandomGenerator interface.
*/
- private static long mix64(long z) {
- z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL;
- z = (z ^ (z >>> 33)) * 0xc4ceb9fe1a85ec53L;
- return z ^ (z >>> 33);
- }
-
private static int mix32(long z) {
z = (z ^ (z >>> 33)) * 0xff51afd7ed558ccdL;
return (int)(((z ^ (z >>> 33)) * 0xc4ceb9fe1a85ec53L) >>> 32);
@@ -162,7 +152,7 @@
static final void localInit() {
int p = probeGenerator.addAndGet(PROBE_INCREMENT);
int probe = (p == 0) ? 1 : p; // skip 0
- long seed = mix64(seeder.getAndAdd(SEEDER_INCREMENT));
+ long seed = RandomSupport.mixMurmur64(seeder.getAndAdd(SEEDER_INCREMENT));
Thread t = Thread.currentThread();
U.putLong(t, SEED, seed);
U.putInt(t, PROBE, probe);
@@ -212,82 +202,6 @@
}
/**
- * The form of nextLong used by LongStream Spliterators. If
- * origin is greater than bound, acts as unbounded form of
- * nextLong, else as bounded form.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final long internalNextLong(long origin, long bound) {
- long r = mix64(nextSeed());
- if (origin < bound) {
- long n = bound - origin, m = n - 1;
- if ((n & m) == 0L) // power of two
- r = (r & m) + origin;
- else if (n > 0L) { // reject over-represented candidates
- for (long u = r >>> 1; // ensure nonnegative
- u + m - (r = u % n) < 0L; // rejection check
- u = mix64(nextSeed()) >>> 1) // retry
- ;
- r += origin;
- }
- else { // range not representable as long
- while (r < origin || r >= bound)
- r = mix64(nextSeed());
- }
- }
- return r;
- }
-
- /**
- * The form of nextInt used by IntStream Spliterators.
- * Exactly the same as long version, except for types.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final int internalNextInt(int origin, int bound) {
- int r = mix32(nextSeed());
- if (origin < bound) {
- int n = bound - origin, m = n - 1;
- if ((n & m) == 0)
- r = (r & m) + origin;
- else if (n > 0) {
- for (int u = r >>> 1;
- u + m - (r = u % n) < 0;
- u = mix32(nextSeed()) >>> 1)
- ;
- r += origin;
- }
- else {
- while (r < origin || r >= bound)
- r = mix32(nextSeed());
- }
- }
- return r;
- }
-
- /**
- * The form of nextDouble used by DoubleStream Spliterators.
- *
- * @param origin the least value, unless greater than bound
- * @param bound the upper bound (exclusive), must not equal origin
- * @return a pseudorandom value
- */
- final double internalNextDouble(double origin, double bound) {
- double r = (nextLong() >>> 11) * DOUBLE_UNIT;
- if (origin < bound) {
- r = r * (bound - origin) + origin;
- if (r >= bound) // correct for rounding
- r = Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
- }
- return r;
- }
-
- /**
* Returns a pseudorandom {@code int} value.
*
* @return a pseudorandom {@code int} value
@@ -297,622 +211,14 @@
}
/**
- * Returns a pseudorandom {@code int} value between zero (inclusive)
- * and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code int} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public int nextInt(int bound) {
- if (bound <= 0)
- throw new IllegalArgumentException(BAD_BOUND);
- int r = mix32(nextSeed());
- int m = bound - 1;
- if ((bound & m) == 0) // power of two
- r &= m;
- else { // reject over-represented candidates
- for (int u = r >>> 1;
- u + m - (r = u % bound) < 0;
- u = mix32(nextSeed()) >>> 1)
- ;
- }
- return r;
- }
-
- /**
- * Returns a pseudorandom {@code int} value between the specified
- * origin (inclusive) and the specified bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code int} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public int nextInt(int origin, int bound) {
- if (origin >= bound)
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextInt(origin, bound);
- }
-
- /**
* Returns a pseudorandom {@code long} value.
*
* @return a pseudorandom {@code long} value
*/
public long nextLong() {
- return mix64(nextSeed());
- }
-
- /**
- * Returns a pseudorandom {@code long} value between zero (inclusive)
- * and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code long} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public long nextLong(long bound) {
- if (bound <= 0)
- throw new IllegalArgumentException(BAD_BOUND);
- long r = mix64(nextSeed());
- long m = bound - 1;
- if ((bound & m) == 0L) // power of two
- r &= m;
- else { // reject over-represented candidates
- for (long u = r >>> 1;
- u + m - (r = u % bound) < 0L;
- u = mix64(nextSeed()) >>> 1)
- ;
- }
- return r;
- }
-
- /**
- * Returns a pseudorandom {@code long} value between the specified
- * origin (inclusive) and the specified bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code long} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public long nextLong(long origin, long bound) {
- if (origin >= bound)
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextLong(origin, bound);
- }
-
- /**
- * Returns a pseudorandom {@code double} value between zero
- * (inclusive) and one (exclusive).
- *
- * @return a pseudorandom {@code double} value between zero
- * (inclusive) and one (exclusive)
- */
- public double nextDouble() {
- return (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT;
- }
-
- /**
- * Returns a pseudorandom {@code double} value between 0.0
- * (inclusive) and the specified bound (exclusive).
- *
- * @param bound the upper bound (exclusive). Must be positive.
- * @return a pseudorandom {@code double} value between zero
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code bound} is not positive
- */
- public double nextDouble(double bound) {
- if (!(bound > 0.0))
- throw new IllegalArgumentException(BAD_BOUND);
- double result = (mix64(nextSeed()) >>> 11) * DOUBLE_UNIT * bound;
- return (result < bound) ? result : // correct for rounding
- Double.longBitsToDouble(Double.doubleToLongBits(bound) - 1);
- }
-
- /**
- * Returns a pseudorandom {@code double} value between the specified
- * origin (inclusive) and bound (exclusive).
- *
- * @param origin the least value returned
- * @param bound the upper bound (exclusive)
- * @return a pseudorandom {@code double} value between the origin
- * (inclusive) and the bound (exclusive)
- * @throws IllegalArgumentException if {@code origin} is greater than
- * or equal to {@code bound}
- */
- public double nextDouble(double origin, double bound) {
- if (!(origin < bound))
- throw new IllegalArgumentException(BAD_RANGE);
- return internalNextDouble(origin, bound);
- }
-
- /**
- * Returns a pseudorandom {@code boolean} value.
- *
- * @return a pseudorandom {@code boolean} value
- */
- public boolean nextBoolean() {
- return mix32(nextSeed()) < 0;
- }
-
- /**
- * Returns a pseudorandom {@code float} value between zero
- * (inclusive) and one (exclusive).
- *
- * @return a pseudorandom {@code float} value between zero
- * (inclusive) and one (exclusive)
- */
- public float nextFloat() {
- return (mix32(nextSeed()) >>> 8) * FLOAT_UNIT;
- }
-
- public double nextGaussian() {
- // Use nextLocalGaussian instead of nextGaussian field
- Double d = nextLocalGaussian.get();
- if (d != null) {
- nextLocalGaussian.set(null);
- return d.doubleValue();
- }
- double v1, v2, s;
- do {
- v1 = 2 * nextDouble() - 1; // between -1 and 1
- v2 = 2 * nextDouble() - 1; // between -1 and 1
- s = v1 * v1 + v2 * v2;
- } while (s >= 1 || s == 0);
- double multiplier = StrictMath.sqrt(-2 * StrictMath.log(s)/s);
- nextLocalGaussian.set(Double.valueOf(v2 * multiplier));
- return v1 * multiplier;
- }
-
- // stream methods, coded in a way intended to better isolate for
- // maintenance purposes the small differences across forms.
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code int} values.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code int} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public IntStream ints(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (0L, streamSize, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code int}
- * values.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code int} values
- * @since 1.8
- */
- public IntStream ints() {
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (0L, Long.MAX_VALUE, Integer.MAX_VALUE, 0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number
- * of pseudorandom {@code int} values, each conforming to the given
- * origin (inclusive) and bound (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public IntStream ints(long streamSize, int randomNumberOrigin,
- int randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * int} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * ints(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code int} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public IntStream ints(int randomNumberOrigin, int randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.intStream
- (new RandomIntsSpliterator
- (0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code long} values.
- *
- * @param streamSize the number of values to generate
- * @return a stream of pseudorandom {@code long} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public LongStream longs(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (0L, streamSize, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code long}
- * values.
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code long} values
- * @since 1.8
- */
- public LongStream longs() {
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (0L, Long.MAX_VALUE, Long.MAX_VALUE, 0L),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code long}, each conforming to the given origin
- * (inclusive) and bound (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public LongStream longs(long streamSize, long randomNumberOrigin,
- long randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
+ return RandomSupport.mixMurmur64(nextSeed());
}
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * long} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * longs(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code long} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public LongStream longs(long randomNumberOrigin, long randomNumberBound) {
- if (randomNumberOrigin >= randomNumberBound)
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.longStream
- (new RandomLongsSpliterator
- (0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values, each between zero
- * (inclusive) and one (exclusive).
- *
- * @param streamSize the number of values to generate
- * @return a stream of {@code double} values
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero
- * @since 1.8
- */
- public DoubleStream doubles(long streamSize) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (0L, streamSize, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values, each between zero (inclusive) and one
- * (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE)}.
- *
- * @return a stream of pseudorandom {@code double} values
- * @since 1.8
- */
- public DoubleStream doubles() {
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (0L, Long.MAX_VALUE, Double.MAX_VALUE, 0.0),
- false);
- }
-
- /**
- * Returns a stream producing the given {@code streamSize} number of
- * pseudorandom {@code double} values, each conforming to the given origin
- * (inclusive) and bound (exclusive).
- *
- * @param streamSize the number of values to generate
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code streamSize} is
- * less than zero, or {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public DoubleStream doubles(long streamSize, double randomNumberOrigin,
- double randomNumberBound) {
- if (streamSize < 0L)
- throw new IllegalArgumentException(BAD_SIZE);
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (0L, streamSize, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Returns an effectively unlimited stream of pseudorandom {@code
- * double} values, each conforming to the given origin (inclusive) and bound
- * (exclusive).
- *
- * @implNote This method is implemented to be equivalent to {@code
- * doubles(Long.MAX_VALUE, randomNumberOrigin, randomNumberBound)}.
- *
- * @param randomNumberOrigin the origin (inclusive) of each random value
- * @param randomNumberBound the bound (exclusive) of each random value
- * @return a stream of pseudorandom {@code double} values,
- * each with the given origin (inclusive) and bound (exclusive)
- * @throws IllegalArgumentException if {@code randomNumberOrigin}
- * is greater than or equal to {@code randomNumberBound}
- * @since 1.8
- */
- public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) {
- if (!(randomNumberOrigin < randomNumberBound))
- throw new IllegalArgumentException(BAD_RANGE);
- return StreamSupport.doubleStream
- (new RandomDoublesSpliterator
- (0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound),
- false);
- }
-
- /**
- * Spliterator for int streams. We multiplex the four int
- * versions into one class by treating a bound less than origin as
- * unbounded, and also by treating "infinite" as equivalent to
- * Long.MAX_VALUE. For splits, it uses the standard divide-by-two
- * approach. The long and double versions of this class are
- * identical except for types.
- */
- private static final class RandomIntsSpliterator
- implements Spliterator.OfInt {
- long index;
- final long fence;
- final int origin;
- final int bound;
- RandomIntsSpliterator(long index, long fence,
- int origin, int bound) {
- this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomIntsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomIntsSpliterator(i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(ThreadLocalRandom.current().internalNextInt(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(IntConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- int o = origin, b = bound;
- ThreadLocalRandom rng = ThreadLocalRandom.current();
- do {
- consumer.accept(rng.internalNextInt(o, b));
- } while (++i < f);
- }
- }
- }
-
- /**
- * Spliterator for long streams.
- */
- private static final class RandomLongsSpliterator
- implements Spliterator.OfLong {
- long index;
- final long fence;
- final long origin;
- final long bound;
- RandomLongsSpliterator(long index, long fence,
- long origin, long bound) {
- this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomLongsSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomLongsSpliterator(i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(ThreadLocalRandom.current().internalNextLong(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(LongConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- long o = origin, b = bound;
- ThreadLocalRandom rng = ThreadLocalRandom.current();
- do {
- consumer.accept(rng.internalNextLong(o, b));
- } while (++i < f);
- }
- }
-
- }
-
- /**
- * Spliterator for double streams.
- */
- private static final class RandomDoublesSpliterator
- implements Spliterator.OfDouble {
- long index;
- final long fence;
- final double origin;
- final double bound;
- RandomDoublesSpliterator(long index, long fence,
- double origin, double bound) {
- this.index = index; this.fence = fence;
- this.origin = origin; this.bound = bound;
- }
-
- public RandomDoublesSpliterator trySplit() {
- long i = index, m = (i + fence) >>> 1;
- return (m <= i) ? null :
- new RandomDoublesSpliterator(i, index = m, origin, bound);
- }
-
- public long estimateSize() {
- return fence - index;
- }
-
- public int characteristics() {
- return (Spliterator.SIZED | Spliterator.SUBSIZED |
- Spliterator.NONNULL | Spliterator.IMMUTABLE);
- }
-
- public boolean tryAdvance(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- consumer.accept(ThreadLocalRandom.current().internalNextDouble(origin, bound));
- index = i + 1;
- return true;
- }
- return false;
- }
-
- public void forEachRemaining(DoubleConsumer consumer) {
- if (consumer == null) throw new NullPointerException();
- long i = index, f = fence;
- if (i < f) {
- index = f;
- double o = origin, b = bound;
- ThreadLocalRandom rng = ThreadLocalRandom.current();
- do {
- consumer.accept(rng.internalNextDouble(o, b));
- } while (++i < f);
- }
- }
- }
-
-
// Within-package utilities
/*
@@ -1039,13 +345,6 @@
*/
private static final long SEEDER_INCREMENT = 0xbb67ae8584caa73bL;
- /**
- * The least non-zero value returned by nextDouble(). This value
- * is scaled by a random value of 53 bits to produce a result.
- */
- private static final double DOUBLE_UNIT = 0x1.0p-53; // 1.0 / (1L << 53)
- private static final float FLOAT_UNIT = 0x1.0p-24f; // 1.0f / (1 << 24)
-
// IllegalArgumentException messages
static final String BAD_BOUND = "bound must be positive";
static final String BAD_RANGE = "bound must be greater than origin";
@@ -1066,10 +365,6 @@
private static final long INHERITEDACCESSCONTROLCONTEXT
= U.objectFieldOffset(Thread.class, "inheritedAccessControlContext");
- /** Rarely-used holder for the second of a pair of Gaussians */
- private static final ThreadLocal<Double> nextLocalGaussian =
- new ThreadLocal<>();
-
/** Generates per-thread initialization/probe field */
private static final AtomicInteger probeGenerator = new AtomicInteger();
@@ -1080,8 +375,8 @@
* The next seed for default constructors.
*/
private static final AtomicLong seeder
- = new AtomicLong(mix64(System.currentTimeMillis()) ^
- mix64(System.nanoTime()));
+ = new AtomicLong(RandomSupport.mixMurmur64(System.currentTimeMillis()) ^
+ RandomSupport.mixMurmur64(System.nanoTime()));
// at end of <clinit> to survive static initialization circularity
static {
--- a/src/java.base/share/classes/module-info.java Thu Nov 14 12:36:46 2019 -0400
+++ b/src/java.base/share/classes/module-info.java Thu Nov 14 12:39:49 2019 -0400
@@ -112,6 +112,7 @@
exports java.util.concurrent.locks;
exports java.util.function;
exports java.util.jar;
+ exports java.util.random;
exports java.util.regex;
exports java.util.spi;
exports java.util.stream;
@@ -350,6 +351,7 @@
uses java.time.chrono.AbstractChronology;
uses java.time.chrono.Chronology;
uses java.time.zone.ZoneRulesProvider;
+ uses java.util.random.RandomGenerator;
uses java.util.spi.CalendarDataProvider;
uses java.util.spi.CalendarNameProvider;
uses java.util.spi.CurrencyNameProvider;
@@ -373,4 +375,16 @@
provides java.nio.file.spi.FileSystemProvider with
jdk.internal.jrtfs.JrtFileSystemProvider;
+
+ provides java.util.random.RandomGenerator with
+ java.security.SecureRandom,
+ java.util.Random,
+ java.util.random.L128X256MixRandom,
+ java.util.random.L64X1024MixRandom,
+ java.util.random.L64X128MixRandom,
+ java.util.random.L64X256MixRandom,
+ java.util.random.MRG32k3a,
+ java.util.random.Xoroshiro128StarStar,
+ java.util.random.Xoshiro256StarStar;
+
}