JPH0667899A - Method for activating plural task periods in task scheduling device - Google Patents

Abstract

PURPOSE:To efficiently execute the repeated activating wok of plural tasks to be activated at their processing at a certain time interval by taking a chance of utilizing a interval timer interruption. CONSTITUTION:The task scheduling device is constituted of a control information part 1 storing frame control information 4 for regulating a time interval or the like for periodically activating each task and task constituting list 5 being activating task information in each frame, a processing part 2 for simultaneously activating plural tasks based upon the information 4 and an input part 3 including an information input means 10 for inputting relation or the like between each frame and an activated task and an interval timer 11 for generating interval timer and constituted so that plural timers are simultaneously activated at every frame based upon the information 4 and the list 5 at the time of generating an interval timer interruption for informing the start of each frame.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a task scheduling device for giving a CPU execution right to a task, by grouping task groups corresponding to the same frame activated on the basis of a frame number counter value and an activation interval. The present invention relates to a method of periodically activating multiple tasks so that tasks can be repeatedly activated within a fixed time.

A task scheduling process for giving a CPU execution right to a task is, for example, to confirm the track of oneself.
In addition, to check the proximity aircraft, etc., we handle aircraft-mounted systems (avionics systems) that repeatedly sample data from electronic equipment such as radar within a certain time, or fluids such as steel and cement in the field of factory automation. It is used for real-time systems such as process control systems that measure temperature, liquid level, concentration, etc. at fixed time intervals in the field and perform the following control according to the values.

In the task scheduling processing in such a system, real-time performance more strictly than that required in accounting systems of financial institutions is strictly required. Therefore, there is a demand for a multi-task cycle activation technique for task scheduling processing that can reduce the overhead of the entire system and exhibit strict real-time performance.

[0004]

2. Description of the Related Art A conventional method of activating a plurality of tasks in a task scheduling apparatus will be described with reference to FIGS.

When it is desired to activate a certain task at a certain time, task request blocks (hereinafter referred to as TRBs) are created in advance for the number of tasks. For example, in the case of TASK1, the time 1H05M00S should be registered when the time 1H00M00S has elapsed. Therefore, at each time, Fig. 6 (c) {This figure shows an example of the queue of execution tasks created before 1H00M00S. After 1H00M00S, the next time,
For example, a queue of tasks to be executed at 1H05M00S is created}, and as many tasks as the number of tasks may be created.

The TRB has the following T
This is a control block in which timer queue information for managing the existence of RBs, a corresponding task control block (hereinafter referred to as TCB) address, and an activation time are stored. The created TRBs are queued in time series by the timer queue information. I'll do it.

For example, as shown in FIG. 6A, TASK1 and TASK1 and TASK1 and TASK1 and TASK1 and TASK5 are TASK1 and TASK1 and TASK1 and TASK1 and TASK1 and TASK1 and TASK3, respectively.
6C, 1TRB (in this example, a total of 5 TRBs) are prepared for each initial start time and queued in time series, as shown in FIG. 6C.

On the other hand, an actual task starting method will be described with reference to FIG. First of all, triggered by the interval timer interrupt,
The TRB whose current time has elapsed from the head of the timer queue is searched (step 101).

If the activation time in the TRB has not passed the current time (step 102), the process branches to step 105 to end the process. If the start time has passed the current time (step 102), the task is known from the TCB address stored in the TRB, and the task can be started (task start request) (step start request).
103).

Further, it is determined whether or not there is a next timer queue.
Knowing from the timer queue information of the RB (step 104), if the next TRB exists, the process returns to step 101 and the same processing is repeated. On the other hand, if the next TRB does not exist (step 104), the presence / absence of the task with the activation request is checked (step 105). If there is not, the process is terminated, and if there is, the process branches to the task scheduler (step 106), C is assigned to the task with the highest priority among the tasks that are requested to start.
Grant PU execution right. That is, it is dequeued.

As described above, in the prior art, in order to activate a plurality of tasks at the same time at the same time, the timer queue is searched sequentially from the beginning, and whether or not the timer queue disappears,
Alternatively, steps 101 to 104 are repeated until the activation time in the TRB does not exceed the current time.

[0012]

By the way, in an aircraft-mounted system or a process control system, a plurality of external devices (display devices, sensors, etc.) are connected, each of which has a different function, and the tasks corresponding to them are functional units. Therefore, there are a plurality of tasks activated in each frame, and it is required to repeatedly process the tasks at a certain time interval.

Even in such a system, conventionally, as shown in FIG.
As described with reference to FIG. 7, the queuing function of the timer queue, the dequeuing function, and the like are used to perform the activation processing of a plurality of tasks.

Therefore, as the number of tasks activated in the same frame increases, the processing of timer queue search and time determination is repeated, so that the processing time from the timer queue search to the task activation becomes longer, which is more likely to occur. The problem is that the overhead of the entire system increases.

It is an object of the present invention to provide a method for cyclically activating a plurality of tasks in a task scheduling device, which is capable of activating a plurality of tasks in a corresponding frame immediately from frame control information and a task configuration list. .

[0016]

FIG. 1 is a block diagram showing the principle of the present invention. The above problems can be solved by a method of activating a plurality of tasks in a task scheduling apparatus configured as follows.

In the task scheduling device, a control information section that stores control information 4 of a frame that defines a time interval of activation of each task that is periodically activated and a task configuration list 5 that is task activation information in each frame. 1 and a processing unit 2 that sets the relationship between each frame and the activation task in the control information unit 1 and that activates a plurality of tasks at once based on the frame control information 4 triggered by an interval timer interrupt; Information input / output means 10 for inputting information such as the relationship between each frame and the activation task, and an interval timer
And the control information unit 1
The frame number counter 4b that manages the number of the target frame by a certain interval timer interrupt
And a task configuration list 5 that manages a group of tasks activated by the frame designated by the frame number counter 4b.
Address information 4c, frame control information 4 including maximum frame number information 4a used for management for periodically activating a task group, the number of tasks activated by the interval timer interrupt, and their task control blocks. A task configuration list 5 that manages addresses of the (TCB) group is provided, and triggered by an interval timer interrupt for notifying the start of the frame reading,
Frame number counter 4b, maximum frame number 4a
From the task configuration list 5 of the relevant frame, and the task control block (TCB) address of the relevant task group for each frame number written on the task configuration list 5 is searched at once to obtain each frame. Each task is configured to start multiple tasks at once and periodically.

[0018]

In the present invention, triggered by the interval timer interrupt, the task configuration list of the corresponding frame is referred to by using the frame number counter value in the frame control information 4 shown in FIG. 1 as an index. , You can grasp multiple tasks that need to be started at once. Further, the maximum frame number on the frame control information 4 and the update of the frame number counter for each interval timer interrupt can set the frame number counter to the same frame number at regular intervals, and as a result, the same task group can be periodically generated. Can be activated.

Therefore, it is not necessary to rely on the conventional method of managing the timer queue such as the queuing and dequeuing functions of the timer queue, so that the overhead of the entire system resulting from the repeated processing of the queue search, the judgment of the passage of time, etc. It is possible to avoid the above, and it is possible to efficiently perform the cyclic activation of multiple tasks.

[0020]

Embodiments of the present invention will be described in detail below with reference to the drawings. The above-mentioned FIG. 1 is an explanatory view of the principle of the present invention.
FIG. 3 is a diagram showing an embodiment of the present invention. The same reference numerals indicate the same objects throughout the drawings.

First, the control information unit 1 is resident in the memory, and sets the initial value of the frame number counter (for example, set to 7) when the present apparatus (task scheduling apparatus) is started or when the task configuration in the frame is changed. , Task configuration list information (task configuration list address for each frame) is set.

As shown in FIG. 3, the configuration includes a frame control information 4 and a task configuration list 5 in which tasks are grouped. As the frame control information 4, a maximum frame number 4a and a frame number counter 4b are used in the entire device. The number of tasks and the TCB address for identifying the tasks are provided as the task configuration list 5 in the unit grouped by the tasks to be activated, that is, the number of combination patterns of the task groups to be activated for each frame. I have it.

The processing unit 2 is composed of the initial setting 7 of the control information unit, the periodical scheduling 8 for activating a plurality of tasks in the frame at once, and the task scheduler 9 for giving the CPU execution right to the task with the highest priority. These are a group of executed programs, which are arranged on a memory and executed by a CPU (processor).

The input unit 3 has a maximum frame number, the number of tasks in each task configuration list grouped by a task group, a registered task number, a first frame number (start frame number) using the list, and the next. It is composed of a program (information input means) 10 in which setting information of the control information section 1 such as a frame interval until the list is used, and an interval timer 11 for generating an interrupt at a constant time interval, and the above-described periodic activation. Enter the required information in
This is for executing the periodic scheduling process at regular time intervals.

FIG. 4 is a processing flow chart of an embodiment of the present invention. The maximum frame number described in the information input means (program) 10 of the input unit 3, the number of tasks in each task configuration list 5 grouped by task group, the registered task number of the task activated for each frame, Task configuration list
After setting the contents of the frame control information 4 and the task configuration list 5 provided in the control information unit 1 as shown in FIG. Set an interrupt time interval in timer 11 (step 201).

Next, an interval timer interrupt is accepted (step 202) and the periodic scheduling process is executed by the CPU.
Executed by. In the periodic scheduling process, the frame number counter (FCNT) 4b arranged in the memory is read, and if the value is the maximum frame number 4a or more, it is "0".
clear. Otherwise, the frame number counter 4b
Is incremented by 1 (step 203).

In the periodic scheduling process, the task configuration list address stored in the task configuration list information 4c in the frame control information 4 is read from the frame number counter 4b (step 204), and the number of tasks 5a stored in the task configuration list is read. The TCB address 5b is read (step 205).

On the basis of the number of tasks 5a and the TCB address 5b acquired here, a plurality of tasks are brought into a state in which a start request is made at one time (a CPU execution right is obtained) (step 206).

Next, the process branches to the task scheduler (step 207) and the CPU execution right is given to the task having the highest priority among the plurality of tasks in the activation request state. The above processing will be described with reference to the operation explanatory diagram of the embodiment of the present invention in FIG. FIG. 5 shows the specific values of the information input by the input unit 3, the frame control information 4 and the contents of the task configuration list 5 set from the values based on the relationship between each frame and the activation task. .

For example, the maximum frame number 4a is set to "7", task-1 is started in all frames (frame intervals are "0"), and task-2 is set to start frame number "1". Task-3 is started with a frame interval of "2", task-3 is started with a frame number of "2" as a start frame number, and task-4 is started with a frame number of "0" as a start frame number. Assuming that the task is started at the frame interval "8" and the task-5 is started at the frame interval "8" with the frame number "4" as the start frame number, the tasks are grouped as shown in FIG. Group is task-1
4, task-1.2, task-1.3, task-1.5
There are four combinations (CNLIST-1 to CNLIST-4).

The maximum frame number value ("7" in this example) is set in the frame number counter 4b as an initial setting value. The contents of the control information section 1 other than the frame number counter 4b are rewritten only at the time of initial setting or when the task configuration in each frame is changed.

When an interval timer interrupt occurs in this state, the content "7" of the frame number counter 4b is equal to the content "7" of the maximum frame number 4a (not less than the maximum frame number value), so the frame number counter 4b Is set to "0", and based on this value, the top address of the task configuration list 5 is read from the 0th content (CNLIST-1 address) of the task configuration list information 4c, and the number of tasks 5a and TCB address (for example, , TCB-1 address) 5b, and activates the task group (task-1 and task-4) of frame number "0" at once. When the second interval timer interrupt occurs, comparing the content "0" of the frame number counter 4b with the content of the maximum frame number 4a, the frame number counter 4b is smaller, so 1 is added to the content of the frame number counter 4b. Set to "1", and task configuration list information 4c based on that value
The address of the task configuration list 5 is read from the first of the, and the task group in the frame number "1" (task-1
And task-2) are started at once.

In this way, the frame number counter 4
By repeating the process until b exceeds the maximum frame number "7" and restarting the process from the frame number "0", each task can be activated periodically.

In the above-mentioned embodiment, the program is used as the information input means, but as another embodiment, a keyboard having alphanumeric keys can be used. Also, 1
The case where the number of frames in one cycle (from the first frame to the last frame) is “8” and the number of tasks in the entire system is “5” has been explained. However, due to a system failure, the function of the entire system is reduced to operate. Such degenerate operation can be applied only by resetting the contents such as the number of frames and the number of tasks and the task configuration list information 4c. That is, it can be applied to a fault tolerant system whose purpose is to make the system operate normally in a short time.

Furthermore, the method for periodically activating a plurality of tasks of the task scheduling apparatus is a method for repeatedly performing routine tasks at a certain time interval, such as a sensor-based system such as a robot control in addition to an aircraft-mounted system (avionics system). Can also be applied to.

[0036]

As described above, according to the present invention,
By using a task configuration list that groups tasks, which is uniquely determined by the start frame number and frame interval, the interval timer interrupt
Based on the frame number counter, a task group in a frame can be searched at one time, and a plurality of tasks can be activated at once at a certain fixed time interval.

Therefore, unlike the conventional method, there is no need for repeated processing such as queue management (searching, queuing, dequeuing) and time determination, which is effective in reducing the overhead of the entire system and is efficient. This enables periodical activation of multiple tasks, contributing to shortening the processing time of the entire system.

[Brief description of drawings]

FIG. 1 is an explanatory view of the principle of the present invention.

FIG. 2 is a configuration diagram of an embodiment of the present invention (No. 1)

FIG. 3 is a configuration diagram of an embodiment of the present invention (part 2)

FIG. 4 is a process flow chart of an embodiment of the present invention.

FIG. 5 is an operation explanatory diagram of an embodiment of the present invention.

FIG. 6 is an explanatory view of a conventional technique (No. 1)

FIG. 7 is an explanatory diagram of a conventional technique (No. 2)

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 control information section 2 processing section 3 input section 4 frame control information 4a maximum frame number 4b frame number counter 4c task configuration list information 5 task configuration list 5a number of tasks 5b TCB (Task Control Block) address 6 task control block (TCB) 7 Initial setting section 8 Multiple task simultaneous activation request section in frame (periodic scheduling section) 9 Task scheduler 10 Information input means (program) 11 Interval timer 101 to 106, 201 to 207 Steps of processing

Claims (1)

[Claims] 1. A task scheduling device, wherein control information (4) of a frame that defines a time interval of activation of each task that is periodically activated, and a task configuration list (5) that is task activation information in each frame. Is stored in the control information section (1), and the relationship between each frame and the activation task is set in the control information section (1). A processing unit (2) for activating tasks at one time, an input / output unit (10) for inputting information such as the relationship between each frame and the activation task, and an input unit (3) including an interval timer (11). And a frame number counter (4b) that manages the number of the target frame by a certain interval timer interrupt in the control information section (1), and the frame number counter (4
Address information (4c) of the task configuration list (5) that manages the task group activated in the frame designated by b)
Frame control information (4) consisting of maximum frame number information (4a) used for management for periodically activating a task group, the number of tasks activated by the interval timer interrupt, and those task control blocks The task configuration list (5) that manages the addresses of the (TCB) group is provided, and the frame number counter (4b) and the maximum frame number are triggered by the interval timer interrupt for notifying the start of the frame reading. From (4a), the address of the task configuration list (5) of the relevant frame is obtained, and the task control block (TC) of the relevant task group for each frame number written on the task configuration list (5).
B) A method for periodically activating multiple tasks in a task scheduling device, wherein a plurality of tasks are activated at once for each frame by retrieving addresses at once.