void MemoryService::add_g1_heap_info(G1CollectedHeap* g1h) {

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

      assert(UseG1GC, "sanity");

  {- -------------------------------------------
  (1) MemoryManager::get_g1YoungGen_memory_manager() と MemoryManager::get_g1OldGen_memory_manager() で, 
      それぞれ Minor GC, Major GC 用の MemoryManager を取得する.
      ---------------------------------------- -}

      _minor_gc_manager = MemoryManager::get_g1YoungGen_memory_manager();
      _major_gc_manager = MemoryManager::get_g1OldGen_memory_manager();
      _managers_list->append(_minor_gc_manager);
      _managers_list->append(_major_gc_manager);

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

      add_g1YoungGen_memory_pool(g1h, _major_gc_manager, _minor_gc_manager);
      add_g1OldGen_memory_pool(g1h, _major_gc_manager);
      add_g1PermGen_memory_pool(g1h, _major_gc_manager);
    }