Add sources for API 35
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Change-Id: I83f78aa820b66edfdc9f8594d17bc7b6cacccec1
diff --git a/android-35/jdk/random/L128X1024MixRandom.java b/android-35/jdk/random/L128X1024MixRandom.java
new file mode 100644
index 0000000..a612233
--- /dev/null
+++ b/android-35/jdk/random/L128X1024MixRandom.java
@@ -0,0 +1,348 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>1152</sup>. Class {@link L128X1024MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L128X1024MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L128X1024MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L128X1024MixRandom}
+ * has 1152 bits of state plus one 128-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L128X1024MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L128X1024MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL128X1024MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L128X1024MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L128X1024MixRandom",
+ group = "LXM",
+ i = 1024, j = 1, k = 128,
+ equidistribution = 1
+)
+public final class L128X1024MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The 128-bit parameter `a` is represented as two long fields `ah` and `al`.
+ * The 128-bit state variable `s` is represented as two long fields `sh` and `sl`.
+ *
+ * The split operation uses the current generator to choose 20
+ * new 64-bit long values that are then used to initialize the
+ * parameters `ah` and `al`, the state variables `sh`, `sl`,
+ * and the array `x` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L128X1024MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate 20 new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /*
+ * The length of the array x.
+ */
+
+ private static final int N = 16;
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Low half of multiplier used in the LCG portion of the algorithm;
+ * the overall multiplier is (2**64 + ML).
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0x1d605bbb58c8abbfdLL
+ * are [0.991889, 0.907938, 0.830964, 0.837980, 0.780378, 0.797464, 0.761493].
+ */
+
+ private static final long ML = 0xd605bbb58c8abbfdL;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd (therefore al must be odd).
+ */
+ private final long ah, al;
+
+ /**
+ * The per-instance state: sh and sl for the LCG; the array x for the XBG;
+ * p is the rotating pointer into the array x.
+ * At least one of the 16 elements of the array x must be nonzero.
+ */
+ private long sh, sl;
+ private final long[] x;
+ private int p = N - 1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param ah high half of the additive parameter for the LCG
+ * @param al low half of the additive parameter for the LCG
+ * @param sh high half of the initial state for the LCG
+ * @param sl low half of the initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ * @param x2 third word of the initial state for the XBG
+ * @param x3 fourth word of the initial state for the XBG
+ * @param x4 fifth word of the initial state for the XBG
+ * @param x5 sixth word of the initial state for the XBG
+ * @param x6 seventh word of the initial state for the XBG
+ * @param x7 eight word of the initial state for the XBG
+ * @param x8 ninth word of the initial state for the XBG
+ * @param x9 tenth word of the initial state for the XBG
+ * @param x10 eleventh word of the initial state for the XBG
+ * @param x11 twelfth word of the initial state for the XBG
+ * @param x12 thirteenth word of the initial state for the XBG
+ * @param x13 fourteenth word of the initial state for the XBG
+ * @param x14 fifteenth word of the initial state for the XBG
+ * @param x15 sixteenth word of the initial state for the XBG
+ */
+ public L128X1024MixRandom(long ah, long al, long sh, long sl,
+ long x0, long x1, long x2, long x3,
+ long x4, long x5, long x6, long x7,
+ long x8, long x9, long x10, long x11,
+ long x12, long x13, long x14, long x15) {
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x = new long[N];
+ this.x[0] = x0;
+ this.x[1] = x1;
+ this.x[2] = x2;
+ this.x[3] = x3;
+ this.x[4] = x4;
+ this.x[5] = x5;
+ this.x[6] = x6;
+ this.x[7] = x7;
+ this.x[8] = x8;
+ this.x[9] = x9;
+ this.x[10] = x10;
+ this.x[11] = x11;
+ this.x[12] = x12;
+ this.x[13] = x13;
+ this.x[14] = x14;
+ this.x[15] = x15;
+ // If x0, x1, ..., x15 are all zero (very unlikely), we must choose nonzero values.
+ if ((x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | x9 | x10 | x11 | x12 | x13 | x14 | x15) == 0) {
+ long v = sh;
+ // At least fifteen of the sixteen values generated here will be nonzero.
+ for (int j = 0; j < N; j++) {
+ this.x[j] = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L128X1024MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L128X1024MixRandom} created with the same seed in the same
+ * program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X1024MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x[0]`,
+ // which will then be used to produce the first generated value.
+ // The other x values are filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ RandomSupport.mixMurmur64(seed += RandomSupport.GOLDEN_RATIO_64),
+ 0,
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X1024MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L128X1024MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X1024MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L128X1024MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X1024MixRandom(byte[] seed) {
+ // Convert the seed to 20 long values, of which the last 16 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 20, 16);
+ long ah = data[0], al = data[1], sh = data[2], sl = data[3];
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x = new long[N];
+ for (int j = 0; j < N; j++) {
+ this.x[j] = data[4+j];
+ }
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for (the low half of) `a`.
+ return new L128X1024MixRandom(source.nextLong(), brine << 1,
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // First part of xoroshiro1024: fetch array data
+ final int q = p;
+ final long s0 = x[p = (p + 1) & (N - 1)];
+ long s15 = x[q];
+
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = RandomSupport.mixLea64(sh + s0);
+
+ // Update the LCG subgenerator
+ // The LCG is, in effect, s = ((1LL << 64) + ML) * s + a, if only we had 128-bit arithmetic.
+ final long u = ML * sl;
+
+ // Note that Math.multiplyHigh computes the high half of the product of signed values,
+ // but what we need is the high half of the product of unsigned values; for this we use the
+ // formula "unsignedMultiplyHigh(a, b) = multiplyHigh(a, b) + ((a >> 63) & b) + ((b >> 63) & a)";
+ // in effect, each operand is added to the result iff the sign bit of the other operand is 1.
+ // (See Henry S. Warren, Jr., _Hacker's Delight_ (Second Edition), Addison-Wesley (2013),
+ // Section 8-3, p. 175; or see the First Edition, Addison-Wesley (2003), Section 8-3, p. 133.)
+ // If Math.unsignedMultiplyHigh(long, long) is ever implemented, the following line can become:
+ // sh = (ML * sh) + Math.unsignedMultiplyHigh(ML, sl) + sl + ah;
+ // and this entire comment can be deleted.
+ sh = (ML * sh) + (Math.multiplyHigh(ML, sl) + ((ML >> 63) & sl) + ((sl >> 63) & ML)) + sl + ah;
+ sl = u + al;
+ if (Long.compareUnsigned(sl, u) < 0) ++sh; // Handle the carry propagation from low half to high half.
+
+ // Second part of xoroshiro1024: update array data
+ s15 ^= s0;
+ x[q] = Long.rotateLeft(s0, 25) ^ s15 ^ (s15 << 27);
+ x[p] = Long.rotateLeft(s15, 36);
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L128X128MixRandom.java b/android-35/jdk/random/L128X128MixRandom.java
new file mode 100644
index 0000000..1b7d258
--- /dev/null
+++ b/android-35/jdk/random/L128X128MixRandom.java
@@ -0,0 +1,277 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>256</sup>. Class {@link L128X128MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L128X128MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L128X128MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L128X128MixRandom}
+ * has 256 bits of state plus one 128-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L128X128MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L128X128MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL128X128MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L128X128MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L128X128MixRandom",
+ group = "LXM",
+ i = 128, j = 1, k = 128,
+ equidistribution = 1
+)
+public final class L128X128MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The split operation uses the current generator to choose four new 64-bit
+ * long values that are then used to initialize the parameter `a` and the
+ * state variables `s`, `x0`, and `x1` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L128X128MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate four new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Low half of multiplier used in the LCG portion of the algorithm;
+ * the overall multiplier is (2**64 + ML).
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0x1d605bbb58c8abbfdLL
+ * are [0.991889, 0.907938, 0.830964, 0.837980, 0.780378, 0.797464, 0.761493].
+ */
+
+ private static final long ML = 0xd605bbb58c8abbfdL;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd (therefore al must be odd).
+ */
+ private final long ah, al;
+
+ /**
+ * The per-instance state: sh and sl for the LCG; x0 and x1 for the XBG.
+ * At least one of x0 and x1 must be nonzero.
+ */
+ private long sh, sl, x0, x1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param ah high half of the additive parameter for the LCG
+ * @param al low half of the additive parameter for the LCG
+ * @param sh high half of the initial state for the LCG
+ * @param sl low half of the initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ */
+ public L128X128MixRandom(long ah, long al, long sh, long sl, long x0, long x1) {
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x0 = x0;
+ this.x1 = x1;
+ // If x0 and x1 are both zero, we must choose nonzero values.
+ if ((x0 | x1) == 0) {
+ long v = sh;
+ // At least one of the two values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = RandomSupport.mixStafford13(v + RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L128X128MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L128X128MixRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X128MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // Then x1 is filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ RandomSupport.mixMurmur64(seed += RandomSupport.GOLDEN_RATIO_64),
+ 0,
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X128MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L128X128MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X128MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L128X128MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X128MixRandom(byte[] seed) {
+ // Convert the seed to 6 long values, of which the last 2 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 6, 2);
+ long ah = data[0], al = data[1], sh = data[2], sl = data[3], x0 = data[4], x1 = data[5];
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x0 = x0;
+ this.x1 = x1;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for (the low half of) `a`.
+ return new L128X128MixRandom(source.nextLong(), brine << 1,
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = RandomSupport.mixLea64(sh + x0);
+
+ // Update the LCG subgenerator
+ // The LCG is, in effect, s = ((1LL << 64) + ML) * s + a, if only we had 128-bit arithmetic.
+ final long u = ML * sl;
+ // Note that Math.multiplyHigh computes the high half of the product of signed values,
+ // but what we need is the high half of the product of unsigned values; for this we use the
+ // formula "unsignedMultiplyHigh(a, b) = multiplyHigh(a, b) + ((a >> 63) & b) + ((b >> 63) & a)";
+ // in effect, each operand is added to the result iff the sign bit of the other operand is 1.
+ // (See Henry S. Warren, Jr., _Hacker's Delight_ (Second Edition), Addison-Wesley (2013),
+ // Section 8-3, p. 175; or see the First Edition, Addison-Wesley (2003), Section 8-3, p. 133.)
+ // If Math.unsignedMultiplyHigh(long, long) is ever implemented, the following line can become:
+ // sh = (ML * sh) + Math.unsignedMultiplyHigh(ML, sl) + sl + ah;
+ // and this entire comment can be deleted.
+ sh = (ML * sh) + (Math.multiplyHigh(ML, sl) + ((ML >> 63) & sl) + ((sl >> 63) & ML)) + sl + ah;
+ sl = u + al;
+ if (Long.compareUnsigned(sl, u) < 0) ++sh; // Handle the carry propagation from low half to high half.
+
+ long q0 = x0, q1 = x1;
+ // Update the XBG subgenerator
+ { // xoroshiro128v1_0
+ q1 ^= q0;
+ q0 = Long.rotateLeft(q0, 24);
+ q0 = q0 ^ q1 ^ (q1 << 16);
+ q1 = Long.rotateLeft(q1, 37);
+ }
+ x0 = q0; x1 = q1;
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L128X256MixRandom.java b/android-35/jdk/random/L128X256MixRandom.java
new file mode 100644
index 0000000..5cb0999
--- /dev/null
+++ b/android-35/jdk/random/L128X256MixRandom.java
@@ -0,0 +1,303 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>384</sup>. Class {@link L128X256MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L128X256MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L128X256MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L128X256MixRandom}
+ * has 384 bits of state plus one 128-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L128X256MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L128X256MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL128X256MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L128X256MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L128X256MixRandom",
+ group = "LXM",
+ i = 256, j = 1, k = 128,
+ equidistribution = 1
+)
+public final class L128X256MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The 128-bit parameter `a` is represented as two long fields `ah` and `al`.
+ * The 128-bit state variable `s` is represented as two long fields `sh` and `sl`.
+ *
+ * The split operation uses the current generator to choose eight
+ * new 64-bit long values that are then used to initialize the
+ * parameters `ah` and `al` and the state variables `sh`, `sl`,
+ * `x0`, `x1`, `x2`, and `x3` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L128X256MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate eight new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * The equidistribution of the algorithm.
+ */
+ private static final int EQUIDISTRIBUTION = 1;
+
+ /*
+ * Low half of multiplier used in the LCG portion of the algorithm;
+ * the overall multiplier is (2**64 + ML).
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0x1d605bbb58c8abbfdLL
+ * are [0.991889, 0.907938, 0.830964, 0.837980, 0.780378, 0.797464, 0.761493].
+ */
+
+ private static final long ML = 0xd605bbb58c8abbfdL;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd (therefore al must be odd).
+ */
+ private final long ah, al;
+
+ /**
+ * The per-instance state: sh and sl for the LCG; x0, x1, x2, and x3 for the XBG.
+ * At least one of the four fields x0, x1, x2, and x3 must be nonzero.
+ */
+ private long sh, sl, x0, x1, x2, x3;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param ah high half of the additive parameter for the LCG
+ * @param al low half of the additive parameter for the LCG
+ * @param sh high half of the initial state for the LCG
+ * @param sl low half of the initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ * @param x2 third word of the initial state for the XBG
+ * @param x3 fourth word of the initial state for the XBG
+ */
+ public L128X256MixRandom(long ah, long al, long sh, long sl, long x0, long x1, long x2, long x3) {
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ // If x0, x1, x2, and x3 are all zero, we must choose nonzero values.
+ if ((x0 | x1 | x2 | x3) == 0) {
+ long v = sh;
+ // At least three of the four values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x2 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x3 = RandomSupport.mixStafford13(v + RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L128X256MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L128X256MixRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X256MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // The other x values are filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ RandomSupport.mixMurmur64(seed += RandomSupport.GOLDEN_RATIO_64),
+ 0,
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X256MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L128X256MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L128X256MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L128X256MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L128X256MixRandom(byte[] seed) {
+ // Android-changed: backport https://bugs.openjdk.org/browse/JDK-8283083.
+ // Convert the seed to 8 long values, of which the last 4 are not all zero.
+ // long[] data = RandomSupport.convertSeedBytesToLongs(seed, 6, 4);
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 8, 4);
+ long ah = data[0], al = data[1], sh = data[2], sl = data[3],
+ x0 = data[4], x1 = data[5], x2 = data[6], x3 = data[7];
+ // Force a to be odd.
+ this.ah = ah;
+ this.al = al | 1;
+ this.sh = sh;
+ this.sl = sl;
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for (the low half of) `a`.
+ return new L128X256MixRandom(source.nextLong(), brine << 1,
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = RandomSupport.mixLea64(sh + x0);
+
+ // Update the LCG subgenerator
+ // The LCG is, in effect, s = ((1LL << 64) + ML) * s + a, if only we had 128-bit arithmetic.
+ final long u = ML * sl;
+ // Note that Math.multiplyHigh computes the high half of the product of signed values,
+ // but what we need is the high half of the product of unsigned values; for this we use the
+ // formula "unsignedMultiplyHigh(a, b) = multiplyHigh(a, b) + ((a >> 63) & b) + ((b >> 63) & a)";
+ // in effect, each operand is added to the result iff the sign bit of the other operand is 1.
+ // (See Henry S. Warren, Jr., _Hacker's Delight_ (Second Edition), Addison-Wesley (2013),
+ // Section 8-3, p. 175; or see the First Edition, Addison-Wesley (2003), Section 8-3, p. 133.)
+ // If Math.unsignedMultiplyHigh(long, long) is ever implemented, the following line can become:
+ // sh = (ML * sh) + Math.unsignedMultiplyHigh(ML, sl) + sl + ah;
+ // and this entire comment can be deleted.
+ sh = (ML * sh) + (Math.multiplyHigh(ML, sl) + ((ML >> 63) & sl) + ((sl >> 63) & ML)) + sl + ah;
+ sl = u + al;
+ if (Long.compareUnsigned(sl, u) < 0) ++sh; // Handle the carry propagation from low half to high half.
+
+ // Update the XBG subgenerator
+ long q0 = x0, q1 = x1, q2 = x2, q3 = x3;
+ { // xoshiro256 1.0
+ long t = q1 << 17;
+ q2 ^= q0;
+ q3 ^= q1;
+ q1 ^= q2;
+ q0 ^= q3;
+ q2 ^= t;
+ q3 = Long.rotateLeft(q3, 45);
+ }
+ x0 = q0; x1 = q1; x2 = q2; x3 = q3;
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L32X64MixRandom.java b/android-35/jdk/random/L32X64MixRandom.java
new file mode 100644
index 0000000..1b64a4b
--- /dev/null
+++ b/android-35/jdk/random/L32X64MixRandom.java
@@ -0,0 +1,258 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>96</sup>. Class {@link L32X64MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L32X64MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L32X64MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L32X64MixRandom}
+ * has 96 bits of state plus one 32-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L32X64MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L32X64MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL32X64MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L32X64MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L32X64MixRandom",
+ group = "LXM",
+ i = 64, j = 1, k = 32,
+ equidistribution = 1
+)
+public final class L32X64MixRandom extends AbstractSplittableWithBrineGenerator {
+ /*
+ * Implementation Overview.
+ *
+ * The split operation uses the current generator to choose four new 32-bit
+ * int values that are then used to initialize the parameter `a` and the
+ * state variables `s`, `x0`, and `x1` for a newly constructed generator.
+ *
+ * With high probability, no two generators so chosen will have the same
+ * `a` parameter, and testing has indicated that the values generated by
+ * two instances of {@link L32X64MixRandom} will be (approximately)
+ * independent if the two instances have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate four new 32-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Multiplier used in the LCG portion of the algorithm.
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0xadb4a92d
+ * are [0.975884, 0.936244, 0.755793, 0.877642, 0.751300, 0.789333, 0.728869].
+ */
+
+ private static final int M = 0xadb4a92d;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd.
+ */
+ private final int a;
+
+ /**
+ * The per-instance state: s for the LCG; x0 and x1 for the XBG.
+ * At least one of x0 and x1 must be nonzero.
+ */
+ private int s, x0, x1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param a additive parameter for the LCG
+ * @param s initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ */
+ public L32X64MixRandom(int a, int s, int x0, int x1) {
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ // If x0 and x1 are both zero, we must choose nonzero values.
+ if ((x0 | x1) == 0) {
+ int v = s;
+ // At least one of the two values generated here will be nonzero.
+ this.x0 = RandomSupport.mixMurmur32(v += RandomSupport.GOLDEN_RATIO_32);
+ this.x1 = RandomSupport.mixMurmur32(v + RandomSupport.GOLDEN_RATIO_32);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L32X64MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L32X64MixRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L32X64MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The high half of the seed is hashed by mixMurmur32 to produce the `a` parameter.
+ // The low half of the seed is hashed by mixLea32 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // Then x1 is filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_32 as the gamma value and mixLea32 as the mixer.
+ this(RandomSupport.mixMurmur32((int)((seed ^= RandomSupport.SILVER_RATIO_64) >>> 32)),
+ 1,
+ RandomSupport.mixLea32((int)(seed)),
+ RandomSupport.mixLea32((int)(seed) + RandomSupport.GOLDEN_RATIO_32));
+ }
+
+ /**
+ * Creates a new instance of {@link L32X64MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L32X64MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L32X64MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L32X64MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L32X64MixRandom(byte[] seed) {
+ // Convert the seed to 4 int values, of which the last 2 are not all zero.
+ int[] data = RandomSupport.convertSeedBytesToInts(seed, 4, 2);
+ int a = data[0], s = data[1], x0 = data[2], x1 = data[3];
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use (the low 31 bits of) the brine for `a`.
+ return new L32X64MixRandom((int)brine << 1, source.nextInt(),
+ source.nextInt(), source.nextInt());
+ }
+
+ @Override
+ public int nextInt() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final int result = RandomSupport.mixLea32(s + x0);
+
+ // Update the LCG subgenerator
+ s = M * s + a;
+
+ // Update the XBG subgenerator
+ int q0 = x0, q1 = x1;
+ { // xoroshiro64
+ q1 ^= q0;
+ q0 = Integer.rotateLeft(q0, 26);
+ q0 = q0 ^ q1 ^ (q1 << 9);
+ q1 = Integer.rotateLeft(q1, 13);
+ }
+ x0 = q0; x1 = q1;
+
+ return result;
+ }
+
+ @Override
+ public long nextLong() {
+ return ((long)nextInt() << 32) ^ (long)nextInt();
+ }
+
+}
diff --git a/android-35/jdk/random/L64X1024MixRandom.java b/android-35/jdk/random/L64X1024MixRandom.java
new file mode 100644
index 0000000..9ec8199
--- /dev/null
+++ b/android-35/jdk/random/L64X1024MixRandom.java
@@ -0,0 +1,321 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>1088</sup>. Class {@link L64X1024MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L64X1024MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L64X1024MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L64X1024MixRandom}
+ * has 1088 bits of state plus one 64-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L64X1024MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L64X1024MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL64X1024MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L64X1024MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L64X1024MixRandom",
+ group = "LXM",
+ i = 1024, j = 1, k = 64,
+ equidistribution = 16
+)
+public final class L64X1024MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The split() operation uses the current generator to choose 18 new 64-bit
+ * long values that are then used to initialize the parameter `a`, the
+ * state variable `s`, and the array `x` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L64X1024MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate 18 new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /*
+ * The length of the array x.
+ */
+
+ private static final int N = 16;
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Multiplier used in the LCG portion of the algorithm.
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0xd1342543de82ef95
+ * are [0.958602, 0.937479, 0.870757, 0.822326, 0.820405, 0.813065, 0.760215].
+ */
+
+ private static final long M = 0xd1342543de82ef95L;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd.
+ */
+ private final long a;
+
+ /**
+ * The per-instance state: s for the LCG; the array x for the XBG;
+ * p is the rotating pointer into the array x.
+ * At least one of the 16 elements of the array x must be nonzero.
+ */
+ private long s;
+ private final long[] x;
+ private int p = N - 1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param a additive parameter for the LCG
+ * @param s initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ * @param x2 third word of the initial state for the XBG
+ * @param x3 fourth word of the initial state for the XBG
+ * @param x4 fifth word of the initial state for the XBG
+ * @param x5 sixth word of the initial state for the XBG
+ * @param x6 seventh word of the initial state for the XBG
+ * @param x7 eight word of the initial state for the XBG
+ * @param x8 ninth word of the initial state for the XBG
+ * @param x9 tenth word of the initial state for the XBG
+ * @param x10 eleventh word of the initial state for the XBG
+ * @param x11 twelfth word of the initial state for the XBG
+ * @param x12 thirteenth word of the initial state for the XBG
+ * @param x13 fourteenth word of the initial state for the XBG
+ * @param x14 fifteenth word of the initial state for the XBG
+ * @param x15 sixteenth word of the initial state for the XBG
+ */
+ public L64X1024MixRandom(long a, long s,
+ long x0, long x1, long x2, long x3,
+ long x4, long x5, long x6, long x7,
+ long x8, long x9, long x10, long x11,
+ long x12, long x13, long x14, long x15) {
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x = new long[N];
+ this.x[0] = x0;
+ this.x[1] = x1;
+ this.x[2] = x2;
+ this.x[3] = x3;
+ this.x[4] = x4;
+ this.x[5] = x5;
+ this.x[6] = x6;
+ this.x[7] = x7;
+ this.x[8] = x8;
+ this.x[9] = x9;
+ this.x[10] = x10;
+ this.x[11] = x11;
+ this.x[12] = x12;
+ this.x[13] = x13;
+ this.x[14] = x14;
+ this.x[15] = x15;
+ // If x0, x1, ..., x15 are all zero (very unlikely), we must choose nonzero values.
+ if ((x0 | x1 | x2 | x3 | x4 | x5 | x6 | x7 | x8 | x9 | x10 | x11 | x12 | x13 | x14 | x15) == 0) {
+ long v = s;
+ // At least fifteen of the sixteen values generated here will be nonzero.
+ for (int j = 0; j < N; j++) {
+ this.x[j] = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L64X1024MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L64X1024MixRandom} created with the same seed in the same
+ * program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X1024MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x[0]`,
+ // which will then be used to produce the first generated value.
+ // The other x values are filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X1024MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L64X1024MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X1024MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L64X1024MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X1024MixRandom(byte[] seed) {
+ // Convert the seed to 18 long values, of which the last 16 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 18, 16);
+ long a = data[0], s = data[1];
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x = new long[N];
+ for (int j = 0; j < N; j++) {
+ this.x[j] = data[2+j];
+ }
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for `a`.
+ return new L64X1024MixRandom(brine << 1, source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // First part of xoroshiro1024: fetch array data
+ final int q = p;
+ final long s0 = x[p = (p + 1) & (N - 1)];
+ long s15 = x[q];
+
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+
+ final long result = RandomSupport.mixLea64(s + s0);
+
+ // Update the LCG subgenerator
+ s = M * s + a; // LCG
+
+ // Second part of xoroshiro1024: update array data
+ s15 ^= s0;
+ x[q] = Long.rotateLeft(s0, 25) ^ s15 ^ (s15 << 27);
+ x[p] = Long.rotateLeft(s15, 36);
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L64X128MixRandom.java b/android-35/jdk/random/L64X128MixRandom.java
new file mode 100644
index 0000000..4188e85
--- /dev/null
+++ b/android-35/jdk/random/L64X128MixRandom.java
@@ -0,0 +1,254 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>192</sup>. Class {@link L64X128MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L64X128MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L64X128MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L64X128MixRandom}
+ * has 192 bits of state plus one 64-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L64X128MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L64X128MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL64X128MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L64X128MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L64X128MixRandom",
+ group = "LXM",
+ i = 128, j = 1, k = 64,
+ equidistribution = 2
+)
+public final class L64X128MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The split operation uses the current generator to choose four new 64-bit
+ * long values that are then used to initialize the parameter `a` and the
+ * state variables `s`, `x0`, and `x1` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L64X128MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate four new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Multiplier used in the LCG portion of the algorithm.
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0xd1342543de82ef95L
+ * are [0.958602, 0.937479, 0.870757, 0.822326, 0.820405, 0.813065, 0.760215].
+ */
+
+ private static final long M = 0xd1342543de82ef95L;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd.
+ */
+ private final long a;
+
+ /**
+ * The per-instance state: s for the LCG; x0 and x1 for the XBG.
+ * At least one of x0 and x1 must be nonzero.
+ */
+ private long s, x0, x1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param a additive parameter for the LCG
+ * @param s initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ */
+ public L64X128MixRandom(long a, long s, long x0, long x1) {
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ // If x0 and x1 are both zero, we must choose nonzero values.
+ if ((x0 | x1) == 0) {
+ long v = s;
+ // At least one of the two values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = RandomSupport.mixStafford13(v + RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L64X128MixRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X128MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // Then x1 is filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L64X128MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L64X128MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X128MixRandom(byte[] seed) {
+ // Convert the seed to 4 long values, of which the last 2 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 4, 2);
+ long a = data[0], s = data[1], x0 = data[2], x1 = data[3];
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for `a`.
+ return new L64X128MixRandom(brine << 1, source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = RandomSupport.mixLea64(s + x0);
+
+ // Update the LCG subgenerator
+ s = M * s + a;
+
+ // Update the XBG subgenerator
+ long q0 = x0, q1 = x1;
+ { // xoroshiro128v1_0
+ q1 ^= q0;
+ q0 = Long.rotateLeft(q0, 24);
+ q0 = q0 ^ q1 ^ (q1 << 16);
+ q1 = Long.rotateLeft(q1, 37);
+ }
+ x0 = q0; x1 = q1;
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L64X128StarStarRandom.java b/android-35/jdk/random/L64X128StarStarRandom.java
new file mode 100644
index 0000000..139b272
--- /dev/null
+++ b/android-35/jdk/random/L64X128StarStarRandom.java
@@ -0,0 +1,254 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>192</sup>. Class {@link L64X128StarStarRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L64X128StarStarRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L64X128StarStarRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L64X128StarStarRandom}
+ * has 192 bits of state plus one 64-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L64X128StarStarRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L64X128StarStarRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL64X128StarStarRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L64X128StarStarRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L64X128StarStarRandom",
+ group = "LXM",
+ i = 128, j = 1, k = 64,
+ equidistribution = 2
+)
+public final class L64X128StarStarRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The split operation uses the current generator to choose four new 64-bit
+ * long values that are then used to initialize the parameter `a` and the
+ * state variables `s`, `x0`, and `x1` for a newly constructed generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L64X128StarStarRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate four new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Multiplier used in the LCG portion of the algorithm.
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0xd1342543de82ef95
+ * are [0.958602, 0.937479, 0.870757, 0.822326, 0.820405, 0.813065, 0.760215].
+ */
+
+ private static final long M = 0xd1342543de82ef95L;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd.
+ */
+ private final long a;
+
+ /**
+ * The per-instance state: s for the LCG; x0 and x1 for the XBG.
+ * At least one of x0 and x1 must be nonzero.
+ */
+ private long s, x0, x1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param a additive parameter for the LCG
+ * @param s initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ */
+ public L64X128StarStarRandom(long a, long s, long x0, long x1) {
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ // If x0 and x1 are both zero, we must choose nonzero values.
+ if ((x0 | x1) == 0) {
+ long v = s;
+ // At least one of the two values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = RandomSupport.mixStafford13(v + RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128StarStarRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L64X128StarStarRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X128StarStarRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // Then x1 is filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128StarStarRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L64X128StarStarRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X128StarStarRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L64X128StarStarRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X128StarStarRandom(byte[] seed) {
+ // Convert the seed to 4 long values, of which the last 2 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 4, 2);
+ long a = data[0], s = data[1], x0 = data[2], x1 = data[3];
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for `a`.
+ return new L64X128StarStarRandom(brine << 1, source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = Long.rotateLeft((s + x0) * 5, 7) * 9; // "starstar" scrambler
+
+ // Update the LCG subgenerator
+ s = M * s + a;
+
+ // Update the XBG subgenerator
+ long q0 = x0, q1 = x1;
+ { // xoroshiro128v1_0
+ q1 ^= q0;
+ q0 = Long.rotateLeft(q0, 24);
+ q0 = q0 ^ q1 ^ (q1 << 16);
+ q1 = Long.rotateLeft(q1, 37);
+ }
+ x0 = q0; x1 = q1;
+
+ return result;
+ }
+
+}
diff --git a/android-35/jdk/random/L64X256MixRandom.java b/android-35/jdk/random/L64X256MixRandom.java
new file mode 100644
index 0000000..0c0cbb4
--- /dev/null
+++ b/android-35/jdk/random/L64X256MixRandom.java
@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.AbstractSplittableWithBrineGenerator;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "splittable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>320</sup>. Class {@link L64X256MixRandom} implements
+ * interfaces {@link RandomGenerator} and {@link SplittableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new split-off {@link L64X256MixRandom}
+ * objects or streams of such objects.
+ *
+ * <p>The {@link L64X256MixRandom} algorithm is a specific member of
+ * the LXM family of algorithms for pseudorandom number generators;
+ * for more information, see the documentation for package
+ * {@link jdk.random}. Each instance of {@link L64X256MixRandom}
+ * has 320 bits of state plus one 64-bit instance-specific parameter.
+ *
+ * <p>If two instances of {@link L64X256MixRandom} are created with
+ * the same seed within the same program execution, and the same
+ * sequence of method calls is made for each, they will generate and
+ * return identical sequences of values.
+ *
+ * <p>As with {@link java.util.SplittableRandom}, instances of
+ * {@link L64X256MixRandom} are <em>not</em> thread-safe. They are
+ * designed to be split, not shared, across threads (see the {@link #split}
+ * method). For example, a {@link java.util.concurrent.ForkJoinTask}
+ * fork/join-style computation using random numbers might include a
+ * construction of the form
+ * {@code new Subtask(someL64X256MixRandom.split()).fork()}.
+ *
+ * <p>This class provides additional methods for generating random
+ * streams, that employ the above techniques when used in
+ * {@code stream.parallel()} mode.
+ *
+ * <p>Instances of {@link L64X256MixRandom} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "L64X256MixRandom",
+ group = "LXM",
+ i = 256, j = 1, k = 64,
+ equidistribution = 4
+)
+public final class L64X256MixRandom extends AbstractSplittableWithBrineGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * The split operation uses the current generator to choose six new 64-bit
+ * long values that are then used to initialize the parameter `a` and the
+ * state variables `s`, `x0`, `x1`, `x2`, and `x3` for a newly constructed
+ * generator.
+ *
+ * With extremely high probability, no two generators so chosen
+ * will have the same `a` parameter, and testing has indicated
+ * that the values generated by two instances of {@link L64X256MixRandom}
+ * will be (approximately) independent if have different values for `a`.
+ *
+ * The default (no-argument) constructor, in essence, uses
+ * "defaultGen" to generate six new 64-bit values for the same
+ * purpose. Multiple generators created in this way will certainly
+ * differ in their `a` parameters. The defaultGen state must be accessed
+ * in a thread-safe manner, so we use an AtomicLong to represent
+ * this state. To bootstrap the defaultGen, we start off using a
+ * seed based on current time unless the
+ * java.util.secureRandomSeed property is set. This serves as a
+ * slimmed-down (and insecure) variant of SecureRandom that also
+ * avoids stalls that may occur when using /dev/random.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /*
+ * Multiplier used in the LCG portion of the algorithm.
+ * Chosen based on research by Sebastiano Vigna and Guy Steele (2019).
+ * The spectral scores for dimensions 2 through 8 for the multiplier 0xd1342543de82ef95
+ * are [0.958602, 0.937479, 0.870757, 0.822326, 0.820405, 0.813065, 0.760215].
+ */
+
+ private static final long M = 0xd1342543de82ef95L;
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The parameter that is used as an additive constant for the LCG.
+ * Must be odd.
+ */
+ private final long a;
+
+ /**
+ * The per-instance state: s for the LCG; x0, x1, x2, and x3 for the XBG.
+ * At least one of the four fields x0, x1, x2, and x3 must be nonzero.
+ */
+ private long s, x0, x1, x2, x3;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param a additive parameter for the LCG
+ * @param s initial state for the LCG
+ * @param x0 first word of the initial state for the XBG
+ * @param x1 second word of the initial state for the XBG
+ * @param x2 third word of the initial state for the XBG
+ * @param x3 fourth word of the initial state for the XBG
+ */
+ public L64X256MixRandom(long a, long s, long x0, long x1, long x2, long x3) {
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ // If x0, x1, x2, and x3 are all zero, we must choose nonzero values.
+ if ((x0 | x1 | x2 | x3) == 0) {
+ long v = s;
+ // At least three of the four values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x2 = RandomSupport.mixStafford13(v += RandomSupport.GOLDEN_RATIO_64);
+ this.x3 = RandomSupport.mixStafford13(v + RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link L64X256MixRandom} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link L64X256MixRandom} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X256MixRandom(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The seed is hashed by mixMurmur64 to produce the `a` parameter.
+ // The seed is hashed by mixStafford13 to produce the initial `x0`,
+ // which will then be used to produce the first generated value.
+ // The other x values are filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and mixStafford13 as the mixer.
+ this(RandomSupport.mixMurmur64(seed ^= RandomSupport.SILVER_RATIO_64),
+ 1,
+ RandomSupport.mixStafford13(seed),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X256MixRandom} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public L64X256MixRandom() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link L64X256MixRandom} using the specified array of
+ * initial seed bytes. Instances of {@link L64X256MixRandom} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public L64X256MixRandom(byte[] seed) {
+ // Convert the seed to 6 long values, of which the last 4 are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 6, 4);
+ long a = data[0], s = data[1], x0 = data[2], x1 = data[3], x2 = data[4], x3 = data[5];
+ // Force a to be odd.
+ this.a = a | 1;
+ this.s = s;
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ @Override
+ public SplittableGenerator split(SplittableGenerator source, long brine) {
+ // Pick a new instance "at random", but use the brine for `a`.
+ return new L64X256MixRandom(brine << 1, source.nextLong(),
+ source.nextLong(), source.nextLong(),
+ source.nextLong(), source.nextLong());
+ }
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = RandomSupport.mixLea64(s + x0);
+
+ // Update the LCG subgenerator
+ s = M * s + a;
+
+ // Update the XBG subgenerator
+ long q0 = x0, q1 = x1, q2 = x2, q3 = x3;
+ { // xoshiro256 1.0
+ long t = q1 << 17;
+ q2 ^= q0;
+ q3 ^= q1;
+ q1 ^= q2;
+ q0 ^= q3;
+ q2 ^= t;
+ q3 = Long.rotateLeft(q3, 45);
+ }
+ x0 = q0; x1 = q1; x2 = q2; x3 = q3;
+
+ return result;
+ }
+
+ }
diff --git a/android-35/jdk/random/Xoroshiro128PlusPlus.java b/android-35/jdk/random/Xoroshiro128PlusPlus.java
new file mode 100644
index 0000000..ba8daaf
--- /dev/null
+++ b/android-35/jdk/random/Xoroshiro128PlusPlus.java
@@ -0,0 +1,276 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import java.util.random.RandomGenerator.LeapableGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "jumpable and leapable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>128</sup>. Class {@link Xoroshiro128PlusPlus} implements
+ * interfaces {@link RandomGenerator} and {@link LeapableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, {@code float}, and {@code double}
+ * as well as creating new {@link Xoroshiro128PlusPlus} objects
+ * by "jumping" or "leaping".
+ * <p>
+ * The class {@link Xoroshiro128PlusPlus} uses the {@code xoroshiro128} algorithm
+ * (parameters 49, 21, 28) with the "++" scrambler that computes
+ * {@code Long.rotateLeft(s0 + s1, 17) + s0}.
+ * (See David Blackman and Sebastiano Vigna, "Scrambled Linear Pseudorandom
+ * Number Generators," ACM Transactions on Mathematical Software, 2021.)
+ * Its state consists of two {@code long} fields {@code x0} and {@code x1},
+ * which can take on any values provided that they are not both zero.
+ * The period of this generator is 2<sup>128</sup>-1.
+ * <p>
+ * The 64-bit values produced by the {@code nextLong()} method are equidistributed.
+ * To be precise, over the course of the cycle of length 2<sup>128</sup>-1,
+ * each nonzero {@code long} value is generated 2<sup>64</sup> times,
+ * but the value 0 is generated only 2<sup>64</sup>-1 times.
+ * The values produced by the {@code nextInt()}, {@code nextFloat()}, and {@code nextDouble()}
+ * methods are likewise equidistributed.
+ * <p>
+ * Instances {@link Xoroshiro128PlusPlus} are <em>not</em> thread-safe.
+ * They are designed to be used so that each thread as its own instance.
+ * The methods {@link #jump} and {@link #leap} and {@link #jumps} and {@link #leaps}
+ * can be used to construct new instances of {@link Xoroshiro128PlusPlus} that traverse
+ * other parts of the state cycle.
+ * <p>
+ * Instances of {@link Xoroshiro128PlusPlus} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "Xoroshiro128PlusPlus",
+ group = "Xoroshiro",
+ i = 128, j = 1, k = 0,
+ equidistribution = 1
+)
+public final class Xoroshiro128PlusPlus implements LeapableGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * This is an implementation of the xoroshiro128++ algorithm version 1.0,
+ * written in 2019 by David Blackman and Sebastiano Vigna ([email protected]).
+ *
+ * The jump operation moves the current generator forward by 2*64
+ * steps; this has the same effect as calling nextLong() 2**64
+ * times, but is much faster. Similarly, the leap operation moves
+ * the current generator forward by 2*96 steps; this has the same
+ * effect as calling nextLong() 2**96 times, but is much faster.
+ * The copy method may be used to make a copy of the current
+ * generator. Thus one may repeatedly and cumulatively copy and
+ * jump to produce a sequence of generators whose states are well
+ * spaced apart along the overall state cycle (indeed, the jumps()
+ * and leaps() methods each produce a stream of such generators).
+ * The generators can then be parceled out to other threads.
+ *
+ * File organization: First the non-public methods that constitute the
+ * main algorithm, then the public methods. Note that many methods are
+ * defined by classes {@link AbstractJumpableGenerator} and {@link AbstractGenerator}.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * Group name.
+ */
+ private static final String GROUP = "Xoroshiro";
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong defaultGen = new AtomicLong(RandomSupport.initialSeed());
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The per-instance state.
+ * At least one of the two fields x0 and x1 must be nonzero.
+ */
+ private long x0, x1;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param x0 first word of the initial state
+ * @param x1 second word of the initial state
+ */
+ public Xoroshiro128PlusPlus(long x0, long x1) {
+ this.x0 = x0;
+ this.x1 = x1;
+ // If x0 and x1 are both zero, we must choose nonzero values.
+ if ((x0 | x1) == 0) {
+ this.x0 = RandomSupport.GOLDEN_RATIO_64;
+ this.x1 = RandomSupport.SILVER_RATIO_64;
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link Xoroshiro128PlusPlus} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link Xoroshiro128PlusPlus} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public Xoroshiro128PlusPlus(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The x values are then filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and Stafford13 as the mixer.
+ this(RandomSupport.mixStafford13(seed ^= RandomSupport.SILVER_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link Xoroshiro128PlusPlus} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public Xoroshiro128PlusPlus() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(defaultGen.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link Xoroshiro128PlusPlus} using the specified array of
+ * initial seed bytes. Instances of {@link Xoroshiro128PlusPlus} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public Xoroshiro128PlusPlus(byte[] seed) {
+ // Convert the seed to 2 long values, which are not both zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 2, 2);
+ long x0 = data[0], x1 = data[1];
+ this.x0 = x0;
+ this.x1 = x1;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ public Xoroshiro128PlusPlus copy() {
+ return new Xoroshiro128PlusPlus(x0, x1);
+ }
+
+ /*
+ * The following two comments are quoted from http://prng.di.unimi.it/xoroshiro128plusplus.c
+ */
+
+ /*
+ * To the extent possible under law, the author has dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ * <p>
+ * See http://creativecommons.org/publicdomain/zero/1.0/.
+ */
+
+ /*
+ * This is xoroshiro128++ 1.0, one of our all-purpose, rock-solid,
+ * small-state generators. It is extremely (sub-ns) fast and it passes all
+ * tests we are aware of, but its state space is large enough only for
+ * mild parallelism.
+ * <p>
+ * For generating just floating-point numbers, xoroshiro128+ is even
+ * faster (but it has a very mild bias, see notes in the comments).
+ * <p>
+ * The state must be seeded so that it is not everywhere zero. If you have
+ * a 64-bit seed, we suggest to seed a splitmix64 generator and use its
+ * output to fill s.
+ */
+
+ @Override
+ public long nextLong() {
+ final long s0 = x0;
+ long s1 = x1;
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = Long.rotateLeft(s0 + s1, 17) + s0; // "plusplus" scrambler
+
+ s1 ^= s0;
+ x0 = Long.rotateLeft(s0, 49) ^ s1 ^ (s1 << 21); // a, b
+ x1 = Long.rotateLeft(s1, 28); // c
+
+ return result;
+ }
+
+ @Override
+ public double jumpDistance() {
+ return 0x1.0p64;
+ }
+
+ @Override
+ public double leapDistance() {
+ return 0x1.0p96;
+ }
+
+ private static final long[] JUMP_TABLE = { 0x2bd7a6a6e99c2ddcL, 0x0992ccaf6a6fca05L };
+
+ private static final long[] LEAP_TABLE = { 0x360fd5f2cf8d5d99L, 0x9c6e6877736c46e3L };
+
+ @Override
+ public void jump() {
+ jumpAlgorithm(JUMP_TABLE);
+ }
+
+ @Override
+ public void leap() {
+ jumpAlgorithm(LEAP_TABLE);
+ }
+
+ private void jumpAlgorithm(long[] table) {
+ long s0 = 0, s1 = 0;
+ for (int i = 0; i < table.length; i++) {
+ for (int b = 0; b < 64; b++) {
+ if ((table[i] & (1L << b)) != 0) {
+ s0 ^= x0;
+ s1 ^= x1;
+ }
+ nextLong();
+ }
+ }
+ x0 = s0;
+ x1 = s1;
+ }
+}
diff --git a/android-35/jdk/random/Xoshiro256PlusPlus.java b/android-35/jdk/random/Xoshiro256PlusPlus.java
new file mode 100644
index 0000000..5c9cc60
--- /dev/null
+++ b/android-35/jdk/random/Xoshiro256PlusPlus.java
@@ -0,0 +1,307 @@
+/*
+ * Copyright (c) 2021, 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
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package jdk.random;
+
+import java.util.concurrent.atomic.AtomicLong;
+import java.util.random.RandomGenerator;
+import java.util.random.RandomGenerator.LeapableGenerator;
+import jdk.internal.util.random.RandomSupport;
+import jdk.internal.util.random.RandomSupport.RandomGeneratorProperties;
+
+/**
+ * A "jumpable and leapable" pseudorandom number generator (PRNG) whose period
+ * is roughly 2<sup>256</sup>. Class {@link Xoshiro256PlusPlus} implements
+ * interfaces {@link RandomGenerator} and {@link LeapableGenerator},
+ * and therefore supports methods for producing pseudorandomly chosen
+ * values of type {@code int}, {@code long}, {@code float}, {@code double},
+ * and {@code boolean} (and for producing streams of pseudorandomly chosen
+ * numbers of type {@code int}, {@code long}, and {@code double}),
+ * as well as methods for creating new {@link Xoshiro256PlusPlus} objects
+ * by moving forward either a large distance (2<sup>128</sup>) or a very large
+ * distance (2<sup>192</sup>) around the state cycle.
+ * <p>
+ * Series of generated values pass the TestU01 BigCrush and PractRand test suites
+ * that measure independence and uniformity properties of random number generators.
+ * (Most recently validated with
+ * <a href="http://simul.iro.umontreal.ca/testu01/tu01.html">version 1.2.3 of TestU01</a>
+ * and <a href="http://pracrand.sourceforge.net">version 0.90 of PractRand</a>.
+ * Note that TestU01 BigCrush was used to test not only values produced by the {@code nextLong()}
+ * method but also the result of bit-reversing each value produced by {@code nextLong()}.)
+ * These tests validate only the methods for certain
+ * types and ranges, but similar properties are expected to hold, at
+ * least approximately, for others as well.
+ * <p>
+ * The class {@link Xoshiro256PlusPlus} uses the {@code xoshiro256} algorithm,
+ * version 1.0 (parameters 17, 45), with the "++" scrambler that computes
+ * {@code Long.rotateLeft(s0 + s3, 23) + s0}.
+ * (See David Blackman and Sebastiano Vigna, "Scrambled Linear Pseudorandom
+ * Number Generators," ACM Transactions on Mathematical Software, 2021.)
+ * Its state consists of four {@code long} fields {@code x0}, {@code x1}, {@code x2},
+ * and {@code x3}, which can take on any values provided that they are not all zero.
+ * The period of this generator is 2<sup>256</sup>-1.
+ * <p>
+ * The 64-bit values produced by the {@code nextLong()} method are equidistributed.
+ * To be precise, over the course of the cycle of length 2<sup>256</sup>-1,
+ * each nonzero {@code long} value is generated 2<sup>192</sup> times,
+ * but the value 0 is generated only 2<sup>192</sup>-1 times.
+ * The values produced by the {@code nextInt()}, {@code nextFloat()}, and {@code nextDouble()}
+ * methods are likewise equidistributed.
+ * Moreover, the 64-bit values produced by the {@code nextLong()} method are 3-equidistributed.
+ * <p>
+ * Instances {@link Xoshiro256PlusPlus} are <em>not</em> thread-safe.
+ * They are designed to be used so that each thread as its own instance.
+ * The methods {@link #jump} and {@link #leap} and {@link #jumps} and {@link #leaps}
+ * can be used to construct new instances of {@link Xoshiro256PlusPlus} that traverse
+ * other parts of the state cycle.
+ * <p>
+ * Instances of {@link Xoshiro256PlusPlus} are not cryptographically
+ * secure. Consider instead using {@link java.security.SecureRandom}
+ * 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}.
+ *
+ * @since 17
+ *
+ */
+@RandomGeneratorProperties(
+ name = "Xoshiro256PlusPlus",
+ group = "Xoshiro",
+ i = 256, j = 1, k = 0,
+ equidistribution = 3
+)
+public final class Xoshiro256PlusPlus implements LeapableGenerator {
+
+ /*
+ * Implementation Overview.
+ *
+ * This is an implementation of the xoshiro256++ algorithm version 1.0,
+ * written in 2019 by David Blackman and Sebastiano Vigna ([email protected]).
+ *
+ * The jump operation moves the current generator forward by 2*128
+ * steps; this has the same effect as calling nextLong() 2**128
+ * times, but is much faster. Similarly, the leap operation moves
+ * the current generator forward by 2*192 steps; this has the same
+ * effect as calling nextLong() 2**192 times, but is much faster.
+ * The copy method may be used to make a copy of the current
+ * generator. Thus one may repeatedly and cumulatively copy and
+ * jump to produce a sequence of generators whose states are well
+ * spaced apart along the overall state cycle (indeed, the jumps()
+ * and leaps() methods each produce a stream of such generators).
+ * The generators can then be parceled out to other threads.
+ *
+ * File organization: First static fields, then instance
+ * fields, then constructors, then instance methods.
+ */
+
+ /* ---------------- static fields ---------------- */
+
+ /**
+ * The seed generator for default constructors.
+ */
+ private static final AtomicLong DEFAULT_GEN = new AtomicLong(RandomSupport.initialSeed());
+
+ /* ---------------- instance fields ---------------- */
+
+ /**
+ * The per-instance state.
+ * At least one of the four fields x0, x1, x2, and x3 must be nonzero.
+ */
+ private long x0, x1, x2, x3;
+
+ /* ---------------- constructors ---------------- */
+
+ /**
+ * Basic constructor that initializes all fields from parameters.
+ * It then adjusts the field values if necessary to ensure that
+ * all constraints on the values of fields are met.
+ *
+ * @param x0 first word of the initial state
+ * @param x1 second word of the initial state
+ * @param x2 third word of the initial state
+ * @param x3 fourth word of the initial state
+ */
+ public Xoshiro256PlusPlus(long x0, long x1, long x2, long x3) {
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ // If x0, x1, x2, and x3 are all zero, we must choose nonzero values.
+ if ((x0 | x1 | x2 | x3) == 0) {
+ // At least three of the four values generated here will be nonzero.
+ this.x0 = RandomSupport.mixStafford13(x0 += RandomSupport.GOLDEN_RATIO_64);
+ this.x1 = (x0 += RandomSupport.GOLDEN_RATIO_64);
+ this.x2 = (x0 += RandomSupport.GOLDEN_RATIO_64);
+ this.x3 = (x0 += RandomSupport.GOLDEN_RATIO_64);
+ }
+ }
+
+ /**
+ * Creates a new instance of {@link Xoshiro256PlusPlus} using the
+ * specified {@code long} value as the initial seed. Instances of
+ * {@link Xoshiro256PlusPlus} created with the same seed in the same
+ * program generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public Xoshiro256PlusPlus(long seed) {
+ // Using a value with irregularly spaced 1-bits to xor the seed
+ // argument tends to improve "pedestrian" seeds such as 0 or
+ // other small integers. We may as well use SILVER_RATIO_64.
+ //
+ // The x values are then filled in as if by a SplitMix PRNG with
+ // GOLDEN_RATIO_64 as the gamma value and Stafford13 as the mixer.
+ this(RandomSupport.mixStafford13(seed ^= RandomSupport.SILVER_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed += RandomSupport.GOLDEN_RATIO_64),
+ RandomSupport.mixStafford13(seed + RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link Xoshiro256PlusPlus} that is likely to
+ * generate sequences of values that are statistically independent
+ * of those of any other instances in the current program execution,
+ * but may, and typically does, vary across program invocations.
+ */
+ public Xoshiro256PlusPlus() {
+ // Using GOLDEN_RATIO_64 here gives us a good Weyl sequence of values.
+ this(DEFAULT_GEN.getAndAdd(RandomSupport.GOLDEN_RATIO_64));
+ }
+
+ /**
+ * Creates a new instance of {@link Xoshiro256PlusPlus} using the specified array of
+ * initial seed bytes. Instances of {@link Xoshiro256PlusPlus} created with the same
+ * seed array in the same program execution generate identical sequences of values.
+ *
+ * @param seed the initial seed
+ */
+ public Xoshiro256PlusPlus(byte[] seed) {
+ // Convert the seed to 4 long values, which are not all zero.
+ long[] data = RandomSupport.convertSeedBytesToLongs(seed, 4, 4);
+ long x0 = data[0], x1 = data[1], x2 = data[2], x3 = data[3];
+ this.x0 = x0;
+ this.x1 = x1;
+ this.x2 = x2;
+ this.x3 = x3;
+ }
+
+ /* ---------------- public methods ---------------- */
+
+ public Xoshiro256PlusPlus copy() {
+ return new Xoshiro256PlusPlus(x0, x1, x2, x3);
+ }
+
+ /*
+ * The following two comments are quoted from http://prng.di.unimi.it/xoshiro256plusplus.c
+ */
+
+ /*
+ * To the extent possible under law, the author has dedicated all copyright
+ * and related and neighboring rights to this software to the public domain
+ * worldwide. This software is distributed without any warranty.
+ * <p>
+ * See http://creativecommons.org/publicdomain/zero/1.0/.
+ */
+
+ /*
+ * This is xoshiro256++ 1.0, one of our all-purpose, rock-solid generators.
+ * It has excellent (sub-ns) speed, a state (256 bits) that is large
+ * enough for any parallel application, and it passes all tests we are
+ * aware of.
+ *
+ * For generating just floating-point numbers, xoshiro256+ is even faster.
+ *
+ * The state must be seeded so that it is not everywhere zero. If you have
+ * a 64-bit seed, we suggest to seed a splitmix64 generator and use its
+ * output to fill s.
+ */
+
+ @Override
+ public long nextLong() {
+ // Compute the result based on current state information
+ // (this allows the computation to be overlapped with state update).
+ final long result = Long.rotateLeft(x0 + x3, 23) + x0; // "plusplus" scrambler
+
+ long q0 = x0, q1 = x1, q2 = x2, q3 = x3;
+ { // xoshiro256 1.0
+ long t = q1 << 17;
+ q2 ^= q0;
+ q3 ^= q1;
+ q1 ^= q2;
+ q0 ^= q3;
+ q2 ^= t;
+ q3 = Long.rotateLeft(q3, 45);
+ }
+ x0 = q0; x1 = q1; x2 = q2; x3 = q3;
+ return result;
+ }
+
+ @Override
+ public double jumpDistance() {
+ return 0x1.0p128;
+ }
+
+ @Override
+ public double leapDistance() {
+ return 0x1.0p192;
+ }
+
+ private static final long[] JUMP_TABLE = {
+ 0x180ec6d33cfd0abaL, 0xd5a61266f0c9392cL, 0xa9582618e03fc9aaL, 0x39abdc4529b1661cL };
+
+ private static final long[] LEAP_TABLE = {
+ 0x76e15d3efefdcbbfL, 0xc5004e441c522fb3L, 0x77710069854ee241L, 0x39109bb02acbe635L };
+
+ @Override
+ public void jump() {
+ jumpAlgorithm(JUMP_TABLE);
+ }
+
+ @Override
+ public void leap() {
+ jumpAlgorithm(LEAP_TABLE);
+ }
+
+ private void jumpAlgorithm(long[] table) {
+ long s0 = 0, s1 = 0, s2 = 0, s3 = 0;
+ for (int i = 0; i < table.length; i++) {
+ for (int b = 0; b < 64; b++) {
+ if ((table[i] & (1L << b)) != 0) {
+ s0 ^= x0;
+ s1 ^= x1;
+ s2 ^= x2;
+ s3 ^= x3;
+ }
+ nextLong();
+ }
+ }
+ x0 = s0;
+ x1 = s1;
+ x2 = s2;
+ x3 = s3;
+ }
+
+}
