JPH04180128A - Process controller - Google Patents

Abstract

PURPOSE:To improve the throughput of a process controller by counting the generating times of notifying signals in order to notify a process with which a program is over and also to reduce the count value by one unit if the notifying signals are produced after reception of an interruption request in a multi- task system. CONSTITUTION:An interruption detecting part 2 detects the notifying signal received from a CPU with an external interruption request. A state deciding part 4 scans the process of a queue train 3 based on the detected notifying signal and applies the notifying signal to the process which is not kept in a run state. Meanwhile a notifying unable signal is outputted when all processes are kept in the run states. A counter 5 counts these notifying unable signals. When a processing end detecting part 6 detects the end of a process program, a remaining interruption deciding part 7 reduces the count value of the counter 5 by one unit and at the same time notifies again the process whose program has just ended.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a process control device in a multitasking system.
The present invention relates to a process control device that can notify the user.

(Prior Art) In a multitasking system, when an interrupt signal such as Interrupt or Fault is received while executing instructions,
A notify signal is issued to multiple processes that make up the queue, and one of the processes in the STOP state
is notified and becomes ready (READY), that is, executable. Then, when interrupts are successively accepted and a plurality of processes become ready, the processes in the ready state are activated in order starting from the one with the highest priority to execute the scheduled program.

However, if an interrupt request is further input and a notify signal is issued after all of the prepared processes are in the ready state, the notify signal based on the subsequently input interrupt request The process cannot accept the interrupt, and the process cannot recognize that an interrupt has occurred. In other words, it is not notified.

In order to improve this kind of problem, the number of processes can be increased, but since memory capacity is limited, it is desirable to have as few processes as possible.

In order to solve the above problems without increasing the number of processes, the following methods can be considered.

In a multitasking system, a plurality of processes exist for each type of fault and interconnected level, and each process constitutes a queue. Each queue has a queue header containing a pointer to the process. In addition to the pointer, a notify record flag is provided in this queue header.

In a system with such a queue header, for example, if an interrupt occurs and all processes that handle it are notified and become ready,
The CPU detects that there is no process that has received the notify signal and sets the notify record flag.

As a result, when the processing of the program being executed is finished, it is recognized that the notify record flag is set, and the process that has finished processing the program can
You will be notified again immediately.

In this way, by simply providing a 1-bit flag, the same effect as increasing the number of processes by one can be obtained.

(Problem to be solved by the invention) The above conventional technology has the following problems.

That is, in the above technique, the number of notifications that can be recorded by the notify recording flag is only one per queue, and therefore many notifications cannot be recorded.

Therefore, in a system in which a large number of interrupt requests occur continuously, there is a problem in that the system response is poor and the system may go down.

An object of the present invention is to solve the above-mentioned problems and provide a process control device that can reliably accept a larger number of consecutive interrupt requests and execute a scheduled program. be.

(Means and Effects for Solving the Problems) In order to solve the above problems and achieve the objects, the present invention provides that a plurality of processes that perform interrupt processing of the same interrupt level are all in a ready state, and When a request is accepted and a notify signal is generated, the number of times this notify signal is generated is counted, and if this count is greater than or equal to the expected value, the process that has finished processing the program is notified and the It is distinctive in that it is configured so that the numerical value is decreased by one unit.

According to the present invention configured as described above, even if an interrupt request is accepted after all processes for each interrupt level have been notified, this interrupt request is recorded as a count value. I can keep it.

Therefore, when the scheduled program has been executed, the CPU can detect the occurrence of an interrupt based on the count value, and can notify the process that has finished executing the program again.

(Example) Hereinafter, the present invention will be described in detail with reference to the drawings.

FIG. 3 is a block diagram of main parts of a memory in a computer system employing a multitasking system showing an embodiment of the present invention, and FIG. FIG.

In FIG. 3, queue headers fl, f2 . il, i2 are provided,
Furthermore, notify recording counters C1 to C4 are provided corresponding to these queue headers.

Further, in FIG. 4, the processes la and lb form a queue having a list structure, and the pointer of the queue header 11 points to the head of the queue.

In such a configuration, for example, if interrupt requests to Included A occur continuously, either the process 1a pointed to by the ladder 11 or the subsequent process 1b to the queue of Included A is notified and placed in a ready state. Make it.

If both processes la and lb are already in the ready state, the counter C3 corresponding to interwoven A is incremented.

Next, the main functions of the process control device of this embodiment will be explained.

In FIG. 1, the queue array 3 consists of a plurality of queues for each included and fault level, that is, for each same interrupt level, and each queue consists of a plurality of processes, as shown in FIG. 4.

The interrupt detection unit 2 detects C based on an external interrupt request signal.
Detects the notify signal emitted from the PU. Then, the detection signal of the notify signal and the information of the notify signal are supplied to the process state determination section 4.

The process state determination unit 4, which has been supplied with the notify signal detection signal and the notify signal information, scans the processes in the queue queue 3 based on the notify signal information and detects the state thereof.

The process state determining unit 4 analyzes process information and gives the notification to a process that is not in a ready or running state to put it in a ready state.

Further, if all the processes scanned by the process state determining unit 4 are in the ready or running state, a notify disable signal is output.

Counter 5 is incremented in response to this notify disabled signal. This counter 5 is a collection of the notify recording counters C1 to C4, and is provided for each interrupt level.

The processing end detection unit 6 detects that processing of a program scheduled to be started based on a process request has ended.

When it is detected that the processing of the program has ended, the remaining interrupt determining unit 7 analyzes the value of the counter 5 and determines whether there are any remaining interrupt requests that require notification of the process.

When the remaining interrupt determination unit 7 determines that there are remaining notifications that have not been accepted, it outputs a decrement signal to the counter 5 and also outputs a decrement signal to the counter 5 and updates the current notifications in the queue queue 3.
Notify the process that has just finished processing the program again and change it to the ready state.

Next, the operation of this embodiment, that is, the notify control operation will be explained. FIG. 2 is a flowchart showing the operation of this embodiment.

In the same figure, in step S1, an interrupt request is monitored depending on the presence or absence of a notify signal issued from the CPU, and if a notify signal is detected, step S1 is performed.
Proceed to step 2.

In step S2, it is determined whether or not there is a process in the queue that is not in a ready state, that is, a process that can accept a notify signal. If there is a process that is not in a ready state, the process advances to step S3 and the process is notified. Make it ready.

If there is no process that can be notified even though there is an interrupt request, step S2 to step S
Proceed to step 4.

In step S4, the counter value of the counter 5, which records that there was a notify signal that was not accepted, is incremented (+1).

In step S5, it is determined whether there is a process that has returned to the queue after completing the scheduled program processing, that is, a process that can now accept a notify signal.

If the determination in step S5 is negative, one cycle of notify control processing ends.

On the other hand, if the determination in step S5 is affirmative, step S
The process proceeds to step 6, where it is determined whether the counter value of the counter 5 is "0", that is, whether there is a notify signal that has not been accepted.

If the counter value is "0", one cycle of notify control processing is completed, but if the counter value is not "0°", the process proceeds to step S7, and the process that has finished processing the scheduled program and returned to the queue Notify and make it ready.

In step S8, since one process has been notified, the counter value of counter 5 is decremented (
-1) Do.

Note that if no interrupt request is detected in step S1, step S2. Skip S4 and proceed to step S5.

A process that is notified and becomes ready by the above control operation executes a scheduled program in accordance with the priority order. Note that the priority order is arbitrarily selected by the system.

(Effects of the Invention) As is clear from the above description, according to the present invention, the number of unaccepted notify signals, that is, the number of unaccepted interrupt requests remaining in the process queue can be notified. It can be recognized by the counter value of the recording counter.

Therefore, by simply securing a few bits of memory for the notify record counter, the same effect of improving processing performance as increasing the number of processes can be obtained.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram of main parts of a system showing an embodiment of the present invention, FIG. 2 is a flowchart showing the operation of the embodiment,
FIG. 3 is a block diagram showing a main part of a memory showing an embodiment of the present invention, and FIG. 4 is a block diagram showing an example of a process queue structure. la, lb...process, 2...interrupt detection unit, 3.
...Queue line, 4...Process state determination section, 5...
Counter, 6...Processing end detection unit, 7...Remaining interrupt judgment unit Agent Patent attorney Michito Hiraki and 1 other person Figure 3 Figure 2

Claims (1)

[Claims] (1) In a process control device for a multitasking system in which a plurality of processes that perform interrupt processing of the same interrupt level are provided, an interrupt detection means for detecting a notify signal for activating the process; process state determining means for outputting a notify disabled signal if the notify signal is accepted when everything is in a ready state;
a counting means for counting the number of occurrences of a notify signal by incrementing the number of times a notify signal is generated; and when the counting means has a count value and a process that has finished processing a program occurs, notifies this process; A process control device comprising means for decreasing the count value by one unit.