/* Free the current process's resources. */
void
process_exit (int status)
{
  struct thread *cur = thread_current ();
  uint32_t *pd;

  // update child status in parent_child_list
  update_status(thread_current ()->parent_pid , thread_current ()->tid , -1 , status);
  thread_current ()->exit_status = status ;

  // close all files
  process_close_all();

  // termination print
  printf ("%s: exit(%d)\n", thread_current()->name, status);

  /* Destroy the current process's page directory and switch back
     to the kernel-only page directory. */
  pd = cur->pagedir;
  if (pd != NULL)
    {
      /* Correct ordering here is crucial.  We must set
         cur->pagedir to NULL before switching page directories,
         so that a timer interrupt can't switch back to the
         process page directory.  We must activate the base page
         directory before destroying the process's page
         directory, or our active page directory will be one
         that's been freed (and cleared). */
      cur->pagedir = NULL;
      pagedir_activate (NULL);
      pagedir_destroy (pd);
    }
}



void process_close (int fd)
{
  if (get_elem(fd) != NULL){
    // get file
    struct file * fil = get_elem(fd);
    // close file
    file_close(fil);
    // remove file descriptor from decriptor list
    remove_elem(fd);
  }
}

void process_close_all()
{
  // get descriptor list of thread
  struct list *fd_table = &thread_current()->description_table;
  struct list_elem *e = list_begin (fd_table);

  // close all open files
  while (e != list_end (fd_table)){
      struct file_descriptor * tmp = list_entry (e, struct file_descriptor , desc_element);
      e = list_next (e);
      process_close(tmp->file_number);
  }
  // close excutable
  file_close (thread_current()->exe);
}