static MySingleton* getInstance(){
   MySingleton* sin = instance.load(std::memory_order_acquire);
   if (!sin){
     std::lock_guard<std::mutex> myLock(myMutex);
     sin = instance.load(std::memory_order_relaxed);
     if (!sin){
       sin = new MySingleton();
       instance.store(sin, std::memory_order_release);
     }
   }
   volatile int dummy{};
   return sin;
 }