Traffic Light Problems (Readers and Writers)

Question

I am trying to implement the problem of readers and writers in Java, and for this I am basing myself on the method used by Tanenbaum in the book Operating Systems. With only one writer thread and one reader the program works well, the problem is that when I create more than one reader thread the program goes into a kind of infinite loop and stops printing on the screen. Could you tell me where the problem is?

public class Principal {

  public static void main(String[] args) {
    Semaphore mutex = new Semaphore(1);
    Semaphore db = new Semaphore(1);
    int rc = 0;

    Escritores e1 = new Escritores(db, mutex);
    Leitores l1 = new Leitores(db, mutex, rc);
    Leitores l2 = new Leitores(db, mutex, rc);

    e1.start();
    l1.start();
    l2.start();
  }

}

public class Escritores extends Thread {
  Semaphore db;
  Semaphore mutex;
  int rc;

  public Escritores(Semaphore db, Semaphore mutex){
    this.db = db;
    this.mutex = mutex;
  }

  public void run(){
    while(true){
        try {
            Thread.sleep(this.aleatoriar(0, 100));
            this.db.acquire();
            System.out.println("Escreveu!");
            this.db.release();
        } catch (InterruptedException ex) {
            Logger.getLogger(Escritores.class.getName()).log(Level.SEVERE, null, ex);
        }

    }
  }

  public int aleatoriar(int minimo, int maximo) {
    Calendar lCDateTime = Calendar.getInstance();
    return (int)(lCDateTime.getTimeInMillis() % (maximo - minimo + 1) + minimo);
    }
}

public class Leitores extends Thread {
  Semaphore db;
  Semaphore mutex;
  int rc;


  public Leitores(Semaphore db, Semaphore mutex, int rc){
    this.db = db;
    this.mutex = mutex;
    this.rc = rc;
  }

  public void run(){
    while(true){
        try {
            Thread.sleep(this.aleatoriar(0, 100));
            this.mutex.acquire();
            this.rc = this.rc + 1;
            if(this.rc == 1){
                this.db.acquire();
            }
            this.mutex.release();
            System.out.println("Leu");
            this.mutex.acquire();
            this.rc = this.rc - 1;
            if(this.rc == 0){
                this.db.release();
            }
            this.mutex.release();
        } catch (InterruptedException ex) {
            Logger.getLogger(Leitores.class.getName()).log(Level.SEVERE, null, ex);
        }
    }
  }

  public int aleatoriar(int minimo, int maximo) {
    Calendar lCDateTime = Calendar.getInstance();
    return (int)(lCDateTime.getTimeInMillis() % (maximo - minimo + 1) + minimo);
  }
}