/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You under the Apache License, Version 2.0
* (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package org.apache.commons.math3.random;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.Callable;
import java.util.concurrent.ExecutionException;
import java.util.concurrent.ExecutorService;
import java.util.concurrent.Executors;
import java.util.concurrent.Future;
import org.junit.Assert;
import org.junit.Test;
public class SynchronizedRandomGeneratorTest {
private final int numberOfThreads = 5;
private final int numberOfGenerators = 5;
private final int numberOfSamples = 100000;
@Test
public void testAdapter() {
final int seed = 12345;
final RandomGenerator orig = new MersenneTwister(seed);
final RandomGenerator wrap
= new SynchronizedRandomGenerator(new MersenneTwister(seed));
final int bSize = 67;
final byte[] bOrig = new byte[bSize];
final byte[] bWrap = new byte[bSize];
for (int i = 0; i < 100; i++) {
orig.nextBytes(bOrig);
wrap.nextBytes(bWrap);
for (int k = 0; k < bSize; k++) {
Assert.assertEquals(bOrig[k], bWrap[k]);
}
Assert.assertEquals(orig.nextInt(), wrap.nextInt());
final int range = (i + 1) * 89;
Assert.assertEquals(orig.nextInt(range), wrap.nextInt(range));
Assert.assertEquals(orig.nextLong(), wrap.nextLong());
Assert.assertEquals(orig.nextBoolean(), wrap.nextBoolean());
Assert.assertEquals(orig.nextFloat(), wrap.nextFloat(), 0);
Assert.assertEquals(orig.nextDouble(), wrap.nextDouble(), 0);
Assert.assertEquals(orig.nextGaussian(), wrap.nextGaussian(), 0);
}
}
@Test
public void testMath899Sync() throws Throwable {
try {
// Running the test several times in order to decrease the
// probability that a non-thread-safe code did not trigger
// a concurrency problem.
for (int i = 0; i < 10; i++) {
doTestMath899(true, numberOfThreads, numberOfGenerators, numberOfSamples);
}
} catch (InterruptedException e) {
Assert.fail(e.getMessage());
} catch (ExecutionException e) {
throw e.getCause();
}
}
/**
* @param sync Whether to use a synchronizing wrapper.
*/
private double[] doTestMath899(final boolean sync,
final int numThreads,
final int numGenerators,
final int numSamples)
throws InterruptedException,
ExecutionException {
final RandomGenerator rng = new MersenneTwister();
final RandomGenerator wrapper = sync ? new SynchronizedRandomGenerator(rng) : rng;
final List<Callable<Double>> tasks = new ArrayList<Callable<Double>>();
for (int i = 0; i < numGenerators; i++) {
tasks.add(new Callable<Double>() {
public Double call() {
Double lastValue = 0d;
for (int j = 0; j < numSamples; j++) {
lastValue = wrapper.nextGaussian();
}
return lastValue;
}
});
}
final ExecutorService exec = Executors.newFixedThreadPool(numThreads);
final List<Future<Double>> results = exec.invokeAll(tasks);
final double[] values = new double[numGenerators];
for (int i = 0; i < numGenerators; i++) {
values[i] = results.get(i).get();
}
return values;
}
}