forked from Silverfish/proton-bridge
This change implements safe.Mutex and safe.RWMutex, which wrap the sync.Mutex and sync.RWMutex types and are assigned a globally unique integer ID. The safe.Lock and safe.RLock methods sort the mutexes by this integer ID before locking to ensure that locks for a given set of mutexes are always performed in the same order, avoiding deadlocks.