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 */
package lab4;

import java.util.concurrent.Semaphore;
import java.util.logging.Level;
import java.util.logging.Logger;

/**
 *
 * @author k3liang
 */
public class Philosphers implements Runnable {
    private static final long startTime= System.currentTimeMillis();
    public static final int MAX_ITERATIONS=3;
    private State state;
    private int  philID;
    private static int nextID=1;
    public Semaphore semaphore;
    public static Semaphore semaphore2;

    public Philosphers Left;
    public Philosphers Right;

    public Philosphers()
    {
    philID=nextID++;
    semaphore= new Semaphore(0,true);
    semaphore2= new Semaphore(1,true);


    }

@Override
public void run() {
   System.out.println("STARTING #" + philID);
   for (int i = 0; i < MAX_ITERATIONS; i++) {
      state = State.THINKING;


      displayState();
      sleepAndDisplay();
       try {
                getFork();
            } catch (InterruptedException ex) {
                Logger.getLogger(Philosphers.class.getName()).log(Level.SEVERE, null, ex);
       }
   //   state = State.HUNGRY;
      sleepAndDisplay();
   //   state = State.EATING;
      sleepAndDisplay();

      try{
     putFork();
                  } catch (InterruptedException ex) {
                Logger.getLogger(Philosphers.class.getName()).log(Level.SEVERE, null, ex);
       }

   }
}

private void sleepAndDisplay() {
   try {
      Thread.sleep(0, (int) (1000000 * Math.random()));
   } catch (InterruptedException ex) {
   }
   displayState();
}

private void displayState() {
    long timeNow = System.currentTimeMillis() - startTime;
    System.out.println("Philosoper #" + philID + ": "
            + state + " time: " + timeNow + "ms");
  }



private void getFork() throws InterruptedException
{


state = State.HUNGRY;
while ( state == State.HUNGRY )
{
   semaphore.acquire();
   if ( state == State.HUNGRY && Left.state != State.EATING && Right.state != State.EATING )
            {
                  state = State.EATING;
                  semaphore2.release();
             }
                semaphore.release();
                semaphore2.acquire();
   }
}




private void putFork() throws InterruptedException
{
    semaphore.acquire();
state= State.THINKING;
if ( Left.state == State.HUNGRY)
        semaphore2.release();
if ( Right.state == State.HUNGRY)
       semaphore2.release();
    semaphore.release();


}



}