--- jsr166/src/main/java/util/SplittableRandom.java 2015/09/13 16:28:14 1.27 +++ jsr166/src/main/java/util/SplittableRandom.java 2018/12/02 23:06:16 1.41 @@ -80,7 +80,7 @@ import java.util.stream.StreamSupport; * in security-sensitive applications. Additionally, * default-constructed instances do not use a cryptographically random * seed unless the {@linkplain System#getProperty system property} - * {@code java.util.secureRandomSeed} is set to {@code true}. + * {@systemProperty java.util.secureRandomSeed} is set to {@code true}. * * @author Guy Steele * @author Doug Lea @@ -219,31 +219,33 @@ public final class SplittableRandom { 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(initialSeed()); - - private static long initialSeed() { - String pp = java.security.AccessController.doPrivileged( - new sun.security.action.GetPropertyAction( - "java.util.secureRandomSeed")); - if (pp != null && pp.equalsIgnoreCase("true")) { + private static final AtomicLong defaultGen + = new AtomicLong(mix64(System.currentTimeMillis()) ^ + mix64(System.nanoTime())); + + // at end of to survive static initialization circularity + static { + if (java.security.AccessController.doPrivileged( + new java.security.PrivilegedAction() { + public Boolean run() { + return Boolean.getBoolean("java.util.secureRandomSeed"); + }})) { byte[] seedBytes = java.security.SecureRandom.getSeed(8); - long s = (long)(seedBytes[0]) & 0xffL; + long s = (long)seedBytes[0] & 0xffL; for (int i = 1; i < 8; ++i) - s = (s << 8) | ((long)(seedBytes[i]) & 0xffL); - return s; + s = (s << 8) | ((long)seedBytes[i] & 0xffL); + defaultGen.set(s); } - return (mix64(System.currentTimeMillis()) ^ - mix64(System.nanoTime())); } - // IllegalArgumentException messages - static final String BadBound = "bound must be positive"; - static final String BadRange = "bound must be greater than origin"; - static final String BadSize = "size must be non-negative"; - /* * Internal versions of nextX methods used by streams, as well as * the public nextX(origin, bound) methods. These exist mainly to @@ -373,7 +375,7 @@ public final class SplittableRandom { * may, and typically does, vary across program invocations. */ public SplittableRandom() { // emulate defaultGen.split() - long s = defaultGen.getAndAdd(2 * GOLDEN_GAMMA); + long s = defaultGen.getAndAdd(GOLDEN_GAMMA << 1); this.seed = mix64(s); this.gamma = mixGamma(s + GOLDEN_GAMMA); } @@ -397,6 +399,26 @@ public final class SplittableRandom { } /** + * 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; + } + + /** * Returns a pseudorandom {@code int} value. * * @return a pseudorandom {@code int} value @@ -416,7 +438,7 @@ public final class SplittableRandom { */ public int nextInt(int bound) { if (bound <= 0) - throw new IllegalArgumentException(BadBound); + throw new IllegalArgumentException(BAD_BOUND); // Specialize internalNextInt for origin 0 int r = mix32(nextSeed()); int m = bound - 1; @@ -444,7 +466,7 @@ public final class SplittableRandom { */ public int nextInt(int origin, int bound) { if (origin >= bound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return internalNextInt(origin, bound); } @@ -468,7 +490,7 @@ public final class SplittableRandom { */ public long nextLong(long bound) { if (bound <= 0) - throw new IllegalArgumentException(BadBound); + throw new IllegalArgumentException(BAD_BOUND); // Specialize internalNextLong for origin 0 long r = mix64(nextSeed()); long m = bound - 1; @@ -496,7 +518,7 @@ public final class SplittableRandom { */ public long nextLong(long origin, long bound) { if (origin >= bound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return internalNextLong(origin, bound); } @@ -522,7 +544,7 @@ public final class SplittableRandom { */ public double nextDouble(double bound) { if (!(bound > 0.0)) - throw new IllegalArgumentException(BadBound); + 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); @@ -541,7 +563,7 @@ public final class SplittableRandom { */ public double nextDouble(double origin, double bound) { if (!(origin < bound)) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return internalNextDouble(origin, bound); } @@ -569,7 +591,7 @@ public final class SplittableRandom { */ public IntStream ints(long streamSize) { if (streamSize < 0L) - throw new IllegalArgumentException(BadSize); + throw new IllegalArgumentException(BAD_SIZE); return StreamSupport.intStream (new RandomIntsSpliterator (this, 0L, streamSize, Integer.MAX_VALUE, 0), @@ -610,9 +632,9 @@ public final class SplittableRandom { public IntStream ints(long streamSize, int randomNumberOrigin, int randomNumberBound) { if (streamSize < 0L) - throw new IllegalArgumentException(BadSize); + throw new IllegalArgumentException(BAD_SIZE); if (randomNumberOrigin >= randomNumberBound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.intStream (new RandomIntsSpliterator (this, 0L, streamSize, randomNumberOrigin, randomNumberBound), @@ -636,7 +658,7 @@ public final class SplittableRandom { */ public IntStream ints(int randomNumberOrigin, int randomNumberBound) { if (randomNumberOrigin >= randomNumberBound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.intStream (new RandomIntsSpliterator (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), @@ -655,7 +677,7 @@ public final class SplittableRandom { */ public LongStream longs(long streamSize) { if (streamSize < 0L) - throw new IllegalArgumentException(BadSize); + throw new IllegalArgumentException(BAD_SIZE); return StreamSupport.longStream (new RandomLongsSpliterator (this, 0L, streamSize, Long.MAX_VALUE, 0L), @@ -696,9 +718,9 @@ public final class SplittableRandom { public LongStream longs(long streamSize, long randomNumberOrigin, long randomNumberBound) { if (streamSize < 0L) - throw new IllegalArgumentException(BadSize); + throw new IllegalArgumentException(BAD_SIZE); if (randomNumberOrigin >= randomNumberBound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.longStream (new RandomLongsSpliterator (this, 0L, streamSize, randomNumberOrigin, randomNumberBound), @@ -722,7 +744,7 @@ public final class SplittableRandom { */ public LongStream longs(long randomNumberOrigin, long randomNumberBound) { if (randomNumberOrigin >= randomNumberBound) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.longStream (new RandomLongsSpliterator (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), @@ -741,7 +763,7 @@ public final class SplittableRandom { */ public DoubleStream doubles(long streamSize) { if (streamSize < 0L) - throw new IllegalArgumentException(BadSize); + throw new IllegalArgumentException(BAD_SIZE); return StreamSupport.doubleStream (new RandomDoublesSpliterator (this, 0L, streamSize, Double.MAX_VALUE, 0.0), @@ -777,16 +799,15 @@ public final class SplittableRandom { * @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} + * 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(BadSize); + throw new IllegalArgumentException(BAD_SIZE); if (!(randomNumberOrigin < randomNumberBound)) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.doubleStream (new RandomDoublesSpliterator (this, 0L, streamSize, randomNumberOrigin, randomNumberBound), @@ -810,7 +831,7 @@ public final class SplittableRandom { */ public DoubleStream doubles(double randomNumberOrigin, double randomNumberBound) { if (!(randomNumberOrigin < randomNumberBound)) - throw new IllegalArgumentException(BadRange); + throw new IllegalArgumentException(BAD_RANGE); return StreamSupport.doubleStream (new RandomDoublesSpliterator (this, 0L, Long.MAX_VALUE, randomNumberOrigin, randomNumberBound), @@ -825,7 +846,8 @@ public final class SplittableRandom { * approach. The long and double versions of this class are * identical except for types. */ - static final class RandomIntsSpliterator implements Spliterator.OfInt { + private static final class RandomIntsSpliterator + implements Spliterator.OfInt { final SplittableRandom rng; long index; final long fence; @@ -880,7 +902,8 @@ public final class SplittableRandom { /** * Spliterator for long streams. */ - static final class RandomLongsSpliterator implements Spliterator.OfLong { + private static final class RandomLongsSpliterator + implements Spliterator.OfLong { final SplittableRandom rng; long index; final long fence; @@ -936,7 +959,8 @@ public final class SplittableRandom { /** * Spliterator for double streams. */ - static final class RandomDoublesSpliterator implements Spliterator.OfDouble { + private static final class RandomDoublesSpliterator + implements Spliterator.OfDouble { final SplittableRandom rng; long index; final long fence;