JPH07200315A - Scheduling device for process in computer system - Google Patents

Abstract

PURPOSE:To attain proper scheduling by preventing a CPU from being continuously occupied by real time process. CONSTITUTION:A same process running counter is incremented by 1 (S21), information relating to a process running at present is acquired from process information running at present (S26) to discriminate whether or not the process running at present has priority in real time. In the case of the priority of real time (S27Y), a count of a same process running counter in the process information running at present is compared with monitor time information and when the count of the same process running counter is larger than or equal to the monitor time information value (S28N), an interactive process changeover module is executed (S44), and the same process running counter in the process information running at present is set to zero and the program is terminated (S47).

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scheduling device for allocating a CPU to an interactive process and a real-time process by a fixed-cycle timer interrupt in one operating system.

[0002]

2. Description of the Related Art Conventionally, in computer systems, real-time processes and interactive processes may coexist on one operating system. The real-time process here is a process whose response time is strictly limited, and the processing time can be predicted because the processing is completed within a predetermined time. Further, the interactive process is not severely limited in response time, but CPUs are equally allocated to all processes.

More specifically, when a real-time process is composed of a plurality of processes, each process is assigned a priority order for allocating a CPU, and the process with the highest priority order acquires the exclusive right to the CPU. To do. Further, the process that occupies the CPU does not relinquish the exclusive right until the processing is completed. That is, while a process occupies the CPU, a process having a lower priority than this process continues to wait for the CPU allocation. However, when a process with a high priority has a processing request, the process takes the exclusive right of the CPU from the process occupying the CPU and occupies the CPU by itself. In this way, the processes with the highest priority are processed in order. The priority order is designated by the user.

On the other hand, the priority of each interactive process is determined by the operating system. That is, when the computer system is started up, each process has the same priority, but each process has a CPU.
Each time it occupies, the priority of that process changes to low. As a result, the process having a smaller number of CPU occupations has a relatively higher priority, and the CPU having the highest number in sequence is occupied with the CPU. as a result,
On average, the CPU allocation time is even for each process.

In a computer system having such an interactive process, a fixed-cycle timer interrupt at fixed intervals is performed as an operating system, and if the interrupt interval is 1 unit time, the interactive process is 1 unit.
The CPU allocation switches in a unit time. That is, when an interactive process occupies the CPU for one unit time, the process changes the priority to low and then relinquishes the exclusive right of the CPU. Then, the exclusive right of the CPU is handed over to the next priority interactive process. A scheduling method in a computer system in which these real-time processes and interactive processes coexist on one operating system is performed as follows.

The real-time process and the interactive process have different priorities for both processes. For example, if the system has 128 priorities, priorities 0-63 are real-time processes and the remaining priorities 64-127 are interactive processes. The smaller the number, the higher the priority. Also, in order to link processes that are executable and to which no CPU is assigned, a queue is provided for each priority of processes. As a result, when the process that has occupied the CPU relinquishes the exclusive right, the process with the highest priority in this queue acquires the exclusive right to the CPU. If there are multiple processes with the same priority, the arrival order (FCFS: First Come First)
Service) to acquire the exclusive right of the CPU.

Regarding the occupation of the CPU between the real-time process and the interactive process, the real-time process is given priority, and after the processing of all the real-time processes is completed, the interactive process is given the exclusive right of the CPU.
Further, even when the interactive process has acquired the exclusive right of the CPU, when a new processing request of the real-time process occurs, the exclusive right of the CPU of the interactive process is taken by the real-time process. FIG. 14 shows the configuration of a conventional operating system that performs these processes.
FIG. 11, FIG. 12, and FIG. 13 are system diagrams of the scheduling process.

As shown in FIG. 14, in the operating system, a timer interrupt is composed of a processing module, a process selection processing module, a process switching processing module, a process queue and process information of the currently running process. When it occurs, the timer interrupt process is called. FIG. 11 shows a timer interrupt processing module. This module first performs a predetermined timer process, and then proceeds to the process selection processing module.

FIG. 12 shows the contents of the process selection processing module. This module first obtains information about the currently running process (S26) and then determines whether the currently running process is a real-time priority (S27). In the case of real-time priority (S27Y), information of the highest priority process is acquired from the process queue (S31). Next, the process in the queue determines whether it has the real-time priority (S32), and if it has the real-time priority (S32).
Y) further determines whether the process in the queue has a higher priority than the process currently running (S3).
3).

If the priority is high (S33Y), that is, if a real-time process having a higher priority than the currently running process is linked to the process queue of FIG. 14, the process switching processing module (S34) is performed. When the process in the queue has an interactive priority instead of the real-time priority (S32N) and the priority is not high but low (S33N), the currently running process continues to occupy the CPU. Also, S2
Even if the priority order is not 7 in Step 7, the process switching processing module (S34) is performed.

FIG. 13 shows the contents of the process switching processing module. This module first links the currently running process to the process queue (S11).
If the process currently running is an interactive process, the priority is recalculated before linking. This is because the interactive process lowers the priority each time it occupies the CPU, thereby relatively increasing the priority of the process having a small CPU allocation. Next, the process with the highest priority is selected from the process queue, removed from the process queue link (S12), and the CPU is assigned (S13). Finally, the identifier and priority of the process to which the CPU is newly assigned are set in the process information (FIG. 14) currently running (S14).

[0012]

However, in the above-described operating system scheduling method, for example, a real-time process causes C
If the exclusive right of PU is not abandoned or the processing is not completed within the predetermined time, the deadlock occurs in the computer system, the interactive process does not operate at all, the response time is abnormally slow. There was a problem such as becoming. The present invention has been made to solve the above problems, and an object of the present invention is to provide a process in a computer system capable of stabilizing the operation by preventing the real-time process from continuously occupying the CPU. It is to provide a scheduling device.

[0013]

In order to achieve the above object, a first aspect of the present invention provides a CPU with a fixed period timer interrupt for interactive processes and real-time processes linked to a process queue based on their respective priorities.
In a process scheduling device in a computer system for allocating occupancy, means for counting the number of times the same real-time process occupies the CPU in succession, and a process queue when the count value of the counting means reaches a predetermined value Means for allocating CPU occupancy to the interactive process with the highest priority among the interactive processes.

According to a second aspect of the present invention, in a process scheduling device in a computer system for allocating CPU occupation by a constant period timer interrupt to an interactive process and a real-time process linked to a process queue based on their respective priorities, a process scheduling apparatus is provided by a user. A storage means for storing the created handler program in advance, a means for counting the number of times the same real-time process occupies the CPU continuously, and a scheduling by the handler program of the storage means when the count value of the counting means reaches a predetermined value. And means for executing.

A third aspect of the present invention is the same process scheduling device in a computer system in which CPU occupation is assigned to interactive processes and real-time processes linked to a process queue by a fixed period timer interrupt based on their respective priorities. A means for counting the number of times the real-time process occupies the CPU continuously, and a means for forcibly ending the currently running real-time process and removing it from the link of the process queue when the count value of the counting means reaches a predetermined value It is characterized by that.

A fourth aspect of the present invention is the same process scheduling device in a computer system in which CPU occupation is assigned to interactive processes and real-time processes linked to a process queue by a fixed period timer interrupt based on respective priorities. A means for counting the number of times the real-time process occupies the CPU continuously, and a real-time process that is currently running when the count value of the counting means reaches a predetermined value and a real-time process of the next priority linked to the process queue. And a means for exchanging the order of priority of each other.

A fifth aspect of the present invention is a process scheduling apparatus in a computer system for allocating CPU occupation by a fixed period timer interrupt to an interactive process and a real time process linked to a process queue based on respective priorities, in a real time class. Means for counting the number of times the process occupies the CPU continuously, and the interactive process with the highest priority among the interactive classes linked to the process queue when the count value of the counting means reaches a predetermined value And means for allocating the CPU occupation.

According to a sixth aspect of the present invention, a user is provided in a process scheduling device in a computer system for allocating CPU occupancy by a fixed-cycle timer interrupt based on respective priorities to interactive processes and real-time processes linked to a process queue. A storage means for storing the created handler program in advance, a means for counting the number of times the real-time class process occupies the CPU continuously, and a scheduling by the handler program of the storage means when the count value of the counting means reaches a predetermined value. And means for executing.

[0019]

According to the first aspect of the invention, the number of times the same real-time process occupies the CPU continuously is counted, and when the count value reaches a predetermined value, among the interactive processes linked to the process queue, The CPU process is assigned to the highest priority interactive process. This prevents the same real-time process from occupying the CPU indefinitely continuously.

In the second invention, the number of times that the same real-time process occupies the CPU continuously is counted, and when the count value reaches a predetermined value, the subsequent scheduling is performed by the handler program created by the user in advance. Is executed. This allows the user to take any action when the same real-time process continuously occupies the CPU.

In the third invention, the number of times the same real-time process occupies the CPU continuously is counted, and when the count value reaches a predetermined value, the real-time process currently running is forcibly terminated and the real-time process is executed. The process is unlinked from the process queue. As a result, the CPU is continuously
The real-time process that occupies is removed, and then normal operation is restored.

In the fourth invention, the number of times the same real-time process occupies the CPU continuously is counted, and when the count value reaches a predetermined value, the real-time process currently running and the process queue are linked. The priority of each other is exchanged with the next real-time process having the next priority. This prevents the same real-time process from occupying the CPU indefinitely continuously.

In the fifth invention, the number of times the real-time class process continuously occupies the CPU is counted, and when the count value reaches a predetermined value, among the interactive classes linked to the process queue. The CPU process is assigned to the highest priority interactive process. This prevents the real-time process from occupying the CPU indefinitely and continuously.

In the sixth invention, the number of times the real-time class process continuously occupies the CPU is counted, and when the count value reaches a predetermined value, the subsequent scheduling is performed by the handler program created by the user in advance. Is executed. As a result, the user can take any action when the real-time process continuously occupies the CPU.

[0025]

Embodiments of the present invention will be described below with reference to the drawings. The operating system of the computer system targeted in this embodiment manages the allocation of interactive processes and real-time processes to CPUs based on the priority of processes, and operates under the following conditions. (1) The fixed-cycle timer issues an interrupt to the operating system at fixed intervals (for example, 10 ms). (2) Interactive processes and real-time processes have different priorities for others. That is, even if processes of the same type may have the same priority, the interactive process and the real-time process do not have the same priority. (3) A queue of processes for waiting for CPU allocation is provided for each priority. (4) Each process has a unique identifier in the system.

FIG. 1 is a conceptual diagram showing the configuration of an operating system to which the present invention is applied. As shown in the figure, the operating system includes a timer interrupt processing module, a process selection processing module, a process switching processing module, an interactive process switching processing module, a process queue, currently running process information, monitoring time information, a handler program registration table and It consists of real-time process suppression flags. Here, the timer interrupt processing module and the process switching processing module that receive the interrupt of the fixed cycle timer are
Since it is the same as the operation of FIG. 14 shown in the section of the prior art, detailed description thereof will be omitted. The process selection processing module and the interactive process switching processing module are the main features of the present invention, and detailed operations will be described later.

The process queue has a link terminal corresponding to the priority of each process, and links a real-time process and an interactive process waiting for CPU allocation to the link terminals of the corresponding priorities. In the illustrated example, the priority order is 128 from 0 to 127, and the smaller the numerical value, the higher the priority order. Among them, the priority order of the higher order 0 to 63 is set as the real time class and is set as the priority order of the real time process. Further, the priority of the remaining lower 64 to 127 is set as the interactive class to be the priority of the interactive process.

The currently running process information includes a process identifier, a process priority, a same process running counter, and a same class process running counter. The identifier of the process to which the CPU is currently assigned is stored in this process identifier. The process priority stores the priority of the process to which the CPU is currently assigned. The same process running counter stores the time when the CPU is continuously allocated to the same process as the number of unit time (CPU occupying time per fixed-cycle timer interrupt), and the CPU is allocated to different processes. This counter is cleared to zero.

The same class process running counter stores the time when CPUs are continuously allocated to processes of the same class as the number of unit time, and this counter is set when the CPUs are allocated to processes of different classes. It is cleared to zero. The monitoring time information is used as a reference value when checking whether a real-time process occupies the CPU for a predetermined time or longer. That is, the number n of unit times described above is set in advance in this monitoring time information as a value according to the system, and the count value of the same process running counter or the same class process running counter is compared with the value of the monitoring time information, When the count value reaches the value of the monitoring time information, it is considered that an abnormal situation has occurred.

The handler program registration table stores the entry address of the handler program executed when the real-time process occupies the CPU for a predetermined time or longer. This handler program is registered in advance by the user. The real-time process inhibition flag inhibits allocation of real-time class processes to CPUs.

Next, each invention will be described based on a flowchart. FIG. 2 is a flowchart showing a first embodiment of the process selection processing module according to the first invention.
This module first increments the same process running counter included in the currently running process information by 1 in order to know the time during which the currently running real time process continuously occupies the CPU (S21). Next, information regarding the currently running process is acquired from the currently running process information (S26), and then it is determined whether the currently running process has a real-time priority (S27). If the priority is in real time (S27Y), the value of the same process running counter in the currently running process information is further compared with the value of the monitoring time information, and if the value is small (S28Y), the process queue has the highest priority. Information on a process having a high rank is acquired (S31).

Next, it is judged whether or not the process in the queue has the real-time priority (S32). If the process has the real-time priority (S32Y), the process in the queue has priority over the process currently running. It is determined whether or not is high (S33). When the priority is high (S33
Y), that is, if a real-time process having a higher priority than the currently running process is linked to the process queue of FIG. 1, the process switching processing module of FIG. 13 is executed (S34), and then the currently running process information is displayed. Then, the same process running counter is reset to 0 (S37).

If it is determined in S27 that the priority is not the real time priority, the process switching processing module in S34 is executed. Furthermore, if the value of the same process running counter is greater than or equal to the value of the monitoring time information in S28, the interactive process switching module of FIG. 3 is executed (S44),
Next, the same process running counter of the currently running process information is set to 0, and the process ends (S47). Furthermore, S
If the process in the queue is not the real-time priority but the interactive priority in 32 and the priority is not high in S33, that is, if it is low, the process is terminated and the currently running process remains in the CPU. Let the possession continue.

FIG. 3 is a flow chart showing the interactive process switching module. First, information on the process with the highest priority is acquired from the process queue of the interactive class (S61). Next, it is determined whether or not the obtained process is an interactive process, and if it is not an interactive process (S62N), the process ends. If it is an interactive process (S62Y), the currently running process is linked to the process queue (S63). If the process linked here is an interactive process,
Recalculate priorities and then link.

Next, the link of the process with the highest priority is removed from the process queue of the interactive class (S6).
4) Then, the CPU is assigned to the process whose link is removed from the queue (S65), and at the same time, the identifier of the process to which the CPU is assigned and the priority are set in the currently running process information, and the process is terminated (S66). In the processing according to the first embodiment, by executing the processing of S28 and S44, the CPU can be executed by the same real-time process.
Even if the CPUs are continuously occupied, after the CPU is occupied for n times set in the same process running counter,
Occupation of the CPU by the interactive process is done once. That is, the interactive process is executed at least once during the n + 1 periodic interrupts.

As a result, the same real-time process may run away, or even if the processing is not completed within a certain time, the computer system may deadlock or the interactive process may not operate at all. Disappear. Also, the same real-time process that has runaway from the interactive process can be forcibly terminated. Furthermore, even if the same real-time process runs out of control, this embodiment is effective for a system in which it is desired to continue real-time processing without considering it as an abnormality.

FIG. 4 is a flow chart showing a second embodiment of the process selection processing module according to the first invention. This flowchart corresponds to the flowchart of FIG.
22, S41 and S42 are added, and the others are shown in FIG.
The description of the common part is omitted and only different parts will be described. That is, in S21, 1 is added to the same process running counter in the process information currently running.
After adding, the real-time process inhibition flag is checked, and if 1 is set (S22Y), the process proceeds to S26 as it is, and if 1 is not set (S22).
N), and proceeds to S41.

In S28, the value of the same process running counter in the currently running process information is compared with the value of the monitoring time information, and if not smaller (S28N), the process proceeds to S41.
In S41, the real-time process inhibition flag is checked, and if 1 is set (S41N), the process proceeds to S44 as it is, and if 1 is not set (S41).
Y), the process proceeds to S42, the real-time process inhibition flag is set to 1, and the process proceeds to S44. In the processing according to the second embodiment, when the same real-time process occupies the CPU n times consecutively, the real-time process inhibition flag is set to 1 and the interactive process C
The control right of the PU is passed, and thereafter, the interactive process switching module of FIG. 3 is executed every time.

As a result, even if the same real-time process runs out of control or the processing is not completed within a fixed time, the computer system will not deadlock or the interactive process will not operate at all. Also, the same real-time process that has runaway from the interactive process can be forcibly terminated. Furthermore, if the same real-time process runs out of control, it is considered that an abnormality has occurred in the system, and this embodiment is effective for a system in which it is desired to investigate some cause without continuing the real-time processing.

FIG. 5 is a flow chart showing a third embodiment of the process selection processing module according to the second invention. This flow chart is based on S44 of FIG.
The other parts are the same as those in FIG. 2, and therefore the description of the common parts will be omitted and only different parts will be described. That is, in S28, the value of the same process running counter in the currently running process information is compared with the value of the monitoring time information, and if not smaller (S28N), the process proceeds to S45.

In S45, it is determined whether or not the entry address of the handler program is registered in the handler program registration table, and if it is not registered (S4).
5N), the process directly proceeds to S47. If registered (S
45Y), the handler program is called from the entry address and executed (S46), and the process proceeds to S47. In the processes according to the third embodiment, when the same real-time process occupies the CPU n times consecutively, the handler program is called and executed. Since this handler program is registered in advance by the user, the user can freely set the CPU allocation scheduling and construct an optimum system unique to the user.

FIG. 6 is a flow chart showing a fourth embodiment of the process selection processing module according to the third invention. This flowchart corresponds to S44 and S47 of FIG.
The other parts are the same as those in FIG. 2, and therefore the description of the common parts will be omitted and only different parts will be described. That is, in S28, the value of the same process running counter in the currently running process information is compared with the value of the monitoring time information, and if not smaller (S28N), the process proceeds to S48. S
48, the CPU of the real-time process currently running
Terminate occupancy. At this time, the terminated real-time process is not connected to the queue link terminal. Next, by executing the process switching processing module of S34, the CPU is assigned to the process of the next priority.

In the processing according to the fourth embodiment, when the same real-time process occupies the CPU n times in a row, the real-time process that has been running until then is forcibly terminated, and the next priority is assigned. C for high process
By allocating the PU, the monopolization of the CPU by the same real-time process is avoided. As a result, the same real-time process will runaway, or even if the processing is not completed within a certain time, the computer system will deadlock,
The interactive process never stops working.

However, the interactive process operates only after the real-time process ends. Also, the same real-time process that has runaway from the interactive process can be forcibly terminated. Furthermore, if the same real-time process runs out of control, this embodiment is effective for a system in which it is considered that an error has occurred only in that process and the real-time processing is to be continued.

FIG. 7 is a flow chart showing a fifth embodiment of the process selection processing module according to the fourth invention. This flowchart corresponds to S44 and S47 of FIG.
49 to S52, and others are common to FIG. 2, and therefore description of common parts will be omitted and only different parts will be described. That is, in S28, the value of the same process running counter in the currently running process information is compared with the value of the monitoring time information, and if not smaller (S28N), the process proceeds to S49. In S49, information on the process with the highest priority is acquired from the queue of real-time processes.

Then, it is determined whether the acquired information is a real-time process. If it is not a real-time process (S50N), the process is terminated. If it is a real-time process (S50Y), the priority of the real-time process currently running and the process having the highest priority in the process queue of the real-time class are exchanged (S51). Next, the currently running real-time process is linked to the process queue of the real-time class (S52), and then the process switching processing module of S34 is executed to allocate the CPU to the real-time process of the next priority.

In the processing according to the fifth embodiment, when the same real-time process occupies the CPU n times in succession, the real-time process that has been running and the real-time process having the next highest priority are prioritized. By exchanging the ranks and allocating the CPU to the real-time process that was the next priority until then, the same real-time process may run away or the computer system may deadlock even if the processing is not completed within a certain time. , Interactive processes never stop working.

However, the interactive process operates only after the real-time process ends. Further, even if the same real-time process runs out of control, this embodiment is effective for a system in which it is desired to continue real-time processing without considering it as an abnormality, and without giving the exclusive right of the CPU to the interactive process. is there. Further, in the case of this embodiment, if the same real-time process that has runaway is to be forcibly terminated, it is important to process the process with the next highest priority.

FIG. 8 is a flow chart showing a sixth embodiment of the process selection processing module according to the fifth invention. This module first increments the same class process running counter in the currently running process information by 1 in order to know the time during which the currently running real time class process continuously occupies the CPU (S23). .
Next, information regarding the currently running process is acquired from the currently running process information (S26), and then it is determined whether the currently running process has a real-time priority (S27).

If the priority is real-time (S
27Y), and the value of the same-class process running counter in the currently running process information is compared with the value of the monitoring time information, and if it is smaller (S29Y), the information of the process with the highest priority is acquired from the process queue. Yes (S3
1). Next, it is determined whether or not the process in the queue has a real-time priority (S32). If the process has a real-time priority (S32Y), whether the process in the queue has a higher priority than the process currently running. It is determined whether or not (S33).

If the priority is high (S33Y), that is, if a real-time process having a higher priority than the currently running process is linked to the process queue of FIG. 1, the process switching processing module of FIG. 13 is executed (S34). ). Here, it is further determined whether or not the class of the previously running process and the class of the currently running process are different, and if they are different (S35Y), the same class process running counter of the currently running process information is set to 0 and the process ends. Yes (S37). If the priority order is not the real time priority in S27, the process switching processing module (S34) is performed.

Further, if the value of the same-class process running counter is greater than or equal to the value of the monitoring time information in S29, the interactive process switching module of FIG. 3 is executed (S44), and the process previously running It is determined whether or not the class of the currently running process is different. If the class is different (S53Y), the same class process running counter of the currently running process information is set to 0 and the process is terminated (S54). If the process classes are the same (S53N), the process ends. Furthermore, if the process in the queue has an interactive priority rather than the real-time priority in S32, the priority is not high in S33, and S35.
If the class of the process that was previously running and the class of the process that is currently running are the same, the process is ended, and the process that is currently running continues to occupy the CPU.

In the processing according to the sixth embodiment,
By executing the processing of S29 and S44, even if the CPU is continuously occupied by the real-time class process, the interactive process is performed after the CPU has been occupied n times set in the same-class process running counter. Occupation of the CPU is performed once. That is, the interactive process is executed at least once during the n + 1 periodic interrupts. The sixth embodiment is the first
The effect similar to that of the embodiment is obtained, and the abnormally slow response time of the interactive process is eliminated.

FIG. 9 is a flow chart showing a seventh embodiment of the process selection processing module according to the fifth invention. This flowchart corresponds to the flowchart of FIG.
24, S41, S42 are added, and the others are shown in FIG.
The description of the common part is omitted and only different parts will be described. That is, in S23, after adding 1 to the same-class process running counter, the real-time process inhibition flag is checked, and if 1 is set (S24Y), the process proceeds directly to S26 and if 1 is not set (S24N). ), And proceeds to S41. In S29, the value of the same class process running counter in the currently running process information is compared with the value of the monitoring time information,
If not smaller (S29N), the process proceeds to S41.

In S41, the real-time process inhibition flag is checked, and if 1 is set (S41
N), the process directly proceeds to S44. If 1 is not set (S41Y), the process proceeds to S42, the real-time process inhibition flag is set to 1, and the process proceeds to S44. In the processing according to the seventh embodiment, when the CPU is continuously occupied by the real-time class process n times, the real-time process inhibition flag is set to 1, and thereafter, the interactive process switching of FIG. 3 is performed every time. The module will be executed. In addition, the seventh embodiment has almost the same effect as the second embodiment, and also eliminates the abnormally slow response time of the interactive process.

FIG. 10 is a flow chart showing an eighth embodiment of the process selection processing module according to the sixth invention. In this flowchart, S44 of FIG.
This is a modification of S46, and the other parts are common to those in FIG. 8, and therefore description of common parts will be omitted and only different parts will be described. That is, in S29, the value of the same-class process running counter in the currently running process information is compared with the value of the monitoring time information, and if not smaller (S29N), the process proceeds to S45. In S45, it is determined whether or not the entry address of the handler program is registered in the handler program registration table, and if it is not registered (S45N),
Then, the process proceeds to S53. If registered (S45
Y), the handler program is called from the entry address and executed (S46), and the process proceeds to S53.

In the processing according to the eighth embodiment, when the CPU of the real time class is occupied n times in succession, the handler program is called and executed. Since this handler program is registered in advance by the user, the user can freely set the CPU allocation scheduling and construct an optimum system unique to the user. The eighth embodiment is the third embodiment.
The effect similar to that of the embodiment is obtained, and the abnormally slow response time of the interactive process is eliminated.

[0058]

As described above, according to the first invention,
When the same real-time process consecutively occupies the CPU a predetermined number of times, by assigning the CPU occupancy to the interactive process with the highest priority among the interactive processes linked to the process queue, The same real-time process does not occupy the CPU indefinitely continuously.

According to the second aspect of the invention, when the same real-time process consecutively occupies the CPU reaches a predetermined number of times, the subsequent scheduling is executed by the handler program created by the user in advance. When the same real-time process continuously occupies the CPU, the user can take arbitrary measures.

According to the third aspect of the invention, when the same real-time process occupies the CPU continuously for a predetermined number of times, the real-time process currently running is forcibly terminated and the real-time process is linked to the process queue. By removing the CPU from the real time process, the real-time process that continuously occupies the CPU due to the cause of the abnormality or the like is removed, and thereafter, the normal operation is restored.

According to the fourth invention, when the number of times the same real-time process occupies the CPU in succession reaches a predetermined number, the real-time process currently running and the next priority order linked to the process queue. By exchanging the priorities of the real-time processes with each other, the same real-time process does not occupy the CPU continuously without limitation.

According to the fifth aspect, when the number of times that the real-time class process continuously occupies the CPU reaches a predetermined number, the dialog with the highest priority among the interactive classes linked to the process queue is provided. CPU for mold process
By assigning the occupancy, the real-time process does not continuously occupy the CPU indefinitely.

According to the sixth aspect, when the number of times that the real-time class process continuously occupies the CPU reaches a predetermined number, the subsequent scheduling is executed by the handler program created by the user in advance. The user can take arbitrary measures when the real-time process continuously occupies the CPU.

From the above, the following effects can be obtained in each invention. (1) It is possible to prevent runaway of real-time processes of the same or the same class. (2) Even if the processing is not completed within a fixed time, it is possible to prevent the computer system from falling into a deadlock. (3) Similarly, even if the processing is not completed within a certain period of time, it is possible to avoid the situation where the interactive process does not operate at all. (4) It is also possible to forcibly terminate the same real-time process that caused a runaway from an interactive process. (5) Furthermore, even if the same real-time process causes a runaway or the like, it is possible to continue the real-time processing as it is without considering it as an abnormality.

[Brief description of drawings]

FIG. 1 is a conceptual diagram showing a configuration of an operating system to which the present invention is applied.

FIG. 2 is a flowchart showing a first embodiment according to the first invention.

FIG. 3 is a flowchart showing a main part of FIG.

FIG. 4 is a flowchart showing a second embodiment according to the first invention.

FIG. 5 is a flowchart showing a third embodiment according to the second invention.

FIG. 6 is a flowchart showing a fourth embodiment according to the third invention.

FIG. 7 is a flowchart showing a fifth embodiment according to the fourth invention.

FIG. 8 is a flowchart showing a sixth embodiment according to the fifth invention.

FIG. 9 is a flowchart showing a seventh embodiment according to the fifth invention.

FIG. 10 is a flowchart showing an eighth embodiment according to the sixth invention.

FIG. 11 is a flowchart showing a conventional scheduling process.

FIG. 12 is a flowchart showing a conventional scheduling process.

FIG. 13 is a flowchart showing a conventional scheduling process.

FIG. 14 is a conceptual diagram showing a configuration of a conventional operating system.

Claims (6)

[Claims] 1. A process scheduling device in a computer system for allocating CPU occupation by a fixed-cycle timer interrupt to an interactive process and a real-time process linked to a process queue based on respective priorities, wherein the same real-time process is continuous. And counting the number of times the CPU is occupied, and when the count value of the counting means reaches a predetermined value, the CPU process is occupied by the interactive process with the highest priority among the interactive processes linked to the process queue. A process scheduling device in a computer system, comprising: allocating means. 2. A handler created by a user in a process scheduling device in a computer system for allocating CPU occupation by a fixed-cycle timer interrupt based on respective priorities to interactive processes and real-time processes linked to a process queue. A storage means for storing a program in advance, a means for counting the number of times the same real-time process occupies the CPU continuously, and a means for executing scheduling by the handler program of the storage means when the count value of the counting means reaches a predetermined value. And a process scheduling device in a computer system. 3. A process scheduling device in a computer system for allocating CPU occupation by a fixed period timer interrupt to an interactive process and a real-time process linked to a process queue based on respective priorities, wherein the same real-time process is continuous. And a means for counting the number of times the CPU has been occupied and a means for forcibly ending the currently running real-time process and removing it from the link of the process queue when the count value of the counting means reaches a predetermined value. A process scheduling device in a characteristic computer system. 4. A process scheduling device in a computer system for allocating CPU occupancy by a fixed-cycle timer interrupt based on respective priorities to interactive processes and real-time processes linked to a process queue, wherein the same real-time process is continuous. Between the real-time process currently running and the real-time process of the next priority linked to the process queue when the count value of the count means reaches a predetermined value. A process scheduling device in a computer system, comprising: means for exchanging mutual priorities. 5. A process scheduling device in a computer system for allocating CPU occupation by a fixed-cycle timer interrupt to an interactive process and a real-time process linked to a process queue based on their respective priorities, wherein a real-time class process is continuous. And counting the number of times the CPU is occupied, and when the count value of the counting means reaches a predetermined value, the interactive process with the highest priority in the interactive class linked to the process queue is assigned the CPU. A process scheduling device in a computer system, comprising: allocating means. 6. A handler created by a user in a process scheduling device in a computer system for allocating CPU occupation by a fixed-cycle timer interrupt based on respective priorities to interactive processes and real-time processes linked to a process queue. A storage means for storing a program in advance, a means for counting the number of times a real-time class process has occupied the CPU continuously, and a means for executing scheduling by a handler program of the storage means when the count value of the counting means reaches a predetermined value. And a process scheduling device in a computer system.