void ThreadSafepointState::create(JavaThread *thread) {

  {- -------------------------------------------
  (1) 新しい ThreadSafepointState オブジェクトを作成し,  
      引数で指定されたスレッドの safepoint_state フィールドにセットする.
      (See: ThreadSafepointState)
      ---------------------------------------- -}

      ThreadSafepointState *state = new ThreadSafepointState(thread);
      thread->set_safepoint_state(state);
    }