Abstract: A system and method for efficiently managing lock contention for a central processing unit (CPU) of a computer system. The present invention uses both spinning and blocking (or undispatching) to manage threads when they are waiting to acquire a lock. In addition, the present invention intelligently determines when the program thread should spin and when the program thread should become undispatched. If it is determined that the program thread should become undispatched, the present invention provides efficient undispatching of program threads that improves throughput by reducing wait time to acquire the lock.

Abstract: An apparatus and method for communicating the completion of asynchronous I/O requests is provided. In particular, the apparatus and method make use of a new function call which is capable of waiting for a predetermined number of I/O requests to be completed prior to returning to the calling application. Control blocks for the I/O requests are updated after a predetermined number of I/O requests have been completed, i.e. in a process context rather than in an interrupt context as in the known systems. In this way, the overhead associated with known asynchronous I/O system calls is reduced.

Abstract: The lock architecture for a computer system comprises several processors (10, 11, 12, 13) such that each processor (10) requesting a resource of the system takes control of said resource if a first lock state indicates that said resource is free. The requesting processor is placed on active standby if a second lock state indicates that said resource is busy. A lock includes a first and second lock state. The first lock state corresponds to a null value, and the second lock state corresponds to a non-null value.

Abstract: A system and method for efficiently managing lock contention for a central processing unit (CPU) of a computer system. The present invention uses both spinning and blocking (or undispatching) to manage threads when they are waiting to acquire a lock. In addition, the present invention intelligently determines when the program thread should spin and when the program thread should become undispatched. If it is determined that the program thread should become undispatched, the present invention provides efficient undispatching of program threads that improves throughput by reducing wait time to acquire the lock.

Abstract: The invention relates to a process for synchronizing a computer system with regard to a date which changes over time. The computer system comprises one or more modules (1, 2, 3, 4), each module (1, 2) comprising several processors (10, 11, 12, 13, 20, 21, 22, 23) regulated by a clock specific to a module (1, 2). Each processor (10, 11, 12, 13, 20, 21, 22, 23) comprises a private register TBR (16, 17, 18, 19, 26, 27, 28, 29) adapted to contain a value corresponding to said date and to undergo an incrementation by the clock specific to the module (1, 2) comprising this processor (10, 11, 12, 13, 20, 21, 22, 23).