This feature can adjust the value of SPINCOUNT dynamically for the best use of CPU cycle.

The Tuxedo bulletin board (BB) is one or more shared memory segments in which all the application configuration and dynamic processing information are held at run time. For some Tuxedo system operations (such as service name lookups and transactions), the BB must be locked for exclusive access: that is, it must be accessible by only one process. If a process or thread finds that the BB is locked by another process or thread, it retries, or spins on the lock for SPINCOUNT number of times (user level method via spin) before giving up and going to sleep on a waiting queue (system level method via system semaphore). Because sleeping is a costly operation, it is efficient to do some amount of spinning before sleeping.

Because the value of the SPINCOUNT parameter is application- and system-dependent, the administrator had to tune the SPINCOUT to be a proper value manually by observing the application throughput under different values of SPINCOUNT.

Self-Tuning Lock Mechanism takes the job of tuning automatically. It is designed to figure out a proper value of SPINCOUNT so that most requests to lock BB are completed by spinning instead of sleeping on a waiting queue.

For more information about configuration, see Introduction to Using Oracle Tuxedo Advanced Performance Pack.