performance measurements

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

 N  CPU secs Elapsed secs Memory KB Code B ≈ CPU Load
60,0000.740.322481429  47% 50% 48% 87%
600,0004.371.5131,5041429  62% 70% 78% 82%
6,000,00038.7813.3132,7441429  77% 81% 72% 65%

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 "1.8.0"
Java(TM) SE Runtime Environment (build 1.8.0-b132)
Java HotSpot(TM) Server VM (build 25.0-b70, mixed mode)

 chameneos-redux Java #2 program source code

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

   contributed by Michael Barker
   based on a contribution by Luzius Meisser
*/

/**
 * This implementation uses standard Java threading (native threads).
 * 
 * This implementation simply adds the new functionality to the orginal 
 * implementation by Luzius Meisser from old chameneos shootout.  The interesting
 * part of this implementation, is that while a creature is waiting it does not
 * block its thread, rather it spins in a loop using a Thread.yield().
 */
public class chameneosredux {

    enum Colour {
        blue,
        red,
        yellow
    }
        
    private static Colour doCompliment(Colour c1, 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 class MeetingPlace {
        
        private int meetingsLeft;

        public MeetingPlace(int meetings) {
            this.meetingsLeft = meetings;
        }
        
        private Colour firstColour = null;
        private int firstId = 0;
        Future<Pair> current;
        
        public Pair meet(int id, Colour c) throws Exception {
            Future<Pair> newPair;
            synchronized (this) {
                if (meetingsLeft == 0) {
                    throw new Exception("Finished");
                } else {
                    if (firstColour == null) {
                        firstColour = c;
                        firstId = id;
                        current = new Future<Pair>();
                    } else {
                        Colour newColour = doCompliment(c, firstColour);
                        current.setItem(new Pair(id == firstId, newColour));
                        firstColour = null;
                        meetingsLeft--;
                    }
                    newPair = current;
                }
            }
            return newPair.getItem();
            
        }
    }
        
    public static class Future<T> {

        private volatile T t;

        public T getItem() {
            while (t == null) {
                Thread.yield();
            }
            return t;
        }

        // no synchronization necessary as assignment is atomic
        public void setItem(T t) {
            this.t = t;
        }
    }    
    
    static class Creature implements Runnable {

        private final MeetingPlace place;
        private int count = 0;
        private int sameCount = 0;
        private Colour colour;
        private int id;

        public Creature(MeetingPlace place, Colour colour) {
            this.place = place;
            this.id = System.identityHashCode(this);
            this.colour = colour;
        }
        
        public void run() {
            try {
                
                while (true) {
                    Pair p = place.meet(id, colour);
                    colour = p.colour;
                    if (p.sameId) {
                        sameCount++;
                    }
                    count++;
                }
                
            } catch (Exception e) {}
        }
        
        public int getCount() {
            return count;
        }
        
        public String toString() {
            return String.valueOf(count) + getNumber(sameCount);
        }
    }    
    
    private static void run(int n, Colour...colours) {
        MeetingPlace place = new MeetingPlace(n);
        Creature[] creatures = new Creature[colours.length];
        for (int i = 0; i < colours.length; i++) {
            System.out.print(" " + colours[i]);
            creatures[i] = new Creature(place, colours[i]);
        }
        System.out.println();
        Thread[] ts = new Thread[colours.length];
        for (int i = 0; i < colours.length; i++) {
            ts[i] = new Thread(creatures[i]);
            ts[i].start();
        }
        
        for (Thread t : ts) {
            try {
                t.join();
            } catch (InterruptedException e) {
            }
        }
        
        int total = 0;
        for (Creature creature : creatures) {
            System.out.println(creature);
            total += creature.getCount();
        }
        System.out.println(getNumber(total));
        System.out.println();
    }
    
    public static void main(String[] args) {
        
        int n = 600;
        try {
            n = Integer.parseInt(args[0]);
        } catch (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);
    }    

    public static class Pair {
        public final boolean sameId;
        public final Colour colour;

        public Pair(boolean sameId, Colour c) {
            this.sameId = sameId;
            this.colour = c;
        }
    }
    
    private static final String[] NUMBERS = {
        "zero", "one", "two", "three", "four", "five", 
        "six", "seven", "eight", "nine"
    };
    
    private static String getNumber(int n) {
        StringBuilder sb = new StringBuilder();
        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(Colour c1, Colour c2) {
        System.out.println(c1 + " + " + c2 + " -> " + doCompliment(c1, c2));
    }
    
    
}

 make, command-line, and program output logs

Wed, 19 Mar 2014 06:31:34 GMT

MAKE:
mv chameneosredux.java-2.java chameneosredux.java
/usr/local/src/jdk1.8.0/bin/javac chameneosredux.java
0.80s to complete and log all make actions

COMMAND LINE:
/usr/local/src/jdk1.8.0/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
4747870 zero
2641455 zero
4610675 zero
 one two zero zero zero zero zero zero

 blue red yellow red yellow blue red yellow red blue
1217566 zero
1226370 zero
1175087 zero
1211223 zero
1197377 zero
1212087 zero
1200571 zero
1200683 zero
1176924 zero
1182112 zero
 one two zero zero zero zero zero zero

Revised BSD license

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