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aherbert pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/commons-rng.git
The following commit(s) were added to refs/heads/master by this push:
new 7f95834 Add option to combine generator output with ThreadLocalRandom.
7f95834 is described below
commit 7f95834e3c45fd7a3e16db3bfb46a401551ac728
Author: aherbert <[email protected]>
AuthorDate: Tue Jun 4 15:39:21 2019 +0100
Add option to combine generator output with ThreadLocalRandom.
---
.../commons/rng/examples/stress/RNGUtils.java | 29 +++++++++++++++++++++-
.../rng/examples/stress/StressTestCommand.java | 22 +++++++++++++---
2 files changed, 46 insertions(+), 5 deletions(-)
diff --git
a/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/RNGUtils.java
b/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/RNGUtils.java
index a7f77d5..ab1ee17 100644
---
a/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/RNGUtils.java
+++
b/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/RNGUtils.java
@@ -19,6 +19,8 @@ package org.apache.commons.rng.examples.stress;
import org.apache.commons.rng.UniformRandomProvider;
import org.apache.commons.rng.core.source32.IntProvider;
+import java.util.concurrent.ThreadLocalRandom;
+
/**
* Utility methods for a {@link UniformRandomProvider}.
*/
@@ -89,7 +91,7 @@ final class RNGUtils {
* Note: This generator will be slow.
*
* @param rng The random generator.
- * @return the hash code combined random generator.
+ * @return the combined random generator.
* @see System#identityHashCode(Object)
*/
static UniformRandomProvider createHashCodeIntProvider(final
UniformRandomProvider rng) {
@@ -107,6 +109,31 @@ final class RNGUtils {
}
/**
+ * Wrap the random generator with an {@link IntProvider} that will combine
the bits
+ * using a {@code xor} operation with the output from {@link
ThreadLocalRandom}.
+ *
+ * <pre>{@code
+ * ThreadLocalRandom.current().nextInt() ^ rng.nextInt()
+ * }</pre>
+ *
+ * @param rng The random generator.
+ * @return the combined random generator.
+ */
+ static UniformRandomProvider createThreadLocalRandomIntProvider(final
UniformRandomProvider rng) {
+ return new IntProvider() {
+ @Override
+ public int next() {
+ return ThreadLocalRandom.current().nextInt() ^ rng.nextInt();
+ }
+
+ @Override
+ public String toString() {
+ return "ThreadLocalRandom ^ " + rng.toString();
+ }
+ };
+ }
+
+ /**
* Parses the argument into an object suitable for the RandomSource
constructor. Supports:
*
* <ul>
diff --git
a/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/StressTestCommand.java
b/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/StressTestCommand.java
index a34721e..7a6b20e 100644
---
a/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/StressTestCommand.java
+++
b/commons-rng-examples/examples-stress/src/main/java/org/apache/commons/rng/examples/stress/StressTestCommand.java
@@ -139,6 +139,15 @@ class StressTestCommand implements Callable<Void> {
"System.identityHashCode(new Object()) ^
rng.nextInt()."})
private boolean xorHashCode;
+ /**
+ * Flag to indicate the output should be combined with output from
ThreadLocalRandom.
+ *
+ * @see System#identityHashCode(Object)
+ */
+ @Option(names = {"--local-random"},
+ description = {"Combine the bits with ThreadLocalRandom (default:
${DEFAULT-VALUE})."})
+ private boolean xorLocalRandom;
+
/** The flag to indicate a dry run. */
@Option(names = {"--dry-run"},
description = "Perform a dry run where the generators and output
files are created " +
@@ -402,14 +411,19 @@ class StressTestCommand implements Callable<Void> {
}
// Create the generator
UniformRandomProvider rng = testData.createRNG();
- if (byteOrder.equals(ByteOrder.LITTLE_ENDIAN)) {
- rng = RNGUtils.createReverseBytesIntProvider(rng);
+ // Combined generators must be created first
+ if (xorHashCode) {
+ rng = RNGUtils.createHashCodeIntProvider(rng);
+ }
+ if (xorLocalRandom) {
+ rng = RNGUtils.createThreadLocalRandomIntProvider(rng);
}
if (reverseBits) {
rng = RNGUtils.createReverseBitsIntProvider(rng);
}
- if (xorHashCode) {
- rng = RNGUtils.createHashCodeIntProvider(rng);
+ // Manipulation of the bytes for the platform is done on the
entire generator
+ if (byteOrder.equals(ByteOrder.LITTLE_ENDIAN)) {
+ rng = RNGUtils.createReverseBytesIntProvider(rng);
}
// Run the test
final Runnable r = new StressTestTask(testData.getRandomSource(),
rng, output, command,
