TestCaseRunner.java

package serializers;

import java.util.Arrays;

public final class TestCaseRunner<J>
{
    static double measurementVals[] = new double[1000*1000]; 
    // because full gc is triggered by main loop, this should move to oldgen 
    private final Transformer<J,Object> transformer;
    private final Serializer<Object> serializer;
    private final J value;

    public TestCaseRunner(Transformer<J,Object> transformer, Serializer<Object> serializer, J value)
    {
            this.transformer = transformer;
            this.serializer = serializer;
            this.value = value;
    }

    public double run(TestCase tc, int iterations) throws Exception
    {
            return tc.run(transformer, serializer, value, iterations);
    }

    public double runWithTimeMeasurement(int timeMillis, TestCase tc, int iterations) throws Exception
    {
        // ruediger: 
        // 1. made this also time based (like warmup). 
        //    fast serializers get more exposure to hotspot and the slow ones will
        //    finish below 30 minute runtime :-).
        //    this is reasonable as the faster a serializer is, the more significant
        //    some few nanos become. A slow serializer being > 10seconds will not be biased
        //    by having some fewer loops.
        // 2. taking the minimum time makes results very erratic. You get very different results
        //    with each run. Especially effects of bad allocation is hidden this way, as you only
        //    capture the "good" runs.
        //    therefore i switch to average measurement (and increase warmup time to avoid measurement of
        //    unjitted runs, see Params).
        //    We can do this when running each serializer isolated in an own VM.
        long start = System.currentTimeMillis();
        
        double sumTime = 0;
        int count = 0;
        System.err.println("test-time "+timeMillis+" iteration "+iterations);
        while ( System.currentTimeMillis()-start < timeMillis ) 
        {
            double time = tc.run(transformer, serializer, value, iterations);
            sumTime += time;
            measurementVals[count] = time;
            count++;
        }
        double avg = sumTime / count;
        Arrays.sort(measurementVals,0,count);
        System.err.println("-----------------------------------------------------------------------------");
        System.err.println(serializer.getName());
        System.err.println("min:" + measurementVals[0]);
        System.err.println("1/4:"+measurementVals[count/4]);
        System.err.println("1/2:"+measurementVals[count/2]);
        System.err.println("3/4:"+measurementVals[count/4*3]);
        System.err.println("max:"+measurementVals[count-1]);
        System.err.println("average:"+ avg +"ms deviation:"+(avg-measurementVals[count/2])+"ms");
        System.err.println("-----------------------------------------------------------------------------");
        return avg;
    }
}