SortedTest.java

package org.openjdk.jmh.samples;

import org.openjdk.jmh.annotations.Benchmark;
import org.openjdk.jmh.annotations.Scope;
import org.openjdk.jmh.annotations.Setup;
import org.openjdk.jmh.annotations.State;
import org.openjdk.jmh.runner.Runner;
import org.openjdk.jmh.runner.options.Options;
import org.openjdk.jmh.runner.options.OptionsBuilder;

import java.util.ArrayList;
import java.util.List;
import java.util.Random;

@State(Scope.Benchmark)
public class SortedTest {
    private static final int NO_OF_ITEMS = 5_000_000;

    private List<Integer> arrayListValues = new ArrayList<>(NO_OF_ITEMS);
    private Integer[] boxedValues = new Integer[NO_OF_ITEMS];
    private int[] primitiveValues = new int[NO_OF_ITEMS];

    private int[] unsortedOrder = new int[NO_OF_ITEMS];
    private int[] sortedOrder = new int[NO_OF_ITEMS];

    private Random r;


    @Setup
    public void setUp() {
        r = new Random();
        for (int i = 0; i < NO_OF_ITEMS; i++) {
            unsortedOrder[i] = i;
            sortedOrder[i] = i;

            int value = r.nextInt();
            arrayListValues.add(value);
            primitiveValues[i] = value;
            boxedValues[i] = value;

        }
        shuffleArray(unsortedOrder);

    }

    @Benchmark
    public int testSortedPrimitive() {
        int res = 0;
        for (int i : sortedOrder) {
            res += primitiveValues[i];
        }
        return res;
    }

    @Benchmark
    public int testSortedBoxed() {
        int res = 0;
        for (int i : sortedOrder) {
            res += boxedValues[i];
        }
        return res;
    }

    @Benchmark
    public int testSortedArrayList() {
        int res = 0;
        for (int i : sortedOrder) {
            res += arrayListValues.get(i);
        }
        return res;
    }

    @Benchmark
    public int testUnsortedPrimitive() {
        int res = 0;
        for (int i : unsortedOrder) {
            res += primitiveValues[i];
        }
        return res;
    }

    @Benchmark
    public int testUnsortedBoxed() {
        int res = 0;
        for (int i : unsortedOrder) {
            res += boxedValues[i];
        }
        return res;
    }

    @Benchmark
    public int testUnsortedArrayList() {
        int res = 0;
        for (int i : unsortedOrder) {
            res += arrayListValues.get(i);
        }
        return res;
    }

    public static void main(String[] args) throws Throwable {
        Options opt = new OptionsBuilder()
                .include(SortedTest.class.getSimpleName())
                .warmupIterations(10)
                .measurementIterations(20)
                .threads(1)
                .forks(2)
                .build();

        new Runner(opt).run();
    }

    static void shuffleArray(int[] ar)
    {
        Random rnd = new Random();
        for (int i = ar.length - 1; i > 0; i--)
        {
            int index = rnd.nextInt(i + 1);
            // Simple swap
            int a = ar[index];
            ar[index] = ar[i];
            ar[i] = a;
        }
    }
}

Benchmark                                    Mode  Samples    Score  Score error  Units
o.o.j.s.SortedTest.testSortedArrayList      thrpt       40  105.613        5.343  ops/s
o.o.j.s.SortedTest.testSortedBoxed          thrpt       40  107.609        4.459  ops/s
o.o.j.s.SortedTest.testSortedPrimitive      thrpt       40  358.130       21.637  ops/s
o.o.j.s.SortedTest.testUnsortedArrayList    thrpt       40    9.875        0.203  ops/s
o.o.j.s.SortedTest.testUnsortedBoxed        thrpt       40   10.107        0.287  ops/s
o.o.j.s.SortedTest.testUnsortedPrimitive    thrpt       40   22.477        0.505  ops/s