inline size_t ThreadLocalAllocBuffer::compute_size(size_t obj_size) {

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

      const size_t aligned_obj_size = align_object_size(obj_size);

  {- -------------------------------------------
  (1) 次に確保する TLAB の大きさを計算する (以下の new_tlab_size).
      ---------------------------------------- -}

      // Compute the size for the new TLAB.
      // The "last" tlab may be smaller to reduce fragmentation.
      // unsafe_max_tlab_alloc is just a hint.
      const size_t available_size = Universe::heap()->unsafe_max_tlab_alloc(myThread()) /
                                                      HeapWordSize;
      size_t new_tlab_size = MIN2(available_size, desired_size() + aligned_obj_size);

  {- -------------------------------------------
  (1) もし (計算結果が, オブジェクトと dummy 用の int 配列を入れるのに必要な量より小さければ? #TODO)
      確保は失敗として, ここでリターン (0 をリターンする).
      ---------------------------------------- -}

      // Make sure there's enough room for object and filler int[].
      const size_t obj_plus_filler_size = aligned_obj_size + alignment_reserve();
      if (new_tlab_size < obj_plus_filler_size) {

    {- -------------------------------------------
  (1.1) (トレース出力)
        ---------------------------------------- -}

        // If there isn't enough room for the allocation, return failure.
        if (PrintTLAB && Verbose) {
          gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
                        " returns failure",
                        obj_size);
        }
        return 0;
      }

  {- -------------------------------------------
  (1) (トレース出力)
      ---------------------------------------- -}

      if (PrintTLAB && Verbose) {
        gclog_or_tty->print_cr("ThreadLocalAllocBuffer::compute_size(" SIZE_FORMAT ")"
                      " returns " SIZE_FORMAT,
                      obj_size, new_tlab_size);
      }

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

      return new_tlab_size;
    }