bool ParallelCompactData::initialize(MemRegion covered_region)
{

  {- -------------------------------------------
  (1) (変数宣言など)
      ---------------------------------------- -}

      _region_start = covered_region.start();
      const size_t region_size = covered_region.word_size();
      DEBUG_ONLY(_region_end = _region_start + region_size;)

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

      assert(region_align_down(_region_start) == _region_start,
             "region start not aligned");
      assert((region_size & RegionSizeOffsetMask) == 0,
             "region size not a multiple of RegionSize");

  {- -------------------------------------------
  (1) ParallelCompactData::initialize_region_data() を呼んで, 
      ParallelCompactData::
      ---------------------------------------- -}

      bool result = initialize_region_data(region_size);

  {- -------------------------------------------
  (1) 結果をリターン
      ---------------------------------------- -}

      return result;
    }