PROGRAM CORRECTING METHOD AND SYSTEM

Correction of a program which resides on a main storage and which is simultaneously callable by a plurality of command processors is performed by minimizing the stop time of a computer system without reloading a program. A particular command processor calls a correction execution program which corrects a program in accordance with a program correction command. The correction execution program reads program correction information, sets correction execution declaration information in all entries of other command processor in the correction execution declaration area of the main storage and after clearing all entries, the correction execution program corrects the program in accordance with the program correction information. The correction execution program sets correction completion reporting information in all entries for all of the other command processors in the correction completion reporting area of the main storage. The correction execution program waits for the correction completion reporting area to be cleared, at which time it sends the corrected program to the external storage. The program to be corrected calls a correction wait program, which recognizes the command processor which has called the correction wait program itself, checks an entry of the appropriate command processor in the correction execution declaration area.