Abstract: A multiprocessor data processing system is implemented with processors, each of which may request for a temporary time the exclusive lock on an object which is stored on a data base. To achieve this a lock processor synchronizes the locking and unlocking of the objects. The requesting processor directs the storage of the object from the data base into a selected high performance storage unit, where it has exclusive rights to modify or write into the object until the object is unlocked by the processor. An audit tape or disk records all modifications made to any object during a transaction. A non-volatile cache memory is inserted in the audit trail to store a before-look image of the object that resides in the high performance storage unit. Data compaction occurs by comparison of the before-look image with an after-look image to provide a difference image, which is supplied to an audit buffer that is coupled to the audit tape.

Abstract: A Record Lock Processor is utilized in a multi-host data processing system to control the locking of Objects upon request of each of the multiple host data processors in non-conflicting manner. The Record Lock Processor has storage provisions which include a Lock List for storing bits that identify the Objects and bits that identify the requesting processor, a Queue List that stores entries that are formatted like the Lock List entry when a prior Lock List entry has been made for the same Object, and a Cache List for each processor that stores Cache List entries that identify each Object that is stored in the cache memories, each of which Cache List entries is associated with one of the requesting processors, wherein such Cache List entries include validity bits that identify whether each Object stored in a Cache List has a Valid or an Invalid status.