void BiasedLocking::restore_marks() {

  {- -------------------------------------------
  (1) UseBiasedLocking オプションが指定されていない場合は, 何もすることはないので, ここでリターン.
      ---------------------------------------- -}

      if (!UseBiasedLocking)
        return;

  {- -------------------------------------------
  (1) (assert)
      ---------------------------------------- -}

      assert(_preserved_oop_stack  != NULL, "double free");
      assert(_preserved_mark_stack != NULL, "double free");

  {- -------------------------------------------
  (1) _preserved_oop_stack 内の全ての要素について, 
      oopDesc::set_mark() を呼んで
      mark フィールドの値を GC 前の値に戻す.
      ---------------------------------------- -}

      int len = _preserved_oop_stack->length();
      for (int i = 0; i < len; i++) {
        Handle owner = _preserved_oop_stack->at(i);
        markOop mark = _preserved_mark_stack->at(i);
        owner->set_mark(mark);
      }

  {- -------------------------------------------
  (1) _preserved_oop_stack と _preserved_mark_stack 用のメモリを解放する.
      ---------------------------------------- -}

      delete _preserved_oop_stack;
      _preserved_oop_stack = NULL;
      delete _preserved_mark_stack;
      _preserved_mark_stack = NULL;
    }