JP3711642B2 - Processing management system - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a processing management system that executes processing by managing computer resources and the like given to a plurality of processes based on execution priority, and in particular, cancels priority inversion that occurs between processes.Processing management system and methodAbout.
[0002]
[Prior art]
The processing management system manages the allocation of computer resources such as a CPU and enables a plurality of processes to be executed. For example, a round in which a process for allocating computer resources at a predetermined time is switched to execute a plurality of processes. There is a robin method and the like, and there is also a method for deciding the processing for allocating the computer resources according to the execution priority in the round robin method.
[0003]
In addition to the round robin method described above, for example, a method suitable for real-time processing such as playback of continuous media data such as video and audio, search to a database subject to time constraints from the user, etc. There is a method for executing processing by occupying computer resources according to execution priority (hereinafter referred to as a subordinate priority occupation method).
[0004]
This secondary priority occupancy method occupies computer resources according to the execution priority when executing a process, so when executing a process with a high execution priority specified, another low execution priority is specified. It is possible to prevent deprivation of computer resources due to the processing, and to give a large amount of computer resources to the processing designated with high execution priority.
[0005]
Therefore, it is possible to shorten the response time from the start to the end of the process for which the high execution priority is designated, and the value of the process is invalid or deteriorated unless it is completed within the designated end time limit or early. Therefore, execution suitable for real-time processing having such a property is possible.
[0006]
In the processing management system described above, it is desirable to execute more processing by effectively using computer resources. Further, in the processing management system using the execution priority, the order according to the execution priority. It is desirable to execute the process.
This is strongly desired in a process management system that executes processing by the subordinate occupation method as compared with a process management system that executes processes by another method.
[0007]
In such a process management system, when executing the round robin method, not only when executing the subordinate priority occupation method, etc., when executing the process according to the execution priority, the high execution priority Processing T_highProcess T with low execution priority for the data for which the lock is requested_lowProcess T with high execution priority because_highPriority reversal occurs, such as blocking the lock, and processing T with high execution priority_highThere has been a problem that the response time becomes longer.
[0008]
The above problems are particularly fatal in the subordinate priority occupation method.
For example, when one CPU is provided (in the case of a so-called single processor), the number of processes that can be occupied is only one, and the process T with a high execution priority is performed._highProcesses other than are not executed and process T with high execution priority_highIs a low-priority processing T_lowSince the data locked to the password cannot be used, the execution cannot proceed and the response time is extended as much as possible.
Further, when a plurality of CPUs are provided (so-called multiprocessor), the above-described high execution priority processing T_highAlthough it is possible to avoid a situation in which the response time of the system is prolonged, the high execution priority T_highThe response time is long.
[0009]
That is, in the case of a multiprocessor, the number of processes that can be performed exclusively can be made plural, and a process with higher execution priority (process T_highLow execution priority T after execution of_lowIs executed, the low execution priority process T_lowProcess T with high execution priority after_highExecution can proceed. However, high execution priority processing T_highThe execution of the process proceeds with a process with a higher execution priority than a process with a lower execution priority (process T_highAfter the execution of (Excluding) is completed, processing T with a lower execution priority_lowAfter a long time, such as after
[0010]
R. Abbott and H. Garcia-Molina, Scheduling Real-Time Transactions: A Performance Evaluation, ACM Transactions on Database Systems, Vol. 17, No. 3, 1992. (Hereinafter referred to as Document 1) includes a process T with a low execution priority._lowIs aborted (invalidated) and processing T with high execution priority_highAn HP (High Priority) method has been proposed in which the lock can be secured to the data by the process and the process proceeds.
[0011]
This HP method is an excellent method in terms of executing a process with a high execution priority with the highest priority, but cannot be said to be excellent in terms of executing a plurality of processes as efficiently as possible. . That is, in order to abort the low-priority processing, the computer resources given to the low-priority processing were wasted, and the execution efficiency for the processing was reduced when multiple processing was executed. .
[0012]
As a method for improving the execution efficiency for a plurality of processes with respect to the above-described HP method, Document 1 describes a WP (Wait Promote) method.
This WP method is a method for reducing the waste of computer resources, and processing T with high execution priority._highAnd low execution priority processing T_lowWhen priority inversion occurs between_lowProcess execution priority of T_highBy raising the execution priority to the same as process T_low, And then process T_highIs executed. Therefore, process T_lowIt is possible to reduce the waste of computer resources such as aborting.
[0013]
Furthermore, the low execution priority process T_lowProcess T with high execution priority_highIn order to raise the execution priority to_lowImmediately after execution is finished, process T_highFor example, the processing T occurring in the multiprocessor described above is performed._highProcessing with lower execution priority (Process T_lowProcess T if not waiting for other)_highProcess T can be prevented, process T_highThe response time can be shortened.
[0014]
Further, Document 1 proposes a CR (Conditional Restart) method combining the WP method and the HP method for the purpose of ending a process with high execution priority within a time limit.
This CR method is a process T with high execution priority._highAnd low execution priority processing T_lowEven if the WP method is applied when priority inversion occurs between_highIs determined to end within the deadline, the WP method is applied when it can be completed within the expiration date, and the HP method is applied when it cannot be completed.
[0015]
[Problems to be solved by the invention]
As described above, there are an HP method, a WP method, a CR method, and the like as countermeasures when priority inversion occurs.
However, each method described above is not suitable for executing a plurality of processes in the process management system.
For example, although the HP method is an excellent method in that processing is executed in the order of execution priority, computer resources such as aborting the processing are wasted, and the processing cannot be executed efficiently.
In addition, the WP method is an excellent method in terms of reducing the waste of computer resources such as aborting the process and executing the process efficiently, but the process could not be executed according to the order of execution priority. .
[0016]
In addition, the CR method is an excellent method in that the processing is completed within the time limit by selectively using the HP method and the WP method and having the advantages of both, but in order to use this CR method It is necessary to know in advance the execution time required for the process, for example, for a process in which the execution time cannot be grasped before executing the process, such as a search for a database in which the processing amount cannot be determined. Was not applicable and could not achieve any effect.
[0017]
Therefore, the present invention has been made in view of the above-described conventional circumstances, and even when the execution time required for processing is not known, the WP method and the HP method can be selected and applied as a response to the priority inversion. Executes processing as faithfully as possible with execution priority, and can efficiently execute processing without wasting computer resourcesProcessing management system and methodThe purpose is to provide.
[0018]
[Means for Solving the Problems]
In order to achieve the above object, according to the present invention, when the difference in execution priority between two processes is relatively small, the restriction on the order of executing the processes is weak, and the execution priority between the two processes is also low. When the difference in degrees is relatively large, it was made by paying attention to the fact that there is a strong restriction on the order in which the executions are executed. When priority inversion occurs, two priority inversions occur. Based on the execution priority difference between processes, a method for dealing with priority inversion is selected and applied.
In other words, when the execution order restriction for processing such as a relatively small execution priority difference is weak, the WP method that prevents the waste of computer resources is applied, and when the execution priority restriction is strong such that the execution priority difference is relatively large. The HP method is applied.
[0019]
Furthermore, the present invention provides an occupancy process that is executed while occupying a computer resource for which a relatively high execution priority is specified, and a non-execution process that is executed without occupying a computer resource for which a relatively low execution priority is specified. It was made with a focus on the fact that there is a strong restriction on the order in which processes are executed between exclusive processes. When priority inversion occurs between exclusive processes and non-exclusive processes, the non-exclusive processes are aborted. And execute the occupancy process.
[0020]
  Therefore, the process management system according to claim 1 includes a process execution unit that executes a process, and the process execution system executes a process according to a specified execution priority. A priority inversion detection unit that detects that a priority inversion has occurred between the two processes by managing the execution state;
Based on the detection of priority inversion by the priority inversion detection unit,High of the two processesA first process with an execution priority specified;LowA priority difference calculating unit that calculates a difference in execution priority with the second process for which the execution priority is specified, and a priority difference determining unit that compares the calculated execution priority difference with a preset specified value. And the priority difference determining unit determines that the execution priority difference is less than the specified value, and sets the execution priority of the second process to be equal to or higher than the execution priority of the first process. And an abort control unit that aborts the second process based on the fact that the priority difference determination unit determines that the execution priority difference is equal to or greater than a specified value. To do.
[0021]
In the process management system according to claim 1, the priority inversion detection unit detects the occurrence of priority inversion between the two processes by managing the execution state of the two processes being executed. Then, based on the detection, the priority calculation unit calculates a difference in execution priority between the first process in which the relatively high execution priority is specified and the second process in which the relatively low execution priority is specified. To do. Next, the priority difference determining unit compares the calculated execution priority difference with a predetermined value set in advance, and if it is determined that the execution priority difference is less than the specified value, the execution control corresponding unit sets the second When the execution priority of the process is set to be equal to or higher than the execution priority of the first process and the process execution unit is caused to execute the second process, if the execution priority difference is determined to be equal to or greater than the specified value, the abort handling unit Abort processing.
[0022]
  The process management system according to claim 2 includes a process execution unit that executes a process, and in the process management system in which the process execution unit executes a process according to a specified execution priority, a range that can be specified as the execution priority is , Having a range of high execution priority specified for processing executed while occupying the processing execution unit, and a range of low execution priority specified for processing executed without occupying the processing execution unit A priority inversion detection unit that detects that a priority inversion has occurred between the two processes by managing execution states of two processes in the middle, and a priority inversion detection unit detects priority inversion Based onHigh of the two processesA first process with an execution priority specified;LowA priority inversion determination unit for determining which range the execution priority of the second process for which the execution priority is specified belongs to each of the above ranges, and the first process has a high execution priority by the priority inversion determination unit. And a second abort handling unit that aborts the second process when it is determined that the second process belongs to the range of the low execution priority.
[0023]
In the process management system according to claim 2, the priority inversion detection unit detects the occurrence of priority inversion between the two processes by managing the execution status of the two processes being executed. To do. Based on this detection, the execution priority of the first process in which the priority inversion determination unit is designated with a relatively high execution priority and the second process in which a relatively low execution priority is designated are respectively the process execution units. The high execution priority range specified for processing executed exclusively and the low execution priority range specified for processing executed without occupying the processing execution unit To do. When the priority inversion determination unit determines that the first process belongs to the high execution priority range and the second process belongs to the low execution priority range, the second abort handling unit determines that the second abort response unit Abort processing.
[0024]
The process management system according to claim 3 is the process management system according to claim 2, wherein both the first process and the second process are determined to belong to a set of high execution priorities by the priority inversion determination unit. A priority difference calculation unit that calculates a difference in execution priority between the first process and the second process, and a priority difference determination that compares the calculated execution priority difference with a preset specified value The execution priority difference of the second process is set to be equal to or higher than the execution priority of the first process. An execution control responding unit that executes the process, and an abort responding unit that aborts the second process based on the determination that the execution priority difference is greater than or equal to the specified value by the priority difference determination unit. And
[0025]
  In the process management system according to claim 3, when the priority inversion determination unit determines that both the first process and the second process belong to the set of high execution priorities, the priority difference calculation unit is the first A difference in execution priority between the process and the second process is calculated, and the priority difference determination unit compares the calculated execution priority difference with a preset specified value. If the priority difference determination unit determines that the execution priority difference is less than the specified value, the execution control support unit sets the execution priority of the second process to be equal to or higher than the execution priority of the first process. When the execution priority difference is determined to be greater than or equal to the specified value, the abort handling unit aborts the second process.
  A process management method according to claim 4 and a process management method according to claim 5 are provided.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
A processing management system according to a first embodiment of the present invention will be described with reference to FIG.
The processing management system includes a processing request receiving unit 1 that receives processing requests, a priority determining unit 2 that specifies an execution priority for processing, a processing information management table 3 that stores information about processing, and a processing information management table A processing information management unit 4 that manages information to be stored in the computer, an operating system 5 that executes processing (hereinafter referred to as an OS), and a priority inversion detection unit that detects that a priority inversion has occurred in the process being executed. 6, a priority inversion handling unit 7 for handling the occurrence of priority inversion, an overload detection unit 8 for detecting an overload state in which a process being executed is executed beyond the end deadline, and an overload state There are provided an overload handling unit 9 for handling the processing that has become, and an end processing unit 10 for ending the processing.
[0027]
The process request accepting unit 1 has a queue for storing a plurality of processes requested to be executed. The process request accepting unit 1 is periodically started by interrupting the OS 5 and receives a process request. Are sequentially stored in the queue, and the stored processing is sequentially transferred to the priority determination unit 2.
[0028]
The priority determination unit 2 specifies an execution priority for the process based on the process received from the process request reception unit 1, and passes the specified execution priority together with the process to the process information management unit 4.
The execution priority includes the instruction from the user, the length of time required to execute the process, the priority given to the user who requested the process, the priority given to the terminal that requested the process, and the process. It is specified based on any one or a plurality of criteria such as a given time limit.
[0029]
The processing information management table 3 holds information relating to processing, and the information to be held is specified for the processing identification number (processing ID), processing end time limit, processing, for example, as shown in FIG. Execution priority, etc.
[0030]
The process information management unit 4 is activated upon receiving a process from the priority determination unit 2, sets information related to the process in the process information management table 3, and passes the process to the OS 5.
That is, when a process is received from the priority determination unit 2 and activated, the process information management unit 4 newly adds a table of information related to the received process to the process information management table 3, and the process of the process is added to the added table. The ID, process end time limit, and designated execution priority are set, and the process is passed to the OS 5.
Next, the processing information management unit 4 checks whether or not other processing is stored in the execution request receiving unit 1, and if the processing is not stored, the control is transferred to the OS 5 while the processing is stored. If so, the control is transferred to the processing request receiving unit 1.
[0031]
The OS 5 includes an execution waiting process holding unit 5a that stores a process passed from the process information management unit 4, an execution process determining unit 5b that gives an execution right to the process, and a process that executes the process given the execution right It has an execution unit 5c and an interruption process holding unit 5d that stores a process whose execution right has been taken away by a new process.
[0032]
The execution waiting process holding unit 5a includes a queue for temporarily storing processes. In the queue, execution priority is set and processes in the execution waiting state are stored, and the processes are arranged in descending order of execution priority. It is in a state.
[0033]
The execution process determination unit 5b immediately after a new process is stored in the execution waiting process holding unit 5a, immediately after the process executed by the process execution unit 5c is completed, or immediately after an instruction is given by the priority inversion processing unit 7. The processing with the highest execution priority is detected from the processing stored in the waiting processing holding unit 5a, the processing executed in the processing execution unit 6c, and the processing stored in the interruption processing holding unit 5d. The execution right is given to the process.
[0034]
For example, when the execution right is given to the process stored in the waiting process holding unit 5a, the process is taken out from the queue of the waiting process holding unit 5a and transferred to the process executing unit 5c. If the process execution unit 5c is executing a process at this time, the process being executed is stored in the interrupt process holding unit 5d.
When the execution right is given to the process stored in the interrupt process holding unit 5d, the process is removed from the queue of the interrupt process holding unit 5d and transferred to the process execution unit 5c.
When there are a plurality of processes to which the same execution priority is given, the execution right is given in order from the process that has been requested to be executed first.
[0035]
The process execution unit 5c executes the process passed from the execution process determination unit 5b, and continuously executes the process until interrupted by the process request receiving unit 1 or until the process being executed ends. In addition, when the process is normally completed, the completion processing unit 10 is notified that the process has been normally completed.
[0036]
The interrupt process holding unit 5d is executed by the process execution unit 5c, but the process that has been deprived of the execution right by the process having a high execution priority that has issued a new process request, or the priority inversion processing unit 7 The queue is stored in a state where the processing is interrupted, and the queue is stored in order from the processing having the highest execution priority.
The interrupted state represents, for example, a state in which the lock is secured when the process secures the lock on the data.
[0037]
The priority inversion detection unit 6 periodically determines whether or not priority inversion occurs in the process being executed, such as the process being executed by the process execution unit 5c or the process being held by the interruption process holding unit 5d. If priority inversion has occurred, two processes in which the priority inversion has occurred are passed to the priority inversion handling unit 7.
[0038]
Note that the occurrence of priority inversion occurs when, for example, a process that secures a lock for each data of a certain unit amount is grasped, and a certain process uses the data. It is possible to detect whether another process has secured the lock on the data. That is, in this embodiment, there is one process execution unit 5c, and the process is executed by the subordinate priority occupation method. Therefore, the execution priority of the process executed by the process execution unit 5c is the highest, and the process If other processing has secured the lock on the data that the user wants to use, this means that priority inversion has occurred, so other processing has secured the lock on the data that the processing wants to use. It is possible to detect the occurrence of priority inversion by detecting whether or not this is done.
[0039]
The priority inversion correspondence unit 7 compares a priority difference calculation unit that calculates a difference in execution priority between two processes in which priority inversion has occurred, and a priority that compares the execution priority difference with a preset specified value. A difference determination unit, an execution control response unit corresponding to the execution priority difference determined to be less than the specified value, and an abort response unit corresponding to the execution priority difference determined to be equal to or greater than the specified value When the priority inversion occurs, the difference between the execution priorities between the two processes in which the priority inversion occurs is compared with a preset specified value, and the WP method or Select and apply the HP method.
[0040]
That is, the high-priority priority processing T passed from the priority reverse detection unit 6 by the priority calculation unit_highAnd low execution priority processing T_lowAnd a difference between the execution priorities calculated by the priority difference determination unit and the specified value.
As a result of the comparison, if the execution priority difference is less than the specified value, the execution control corresponding unit performs the process T_lowProcessing T_highSet the same execution priority as process T_highIs transferred to the interruption processing holding unit 5d. Next, the execution control support unit issues an instruction to determine the process for giving the execution right to the execution process determination unit 5b, and the process execution unit 5c receives the process T._lowIs executed.
On the other hand, if the execution priority difference is equal to or greater than the specified value as a result of the comparison, the abort handling unit performs processing T._lowIs aborted and transferred to the execution waiting process holding unit 5a. As a result, processing T_highCan secure the lock on the data, and execution will proceed.
[0041]
Here, processing T_highAnd processing T_lowIs referred to from the processing information management table 3.
In addition, the above-mentioned specified value to be set in advance is a method for executing a process with a low execution priority first rather than aborting a process with a low execution priority in response to a priority inversion occurring between two processes. This is a difference in execution priority at a critical point such as “good” and can be determined by the user or the system.
[0042]
The overload detection unit 8 extracts the time limit D for the process being executed by the process execution unit 5c from the processing information management table 3, receives the current time t from the time management unit (not shown), and receives the time limit D extracted. The time t is compared. As a result, if the time limit D is the same as the time t or the time t is later than the time limit D, the processing executed by the process execution unit 5c is aborted and passed to the overload handling unit 9, while the time limit D Is later than time t, the process execution by the process execution unit 5c is continued.
[0043]
When receiving the process from the overload detection unit 8, the overload handling unit 9 stops the execution of the process and notifies the end processing unit 10 that the execution of the process has been stopped.
[0044]
When the termination processing unit 10 receives a notification of normal processing termination from the OS 5 or a notification for canceling the execution of processing from the overload handling unit 9, the termination processing unit 10 notifies the received notification to the application or the user.
[0045]
Next, the operation of the process management system according to the first embodiment of the present invention will be described.
When a request for executing a certain process is issued, the process request receiving unit 1 receives and stores the process, and passes the sequentially stored processes to the priority determining unit 2.
Then, the priority determination unit 2 determines the execution priority of the process passed from the process request reception unit 1 and passes the execution priority determined together with the process to the process information management unit 4.
[0046]
The processing information management unit 4 adds a table related to the received processing to the processing information management table 3, and passes the processing to the execution waiting processing holding unit 5a. The execution waiting process holding unit 5a stores the received process until the execution right is given by the execution process determining unit 5b.
[0047]
The execution right is given by the execution process determining unit 5b performing the operations shown in FIGS.
First, the execution process determination unit 5b detects whether or not there is a process being executed in the process execution unit 5c (step S1).
[0048]
If there is no process being executed in the process execution unit 5c, it is detected whether or not there is a process in the execution waiting process holding unit 5a (step S2) and further whether or not there is a process in the interrupt process holding unit 5d. (Steps S3 and S4).
If it is detected that the process is stored in both the waiting process holding unit 5a and the interrupt process holding unit 5d, the process t having the highest execution priority stored in the waiting process holding unit 5a_waitAnd the processing t with the highest execution priority stored in the interruption processing holding unit 5d_intAre compared (step S5), and the right of execution is given to the process with the higher execution priority (steps S6 and S7).
[0049]
On the other hand, if it is detected that the process is stored in either the execution waiting process holding unit 5a or the interruption process holding unit 5d, the process stored in the execution waiting process holding unit 5a or the interruption process holding unit 5d The right to execute is given to the process having the highest execution priority among the processes (steps S6 and S7). If it is detected that no process is stored in both the waiting process holding unit 5a and the interrupt process holding unit 5d, no execution right is given because there is no process to be executed.
[0050]
On the other hand, if there is a process being executed in the process execution unit 5c, it is detected whether or not the process is stored in the execution waiting process holding unit 5a (step S8).
If it is detected that the process is stored in the waiting process holding unit 5a, the process t being executed_runExecution priority and the process t with the highest execution priority among the processes stored in the execution waiting process holding unit 5a_waitAre compared with the execution priority (step S9), and the process t stored in the execution waiting process holding unit 5a is compared._waitProcess t whose execution priority is being executed_runWhen the execution priority is higher than the execution priority of the current process t_runIs stored in the interrupt processing holding unit 5d (step S10), and the process t stored in the execution waiting process holding unit 5a is stored._waitIs given an execution right (step S11).
On the other hand, when it is detected that no process is stored in the waiting process holding unit 5a, or when it is detected that a process is stored, the process t stored in the waiting process holding unit 5a_waitMore processing t_runIf it is detected that the execution priority of is high, the process t being executed is_runThe execution right is continuously given to (step S12).
[0051]
When the execution right is given to the process, the process is executed by the process execution unit 5c. When the process is completed normally, the end processing unit 10 is notified that the process has been completed normally.
[0052]
When the process is executed by the process execution unit 5c described above, the overload detection unit 8 detects that an overload state has occurred, and the priority reverse detection unit 6 determines the priority for the process being executed. Detect that reversal is occurring.
That is, the overload detection unit 8 receives the current time from the time management unit, receives the time limit for the process being executed managed in the process management table 3, and the current time exceeds the time limit and is overloaded. If it is, the process being executed is transferred to the overload handling unit 9.
[0053]
On the other hand, the priority inversion detection unit 6 detects whether or not the process being executed by the process execution unit 5c is blocked by the process held in the interruption process holding unit 5d and blocking the data lock. Detect the occurrence of degree reversal. If it is detected that priority inversion has occurred, two processes in which priority inversion has occurred are passed to the priority inversion handling unit 7.
[0054]
When the overload detection unit 8 detects that the process is in an overload state during execution of the process by the execution processing unit 5c and the overload handling unit 7 receives the process, the overload handling unit 9 performs the process. Abort and notify the end processing unit 10 that the processing is not executed.
[0055]
On the other hand, when the priority inversion detection unit 6 detects that the priority inversion has occurred during the execution of the processing by the execution processing unit 5c described above, the two processes in which the priority inversion has occurred are changed to the priority inversion corresponding unit 7. Is received, the priority inversion handling unit 7 performs the following priority inversion handling process.
First, the priority inversion handling unit 7 reads the execution priorities of the two received processes from the process information management table 3 (step S13), and the process T for which a relatively high execution priority is designated._highAnd process T for which a relatively low execution priority is specified_lowThe difference d of the execution priorities is calculated (step S14).
[0056]
Next, the calculated execution priority difference d is compared with a preset specified value (step S15). If the execution priority difference d is less than the specified value, the process T_highAnd processing T_lowThe restriction on the execution order is weak and processing T_lowProcess T rather than aborting_lowRepresents that it is better to execute the process first._lowProcessing T_highSet the same execution priority as the execution priority of_highIs sent to the interruption process holding unit 5d, and an instruction is given to determine the process for giving the execution right to the execution process determination unit 5b (step S16). As a result, the execution right is determined by the execution process determination unit 5b as the process T._lowAnd processing T_lowIs executed by the process execution unit 5c, and then the process T is continued._highWill be executed.
[0057]
On the other hand, when the execution priority difference d is larger than the specified value, the process T_highAnd processing T_lowThere are strong restrictions on the execution order, and process T_highMust be executed first, so process T_lowIs passed to the execution waiting process holding unit 5a (step S17). As a result, processing T_highCan secure a lock on the data and execution proceeds. The aborted process T_lowWill be executed again from the beginning.
[0058]
When the notification that the processing has been normally completed is received from the processing execution unit 5c, or when the notification that the processing is not to be executed is received from the overload handling unit 9, the termination processing unit 10 Information based on the notification received.
[0059]
As described above, when priority inversion occurs, even for a process whose execution time is unknown, there is a restriction on the execution order according to the execution priority due to the execution priority difference between the processes in which the priority inversion has occurred. Appropriate execution of processing in the execution order according to the execution priority when it is strong, and preventing waste of computer resources rather than keeping the execution order when restrictions on the execution order according to the execution priority are weak You can select the appropriate response.
[0060]
In the above embodiment, the processing execution unit 5c executes processing according to the subordinate priority occupation method. However, the present invention is not limited to this, and the processing execution unit 5c performs processing according to the execution priority in a non-occupied method such as a round robin method. The sub priority occupation method and the non-occupancy method described above may be switched and executed depending on the process. In short, any method that executes the process according to the execution priority may be used. .
[0061]
In the case where the process is executed according to the non-occupancy method, the priority inversion detection unit 6 grasps, for example, a process that secures a lock for the data for every certain unit amount of data. In addition, when a certain process uses data, it is detected whether or not another process has secured the lock on the data, and when the lock is secured, Therefore, the occurrence of priority inversion can be detected, and the effects of the present invention can be obtained.
[0062]
A processing management system according to the second embodiment of the present invention will be described with reference to FIG. In addition, the same code | symbol is attached | subjected to the same part as the process management system based on 1st Example shown in FIG. 1, and the overlapping description is abbreviate | omitted.
This processing management system corresponds to the priority inversion according to the processing method of the two processes in which the priority inversion occurs in the processing management system shown in the first embodiment. A priority inversion determination unit 11 is newly provided to determine a processing method of a process in which priority inversion occurs.
[0063]
The OS 5 manages the execution of the occupying process executed while occupying the process execution unit 5c and the non-occupying process executed without occupying the process execution unit 5c. If a new occupancy process is requested while the occupancy process is being executed and the non-occupancy process is being executed, the non-occupancy process is immediately interrupted and a new occupancy process is executed.
[0064]
The priority inversion determination unit 11 is a priority inversion determination unit that determines the processing method of the process in which the priority inversion occurs, and when the priority inversion occurs between the exclusive process and the non-occupied process. A second abort handling unit that performs correspondence, and grasps the range of high execution priority specified for exclusive processing and the range of low execution priority specified for non-occupied processing, and a priority inversion detection unit It is determined which of the two ranges each of the two processes passed from 6 belongs, and the correspondence shown in FIG. 7 is performed according to the determined result.
[0065]
That is, the high execution priority processing T received from the priority inversion detection unit 6_highAnd low execution priority processing T_lowThe priority inversion determination unit determines which of the above-mentioned ranges belongs to.
As a result, processing T_highBelongs to the high execution priority range specified for exclusive processing, and processing T_lowIs determined to belong to the low execution priority range designated as the non-occupied process, the process T in which the second abort part is the non-occupied process_lowIs the exclusive process T_highProcess T is a non-occupied process._lowAbort.
On the other hand, processing T_highAnd processing T_lowAre determined to belong to the low execution priority range designated as the non-occupied process, the two processes are the non-occupied processes, so nothing is performed, and the process T_highAnd processing T_lowAre determined to belong to the high execution priority range designated for the occupancy process, the two processes are passed to the priority inversion handling unit 7.
[0066]
Next, the operation of this processing management system will be described. The description of the same operation as in the first embodiment is omitted.
When the priority inversion detection unit 6 detects the occurrence of the priority inversion while the OS 5 is executing the process, the two processes in which the priority inversion is generated are passed to the priority inversion determination unit 11, Upon receiving the process, the priority inversion determination unit 11 performs a process for handling the priority inversion shown in FIG.
First, the priority inversion determination unit 11 performs a process T having a relatively high execution priority among the received processes._highIs a dedicated process (step S18), and the process T having a relatively low execution priority among the received processes is detected._lowIs detected as an occupancy process (steps S19 and S20).
[0067]
Processing T_highAnd processing T_lowAre both occupied processes, the two processes are transferred to the priority inversion handling unit 7 (step S21).
On the other hand, processing T_highIs the occupancy process and process T_lowIs a non-occupied process, the process T_lowProcess T, which is an exclusive process_highCan be executed (step S22).
Processing T_highAnd processing T_lowIf both are unoccupied processes, nothing is done. Processing T_highIs unoccupied processing, and processing T_lowIs an exclusive process, an error process is performed since it cannot occur.
[0068]
Next, in the processing management system according to the second embodiment, an example in which a commercially available OS, Solaris 2.5 (Solaris is a registered trademark), is used as the OS 5 in comparison with the processing management system according to the first embodiment. Note that Solaris 2.5 has 0 to 159 as execution priorities, 0 to 59 are execution priorities for unoccupied processing, and 60 to 99 are execution priorities for systems that cannot be specified for processing. , 100 to 159 are execution priorities for exclusive processing.
[0069]
Here, a case where priority inversion occurs between an unoccupied process in which the execution priority “59” is designated and an occupied process in which the execution priority “100” is designated will be described as an example.
In this case, in the process management system according to the first embodiment, for example, there is a possibility that the non-occupying process is executed before the occupying process depending on how to obtain the specified value. That is, if the specified value is set to “50”, the difference in execution priority between the two processes in which priority inversion has occurred is less than the specified value “50”, so the unoccupied process is the same as the occupied process. The priority is raised to the execution priority, and the unoccupied process is executed before the occupied process.
This is a problem for exclusive processing where an end deadline or the like is given or early execution is desired.
On the other hand, in the processing management system of the second embodiment, when the above-described priority inversion occurs, the unoccupied process is always aborted, so that the occupied process can be executed immediately.
[0070]
As described above, when priority inversion occurs, the occupation process can be executed without being obstructed by the non-occupancy process. Furthermore, if there are strong restrictions on the execution order according to the execution priority based on the difference in execution priority for the two exclusive processes where priority inversion has occurred, the processes are executed in the execution order according to the execution priority. When the restriction on the execution order according to the execution priority is weak, it is possible to select an appropriate response such as preventing waste of computer resources rather than keeping the execution order.
[0071]
Even if the priority inversion handling unit 7 is not provided in the second embodiment, the occupation process can always be executed without being obstructed by the non-occupancy process when the priority inversion occurs.
The OS 5 of the first and second embodiments described above may use an OS such as Solaris 2.5, Windows NT 3.5 (Windows is a registered trademark), or the like.
[0072]
The priority inversion handling unit 7 sets the low execution priority process to the same execution priority as the high execution priority process as the priority inversion handling. It may be set higher than the execution priority.
In addition, the overload handling unit 9 performs control to stop the re-execution of the received process. For example, the overload handling unit 9 makes computer resources useless from other processes such as lowering the priority of the received process and re-executing it. You may perform control which does not take away.
In addition, the overload detection unit 8 and the overload handling unit 9 may not be provided, but a situation in which a process whose value has been significantly reduced beyond the end deadline by using it prevents the execution of other processes such as using computer resources. Can be prevented.
[0073]
In addition, although each above-mentioned function part 1-11 is comprised when CPU operate | moves according to a program, you may comprise these function parts as an independent hardware circuit.
In the first and second embodiments described above, the single processor having one processing execution unit 5c has been described. However, the present invention can also be applied to a multiprocessor including a plurality of processing execution units 5c.
[0074]
【The invention's effect】
As explained aboveIn the present inventionWhen priority inversion occurs, the HP method or WP method is selected by comparing the difference in execution priority between the two processes in which priority inversion occurs and the preset specified value. As a result, processing can be executed faithfully to the execution priority, computer resources can be saved, and processing can be executed efficiently.
Also,In the present inventionSince the two types of processing in which priority inversion occurred are detected and the two processings are exclusive processing and non-exclusive processing, the non-exclusive processing is aborted. Can be executed, and can be executed suitable for the occupation process.
[Brief description of the drawings]
FIG. 1 is a configuration diagram of a processing management system according to a first embodiment.
FIG. 2 is a diagram illustrating a processing information management table according to the first embodiment.
FIG. 3 is a first flowchart illustrating an operation performed by an execution process determination unit according to the first embodiment.
FIG. 4 is a second flowchart illustrating an operation performed by an execution process determination unit according to the first embodiment.
FIG. 5 is a flowchart illustrating an operation corresponding to priority inversion according to the first embodiment;
FIG. 6 is a configuration diagram of a processing management system according to a second embodiment.
FIG. 7 is a diagram for explaining an operation corresponding to priority inversion according to the second embodiment;
FIG. 8 is a flowchart illustrating an operation corresponding to priority inversion according to the second embodiment.
[Explanation of symbols]
5 ... OS, 5c ... Process execution unit,
6 .... Priority inversion detection section, 7 .... Priority inversion support section,
11. Priority inversion judgment section,

Claims (5)

In a process management system that includes a process execution unit that executes a process, and the process execution unit executes a process according to a specified execution priority,
A priority inversion detection unit that detects that a priority inversion has occurred between the two processes by managing execution states of the two processes in the middle of execution;
Execution of the first process in which the high execution priority is designated and the second process in which the low execution priority is designated among the two processes based on the priority inversion detection unit detecting the priority inversion. A priority difference calculation unit for calculating a difference in priority;
A priority difference determination unit that compares the calculated execution priority difference with a preset specified value;
Based on the fact that the execution priority difference is determined to be less than the specified value by the priority difference determination unit, the execution priority of the second process is set to be equal to or higher than the execution priority of the first process, and the second process is executed by the process execution unit. An execution control support unit
A processing management system, comprising: an abort handling unit that aborts the second process based on a determination that the execution priority difference is greater than or equal to a predetermined value by the priority difference determination unit. In a process management system that includes a process execution unit that executes a process, and the process execution unit executes a process according to a specified execution priority,
The range that can be specified as the execution priority is a range of high execution priority that is specified for a process that occupies a process execution unit and a low execution that is specified for a process that is executed without occupying the process execution unit A range of priorities,
A priority inversion detection unit that detects that a priority inversion has occurred between the two processes by managing execution states of the two processes in the middle of execution;
Execution of the first process in which the high execution priority is designated and the second process in which the low execution priority is designated among the two processes based on the priority inversion detection unit detecting the priority inversion. A priority inversion determination unit for determining which range each of the priorities belongs to;
Corresponding to the second abort in which the first process is determined to belong to the high execution priority range and the second process belongs to the low execution priority range by the priority inversion determination unit. And a processing management system characterized by comprising: In the processing management system according to claim 2,
A difference in execution priority between the first process and the second process is calculated based on the determination that both the first process and the second process belong to the set of high execution priorities by the priority inversion determination unit. A priority difference calculator,
A priority difference determination unit that compares the calculated execution priority difference with a preset specified value;
Based on the fact that the execution priority difference is determined to be less than the specified value by the priority difference determination unit, the execution priority of the second process is set to be equal to or higher than the execution priority of the first process, and the second process is executed by the process execution unit. An execution control support unit
A processing management system, comprising: an abort handling unit that aborts the second process based on a determination that the execution priority difference is greater than or equal to a predetermined value by the priority difference determination unit. In a process management method in a computer process management system comprising a process execution unit for executing a process and performing a process by the process execution unit according to an execution priority,
  Based on detecting that a priority inversion has occurred between two processes in the middle of execution,
  A difference in execution priority between the first process in which a high execution priority is specified and the second process in which a low execution priority is specified is calculated,
  The calculated execution priority difference is compared with a preset specified value. If the execution priority difference is less than the specified value, the execution priority of the second process is set to be equal to or higher than the execution priority of the first process. When the second process is executed and the difference in execution priority is equal to or greater than a specified value, the second process is aborted. In a process management method in a computer process management system comprising a process execution unit for executing a process and performing a process by the process execution unit according to an execution priority,
  The range of high execution priority specified for processing executed exclusively by the processing execution unit, and the processing execution unit And a low execution priority range designated for processing executed without occupying
  A first process in which a high execution priority is designated and a second process in which a low execution priority is designated on the basis of detection of a priority inversion occurring between two processes in the middle of execution; It is determined which of the above ranges each execution priority belongs to,
  A process management method in a computer process management system, wherein a second process is aborted when the first process belongs to a range of high execution priority and the second process belongs to a range of low execution priority.

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