void DefNewGeneration::FastEvacuateFollowersClosure::do_void() {

  {- -------------------------------------------
  (1) 参照を再帰的に辿って処理を行う (参照関係を全て辿り終わったら終了).
      ---------------------------------------- -}

      do {
        _gch->oop_since_save_marks_iterate(_level, _scan_cur_or_nonheap,
                                           _scan_older);
      } while (!_gch->no_allocs_since_save_marks(_level));

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

      guarantee(_gen->promo_failure_scan_is_complete(), "Failed to finish scan");
    }