279 struct LocalLockHolder {  struct
280     using WeakPointer = std::weak_ptr<Mutex>;
281     using StrongPointer = std::shared_ptr<Mutex>;
282     using Map = std::unordered_map<Key, WeakPointer>;
283     using MapLock = std::recursive_mutex;
285     LocalLockHolder(Key key, Map& map, MapLock& mapLock)  in LocalLockHolder()  argument
298     LocalLockHolder(LocalLockHolder&& other) noexcept  in LocalLockHolder()  function
305     ~LocalLockHolder() {  in ~LocalLockHolder()
324     void lock() { mRefLock->lock(); }  in lock()
325     void unlock() { mRefLock->unlock(); }  in unlock()
326     void lock_shared() { mRefLock->lock_shared(); }  in lock_shared()
327     void unlock_shared() { mRefLock->unlock_shared(); }  in unlock_shared()
330     Key mKey;
331     Map& mMap;
332     MapLock& mMapLock;
333     StrongPointer mRefLock;