公开(公告)号：JPH0635726A

公开(公告)日：1994-02-10

申请号：JP14259693

申请日：1993-05-24

Applicant: APPLE COMPUTER

Inventor： ROBAATO BUI UERANDO ,  UORUTAA AARU SUMISU

IPC: G06F9/46 ,  G06F9/48

Abstract: PURPOSE: To eliminate the occurrence of a lock out by maintaining a data structure containing plural tasks which can be executed, giving the relevance of priority to the tasks and selecting at random tasks which are weighted by priority. CONSTITUTION: CPU 10 controls an input device 12 and an output device 14 with an instruction taken out from a memory 14, and operates data of the memory 14. An operating system has data structure with a pair of instructions controlling the operation of a computer system and it executes the selected user task. A probability priority base scheduler as a part for selecting the task in the operating system selects the task based on random numbers weighted by priority. Every task has selected finite probability which is not zero and the probability is proportional to the priority of the task. The task of low priority has a chance to be selected and lock out is executed.