Force RedLockMutex::extend_lock() to return -1ms on failure. (#39)
Force RedLockMutex::extend_lock() to return -1ms on failure. (#39)

This is done by checking if the flag that
RedLockMutexVessel::extend_lock() returns. If false, the lock failed
and -1ms is returned.
sewenew/redis-plus-plus,sewenew/redis-plus-plus