package concorrencia;

import java.awt.*;
import javax.swing.*;

public class WritersHP {
   boolean packFrame = true;

   static int readCount, writeCount, TAcount;
   static Semaforo MutexR, MutexW;
   static Semaforo WSema, RSema, QueueR;
   static Semaforo TAsema;

   static Reader[] vetReader = new Reader[7];
   static Writer[] vetWriter = new Writer[3];
   static boolean stopFlag = false;
   static boolean pauseFlag = false;

   //Construct the application

  public WritersHP() {
      Frame1 frame = new Frame1("WritersHP and Writers - Writers Have Priority");
      frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
      frame.setPreferredSize(new Dimension(800, 600));      
      //Validate frames that have preset sizes
      //Pack frames that have useful preferred size info, e.g. from their layout
      if (packFrame)
         frame.pack();
      else
         frame.validate();         
         
      //Center the window
      Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
      Dimension frameSize = frame.getSize();
      if (frameSize.height > screenSize.height)
         frameSize.height = screenSize.height;
      if (frameSize.width > screenSize.width)
         frameSize.width = screenSize.width;
      frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);        
      frame.setVisible(true);

      MutexR = new Semaforo(1);
      MutexW = new Semaforo(1);
      WSema = new Semaforo(1);
      RSema = new Semaforo(1);
      QueueR = new Semaforo(1);
      TAsema = new Semaforo(1);

      readCount = 0;
      writeCount = 0;
      TAcount = 0;

   }


   public static void startProcess(){
   //comeca o processamento. Foi criada uma classe aninhada para poder
   //liberar a classe chamadora deste método. Caso contrário a classe Frame1,
   //que é quem chama este método, fica presa nesse processamento e não
   //executa as chamadas feitas para a alteração dos campos de texto e de cor.

      Thread processo;

      Runnable r = new Runnable() {
      public void run() {
         double d;
         long a, b=0;
         int i;
         int rCount = 1;
         int wCount = 1;

           Frame1.limpaCampos();
           while (! stopFlag){
               //escolho um aleatório para definir que reader ou writer vai ser criado
               //Defini que tem que ser diferente do anterior pra evitar duas chamadas
               //consecutivas para o mesmo elemento, o que algumas vezes causava erro de estado
               //da thread, já que ela era criada mas não começava no mesmo momento,
               //causando uma dupla chamada ao start()
               do{
                  d = Math.random() * 10;

                  a = Math.round(d);
                  if (a == 10)
                     a = 9;

               }while (a == b);
               b = a;

               if (a < 7){
                  if (vetReader[(int)a] != null){
                     if (! vetReader[(int)a].isAlive()){
                        vetReader[(int)a] = new Reader(MutexR, MutexW, WSema, RSema, QueueR, TAsema, (int)a, rCount);
                        vetReader[(int)a].start();
                        rCount++;
                     }
                  }
                  else{
                     vetReader[(int)a] = new Reader(MutexR, MutexW, WSema, RSema, QueueR, TAsema, (int)a, rCount);
                     vetReader[(int)a].start();
                     rCount++;
                  }
               }
               else{
                  if (vetWriter[((int)a) - 7] != null){
                     if (! vetWriter[((int)a) - 7].isAlive()){
                        vetWriter[((int)a) - 7] = new Writer(MutexR, MutexW, WSema, RSema, QueueR, TAsema, ((int)a) - 7, wCount);
                        vetWriter[((int)a) - 7].start();
                        wCount++;
                     }
                  }
                  else{
                     vetWriter[((int)a) - 7] = new Writer(MutexR, MutexW, WSema, RSema, QueueR, TAsema, ((int)a) - 7, wCount);
                     vetWriter[((int)a) - 7].start();
                     wCount++;
                  }
               }
               try {
                  do{
                     Thread.sleep(500);
                  }while (pauseFlag);
               } catch (InterruptedException e) {}

            }

       }
     };

     //inicia o processo de criação de elementos
     stopFlag = false;
     processo = new Thread(r);
     processo.start();
   }

   public static void stopProcess(){
   //para a execucao geral através da parada da criação de novos readers e writers.
      stopFlag = true;
   }

   public static void setPauseProcess(boolean status){
   //pausa a execucao geral para que possamos ter uma "foto" do processamento em um dado momento.
      pauseFlag = status;
   }

   public static boolean getPauseFlag(){
      return pauseFlag;
   }

   public static void incWriteCount(){
      writeCount++;
   }

   public static void decWriteCount(){
      writeCount--;
   }

   public static int getWriteCount(){
      return writeCount;
   }

   public static void incReadCount(){
      readCount++;
   }

   public static void decReadCount(){
      readCount--;
   }

   public static int getReadCount(){
      return readCount;
   }

   public static void incTACount(){
      TAcount++;
   }

   public static void decTACount(){
      TAcount--;
   }

   public static int getTACount(){
      return TAcount;
   }


   //Main method
  public static void main(String[] args) {
      try  {
         UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
      }
      catch(Exception e) {
      }

      new WritersHP();
   }


}