| 摘要 |
PURPOSE:To remove a defect that the input and output request of low priority is waited for a long time by obtaining correcting function to judge passing allowance to priority control. CONSTITUTION:A request reception means 3 extracts priority control information by the input and output request of a processing program 1. A priority control means 4 receives these information and executes the entry of the information to a priority control table 7 according to the priority of the information. Namely, a request cue address, the priority and the number of passing allowance are registered and the resetting request of the number of passings and the judgement of the passing allowance are requested to a passing allowance judging means 5. The means 5, according to this request, resets the number of the setting passings of the entry of the control table 7 and judges whether the number is the allowing number of the entry or not. When it is not the allowing number, the position of the entry in the control table 7 is moved to a top side according to the number of passings and this operation is repeated for all entries. A request issuing means 6 responds to the request from the means 4 and the top entry of the control table 7 is removed and issued to an input and output device 8. Thus, the defect that the input and output request of the low priority is waited for a long time is removed. |
