void MarkSweep::adjust_marks() {

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

      assert( _preserved_oop_stack.size() == _preserved_mark_stack.size(),
             "inconsistent preserved oop stacks");

  {- -------------------------------------------
  (1) まず _preserved_marks の中に入っている全て oop について, 
      PreservedMark::adjust_pointer() でポインタの修正を行う.
      ---------------------------------------- -}

      // adjust the oops we saved earlier
      for (size_t i = 0; i < _preserved_count; i++) {
        _preserved_marks[i].adjust_pointer();
      }

  {- -------------------------------------------
  (1) 次に, _preserved_oop_stack 内の全ての oop について, 
      MarkSweep::adjust_pointer() でポインタの修正処理を行う.
      ---------------------------------------- -}

      // deal with the overflow stack
      StackIterator<oop> iter(_preserved_oop_stack);
      while (!iter.is_empty()) {
        oop* p = iter.next_addr();
        adjust_pointer(p);
      }
    }