JPH02220138A - Interruption protecting system for real time operating system - Google Patents

Abstract

PURPOSE:To facilitate the introduction of an operating system OS even in such a computer system that applies frequently the interruption processes by incorporating an interruption processing protecting function into the OS. CONSTITUTION:An interruption process handler 7 which produces an external interruption is driven and a system call inhibiting system call is produced right before an inhibition sector 8 where an interruption due to a system call (software interruption) is not desired. Thus an OS turns on an inhibition flag 2. When the process of the sector 8 is over and an inhibition release system call 11 is produced, an interruption process protecting function part 1 of the OS turns off the flag 2 to connect all tasks so far connected to a system call queue part 3 to an active queue part 9 and carries out successively the stored system calls via a scheduler 4. As a result, the system call received from a task under an interruption process can be inhibited in an optional section under the control of the OS.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to an interrupt protection scheme for real-time operating systems in which hardware interrupts occur.

Conventional technology Conventionally, when system call processing of the operating system (hereinafter referred to as O8) occurs during interrupt processing that must be completed within a time limit, the interrupt processing is interrupted and the system call processing time is reduced. Only interrupt processing is awaited. As a result, the time limit for interrupt processing may be exceeded and the interrupt processing may become abnormal.

Problems to be Solved by the Invention As described above, in the configuration of the prior art, when a system call to O8 is issued from a user program, if the system is processing an interrupt, the system call that takes a long processing time is , there was a problem that interrupt processing could not be performed normally.

The present invention aims to solve the problems of the prior art.

Means for Solving the Problems The present invention achieves the above object by providing in O8 a function for managing system calls in a queue.

Effect of the Invention With the above configuration, the present invention can easily perform computer hardware interrupt processing and exclusive processing between O8.

Examples Examples of the present invention will be described below with reference to the drawings.

The figure shows the configuration of O8 in one embodiment of the present invention. In FIG. 1, 1 is an interrupt processing protection function unit for managing system calls during interrupt processing;
2 is a prohibition 7 lag section that is set or reset by system call lot or 11 that inhibits or cancels system call processing during interrupt processing; 12 is a system call that exclusively controls system calls; 3 is system call processing A part of the system call key for storing system calls issued by application task 6 while disabled, 7 is an interrupt handler driven by external (-)/-ware) interrupts, 8 is a system call This is a prohibited area for processing.

The operation of the above configuration will be explained below.

First, when an external interrupt occurs, the interrupt handler 7 is activated, and issues a system call prohibition system call immediately before the prohibited area 8, where interruption by a system call (=software interrupt) from a task is not desired.

Accordingly, O8 turns on prohibition flag 2. On the other hand,
For system calls that may be issued during execution of the system call prohibited area 8, an exclusive control system call 12 is issued immediately before the system call is issued.

By exclusive control system call 12, O8 temporarily connects the system call issued immediately after prohibition flag 2 is ON to system call queue part 3,
The scheduler 4 causes the system call processing to wait and transfers control to another task. Thereafter, system calls issued in the above format until the interrupt processing handler 7 finishes processing the prohibited area 8 are sequentially connected to the system call queue part 3 and are made to wait for their processing.

When the processing of the prohibited area 8 is finished and the release system call 11 is issued, the interrupt processing protection function unit 1 of the O8 outputs the flag 2 to OFF and activates all the tasks connected to the system call queue part 3. The scheduler 4 sequentially executes the accumulated system calls.

By doing this, system calls from a task that is currently processing an interrupt can be prohibited for an arbitrary period under the control of O8.

Effects of the Invention As is clear from the above explanation, according to the present invention, O8
By incorporating an interrupt processing protection function into O8, system call (=software) interrupts can be prohibited within any range during interrupt processing, so even computer systems that frequently use interrupt processing can easily It is possible to introduce the following.

[Brief explanation of the drawing]

The figure is a block diagram of a real-time O8 interrupt protection system in one embodiment of the present invention. 1... Interrupt processing protection function, 2... Flag section, 3
...Part of system call queue, 4...Scheduler, 6...Application task group, 7...Interrupt processing handler, 8...Prohibited area, 9...Active queue part, 10... Forbidden system call, 11°・°
Release system call /l/, 12...Exclusive control system call.

Claims (1)

[Claims] An interrupt protection method for a real-time operating system, characterized by providing means for detecting if an interrupt processing program is being executed and storing system calls to the operating system until the interrupt processing is completed.