template <class T>
void objArrayKlass::objarray_follow_contents(ParCompactionManager* cm, oop obj,
                                             int index) {

  {- -------------------------------------------
  (1) PSParallelCompact::mark_and_push() で marking_stack にプッシュするのは, 
      最大で ObjArrayMarkingStride 個まで.
      それ以上の部分は ParCompactionManager::push_objarray() で objarray に入れて, いったん pending にしておく.
      ---------------------------------------- -}

      objArrayOop a = objArrayOop(obj);
      const size_t len = size_t(a->length());
      const size_t beg_index = size_t(index);
      assert(beg_index < len || len == 0, "index too large");

      const size_t stride = MIN2(len - beg_index, ObjArrayMarkingStride);
      const size_t end_index = beg_index + stride;
      T* const base = (T*)a->base();
      T* const beg = base + beg_index;
      T* const end = base + end_index;

      // Push the non-NULL elements of the next stride on the marking stack.
      for (T* e = beg; e < end; e++) {
        PSParallelCompact::mark_and_push<T>(cm, e);
      }

      if (end_index < len) {
        cm->push_objarray(a, end_index); // Push the continuation.
      }
    }