void os::thread_local_storage_at_put(int index, void* value) {

  {- -------------------------------------------
  (1) pthread_setspecific() で TLS に値をセットするだけ.
      ---------------------------------------- -}

      int rslt = pthread_setspecific((pthread_key_t)index, value);
      assert(rslt == 0, "pthread_setspecific failed");
    }