template<class T>
class lockedqueue{
  std::mutex lock;
  std::queue<T>data;
  HANDLE hsema;
  public:
  lockedqueue(){
    hsema=CreateSemaphore(NULL,0,65535,NULL);
  }
  ~lockedqueue(){
    CloseHandle(hsema);
  }
  void push(T _){
    std::lock_guard _l(lock);
    data.push(std::move(_));
    ReleaseSemaphore(hsema,1,NULL);
  }
  T pop(){
    WaitForSingleObject(hsema,INFINITE);
    std::lock_guard _l(lock);
    auto _=data.front();
    data.pop();
    return _;
  }
  bool empty(){
    std::lock_guard _l(lock);
    return data.empty();
  }
};