oop CollectedHeap::obj_allocate(KlassHandle klass, int size, TRAPS) {

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

      debug_only(check_for_valid_allocation_state());
      assert(!Universe::heap()->is_gc_active(), "Allocation during gc not allowed");
      assert(size >= 0, "int won't convert to size_t");

  {- -------------------------------------------
  (1) CollectedHeap::common_mem_allocate_init() でメモリを確保する
      ---------------------------------------- -}

      HeapWord* obj = common_mem_allocate_init(size, false, CHECK_NULL);

  {- -------------------------------------------
  (1) CollectedHeap::post_allocation_setup_array() で確保したメモリのヘッダー部分を初期化する 
      (mark フィールド, klass フィールド)
      (また, JVMTI や DTrace, JMM のフック点でもある)
      ---------------------------------------- -}

      post_allocation_setup_obj(klass, obj, size);

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

      NOT_PRODUCT(Universe::heap()->check_for_bad_heap_word_value(obj, size));

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

      return (oop)obj;
    }