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 performance measurements

Each table row shows performance measurements for this Java 7 program with a particular command-line input value N.

 N  CPU secs Elapsed secs Memory KB Code B ≈ CPU Load
60,0000.250.262401770  0% 0% 4% 96%
600,0000.660.6716,4201770  0% 0% 3% 98%
6,000,0003.503.5018,0521770  0% 1% 1% 100%

Read the ↓ make, command line, and program output logs to see how this program was run.

Read chameneos-redux benchmark to see what this program should do.

 notes

java version "1.7.0_11"
Java(TM) SE Runtime Environment (build 1.7.0_11-b21)
Java HotSpot(TM) Server VM (build 23.6-b04, mixed mode)

 chameneos-redux Java 7 program source code

/* The Computer Language Benchmarks Game
   http://benchmarksgame.alioth.debian.org/

   contributed by Michael Barker
*/


import java.util.concurrent.ArrayBlockingQueue;
import java.util.concurrent.BlockingQueue;
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.atomic.AtomicInteger;
import java.util.concurrent.atomic.AtomicReference;


/**
 * This implementation uses the java.util.concurrent.atomic library
 * i.e. (compare and set) to avoid locking.  Real threads are used, but
 * are set up as a thread pool and meeting requests are pushed onto a
 * queue that feeds the thread pool.
 */
public final class chameneosredux {

    enum Colour {
        blue,
        red,
        yellow
    }

    private static Colour doCompliment(final Colour c1, final Colour c2) {
        switch (c1) {
        case blue:
            switch (c2) {
            case blue:
                return Colour.blue;
            case red:
                return Colour.yellow;
            case yellow:
                return Colour.red;
            }
        case red:
            switch (c2) {
            case blue:
                return Colour.yellow;
            case red:
                return Colour.red;
            case yellow:
                return Colour.blue;
            }
        case yellow:
            switch (c2) {
            case blue:
                return Colour.red;
            case red:
                return Colour.blue;
            case yellow:
                return Colour.yellow;
            }
        }

        throw new RuntimeException("Error");
    }

    static final class MeetingPlace {

        private final AtomicInteger meetingsLeft;
        private final AtomicReference<Creature> creatureRef = new AtomicReference<Creature>();

        public MeetingPlace(final int meetings) {
            meetingsLeft = new AtomicInteger(meetings);
        }

        public void meet(final Creature incoming) {
            Colour newColour = null;
            Creature first = null;
            Creature next = null;
            do {
                first = creatureRef.get();
                next = incoming;
                if (first != null) {
                    newColour = doCompliment(incoming.colour, first.colour);
                    next = null;
                }
            } while (!creatureRef.compareAndSet(first, next));

            if (first != null) {
                final int meetings = meetingsLeft.decrementAndGet();
                if (meetings >= 0) {
                    first.setColour(incoming.id, newColour);
                    incoming.setColour(first.id, newColour);
                } else {
                    first.complete();
                    incoming.complete();
                }
            }
        }
    }

    static final class Dispatcher implements Runnable {
        private final BlockingQueue<Creature> q;

        public Dispatcher(final BlockingQueue<Creature> q) {
            this.q = q;
        }

        public void run() {
            try {
                while (true) {
                    q.take().run();
                }
            } catch (final InterruptedException e) {
            }
        }
    }

    static final class Creature {

        private final int id;
        private final MeetingPlace place;
        private final BlockingQueue<Creature> q;
        private final CountDownLatch latch;
        private int count = 0;
        private int sameCount = 0;
        private Colour colour;

        public Creature(final MeetingPlace place, final Colour colour,
                        final BlockingQueue<Creature> q, final CountDownLatch latch) {
            this.id = System.identityHashCode(this);
            this.place = place;
            this.latch = latch;
            this.colour = colour;
            this.q = q;
        }

        public void complete() {
            latch.countDown();
        }

        public void setColour(final int id, final Colour newColour) {
            this.colour = newColour;
            count++;
            sameCount += 1 ^ Integer.signum(abs(this.id - id));
            q.add(this);
        }

        private int abs(final int x) {
            final int y = x >> 31;
            return (x ^ y) - y;
        }

        public void run() {
            place.meet(this);
        }

        public int getCount() {
            return count;
        }

        @Override
        public String toString() {
            return String.valueOf(count) + getNumber(sameCount);
        }
    }

    private static void run(final int n, final Colour...colours) {
        final int len = colours.length;
        final MeetingPlace place = new MeetingPlace(n);
        final Creature[] creatures = new Creature[len];
        final BlockingQueue<Creature> q = new ArrayBlockingQueue<Creature>(len);
        final CountDownLatch latch = new CountDownLatch(len - 1);

        for (int i = 0; i < len; i++) {
            System.out.print(" " + colours[i]);
            creatures[i] = new Creature(place, colours[i], q, latch);
        }

        System.out.println();
        final Thread[] ts = new Thread[len];
        for (int i = 0, h = ts.length; i < h; i++) {
            ts[i] = new Thread(new Dispatcher(q));
            ts[i].setDaemon(true);
            ts[i].start();
        }

        for (final Creature creature : creatures) {
            q.add(creature);
        }

        try {
            latch.await();
            for (final Thread t : ts) {
                t.interrupt();
            }
            for (final Thread t : ts) {
                t.join();
            }
        } catch (final InterruptedException e1) {
            System.err.println("Existing with error: " + e1);
        }

        int total = 0;
        for (final Creature creature : creatures) {
            System.out.println(creature);
            total += creature.getCount();
        }
        System.out.println(getNumber(total));
        System.out.println();
    }

    public static void main(final String[] args){
        chameneosredux.program_main(args,true);
    }

    public static void program_main(final String[] args, final boolean isWarm) {

        int n = 600;
        try {
            n = Integer.parseInt(args[0]);
        } catch (final Exception e) {
        }

        printColours();
        System.out.println();
        run(n, Colour.blue, Colour.red, Colour.yellow);
        run(n, Colour.blue, Colour.red, Colour.yellow, Colour.red, Colour.yellow,
               Colour.blue, Colour.red, Colour.yellow, Colour.red, Colour.blue);
    }

    private static final String[] NUMBERS = {
        "zero", "one", "two", "three", "four", "five",
        "six", "seven", "eight", "nine"
    };

    private static String getNumber(final int n) {
        final StringBuilder sb = new StringBuilder();
        final String nStr = String.valueOf(n);
        for (int i = 0; i < nStr.length(); i++) {
            sb.append(" ");
            sb.append(NUMBERS[Character.getNumericValue(nStr.charAt(i))]);
        }

        return sb.toString();
    }

    private static void printColours() {
        printColours(Colour.blue, Colour.blue);
        printColours(Colour.blue, Colour.red);
        printColours(Colour.blue, Colour.yellow);
        printColours(Colour.red, Colour.blue);
        printColours(Colour.red, Colour.red);
        printColours(Colour.red, Colour.yellow);
        printColours(Colour.yellow, Colour.blue);
        printColours(Colour.yellow, Colour.red);
        printColours(Colour.yellow, Colour.yellow);
    }

    private static void printColours(final Colour c1, final Colour c2) {
        System.out.println(c1 + " + " + c2 + " -> " + doCompliment(c1, c2));
    }


}

 make, command-line, and program output logs

Mon, 21 Jan 2013 06:28:00 GMT

MAKE:
mv chameneosredux.java chameneosredux.java
mv: `chameneosredux.java' and `chameneosredux.java' are the same file
make: [chameneosredux.java_run] Error 1 (ignored)
/usr/local/src/jdk1.7.0_11/bin/javac chameneosredux.java
0.57s to complete and log all make actions

COMMAND LINE:
/usr/local/src/jdk1.7.0_11/bin/java  -server -XX:+TieredCompilation -XX:+AggressiveOpts chameneosredux 6000000

PROGRAM OUTPUT:
blue + blue -> blue
blue + red -> yellow
blue + yellow -> red
red + blue -> yellow
red + red -> red
red + yellow -> blue
yellow + blue -> red
yellow + red -> blue
yellow + yellow -> yellow

 blue red yellow
3828572 zero
4098745 zero
4072683 zero
 one two zero zero zero zero zero zero

 blue red yellow red yellow blue red yellow red blue
1042379 zero
1461783 zero
795563 zero
1336868 zero
1195922 zero
1532580 zero
1113862 zero
1258869 zero
1257390 zero
1004784 zero
 one two zero zero zero zero zero zero

Revised BSD license

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