import java.util.LinkedList;

public class BlockingQueue<T> {

    private LinkedList<T> lista = new LinkedList<T>();
    private int maxNumber;

    public BlockingQueue()
    {
        maxNumber = -1;
    }

    public BlockingQueue(int max)
    {
        maxNumber = max;
    }

    public synchronized void offer(T e) throws InterruptedException
    {
        while(size() > maxNumber && maxNumber != -1)
        {
            wait();
        }

        lista.add(e);
        System.out.println("Meteu " + e.toString());
        notifyAll();
    }

    public synchronized T poll() throws InterruptedException
    {
        while(size() == 0)
        {
            wait();
        }

        T e = lista.pop();
        System.out.println("Retirou " + e.toString());
        notifyAll();
        return e;
    }

    public synchronized int size()
    {
        return lista.size();
    }

    public synchronized void clear()
    {
        lista.clear();
        notifyAll();
    }

    public static void main(String[] args) {
        Teste[] vetor = new Teste[10];
        BlockingQueue<Integer> lista =
                new BlockingQueue<Integer>(3);

        for(int i = 0; i< 10; i++)
        {
            vetor[i] = new Teste(lista, i%2==0);
            vetor[i].start();
        }


    }



}

class Teste extends Thread
{
    private BlockingQueue<Integer> lista;
    private boolean consumer;

    public Teste(BlockingQueue<Integer> b, boolean c)
    {
        lista = b;
        consumer = c;
    }

    public void run()
    {
        for(int i = 0; i < 10; i++)
        {
            if(consumer)
            {
                try {
                    Integer e = lista.poll();

                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }
            else
            {
                Integer inte = (int)(Math.random()*100);
                try {
                    lista.offer(inte);
                } catch (InterruptedException e) {
                    // TODO Auto-generated catch block
                    e.printStackTrace();
                }
            }

            try {
                sleep((int)(Math.random() * 1000));
            } catch (InterruptedException e) {
                // TODO Auto-generated catch block
                e.printStackTrace();
            }
        }
    }
}