constantPoolOop constantPoolKlass::allocate(int length, bool is_conc_safe, TRAPS) {

  {- -------------------------------------------
  (1) CollectedHeap::permanent_obj_allocate() により Perm 内に領域を確保する (#TODO).
      ---------------------------------------- -}

      int size = constantPoolOopDesc::object_size(length);
      KlassHandle klass (THREAD, as_klassOop());
      assert(klass()->is_oop(), "Can't be null, else handlizing of c below won't work");
      constantPoolHandle pool;
      {
        constantPoolOop c =
          (constantPoolOop)CollectedHeap::permanent_obj_allocate(klass, size, CHECK_NULL);
        assert(c->klass_or_null() != NULL, "Handlizing below won't work");
        pool = constantPoolHandle(THREAD, c);
      }

  {- -------------------------------------------
  (1) その後, 作成した constantPoolOop の各フィールドを初期化.
      ---------------------------------------- -}

      pool->set_length(length);
      pool->set_tags(NULL);
      pool->set_cache(NULL);
      pool->set_operands(NULL);
      pool->set_pool_holder(NULL);
      pool->set_flags(0);
      // only set to non-zero if constant pool is merged by RedefineClasses
      pool->set_orig_length(0);
      // if constant pool may change during RedefineClasses, it is created
      // unsafe for GC concurrent processing.
      pool->set_is_conc_safe(is_conc_safe);
      // all fields are initialized; needed for GC

      // Note: because we may be in this "conc_unsafe" state when allocating
      // t_oop below, which may in turn cause a GC, it is imperative that our
      // size be correct, consistent and henceforth stable, at this stage.
      assert(pool->is_oop() && pool->is_parsable(), "Else size() below is unreliable");
      assert(size == pool->size(), "size() is wrong");

      // initialize tag array
      typeArrayOop t_oop = oopFactory::new_permanent_byteArray(length, CHECK_NULL);
      typeArrayHandle tags (THREAD, t_oop);
      for (int index = 0; index < length; index++) {
        tags()->byte_at_put(index, JVM_CONSTANT_Invalid);
      }
      pool->set_tags(tags());

      // Check that our size was stable at its old value.
      assert(size == pool->size(), "size() changed");
      return pool();