VolatileVsSynchronized Caliper benchmark

gistfile1.java

package benchmark;

import com.google.caliper.runner.CaliperMain;

import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.atomic.AtomicLong;

public class VolatileVsSynchronized {
    public interface Common {
        public Integer get();
    }

    public static class VolatileWithSynchronized implements Common {
        private volatile Integer field;

        @Override
        public Integer get() {
            Integer f = field;
            if (f == null) {
                synchronized (this) {
                    field = 1;
                    return field;
                }
            }
            return f;
        }
    }

    public static class Synchronized implements Common {
        private Integer field;

        @Override
        public synchronized Integer get() {
            if (field == null) {
                field = 1;
            }
            return field;
        }
    }

    public static void main(String[] args) {
        CaliperMain.main(VolatileVsSynchronized.class, args);
    }

    public void timeSynchronized_001(int iterations) {
        doTime(new Synchronized(), iterations, 1);
    }

    public void timeSynchronized_004(int iterations) {
        doTime(new Synchronized(), iterations, 4);
    }

    public void timeSynchronized_016(int iterations) {
        doTime(new Synchronized(), iterations, 16);
    }

    public void timeSynchronized_064(int iterations) {
        doTime(new Synchronized(), iterations, 64);
    }

    public void timeSynchronized_128(int iterations) {
        doTime(new Synchronized(), iterations, 128);
    }

    public void timeVolatileWithSynchronized_001(int iterations) {
        doTime(new VolatileWithSynchronized(), iterations, 1);
    }

    public void timeVolatileWithSynchronized_004(int iterations) {
        doTime(new VolatileWithSynchronized(), iterations, 4);
    }

    public void timeVolatileWithSynchronized_016(int iterations) {
        doTime(new VolatileWithSynchronized(), iterations, 16);
    }

    public void timeVolatileWithSynchronized_064(int iterations) {
        doTime(new VolatileWithSynchronized(), iterations, 64);
    }

    public void timeVolatileWithSynchronized_128(int iterations) {
        doTime(new VolatileWithSynchronized(), iterations, 128);
    }

    private long doTime(final Common instance, final int iterations, int concurrency) {
        final AtomicLong result = new AtomicLong();
        List<Thread> threads = new ArrayList<Thread>();
        for (int threadIdx = 0; threadIdx < concurrency; threadIdx++) {
            Thread t = new Thread(new Runnable() {
                @Override
                public void run() {
                    long sum = 0;
                    for (int iter = 0; iter < iterations; iter++) {
                        sum += instance.get();
                    }
                    result.set(sum);
                }
            });
            t.start();
            threads.add(t);
        }
        for (Thread t: threads) {
            try {
                t.join();
            } catch (InterruptedException e) {
                throw new RuntimeException(e);
            }
        }
        return result.get();
    }
}