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commit 43047b4e017c82f37321c08c7ace34be584e623f
Author: aherbert <aherb...@apache.org>
AuthorDate: Mon Oct 7 15:21:31 2019 +0100
RNG-122: Use XoRoShiRo1024PlusPlus as the default source of randomness.
---
.../org/apache/commons/rng/simple/internal/SeedFactory.java | 12 ++++++------
src/changes/changes.xml | 3 +++
2 files changed, 9 insertions(+), 6 deletions(-)
diff --git
a/commons-rng-simple/src/main/java/org/apache/commons/rng/simple/internal/SeedFactory.java
b/commons-rng-simple/src/main/java/org/apache/commons/rng/simple/internal/SeedFactory.java
index 4b336ea..c444074 100644
---
a/commons-rng-simple/src/main/java/org/apache/commons/rng/simple/internal/SeedFactory.java
+++
b/commons-rng-simple/src/main/java/org/apache/commons/rng/simple/internal/SeedFactory.java
@@ -23,7 +23,7 @@ import org.apache.commons.rng.core.util.NumberFactory;
import org.apache.commons.rng.UniformRandomProvider;
import org.apache.commons.rng.core.source64.RandomLongSource;
import org.apache.commons.rng.core.source64.SplitMix64;
-import org.apache.commons.rng.core.source64.XorShift1024StarPhi;
+import org.apache.commons.rng.core.source64.XoRoShiRo1024PlusPlus;
/**
* Utilities related to seeding.
@@ -45,8 +45,8 @@ import
org.apache.commons.rng.core.source64.XorShift1024StarPhi;
* @since 1.0
*/
public final class SeedFactory {
- /** Size of the state array of "XorShift1024StarPhi". */
- private static final int XOR_SHIFT_1024_STATE_SIZE = 16;
+ /** Size of the state array of "XoRoShiRo1024PlusPlus". */
+ private static final int XO_RO_SHI_RO_1024_STATE_SIZE = 16;
/** Size of block to fill in an {@code int[]} seed per synchronized
operation. */
private static final int INT_ARRAY_BLOCK_SIZE = 8;
/** Size of block to fill in a {@code long[]} seed per synchronized
operation. */
@@ -68,10 +68,10 @@ public final class SeedFactory {
// Use a secure RNG so that different instances (e.g. in multiple JVM
// instances started in rapid succession) will have different seeds.
final SecureRandom seedGen = new SecureRandom();
- final byte[] bytes = new byte[8 * XOR_SHIFT_1024_STATE_SIZE];
+ final byte[] bytes = new byte[8 * XO_RO_SHI_RO_1024_STATE_SIZE];
seedGen.nextBytes(bytes);
final long[] seed = NumberFactory.makeLongArray(bytes);
- // The XorShift1024StarPhi generator cannot recover from an all zero
seed and
+ // The XoRoShiRo1024PlusPlus generator cannot recover from an all zero
seed and
// will produce low quality initial output if initialised with some
zeros.
// Ensure it is non zero at all array positions using a SplitMix64
// generator (this is insensitive to a zero seed so can use the first
seed value).
@@ -80,7 +80,7 @@ public final class SeedFactory {
seed[i] = ensureNonZero(rng, seed[i]);
}
- SEED_GENERATOR = new XorShift1024StarPhi(seed);
+ SEED_GENERATOR = new XoRoShiRo1024PlusPlus(seed);
}
/**
diff --git a/src/changes/changes.xml b/src/changes/changes.xml
index ae40c29..d45e789 100644
--- a/src/changes/changes.xml
+++ b/src/changes/changes.xml
@@ -75,6 +75,9 @@ re-run tests that fail, and pass the build if they succeed
within the allotted number of reruns (the test will be marked
as 'flaky' in the report).
">
+ <action dev="aherbert" type="update" issue="RNG-122">
+ "SeedFactory": Use XoRoShiRo1024PlusPlus as the default source of
randomness.
+ </action>
<action dev="aherbert" type="update" issue="RNG-121">
"ChengBetaSampler": Algorithms for different distribution parameters
have
been delegated to specialised classes.
