// ********** ObjectPoolDemo.java **********
class ObjectPool {
  public static final int MAX_OBJ = 100000;
  private Object array[] = new Object[MAX_OBJ];
  private int num_elements;
  public ObjectPool() {
    for (int i=0; i<MAX_OBJ; i++)
       array[i] = new Integer(i);
    num_elements = MAX_OBJ; 
  }
  public Object acquire() {
    if (num_elements == 0)
      return null;
    else
      return array[--num_elements];
  }
  public void release(Object obj) {
    array[num_elements++] = obj;
  }
}
public class ObjectPoolDemo {
  public static void main(String args[]) {
    long t1 = System.currentTimeMillis();
    ObjectPool pool = new ObjectPool();
    for (int i=0; i<ObjectPool.MAX_OBJ; i++) {
      Object obj = pool.acquire();
      pool.release(obj);
    }
    long t2 = System.currentTimeMillis();
    System.out.print((t2-t1)+" ");
    System.out.flush();
  }
}