void HeapInspection::find_instances_at_safepoint(klassOop k, GrowableArray<oop>* result) {

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

      assert(SafepointSynchronize::is_at_safepoint(), "all threads are stopped");
      assert(Heap_lock->is_locked(), "should have the Heap_lock");

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

      // Ensure that the heap is parsable
      Universe::heap()->ensure_parsability(false);  // no need to retire TALBs

  {- -------------------------------------------
  (1) CollectedHeap::object_iterate() (をサブクラスがオーバーライドしたもの) を呼び出し, 
      ヒープ中の全てのオブジェクトに対して FindInstanceClosure を適用する.
      ---------------------------------------- -}

      // Iterate over objects in the heap
      FindInstanceClosure fic(k, result);
      // If this operation encounters a bad object when using CMS,
      // consider using safe_object_iterate() which avoids perm gen
      // objects that may contain bad references.
      Universe::heap()->object_iterate(&fic);
    }