void Awake()
        {
#if USE_THREAD
            mainThread = Thread.CurrentThread;
#endif
            _instance = this;
        }
 //[RuntimeInitializeOnLoadMethod]
 public static UnityThreadService Init()
 {
     if (_instance == null)
     {
         var go = new GameObject("_UnityThreadService");
         DontDestroyOnLoad(go);
         _instance = go.AddComponent <UnityThreadService>();
     }
     return(_instance);
 }
 void OnDestroy()
 {
     _instance = null;
     alive     = false;
 }