Types of locks

The Open Software Foundation/1 (OSF/1) 1.1 locking methodology was used as a model for the AIX® multiprocessor lock functions.

However, because the system is preemptable and pageable, some characteristics have been added to the OSF/1 1.1 Locking Model. Simple locks and complex locks are preemptable. Also, a thread may sleep when trying to acquire a busy simple lock if the owner of the lock is not currently running. In addition, a simple lock becomes a sleep lock when a processor has been spinning on a simple lock for a certain amount of time (this amount of time is a system-wide variable).