jmhtest

MyBenchmark.java

package org.sample;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.BenchmarkMode;
import org.openjdk.jmh.annotations.Mode;
import org.openjdk.jmh.annotations.OutputTimeUnit;
import org.openjdk.jmh.infra.Blackhole;

import java.util.concurrent.TimeUnit;
import java.util.Arrays;
import java.util.Random;


@State(Scope.Benchmark)
public class MyBenchmark {

    
    double[] values;


    @Setup
    public void setup()
    {
        Random r = new Random();
        values = new double[1000000];
        for (int i =0; i < values.length;i++) {
            values[i] = r.nextDouble();
        }
    }
    /*
    
    @Benchmark
    @BenchmarkMode(Mode.AverageTime)
    @OutputTimeUnit(TimeUnit.MILLISECONDS)
    public double scalar() {        
        return Arrays.stream(values).reduce(0,(acc,x) -> Math.sin(x));   
    } */

    @Benchmark
    @BenchmarkMode(Mode.AverageTime)
    @OutputTimeUnit(TimeUnit.MILLISECONDS)
    public double parallel() {        
        return Arrays.stream(values).parallel().reduce(0,(acc,x) -> x*x);   
    }

}