// Same as above, but assumes from = _thread_in_Java. This is simpler, since we
  // never block on entry to the VM. This will break the code, since e.g. preserve arguments
  // have not been setup.

  static inline void transition_from_java(JavaThread *thread, JavaThreadState to) {

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

        assert(thread->thread_state() == _thread_in_Java, "coming from wrong thread state");

  {- -------------------------------------------
  (1) JavaThread::set_thread_state() を呼んで JavaThreadState を変更する.
      ---------------------------------------- -}

        thread->set_thread_state(to);
      }