NextEventLoopBenchmark.java

package benchmark;

import org.openjdk.jmh.annotations.GenerateMicroBenchmark;

import java.util.concurrent.atomic.AtomicInteger;

public class NextEventLoopBenchmark {

    @GenerateMicroBenchmark
    public void newNext8 () {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(8);
        bla.newNext10000();
    }

    @GenerateMicroBenchmark
    public void newNext9 () {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(9);
        bla.newNext10000();
    }

    @GenerateMicroBenchmark
    public void newNext16 () {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(16);
        bla.newNext10000();
    }

    @GenerateMicroBenchmark
    public void newNext19 () {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(19);
        bla.newNext10000();
    }

    @GenerateMicroBenchmark
    public void existingNext16() {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(16);
        bla.existingNext10000();
    }

    @GenerateMicroBenchmark
    public void existingNext19() {
        MultiThreadedEventBlabla bla = new MultiThreadedEventBlabla(19);
        bla.existingNext10000();
    }

    private static class MultiThreadedEventBlabla {
        private final AtomicInteger childIndex = new AtomicInteger();
        private final boolean poweroftwo;
        private final int divisor;

        public MultiThreadedEventBlabla(int childrenLength) {
            poweroftwo = (childrenLength & (childrenLength-1)) == 0;
            if (poweroftwo)
                divisor = childrenLength-1;
            else
                divisor = childrenLength;
        }

        public void existingNext10000() {
            int val = 0;

            for (int i=0; i < 10000; i++) {
                val = Math.abs(childIndex.getAndIncrement() % divisor);
            }

            bla(val);
        }

        public void newNext10000() {
            int val = 0;

            for (int i=0; i < 10000; i++) {
                if (poweroftwo) {
                    val = childIndex.getAndIncrement() & divisor;
                } else {
                    val = Math.abs(childIndex.getAndIncrement() % divisor);
                }
            }

            bla(val);
        }

        private void bla(int val) {
            if (val == -1)
                System.out.println(val);
        }
    }
}