When the locking system is configured, the total number of locks available (lock_limit) is set. As each lock is used, a counter is decremented; as each lock is freed the counter is incremented, thus reflecting the number of locks in use.

If the number of available locks drops to zero, a request for a lock cannot be satisfied until a lock is freed. If the number of available locks frequently drops to zero (not a desirable situation), increase the number of locks available in the locking system.