PURPOSE: To execute the exclusive control by the occupied time of information and to smoothly execute the processing by providing an occupied time designating means of information at the time of obtaining a lock, and a means for waiting if the occupancy is ended in a short time, and deciding the lock to be unsuccessful if the occupancy extends over many hours.
CONSTITUTION: A process 10 requests to obtain a lock against shared informa tion 12 to an exclusive control system 14. The exclusive control system 14 decides whether it is successful to obtain the lock or not from exclusive manage ment information 18 on a main storage 16, and repeats success/failure. At the time of requesting to obtain the lock, one of four kinds of locks of classifications of a share lock which does not permit updating from other proc ess and an EXC lock which does not permit reference and updating of informa tion from other process, and whether the occupied time for obtaining to the lock is long or short is designated. At the time of requesting to obtain the lock, when the designated time of the process which is being obtained is short, waiting is executed, and when said time is long, it is decided to be unsuccessful to obtain the lock, and the process processing jam caused by waiting for a lock release for many hours can be prevented.