The Computer Language
Benchmarks Game

chameneos-redux Java #3 program

source code

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

   contributed by Kirill Ilyukhin
*/
import java.util.concurrent.CountDownLatch;
import java.util.concurrent.Exchanger;
import java.util.concurrent.atomic.AtomicInteger;

public class chameneosredux {

   static MeetingPlace meetingPlace;
   static CountDownLatch latch;
   static AtomicInteger meetingsLeft;

   public static void main(String[] args) throws InterruptedException {
      int N = 6_000_000;
      if (args.length > 0) {
         try {
            N = Integer.parseInt(args[0]);
         } catch (NumberFormatException ignore) {
         }
      }
      for (Color color1 : Color.colors) {
         for (Color color2 : Color.colors) {
            System.out.println(color1 + " + " + color2 + " -> " + Color.complement(color1, color2));
         }
      }
      System.out.println();
      run(N, Color.blue, Color.red, Color.yellow);
      run(N, Color.blue, Color.red, Color.yellow, Color.red, Color.yellow, Color.blue, Color.red, Color.yellow, Color.red, Color.blue);
   }

   private static void run(final int N, final Color... colors) throws InterruptedException {
      meetingPlace = new MeetingPlace();
      latch = new CountDownLatch(2*N);
      meetingsLeft = new AtomicInteger(2*N);
      Creature[] creatures = new Creature[colors.length];
      for (int i=0; i < colors.length; i++) {
         System.out.print(" " + colors[i]);
         creatures[i] = new Creature(colors[i]);
      }
      System.out.println();
      for (Creature creature : creatures) {
         creature.start();
      }
      latch.await();
      for (Creature creature : creatures) {
         creature.interrupt();
      }
      for (Creature creature : creatures) {
         creature.join();
      }
      int m = 0;
      for (Creature creature : creatures) {
         System.out.println("" + creature.meetings + spell(creature.meetingsWithSelf));
         m += creature.meetings;
      }
      System.out.println(spell(m));
      System.out.println();
   }

   private static final String[] DIGITS = {
         " zero",
         " one",
         " two",
         " three",
         " four",
         " five",
         " six",
         " seven",
         " eight",
         " nine"
   };
   static String spell(int number) {
      if (number == 0) {
         return DIGITS[0];
      }
      String s = "";
      while (number > 0) {
         s = DIGITS[number % 10] + s;
         number /= 10;
      }
      return s;
   }

   static class Creature extends Thread {
      private static int nameCounter;
      private Color color;
      private final int name;
      int meetings = 0;
      int meetingsWithSelf = 0;

      Creature(Color color) {
         this.name = ++nameCounter;
         this.color = color;
      }

      private Agent createAgent() {
         return new Agent(this);
      }

      @Override
      public void run() {
         while (true) {
            try {
               Agent agent = meetingPlace.enter(this.createAgent());
               if (agent == null) {
                  return;
               }
               if (agent.name == this.name) {
                  meetingsWithSelf++;
               }
               color = Color.complement(this.color, agent.color);
               meetings++;
            } catch (InterruptedException e) {
               break;
            }
         }
      }

   }

   static class MeetingPlace {
      private final Exchanger<Agent> room;

      MeetingPlace() {
         room = new Exchanger<>();
      }

      public Agent enter(Agent visitor) throws InterruptedException {
         if (meetingsLeft.get() < 0) {
            return null;
         }
         Agent agent = room.exchange(visitor);
         latch.countDown();
         if (meetingsLeft.decrementAndGet() < 0) {
            return null;
         }
         return agent;
      }

   }

   static class Agent {
      final int name;
      final Color color;

      Agent(Creature creature) {
         this.name = creature.name;
         this.color = creature.color;
      }
   }

   enum Color {
      blue,
      red,
      yellow;

      static final Color[] colors = {Color.blue, Color.red, Color.yellow};

      public static Color complement(final Color color1, final Color color2) {
         switch (color1) {
            case blue:
               switch (color2) {
                  case blue:      return blue;
                  case red:      return yellow;
                  case yellow:   return red;
               }
            case red:
               switch (color2) {
                  case blue:      return yellow;
                  case red:      return red;
                  case yellow:   return blue;
               }
            case yellow:
               switch (color2) {
                  case blue:      return red;
                  case red:      return blue;
                  case yellow:   return yellow;
               }
         }
         return null;
      }
   }

}
    

notes, command-line, and program output

NOTES:
64-bit Ubuntu quad core
java 9.0.1
Java(TM) SE Runtime Environment (build 9.0.1+11)
Java HotSpot(TM) 64-Bit Server VM (build 9.0.1+11, mixed mode)


Wed, 25 Oct 2017 21:28:01 GMT

MAKE:
mv chameneosredux.java-3.java chameneosredux.java
/opt/src/jdk-9.0.1/bin/javac -d .  chameneosredux.java

1.22s to complete and log all make actions

COMMAND LINE:
/opt/src/jdk-9.0.1/bin/java   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
4597350 zero
4047966 zero
3354684 zero
 one two zero zero zero zero zero zero

 blue red yellow red yellow blue red yellow red blue
1205911 zero
1128775 zero
1377877 zero
1199386 zero
1333386 zero
1084307 zero
1188180 zero
1219669 zero
1165732 zero
1096777 zero
 one two zero zero zero zero zero zero