JP2009169790A - Task controller and task control method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a task controller and a task control method for flexibly changing priority of each task. <P>SOLUTION: The task controller 1 controls order of processing of a plurality of tasks on the basis of priority and includes: an running task priority register 11 for storing original priority to be bit data of many digits having a running task; an execution waiting task priority register 12 for the task waiting to be executed to store original priority; a priority hierarchy mask register 16 for storing mask data to be bit data of many digits whose validity/invalidity is set in a digit unit; a masking means 13 for performing mask operation according to the original priority of the running task and mask data to calculate a first priority; a masking means 14 for performing mask operation according to the original priority of the task waiting to be executed and the mask data to calculate a second priority; and a determining means 15 for comparing the first priority with the second priority to determine a task of higher priority. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a task control apparatus and a task control method, and in particular, by controlling the processing order of a plurality of tasks based on priority, each task is organically executed, thereby realizing a predetermined function. The present invention relates to a task control device and a task control method in a processing system.

  When the recording function is considered as a certain function in the processing system, the recording function is realized by organically operating three tasks as an input processing task, a voice compression processing task, and an output processing task. In general, a certain function is realized by executing a plurality of tasks organically.

  Some functions require performance to be guaranteed. The performance here refers to processing time, processing accuracy, and the like. For example, in the case of the recording function described above, in order to perform real-time recording, all three tasks must complete processing within a certain time. Therefore, in order to realize real-time recording, the processing time of each task must be guaranteed.

  In the processing system, a task control method for assigning priorities to all tasks and executing the tasks in descending order of priority is generally called priority-based scheduling. Priorities are determined at the design stage of the processing system and are managed centrally.

  Patent Document 1 proposes a method of maintaining performance as a function by grouping tasks and giving priority in units of groups. In Patent Document 1, a main priority table (group 0) and a sub priority table (group 1, group 2) are created, and task processing is normally executed with task priorities determined by the main priority table. When the tasks belonging to 1 and group 2 have the highest priority, task processing is executed according to the task priority determined by the respective sub priority tables. As a result, the functions grouped in group 1 and group 2 can obtain performance as functions without being influenced by other tasks and groups.

Further, Patent Document 2 has a plurality of tasks which are execution units of program processing, each of the tasks has execution priority information indicating a priority, and these tasks are divided into a plurality of groups for each task group. The present invention relates to a task management device that manages task execution. The task group switching means included in the task management device in Patent Document 2 determines a task group whose execution is enabled according to the order in which execution of each task group is enabled, execution time data to be assigned, and command timing. To do. Then, the task group switching means included in the task management device increases the execution priority of each task belonging to the task group that enables execution for all tasks in the execution state, the executable state, and the execution waiting state. And lower the execution priority of each task belonging to the task group for which execution is disabled. As a result, the task having the highest execution priority can be selected and executed from the tasks in the execution state and the executable state.
JP 2002-163120 A JP 2004-326486 A

  However, Patent Document 2 has a problem that a group of tasks whose priority is changed is fixed. This is because in Patent Document 2, the priority is changed in units of predetermined task groups. Further, Patent Document 1 does not consider changing the task priority.

  However, even if the performance of the task group itself can be guaranteed, the performance of the entire processing system may not be guaranteed. This becomes more significant as the target processing system is larger.

  In addition, when using the concept of QoS (Quality of Service), functions and tasks may require performance at a certain timing and may not require performance at another timing. That is, the required performance is not constant depending on the status of the processing system.

  That is, the task execution order in the processing system cannot guarantee the required performance only by a fixed grouping, and it is necessary to be able to change the priority of the task flexibly according to the situation.

  The task control device according to the first aspect of the present invention (for example, the task control device 1 according to the first embodiment of the present invention) controls the processing order of a plurality of tasks based on the priority. A first original priority storage unit (for example, an in-execution task priority register 11 according to the first embodiment of the present invention) that stores original priorities that are multi-digit bit data included in one task; A second original priority storage unit (for example, an execution waiting task priority register 12 according to the first embodiment of the present invention) that stores original priorities that are multi-digit bit data of a task, and validity / invalidity in units of digits A mask data storage unit (for example, the priority hierarchy mask register 16 according to the first embodiment of the present invention) that stores mask data that is bit data of a plurality of digits set to the first original priority rank A first priority is calculated by extracting a digit corresponding to a digit set as valid in the mask data stored in the mask data storage unit from the original priority stored in the mask data storage unit; A priority calculation unit that extracts a digit corresponding to a digit set as valid in the mask data from the original priority stored in the original priority storage unit and calculates a second priority (for example, according to the present invention) A determining unit (for example, the present invention) that compares the first priority and the second priority with the mask unit 13 and the mask unit 14 in the first embodiment and determines a task with a high priority. Determination means 15) in the first embodiment.

  As described above, the task control device according to the first aspect of the present invention is set to be effective in the mask data by giving each digit of the original priority of each task meaningful. The priority can be calculated by the process of extracting the digit corresponding to the digit. Therefore, task priority can be changed flexibly.

  The task control method according to the second aspect of the present invention controls the processing order of a plurality of tasks based on the priority, and is based on the original priority that is the multiple-digit bit data of the first task. A step of calculating a first priority by extracting a digit corresponding to a digit set as valid in mask data which is bit data of a plurality of digits in which valid / invalid is set in units of digits, and a second task A step of calculating a second priority by extracting a digit corresponding to a digit set to be valid in the mask data from the original priority, and the first priority and the second priority And determining a task having a high priority.

  The task control method according to the second aspect of the present invention can calculate the priorities of the first task and the second task from the mask data, respectively. This makes it possible to easily change the task priority.

  According to the present invention, a task control device and a task control method for flexibly changing the priority of each task according to the situation by assigning a priority having a meaning to each digit of each task are provided. Can do.

  Hereinafter, specific embodiments to which the present invention is applied will be described in detail with reference to the drawings. In the drawings, the same elements are denoted by the same reference numerals, and redundant description will be omitted as necessary for the sake of clarity.

Embodiment 1 of the Invention
The task targeted in the first embodiment of the present invention has the original priority for calculating the priority. The original priority is data of a plurality of bits, and here, it is assumed that the number of digits of the original priority is 8 bits. However, the number of digits of the original priority is not limited to this, and may be 16 bits, 32 bits, or the like.

  Further, as a premise for the following description, the priority value having a smaller absolute value is set as the higher priority. That is, 0 is the highest priority.

  FIG. 1 is a block diagram illustrating a configuration example of a task control device 1 according to the first embodiment of the present invention. The task control device 1 includes an execution task switching unit 10, a task execution unit 20, an execution waiting task queue 30, and a priority level selection unit 40.

  The execution task switching unit 10 is a unit that switches between a task executed by the task execution unit 20 and a task stored in the execution waiting task queue 30. The execution task switching unit 10 includes an executing task priority register 11, an execution waiting task priority register 12, a mask unit 13, a mask unit 14, a determination unit 15, and a priority hierarchy mask register 16.

  The in-execution task priority register 11 is a register in which the original priority of a task executed by the task execution means 20 is stored. The execution waiting task priority register 12 is a register that stores the original priority of the first task among the execution waiting tasks stored in the execution waiting task queue 30. The priority hierarchy mask register 16 is a register in which mask data which is data of a plurality of bits set by the priority hierarchy selection means 40 is stored. Here, the number of digits of the mask data is 8 bits. However, the number of digits of the mask data is not limited to this, like the number of digits of the original priority.

  The mask unit 13 is a unit that performs an AND operation on the original priority stored in the executing task priority register 11 and the mask data stored in the priority hierarchy mask register 16 and calculates a first calculation result. . The mask means 14 is a means for performing an AND operation on the original priority stored in the execution waiting task priority register 12 and the mask data stored in the priority hierarchy mask register 16 and calculating a second operation result. . The determination unit 15 compares the first calculation result and the second calculation result, and if the absolute value of the second calculation result is smaller, the determination unit 15 sets the value of the execution waiting task priority register 12 to the executing task priority. Means for storing in the register 11.

  The execution task switching means 10 starts processing at the task control timing. Here, the control timing is, for example, an event such as interruption or task execution end by the task execution means 20. Further, the execution task switching unit 10 notifies the task execution unit 20 of the fact after the processing is completed.

  The task execution unit 20 is a unit that acquires a task stored in the execution waiting task queue 30, sets the task to an execution state, and executes the task. The task execution means 20 usually acquires the task in order from the first task in the queue of the execution waiting task queue 30. Further, the task execution means 20 is activated upon receiving a notification of the end of the process of the execution task switching means 10. In that case, the task execution means 20 compares the original priority of the task to be executed with the value of the executing task priority register 11. If they do not match, the task execution means 20 searches the execution waiting task queue 30 for a task whose original priority is the value of the executing task priority register 11, and executes the searched task as an execution target of the task execution means 20. Acquire and execute as a task. Further, the task execution unit 20 notifies the execution task switching unit 10 of the fact after the processing is completed. The specific task switching means is well known as a publicly known technique, and therefore detailed description thereof is omitted here.

  The waiting task queue 30 is a queue that stores tasks that are ready to be executed and are waiting to be executed.

  The priority hierarchy selection means 40 is a means for selecting a digit to be valid in the mask data and updating the mask data stored in the priority hierarchy mask register 16.

  FIG. 2 is a block diagram showing a configuration example of the priority hierarchy selection means 40 and the priority hierarchy mask register 16 according to the first exemplary embodiment of the present invention. As shown in FIG. 2, the priority level selection means 40 includes a Layer1 setting SW41, a Layer2 setting SW42, and a Layer3 setting SW43, which are setting SWs (switches) for each level. The Layer 1 setting SW 41, the Layer 2 setting SW 42, and the Layer 3 setting SW 43 are means for holding 1-bit information, and are connected to each bit of the priority hierarchy mask register 16.

  In FIG. 2, the Layer1 setting SW 41 is connected to 4 bits of the mask register 0th bit 160, the mask register 1st bit 161, the mask register 2nd bit 162, and the mask register 3rd bit 163 of the priority hierarchy mask register 16. The The Layer 2 setting SW 42 is connected to 3 bits of the mask register fourth bit 164, the mask register fifth bit 165, and the mask register sixth bit 166 of the priority hierarchy mask register 16. The Layer 3 setting SW 43 is connected to one bit of the seventh bit 167 of the mask register of the priority hierarchy mask register 16.

  For example, when the priority level selection means 40 sets the setting value of the Layer 1 setting SW 41 to “1”, the setting value of the Layer 2 setting SW 42 to “1”, and the setting value of the Layer 3 setting SW 43 to “0”, the priority level mask The value of the mask data stored in the register 16 is “01111111”, which is “7F” in hexadecimal. Hereinafter, h is added to those representing hexadecimal numbers. For example, in the above example, it is expressed as “7Fh”.

  Here, the definition of the original priority and the digit of the mask data according to the first exemplary embodiment of the present invention will be described with an example. For example, regarding the digits of the original priority, the four digits from the 0th bit to the third bit are set as individual priorities (first regions) representing individual priorities in the task group. This indicates that the priority within the same group can be set in 16 levels.

  In addition, regarding the digits of the original priority, three digits from the fourth bit to the sixth bit are set as a group priority (second region) representing the priority between groups. This indicates that the priority between groups can be set in eight stages.

  Then, with respect to the original priority digit, when the first digit of the seventh bit is specified, it is set as a specific priority (third region) representing a flag for giving priority. This indicates that it can be set (in two steps) whether or not it is a specific task to be prioritized regardless of the group. Or specific priority can be used as a group of the upper or lower hierarchy of group priority. Furthermore, the specific priority can be used as a group different from the group defined by the group priority.

  Further, with respect to the mask data, the Layer 1 setting SW 41 may be assigned to the individual priority, the Layer 2 setting SW 42 to the group priority, and the Layer 3 setting SW 43 to the specific priority in correspondence with the above-described original priority digits.

  In this way, the priority can be easily changed by switching each setting SW by the priority level selection means 40 each time. That is, when managing each task for each group, the group priority of tasks in the same group is set to the same value in advance. Then, by setting the setting value of the Layer 2 setting SW 42 to “1”, the group priority can be validated and the task execution order can be determined.

  In addition to the group priority, a specific priority may be used when giving priority to a specific task. In this case, by setting the Layer 3 setting SW 43 to “1”, the specific priority can be validated and the task execution order can be determined.

  In the first area, the second area, and the third area, the positions of bits connected to each other and the number of digits may be interchanged.

  Note that the type of setting SW and the number of digits connected to each setting SW in the priority level hierarchy selection means 40 are not limited to those described above. Furthermore, a plurality of setting SWs corresponding to the specific priority may exist. The group priority may be represented by a plurality of setting SWs.

  The process of the task control device 1 according to the first embodiment of the present invention will be specifically described below. First, data used in the following will be described. Here, for the definition of the original priority and the digit of the mask data, the above-described example is used.

  FIG. 3 is a diagram showing examples of task names and original priorities executed in the task control apparatus 1 according to the first embodiment of the present invention. As shown in FIG. 3, the group priority of tasks belonging to group 1 is “001”, and the group priority of tasks belonging to group 2 is “010”. That is, group 1 has a higher priority than group 2. In addition, “0” is set as the specific priority only for the task Y, and “1” is set as the specific priority in the other tasks A to D, X, and Z.

  FIG. 4 is a diagram showing an example of the queue state of the execution waiting task queue 30 according to the first embodiment of the present invention. Here, it is assumed that the task being executed by the task execution means 20 is a task X, and other tasks are in the execution waiting task queue 30 in the order shown in FIG.

  The value of the mask data stored in the priority hierarchy mask register 16 is “7Fh”. That is, the individual priority and the group priority are valid, and the specific priority is invalid.

  Next, FIG. 7 is a flowchart showing a processing flow of the execution task switching unit 10 according to the first exemplary embodiment of the present invention. First, at the control timing, the execution task switching means 10 is activated. Therefore, the execution task switching unit 10 stores the original priority of the task being executed in the execution task priority register 11 from the task execution unit 20 (S11). Here, the value stored in the executing task priority register 11 is “A0h” which is the original priority of the task X being executed.

  Next, the execution task switching means 10 determines whether or not there is an unprocessed task in the execution waiting task queue 30 (S12). That is, the execution task switching unit 10 repeats steps S12 to S17 for all tasks in the execution waiting task queue 30.

  If there is an unprocessed task in the waiting task queue 30, the process proceeds to step S13. If not, that is, all tasks in the waiting task queue 30 are processed by the executing task switching means 10. In this case, the execution task switching unit 10 ends the process. Here, since the task shown in FIG. 4 exists in the waiting task queue 30, the process proceeds to step S13.

Then, the mask means 13 of the execution task switching means 10 obtains the first calculation result by AND operation from the mask data stored in the priority hierarchy mask register 16 and the value stored in the executing task priority register 11. Calculate (S13). Specifically, the first calculation result is obtained by Expression (1).
7Fh & A0h = 20h (1)

  Subsequently, the execution task switching means 10 stores the original priority of the first task among the unprocessed tasks stored in the execution waiting task queue 30 in the execution waiting task priority register 12 (S14). Here, as shown in FIG. 4, the original priority “91h” of task B is stored in the execution waiting task priority register 12.

Then, the mask means 14 of the execution task switching means 10 obtains the second operation result by AND operation from the mask data stored in the priority hierarchy mask register 16 and the value stored in the execution waiting task priority register 12. Calculate (S15). Specifically, the second calculation result is obtained by Expression (2).
7Fh & 91h = 11h (2)

  Thereafter, the determination unit 15 of the execution task switching unit 10 compares the first calculation result and the second calculation result, and determines the magnitude of the absolute value (S16). If the absolute value of the second calculation result is smaller than the absolute value of the first calculation result, the process proceeds to step S17. If the absolute value of the second calculation result is large or equal, the process returns to step S12. Here, 20h> 11h, and it is determined that the absolute value of the second calculation result is small, and the process proceeds to step S17.

  The determination unit 15 stores the value of the waiting task priority register 12 in the executing task priority register 11 (S17). Here, the value in the task priority register 11 being executed is rewritten from the original priority “A0h” of the task X to the original priority “91h” of the task B.

  Thereafter, the execution task switching unit 10 repeats steps S12 to S17 for all tasks in the execution waiting task queue 30. Here, the remaining tasks in the execution waiting task queue 30 shown in FIG. 4 are executed. As a result, the original priority “90h” of task A is stored in the executing task priority register 11.

  The execution task switching unit 10 notifies the task execution unit 20 of the fact after the processing is completed. The task execution means 20 starts the processing, and compares the original priority of the executing task with the original priority of the executing task priority register 11 as described above. Here, since the original priority “A0h” of the task X being executed and “90h” stored in the executing task priority register 11 do not match, the task execution means 20 can select from the waiting task queue 30. The task A having the original priority of “90h” is searched, acquired as a task to be executed, and executed.

  Thereby, the task execution means 20 can switch the execution right from the task X to the task A. Further, the task X that has lost the execution right is placed in the execution waiting task queue 30.

  Then, when the task A is completed by the task execution means 20, the execution task switching means 10 is activated again. Thereafter, the execution order of the remaining tasks in the execution waiting task queue 30 is similarly set based on the priority. Determined and executed. As a result, as shown in FIG. 5, the task execution order is based on the group priority of group 1 to group 2, and each task in group 1 and group 2 is ordered based on the individual priority. Become. That is, the task execution order is scheduled in units of groups.

  Here, a case where the mask data setting is changed will be described. Hereinafter, the value of the mask data stored in the priority hierarchy mask register 16 is “FFh”. That is, the specific priority is made effective in addition to the individual priority and the group priority. When the mask data value is “FFh” and the processing of FIG. 7 is applied to the execution waiting task queue 30 of FIG. 4, the task execution order is as shown in FIG. Accordingly, by changing the set value of the Layer3 setting SW 43 to “1” by the priority level selecting means 40, only the task Y having the specific priority “0” can be processed with the highest priority.

  As described above, the task control device 1 according to the first embodiment of the present invention previously sets each task as an original priority with a plurality of digits as one area and different meanings for each area. By using mask data in which validity / invalidity is set corresponding to the area, priority can be calculated flexibly by mask calculation.

  In addition, tasks can be managed in units of groups by setting the original priority digits in a hierarchy. Furthermore, by arbitrarily changing the mask data, it is possible to easily change the priority of only the specific task and group.

  Also, the required performance is not constant depending on the status of the processing system, so that in some situations the best performance can be achieved in groups, and in other situations, only specific tasks can be prioritized without being bound by groups. It is possible to cope with the case where the performance can be improved.

  In addition, since the execution task switching unit 10 according to the first exemplary embodiment of the present invention can determine the final priority only by one mask operation, the number of steps for calculating the priority does not depend on the task or the group. It is constant and has little impact on performance.

Other Embodiments of the Invention
The task in Embodiment 1 of the present invention is not limited to a task because it is a plurality of execution processing units in the information processing apparatus or the like. That is, the task may be called a job or a process.

  The task control device 1 according to the first exemplary embodiment of the present invention may include a unit that sorts waiting tasks according to the original priority and registers them in the waiting task queue 30. For example, it can be realized by performing sorting according to the original priority every time each task becomes executable and is registered in the waiting task queue 30.

  As a result, it is possible to shorten the time for the task execution means 20 to search the task queue 30 for a task whose original priority is the value of the executing task priority register 11. As a result, the time required for scheduling the task processing order in the task control apparatus 1 according to the first embodiment of the present invention can also be shortened.

  The priority level selection means 40 according to the first exemplary embodiment of the present invention may be set based on an instruction from the user. Alternatively, the priority level selection means 40 may be changed based on a predetermined algorithm. For example, it may be changed after a predetermined time has elapsed, or may be changed when a specific task enters the execution waiting task queue 30.

  The mask unit 13 and the mask unit 14 according to the first embodiment of the present invention are AND operations, but are not limited to this. It is only necessary to extract the digit corresponding to the original priority in which the bit value of the mask data is “1”.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention described above.

It is a block diagram which shows the structural example of the task control apparatus 1 concerning Embodiment 1 of this invention. FIG. 3 is a block diagram showing a configuration example of a priority hierarchy selection unit 40 and a priority hierarchy mask register 16 according to the first exemplary embodiment of the present invention. It is the figure which showed the example of the name of the task performed in the task control apparatus 1 concerning Embodiment 1 of this invention, and original priority. It is the figure which showed the example of the queue state of the waiting task queue 30 concerning Embodiment 1 of this invention. It is FIG. (The 1) which showed the example of the task execution order by the task control apparatus 1 concerning Embodiment 1 of this invention. It is FIG. (2) which showed the example of the task execution order by the task control apparatus 1 concerning Embodiment 1 of this invention. It is a flowchart figure which shows the flow of a process of the task control method concerning Embodiment 1 of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Task control apparatus 10 Execution task switching means 11 Executing task priority register 12 Execution task priority register 13 Mask means 14 Mask means 15 Judgment means 16 Priority hierarchy mask register 20 Task execution means 30 Waiting task queue 40 Priority Hierarchy selection means 41 Layer1 setting SW
42 Layer2 setting SW
43 Layer3 setting SW
160 Mask register 0th bit 161 Mask register 1st bit 162 Mask register 2nd bit 163 Mask register 3rd bit 164 Mask register 4th bit 165 Mask register 5th bit 166 Mask register 6th bit 167 Mask register 7th bit

Claims (16)

A task control device that controls the processing order of a plurality of tasks based on priority,
A first original priority storage unit for storing an original priority which is bit data of a plurality of digits included in the first task;
A second original priority storage unit for storing an original priority which is bit data of a plurality of digits included in the second task;
A mask data storage unit that stores mask data that is multi-digit bit data in which valid / invalid is set in units of digits,
A first priority is obtained by extracting, from the original priority stored in the first original priority storage unit, a digit corresponding to a digit set as valid in the mask data stored in the mask data storage unit. Priority for calculating the second priority by calculating a digit corresponding to the digit set as valid in the mask data from the original priority stored in the second original priority storage unit A calculation unit;
A task control device comprising: a determination unit that compares the first priority with the second priority and determines a task with a high priority. The original priority is
A first area indicating the priority within the task group;
A second area indicating priority between task groups;
The task control device according to claim 1, comprising:   The task control device according to claim 2, wherein the original priority further includes a third area assigned to an identifier for designating a specific task.   The task control device according to claim 3, wherein the original priority further includes a plurality of the third areas.   5. The task control device according to claim 1, wherein the priority calculation unit calculates a priority of the task by a mask calculation of the mask data and the original priority. 6.   The task control apparatus according to claim 1, wherein the original priority is hierarchized in units of digits. An execution waiting task storage unit for storing a plurality of execution waiting tasks;
The execution task storage unit is
The task control device according to claim 1, wherein the plurality of tasks waiting for execution are sorted based on an original priority.   The task control device according to claim 1, further comprising a mask data update unit configured to update the mask data. A task control method for controlling the processing order of a plurality of tasks based on priority,
Extract the digit corresponding to the digit set as valid in the mask data, which is the bit data of multiple digits with valid / invalid set for each digit, from the original priority that is the multiple digit bit data of the first task Calculating the first priority by:
Calculating a second priority by extracting a digit corresponding to a digit set to be valid in the mask data from the original priority of a second task;
Comparing the first priority with the second priority and determining a task with a higher priority. The original priority is
A first area indicating the priority within the task group;
A second area indicating priority between task groups;
The task control method according to claim 9, comprising:   The task control method according to claim 10, wherein the original priority further includes a third area assigned to an identifier for designating a specific task.   The task control method according to claim 11, wherein the original priority further includes a plurality of the third areas. The step of calculating the first priority and the step of calculating the second priority include:
The task control method according to claim 9, wherein the priority of the task is calculated by a mask calculation of the mask data and the original priority.   The task control method according to claim 9, wherein the original priority is hierarchized in units of digits.   The task control method according to claim 9, further comprising a step of sorting a plurality of tasks waiting to be executed according to an original priority.   The task control method according to claim 9, further comprising a mask data update step of updating the mask data.

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