OnJava8-Examples/concurrent/FixedDiningPhilosophers.java

// concurrent/FixedDiningPhilosophers.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://OnJava8.com for more book information.
// Dining philosophers without deadlock
// {java FixedDiningPhilosophers 5 5 timeout}
import java.util.concurrent.*;
import onjava.Nap;

public class FixedDiningPhilosophers {
  public static void
  main(String[] args) {
    int ponder = 5;
    if(args.length > 0)
      ponder = Integer.parseInt(args[0]);
    int size = 5;
    if(args.length > 1)
      size = Integer.parseInt(args[1]);
    ExecutorService es = Executors.newCachedThreadPool();
    Chopstick[] sticks = new Chopstick[size];
    for(int i = 0; i < size; i++)
      sticks[i] = new Chopstick();
    for(int i = 0; i < size; i++)
      if(i < (size-1))
        es.execute(new Philosopher(
          sticks[i], sticks[i+1], i, ponder));
      else
        es.execute(new Philosopher(
          sticks[0], sticks[i], i, ponder));
    if(args.length == 3 && args[2].equals("timeout"))
      new Nap(5000);
    else {
      System.out.println("Press 'Enter' to quit");
      try {
        System.in.read();
      } catch(Exception e) {
        throw new RuntimeException(e);
      }
    }
    es.shutdownNow();
  }
}
/* Output: (First and Last 10 Lines)
Philosopher 1 thinking
Philosopher 4 thinking
Philosopher 2 thinking
Philosopher 0 thinking
Philosopher 3 thinking
Philosopher 1 grabbing right
Philosopher 2 grabbing right
Philosopher 4 grabbing right
Philosopher 4 grabbing left
Philosopher 4 eating
...________...________...________...________...
Philosopher 1 thinking
Philosopher 0 grabbing left
Philosopher 0 eating
Philosopher 2 eating
Philosopher 1 grabbing right
Philosopher 3 exiting via interrupt
Philosopher 1 exiting via interrupt
Philosopher 2 exiting via interrupt
Philosopher 0 exiting via interrupt
Philosopher 4 exiting via interrupt
*/