Por Lucas Fernandes da Costa  2016.1

package trab1;


import java.util.concurrent.ExecutorService;

import java.util.concurrent.Executors;

import java.util.concurrent.ScheduledExecutorService;

import java.util.concurrent.TimeUnit;


public class Main {

	public static void main(String[] args) throws InterruptedException {

		
   
   ScheduledExecutorService ste = Executors.newScheduledThreadPool(1);
		
   ExecutorService te = Executors.newFixedThreadPool(4);

		
   
   Buffer buffer = new Buffer();


		
   
   for (int i = 1; i <= 120; i++) {
			
      
      ste.scheduleAtFixedRate(new Escritor(buffer), 0, 1,
TimeUnit.MILLISECONDS);
			
      
      te.execute(new Leitor(buffer));
		
   }
	
}
}

=======================================================

package trab1;


public class Escritor implements Runnable {
    
    
     private Buffer buffer;
    
     private static int valor = 0;
    
    
     public Escritor(Buffer buffer){
        
        this.buffer = buffer;
    }
    
    
     @Override
    
     public void run() {
         
         buffer.escrever(valor++);
    
     }
}

========================================================

package trab1;


public class Leitor implements Runnable {
    
    public Buffer buffer;
    
    
    public Leitor(Buffer buffer){
        
      this.buffer = buffer;
    }
    
   
    
      @Override
    
      public void run() {
        
         buffer.ler();
    
     }
}

=========================================================

package trab1;



public class Buffer {

	int valor;
	
    boolean ocupado = false;

	
    public synchronized void escrever(int valor) {
		
      while (ocupado) {
			
        try {
				
              wait();
			
        } catch (InterruptedException ex) {
				
        ex.printStackTrace();
			
      }

		
    }

		
    ocupado = true;
		
    this.valor = valor;
		
    System.out.println("Escreveu " + valor);

		
    notifyAll();
	
    }

	
    public synchronized int ler() {
		
       while (!ocupado) {
			
         try {
				
                wait();
			
         } catch (InterruptedException ex) {
				
                ex.printStackTrace();
			
         }
		
    }

		
    ocupado = false;
		
    System.out.println("Leu: " + this.valor);
		
		
    notify();
		
    return valor;
	
}
}

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