Famous Pi Bench with Kontraktor 2.0

KontrActorPi.java

public class KontrActorPi {

    public static class PiActor extends Actor<PiActor> {
        public void $calculatePiFor(int start, int nrOfElements, Adder adder) {
            double acc = 0.0;
            for (int i = start * nrOfElements; i <= ((start + 1) * nrOfElements - 1); i++) {
                acc += 4.0 * (1 - (i % 2) * 2) / (2 * i + 1);
            }
            adder.$add(acc);
        }
    }

    public static class Adder extends Actor<Adder> {
        double pi = 0;
        public void $add(double d) {
            pi += d;
        }
        public void $printPi() {
            System.out.println("PI: "+pi);
        }
    }

    // blocking utility method
    static long calcPi(final int numMessages, int step, final int numActors) throws InterruptedException {
        long tim = System.currentTimeMillis();
        CountDownLatch latch = new CountDownLatch(1);
        Adder adder = Actors.AsActor(Adder.class,70000);

        Hoarde<PiActor> hoarde = new Hoarde<>(numActors, PiActor.class);
        for ( int i = 0; i < numMessages; i+=numActors) {
            int finalI = i;
            hoarde.each( (pia,index) -> pia.$calculatePiFor(finalI + index, step, adder) );
        }
        // trigger latch once all actors have finished
        Actors.yield( hoarde.map( (pia,i) -> pia.$sync() ) ).then( (r,e) -> latch.countDown() );
        latch.await();
        long duration = System.currentTimeMillis() - tim;
        adder.$printPi();

        // clean up
        hoarde.each( (pia) -> pia.$stop() );
        adder.$stop();

        System.out.println("TIM ("+numActors+")"+duration);
        return duration;
    }

}

full file is in my fork of Jason Kochs fork of my benchmarks :-)
https://github.com/RuedigerMoeller/examples/blob/master/executors/src/main/java/KontrActorPi.java