JP3783553B2 - Information processing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a technique for ensuring real-time interrupt processing in a processing program in which interrupt processing is executed.
[0002]
[Prior art]
For example, in a control program used in an electronic control device (hereinafter referred to as “ECU”) mounted on a vehicle, it is necessary to execute predetermined processing in real time in order to ensure control responsiveness and safety. For this reason, such processing requiring real-time properties (real-time processing) is generally prepared as an interrupt routine different from the main routine. The interrupt routine is executed preferentially during execution of the main routine, for example, triggered by the occurrence of an event. The preferential execution means that the execution of the main routine is temporarily interrupted by the execution of the interrupt routine, and the main routine is executed again from the interruption position after the interruption routine ends.
[0003]
In recent years, the ECU control program described above also operates on an OS (operating system), and execution units such as a main routine and an interrupt routine are called tasks and are managed by the OS.
A level indicating the priority of execution (task level) is set for this task, and the interrupt processing as described above is realized based on this task level. In other words, under the management of the OS, a higher-order task that is a relatively high-level task has priority (interrupts) over a lower-order task that is a relatively low-level task. In the example described above, the processing by the main routine corresponds to the lower task, and the processing by the interrupt routine corresponds to the upper task.
[0004]
The introduction of such a task concept makes it easy to design an interrupt process by eliminating the need to describe the execution timing between programs with only a very simple information description of setting a task level.
On the other hand, the upper task interrupts at a timing not related to the processing timing of the lower task, such as the occurrence of an event. For this reason, there is a possibility that a problem occurs in the lower task. Here, a problem caused by an interrupt of a higher-level task, which is assumed in the present invention, will be described.
[0005]
Consider a case in which a common variable is manipulated between the upper task and the lower task. For example, when the entire program is composed of a plurality of functions, this common variable is stored in a storage area that can be accessed in common among these functions, and is called a global variable (global variable).
[0006]
For example, consider a case where two global variables a and b are referenced in a lower task and the same global variables a and b are updated in an upper task. At this time, if the upper task interrupts before the variable b is referenced after the variable a is referenced in the lower task, both the global variables a and b are updated, and then the global referenced by the lower task. The variable b becomes the one after the update by the upper task. That is, one global variable a is referred to the old one in time, and the other global variable b is referred to the new one in time. Such a state is expressed as a state in which simultaneity of global variables (sometimes called consistency, consistency, etc.) is lost, and when this simultaneity is required, for example, temporal correlation If it exists between variables, it will cause a problem in control.
[0007]
Further, for example, the same applies when two global variables a and b are updated in a lower task and the same global variables a and b are referred to in an upper task. At this time, after the variable a is updated in the lower task, the global variables a and b may be referred to by the upper task before the variable b is updated. When there is such an interrupt of a higher-level task, one global variable a is referred to in time, and the other global variable b is referred to in time. In other words, the simultaneity of global variables is lost in this case as well.
[0008]
In the above-described example, two global variables are processed, but the same problem occurs when three or more global variables that require simultaneity are processed. The same problem occurs even when one global variable is a processing target. For example, a case where the same global variable is read twice consecutively in the lower task is cited as an example. In this case, if the upper task updates the variable after the lower-level task references the first variable, the variable read the second time is different from the variable read the first time. , Simultaneity will be lost.
[0009]
Conventionally, in order to ensure such simultaneity, an interrupt disable / permit instruction has been described in the lower task program as necessary. The interrupt prohibition instruction is for prohibiting an upper task interrupt, and the interrupt permission instruction is for permitting an upper task interrupt. In other words, the upper task cannot interrupt during the processing step between the interrupt prohibition instruction and the interrupt permission instruction. Therefore, if an interrupt disable instruction and an interrupt enable instruction are described before and after the processing related to a global variable that requires simultaneity, referencing and updating by a higher-level task is not performed, the simultaneity of global variables can be reduced. It can be secured.
[0010]
[Problems to be solved by the invention]
Interrupt processing as described above is an indispensable technique for executing real-time processing, and has been easily designed by the development of computer technology such as task management by the OS. On the other hand, however, if the number of interrupt processes increases, the description of interrupt prohibition / permission instructions increases accordingly, which makes it impossible to secure real-time performance. This will be described.
[0011]
As described above, if an interrupt disable / enable instruction is described in the lower task program, the upper task cannot be interrupted in the middle of the processing step between the interrupt disable instruction and the interrupt enable instruction. In other words, the upper task waits for execution until the lower task is permitted to interrupt, and during this period, the execution priority is substantially reversed. Therefore, as the number of interrupt processes increases and the number of such periods increases, there is a higher possibility that execution of higher-level tasks that are real-time processes will be delayed, making it difficult to ensure control responsiveness and safety, etc. As a result, the control performance is affected.
[0012]
The present invention has been made to solve such a problem, and does not delay interrupt processing by a higher-priority higher-level program, and it can be compared with a lower-level lower-level program. The purpose is to ensure simultaneity when referring to global variables used in common.
[0013]
[Means for Solving the Problems and Effects of the Invention]
The information processing apparatus according to claim 1, which is made to achieve the above-described object, performs a series of functions by executing a plurality of processing programs as execution units based on a priority set for each processing program. To realize. For example, in the case of a program that manages tasks on the OS, a task is generated for each processing program, and the task level set for each task corresponds to the priority mentioned here. In the following, the expression based on the processing program may be used for convenience in realizing each function, but in actuality, each function is realized by executing the processing program mainly by the so-called CPU of the information processing apparatus. It goes without saying that it is done.
[0014]
In the present invention, global variables are stored in duplicate in two areas. A global variable is a variable used in common between a lower-level program having a relatively low priority and a higher-level program having a relatively high priority. Here, “store overlapping two areas” means that each global variable has both one area (hereinafter referred to as “area 1”) and the other area (hereinafter referred to as “area 2”). It means to memorize. Then, for example, the area 1 is set as a public area and the area 2 is set as a work area.
[0015]
In the present invention, the following configuration is adopted for the first case where the global variable may be updated by the upper program while the global variable is being referenced by the lower program.
That is, the upper program updates the global variable using the work area by executing the upper update process, while the lower program uses the public area by executing the lower reference process. It was made to refer to. In other words, global variables are referenced and updated in different areas, ensuring simultaneity when referring to global variables by lower-level programs.
[0016]
Specifically, a case is considered where two global variables a and b are referred to in the lower program and the same global variables a and b are updated in the upper program. At this time, the lower-level program refers to the global variables a and b stored in the public area. On the other hand, the upper program updates the global variables a and b stored in the work area. Therefore, for example, even if the upper program interrupts during the reference by the lower program, only the global variables a and b stored in the work area are updated, and the global variables a and b stored in the public area referred to by the lower program are updated. Will not be updated. That is, the simultaneity of the global variables a and b referred to in the lower program is ensured.
[0017]
When the lower-level program further completes the reference of the global variable by the lower-level reference processing, by executing the area switching process, the work area is newly set as the public area and the public area is newly set as the work area. fix.
“Completing the reference of a global variable” means that a series of reference processing of a global variable that requires simultaneity is completed. For example, it can be considered that all the reference processing of a plurality of global variables that require simultaneity is completed. In addition, it can be considered that all the reference processing of a single global variable that requires simultaneity is completed.
[0018]
When the reference is completed, there is a possibility that the global variable in the work area has been updated by the interruption of the previous upper program. Therefore, by switching between the work area and the public area, the updated global variable is referred to in the next reference process.
[0019]
In this way, it is possible to ensure the simultaneity of global variables referenced in the lower program without delaying the interrupt process by the upper program.
By the way, the configuration described above is for the first case in which a global variable may be updated by a higher-level program in the middle of referring to a global variable by a lower-level program. In contrast, further, A second case in which the global variable may be referred to by the upper program during the update of the global variable by the lower program is also conceivable. To ensure simultaneity when referring to global variables in the lower and upper programs for the first and second cases described above It is conceivable to adopt the configuration shown in claim 2.
[0020]
That is, the upper program executes the upper reference process to reference the global variable using the public area, while the lower program executes the lower update process to execute the global variable using the work area. Is updated.
[0021]
In this case as well, the global variables are referenced and updated in different areas, and at this time, the simultaneity of the global variables at the time of reference by the upper program is ensured.
Specifically, consider a case where two global variables a and b are updated in a lower program and the same global variables a and b are referenced in an upper program. At this time, the lower-level program updates the global variables a and b stored in the work area. On the other hand, the upper program refers to the global variables a and b stored in the public area. Therefore, for example, even when the upper program interrupts during the update by the lower program, the global variables a and b stored in the public area are referred to, and the global variables a and b stored in the work area being updated are referred to. Will never be done. That is, the simultaneity of the global variables a and b referred to in the upper program is ensured.
[0022]
In this case as well, when the update of the global variable by the lower update process is completed, the lower program switches the work area and the public area by executing the area switching process. This is because the updated global variable is referred to in the next reference process. “Completing the update of the global variable” means that, as in the case of the reference, a series of update processing of the global variable that requires simultaneity is completed.
[0023]
This By doing so, it is possible to ensure the simultaneity of the global variables referenced in the upper program or the lower program without delaying the interrupt processing by the upper program.
[0024]
By the way, the present invention has been made for the purpose of ensuring simultaneity when referring to global variables in the first or second case as described above. Therefore, on the assumption that any one of these cases is applicable, each processing program may determine itself as a higher-level program or a lower-level program in relation to other processing programs.
[0025]
For example, when a processing program references a global variable, it is assumed that it is known in advance that the global variable may be updated by another processing program. It can be considered to determine whether the program is a program or a subordinate program. Similarly, when a certain processing program updates a global variable, it is assumed that it is known in advance that there is a possibility that the global variable may be referenced by another processing program. It can be considered to determine whether the program is a program or a subordinate program.
[0026]
Therefore, the claim 3 As shown in FIG. 4, in each processing program, based on the priority of another processing program that references or updates the global variable, a determination process is performed to determine whether the processing program corresponds to the lower processing program or the upper processing program. The corresponding process may be executed based on the determination result of the determination process. Specifically, for example, claims 4 As shown in FIG. 5, the highest priority among the processing programs that reference or update the global variable is stored in the priority storage means, and the stored priority and the priority set in the processing program It can be considered to make a judgment by comparing. This is advantageous in that each processing program can be made more versatile.
[0027]
Note that not all defined global variables are processed by each processing program. Therefore, there is a possibility that a global variable updated or referred to by another processing program is other than the global variable to be processed. In such a case, interference due to interruption does not occur.
[0028]
Therefore, the claim 5 As described above, the determination processing described above may be determined based on the priority of another processing program that performs reference or update on the global variable to be processed in the processing program to be determined. In this case, specifically, the claim 6 As shown in FIG. 6, for each global variable, it is conceivable to store in the priority storage means the highest priority among the processing programs that refer to or update the global variable. At this time, the determination process is determined by comparing the priority corresponding to the global variable to be processed, stored in the priority storage unit, and the priority set in the determination target processing program. .
[0029]
By the way, in the present invention, one of the two areas is set as a public area and the other is set as a work area, and the public area and the work area are switched by area switching processing. Such a region setting is, for example, a claim 7 As shown in FIG. 5, it is possible to realize the configuration by providing the area information storage means and storing the setting information in the area information storage means. For example, “1” or “2” is stored as the setting information. When the setting information is “1”, the area 1 is set as the public area, the area 2 is set as the work area, and the “2” is set. In the opposite case, the area 1 is set as a work area and the area 2 is set as a public area.
[0030]
In this case, the claim 8 As shown in FIG. 4, the area switching process is to newly set the work area as a public area and re-set the public area as a new work area by updating the setting information stored in the area information storage means. It can be considered. Such updating of the setting information can be realized by a single instruction of the CPU. Thus, no interruption is caused during the area switching. As a result, it is possible to ensure the simultaneity of global variables referenced in the upper program or the lower program.
[0031]
DETAILED DESCRIPTION OF THE INVENTION
Embodiments of the present invention will be described below with reference to the drawings.
[Actual Example]
FIG. 1 is a block diagram showing a configuration of an engine control apparatus (hereinafter referred to as “ECU”) 1 that embodies an “information processing apparatus” of the present invention. The ECU 1 controls an internal combustion engine type engine mounted on the vehicle.
[0032]
The ECU 1 is a rotation angle sensor that outputs a pulsed signal every time the crankshaft of the engine rotates by a predetermined angle. Each time the piston of a specific cylinder of the engine comes to a predetermined position (for example, top dead center: TDC), the ECU1 Signals from various sensors 30 that detect the operating state of the engine, such as a reference position sensor that outputs a signal, a water temperature sensor that detects the temperature of the engine coolant, and an oxygen concentration sensor that measures the oxygen concentration, are used to input waveforms. An input circuit 21 that performs shaping and A / D conversion, a microcomputer (hereinafter referred to as a “microcomputer”) 10 that executes various processes for controlling the engine based on sensor signals from the input circuit 21, and a microcomputer 10 Actuators such as injectors (fuel injection devices) and igniters (ignition devices) attached to the engine according to control data from And an output circuit 22 for driving the 0 includes.
[0033]
The microcomputer 10 includes a well-known CPU (central processing unit) 11 that executes programs, a ROM 12 that stores programs executed by the CPU 11, a RAM 13 that stores calculation results and the like by the CPU 11, and an input circuit. 21 and I / O 14 for exchanging signals between the output circuit 22 and various registers and free-run counters (not shown).
[0034]
The ECU 1 configured as described above performs an engine control process for driving the actuator 40 connected to the output circuit 22 based on signals input from the various sensors 30 via the input circuit 21.
The engine control program for realizing this engine control is stored in the ROM 12 provided in the microcomputer 10 as described above. This engine control program is subdivided and described for each execution unit. Each processing program as an execution unit is executed based on a set priority (task level). Specifically, a higher-order program that is a processing program with a relatively high priority is executed in preference to a lower-order program that is a relatively low processing program. The execution unit of these processing programs is called a task and is managed by the OS. Hereinafter, the execution unit of the upper program is described as an upper task, and the execution unit of the lower program is described as a lower task. In this way, each task calculates and updates the control data related to the engine control process described above by the interrupt process based on the priority, or calculates new control data by referring to the calculated control data. Or
[0035]
Global variables are used to process control data in common for each task. For example, when the entire program is composed of a plurality of functions, the global variable is stored in a storage area that can be commonly accessed among these functions.
When considering the reference / update by the higher-order task and the lower-order task of such a global variable, the simultaneity at the time of referring to the global variable may be lost by the above-described interrupt processing.
[0036]
Conventionally, in order to avoid such problems, by executing the interrupt disable / permit instruction in the lower task, the upper task interrupts the global variable in the middle of processing the global variable that requires simultaneity. I couldn't handle it.
However, if the interrupt of the upper task is prohibited by such a method, the upper task waits for execution until the interrupt is permitted by the lower task, and the priority is substantially reversed during this period. Will end up. If the number of interrupt processes increases, the interrupt prohibition period increases accordingly, and the real-time property of the higher-level task cannot be secured, causing a problem in control performance.
[0037]
Therefore Real In the examples, the following was performed.
First, global variables are duplicated and stored in two areas. As shown in FIG. 1, the RAM 13 is provided with a global variable storage area 13b. Real In the embodiment, three control data A, B, and C as global variables are processed. In this case, as shown in FIG. 2, the control data is stored in the area 1 and also in the other area 2. Here, the control data A, B, and C stored in the area 1 are indicated as A1, B1, and C1, respectively, and the control data A, B, and C stored in the area 2 are indicated as A2, B2, and C2, respectively. The RAM 13 is provided with a storage area 13a for area setting information S. Depending on the value of the area setting information S stored therein, one of the two areas 1 and 2 is set as a public area and the other is set as a work area. I set it. Specifically, if the area setting information S is “1”, the area 1 is set as a public area and the area 2 is set as a work area. On the other hand, if the area setting information S is “2”, the area 1 is set as a work area and the area 2 is set as a public area.
[0038]
And Real The example corresponds to the first case where the control data may be updated by the interrupt of the upper task during the reference processing of the control data of the lower task, Real In the embodiment, the lower task processing and the upper task processing are as shown below.
[0039]
First, the lower task processing will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 3 is characterized in that new control data U is calculated based on the control data A, B, C with reference to the control data A, B, C. Other processes that are not related to the characteristic process are indicated by broken lines in the flowchart and omitted.
[0040]
First, in step (hereinafter, the step is simply indicated by symbol S) 100, the control data A stored in the storage area 13b of the RAM 13 is referred to. Similarly, the control data B is referred to in the subsequent S110, and the control data C is referred to in the next S120. The control data A, B, and C are referred to by calling a reference processing subroutine.
[0041]
Here, the reference processing of the control data A, B, C will be described based on the flowchart of FIG.
When the process is started, it is first determined whether or not the region setting information S is “1” (S200). The area setting information S is stored in the storage area 13a of the RAM 13 as described above. If the area setting information S is “1” (S200: YES), the control data is read out from the area 1 (S210), and then this reference process is terminated. On the other hand, if the area setting information S is not “1”, that is, if the area setting information S is “2” (S200: NO), the control data is read from the area 2 (S220), and then this reference process is terminated. .
[0042]
Such a reference process may be prepared individually for each of the three control data A, B, and C. That is, it can be considered that separate subroutines are used, such as a reference process for referring to the control data A, a reference process for referring to the control data B, and a reference process for referring to the control data C. For example, in the reference process for referring to the control data A, the control data A1 or A2 is read from the first storage area of the area 1 or 2. Further, any one of the three control data A, B, and C may be designated to call a common reference process. In this case, for example, if the control data B is designated, the control data B1 or B2 is read from the second storage area of the area 1 or 2.
[0043]
In any case, in this case, the control data A, B, and C are read from the area set as the public area. This is because if the area setting information S is “1”, the area 1 is a public area, and if the area setting information S is “2”, the area 2 is a public area.
[0044]
In S130 following S120 in FIG. 3, it is determined whether or not the region setting information S is “1”. If the area setting information S is “1” (S130: YES), the area setting information S is updated to “2” in S140. On the other hand, if the area setting information S is not “1” (S130: NO), that is, if the area setting information S is “2”, the area setting information S is updated to “1” in S150.
[0045]
In S160 that moves from S140 or S150, new control data U is calculated based on the control data A, B, and C referenced in S100 to S120. Thereafter, the lower task processing is terminated.
Next, the upper task processing will be described based on the flowchart of FIG. The flowchart shown in FIG. 5 is characterized in that the control data A, B, and C are calculated and the control data A, B, and C are updated. Similar to the lower-level task process shown in FIG. 3, other processes not related to these characteristic processes are indicated by broken lines in the flowchart and omitted.
[0046]
First, in the first S300, three control data A, B, and C are calculated.
In subsequent S310, the control data A stored in the storage area 13b of the RAM 13 is updated. Similarly, in the next S320, the control data B is updated, and in S330, the control data C is updated. Thereafter, the upper task processing is terminated.
[0047]
The control data A, B, and C are updated by calling a subroutine for update processing.
Here, the update processing of the control data A, B, C will be described based on the flowchart of FIG.
[0048]
When the process is started, it is first determined whether or not the region setting information S is “1” (S400). If the area setting information S is “1” (S400: YES), the control data is written to the area 2 (S410), and then this update process is terminated. On the other hand, if the area setting information S is not “1”, that is, if the area setting information S is “2” (S400: NO), the control data is written in the area 1 (S420), and then this update process is terminated. .
[0049]
Such an update process may be prepared individually for each of the three control data A, B, and C as in the reference process. Alternatively, any one of the three control data A, B, and C may be designated to call a common update process.
In any case, in this case, control data A, B, and C are written in the area set as the work area. This is because if the area setting information S is “1”, the area 2 is a work area, and if the area setting information S is “2”, the area 1 is a work area.
[0050]
As explained above, Real In the ECU 1 of the embodiment, reference and update of the control data A, B, and C as the global variables are performed in different areas, and synchronization at the time of referring to the control data A, B, and C by the lower task is ensured.
For example, a specific description will be given assuming that the area setting information S is “1”.
[0051]
If the area setting information S is “1”, the area 1 is a public area. Therefore, in the lower task, the control data A1, B1, and C1 stored in the area 1 that is the public area are referred to (S100 to S120 in FIG. 3, see FIG. 4). On the other hand, the higher-order task updates the control data A2, B2, C2 stored in the work area 2 (see S310 to S330 in FIG. 5 and FIG. 6). Therefore, for example, even if a higher-level task interrupts during reference by a lower-level task, only the control data A2, B2, and C2 stored in the area 2 are updated, and the control data A1 stored in the area 1 referenced by the lower-level task. , B1, C1 are not updated. That is, the simultaneity of the control data A1, B1, C1 referred to in the lower task is ensured.
[0052]
Further, when the reference of the control data A1, B1, and C1 that require simultaneity is completed (at the end of S120 in FIG. 3), the control data A2, B2, and C2 in the area 2 are interrupted by the previous upper-level task interrupt. May have been updated. Therefore, by updating the area setting information S from “1” to “2” (S130: YES, S140), the work area and the public area are switched. That is, the area 1 is reset as a work area and the area 2 is reset as a public area. As a result, the updated control data A2, B2, and C2 are referred to in the next reference process.
[0053]
As a result, it is possible to ensure the simultaneity of the control data referred to by the lower task without delaying the interrupt process of the upper task.
further, Real In the embodiment, one of the areas 1 and 2 is set as a public area and the other as a work area by the area setting information S stored in the storage area 13a of the RAM 13, and the area setting information S is updated (see FIG. 3). S130 to S150), the regions 1 and 2 are switched. Such updating of the area setting information S can be realized by one instruction of the CPU, so that no interruption occurs during the area switching. As a result, the simultaneity of the control data referred to by the lower task can be ensured.
[0054]
In addition, Real The RAM 13 in the embodiment corresponds to “region information storage means”. And the process of S100-S120 shown with the dashed-dotted line in FIG. 3 is equivalent to a "lower-order reference process", and the process of S130-S150 is equivalent to a "area | region switching process." Further, the processing of S310 to S330 indicated by the alternate long and short dash line in FIG. 5 corresponds to “upper update processing”.
[ reference Example]
Up Real The embodiment corresponds to a first case in which control data may be updated by an interrupt of a higher-level task in the middle of reference processing of control data of a lower-level task.
[0055]
On the contrary reference The example corresponds to a second case in which control data may be referred to by a higher-level task interrupt during the process of updating control data of a lower-level task. It is to be noted that, including hardware configuration, control data as a global variable is stored in the storage area 13b of the RAM 13 in an overlapping manner, and further, setting one as a public area and the other as a work area by the area setting information S Up Real This is the same as the example. Therefore, in the following, Real Only the lower task processing and the upper task processing different from the embodiment will be described.
[0056]
Book reference In the example, the lower task processing and the upper task processing are as shown below.
First, the lower task processing will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 7 is characterized in that the control data A, B, and C are calculated and the control data A, B, and C are updated. For other processes not related to these characteristic processes, Real Similar to the flowchart of the embodiment, it is indicated by a broken line in the flowchart and omitted.
[0057]
First, in step S500, three control data A, B, and C are calculated.
In subsequent S510, the control data A stored in the storage area 13b of the RAM 13 is updated. Similarly, the control data B is updated in the next S520, and the control data C is updated in the subsequent S530.
[0058]
Update of control data A, B, C Real This is done by calling the update processing subroutine described in the embodiment with reference to FIG. That is, if the area setting information S is “1” (S400: YES), control data is written to the area 2 (S410). On the other hand, if the area setting information S is not “1”, that is, the area setting information S is “1”. If “2” (S400: NO), the control data is written to the area 1 (S420). Of course, on Real Similar to the embodiment, such update processing may be prepared individually for each of the three control data A, B, and C, and any one of the three control data A, B, and C may be designated. A common update process may be called.
[0059]
In any case, in this case, control data A, B, and C are written in the area set as the work area.
In S540 following S530 in FIG. 7, it is determined whether or not the region setting information S is “1”. If the area setting information S is “1” (S540: YES), the area setting information S is updated to “2” in S550. On the other hand, if the area setting information S is not “1” (S540: NO), that is, if the area setting information S is “2”, the area setting information S is updated to “1” in S560.
[0060]
Thereafter, the lower task processing is terminated.
Next, the upper task processing will be described with reference to the flowchart of FIG. The flowchart shown in FIG. 8 is characterized in that new control data U is calculated based on the control data A, B, and C with reference to the control data A, B, and C. Similar to the lower-level task process shown in FIG. 7, other processes not related to these characteristic processes are indicated by broken lines in the flowchart and omitted.
[0061]
First, in the first S600, the control data A stored in the storage area 13b of the RAM 13 is referred to. Similarly, control data B is referred to in the next S610, and control data C is referred to in S620.
In subsequent S630, new control data U is calculated based on the control data A, B, and C referred to in S600 to S620, and then the upper task processing is terminated.
[0062]
Refer to the control data A, B and C above. Real This is done by calling the subroutine of the reference process described with reference to FIG. 4 in the embodiment. That is, if the area setting information S is “1” (S200: YES), the control data is read from the area 1 (S210). On the other hand, if the area setting information S is not “1”, that is, the area setting information S is “1”. If “2” (S200: NO), the control data is read out from the area 2 (S220). Of course, on Real Similar to the embodiment, such reference processing may be prepared individually for each of the three control data A, B, and C, or any one of the three control data A, B, and C is designated. Thus, a common reference process may be called.
[0063]
In any case, in this case, the control data A, B, and C are read from the area set as the public area.
As explained above, the book reference Even on the example Real As in the embodiment, reference and update of the control data A, B, and C as the global variables are performed in different areas. At this time, when the control data A, B, and C are referred to by the upper task Ensured simultaneity.
[0064]
For example, a specific description will be given assuming that the area setting information S is “1”.
If the area setting information S is “1”, the area 1 is a public area. Accordingly, in the lower task, the control data A2, B2, and C2 stored in the area 2 that is the work area are updated (S510 to S530 in FIG. 7, see FIG. 6). On the other hand, the higher-level task refers to the control data A1, B1, and C1 stored in the area 1 that is a public area (see S600 to S620 in FIG. 8 and FIG. 4). Therefore, for example, even if the upper task interrupts during the update by the lower task, the control data A1, B1, C1 stored in the area 1 will be referred to, and the control data A2, B2 stored in the area 2 during the update will be referred to. , C2 is never referenced. That is, the simultaneity of the control data A1, B1, C1 referred to by the upper task is ensured.
[0065]
Further, when the update of the control data A2, B2, and C2 that require simultaneity is completed (at the end of S530 in FIG. 7), the area setting information S is updated from “1” to “2” ( S540: YES, S550), the work area and the public area are switched. Thereby, the updated control data A2, B2, and C2 are referred to in the next reference process.
[0066]
As a result, it is possible to ensure the simultaneity of the control data referred to by the upper task without delaying the interrupt processing of the upper task.
In addition, book reference For example, above Real As in the embodiment, by setting one of the areas 1 and 2 as a public area and the other as a work area by the area setting information S stored in the storage area 13a of the RAM 13, the area setting information S is updated (in FIG. 7). S540 to S560), the regions 1 and 2 are switched. Such updating of the area setting information S can be realized by one instruction of the CPU, so that no interruption occurs during the area switching. As a result, the simultaneity of the control data referred to by the upper task can be ensured.
[0067]
Book reference The RAM 13 in the example corresponds to “region information storage means”. And the process of S510-S530 shown with the dashed-dotted line in FIG. 7 is equivalent to a "lower update process", and the process of S540-S560 is equivalent to an "area | region switching process." Further, the processing of S600 to S620 indicated by the alternate long and short dash line in FIG. 8 corresponds to “upper reference processing”.
[Others]
The above Real The embodiment corresponds to the first case where the control data may be updated by the interrupt of the upper task in the middle of the reference processing of the control data of the lower task. reference The example corresponds to the second case in which the control data may be referred to by the interrupt of the upper task during the process of updating the control data of the lower task.
[0068]
Up With For ease of explanation , Real While the example corresponds to the first case, reference Although the example has been described as corresponding to the second case, of course, it is conceivable that both the first and second cases occur in the engine control process. Therefore, usually, lower and upper processing programs are designed in correspondence with the first case, and lower and upper processing programs are designed in correspondence with the second case. That is, in one engine control process, one lower task process is as shown in FIG. 3, and another lower task process is as shown in FIG. Similarly, one upper task process is as shown in FIG. 5, and another upper task process is as shown in FIG.
[0069]
Considering that both the first and second cases are handled in this way, it is known in advance that when one task refers to the control data, the control data may be updated by another task. Under this assumption, it can be determined whether or not the other task is a higher-order task or a lower-order task. Similarly, if a task updates control data, it knows in advance that there is a possibility that a global variable may be referenced by another task. It can be considered to determine whether it is a task or a subordinate task.
[0070]
Specifically, as shown by a broken line in FIG. 1, a storage area 13c for storing information on priority is provided in the RAM 13, and the control data A, B, C is referred to for each control data A, B, C. The highest priority among the tasks to be updated is stored. For example, as shown in FIG. FIG. 9 shows a state in which the highest priority among the priorities of the tasks for which the three control data A, B, and C are processed is stored as PA, PB, and PC.
[0071]
Then, by comparing the priorities PA, PB, PC corresponding to the control data to be processed with the priority P set in the processing program to be determined, it corresponds to the lower task or the upper task. Judging.
This determination process is shown in the flowchart of FIG. This will be described.
[0072]
When the process is started, the priority P of the determination target task is acquired (S700). The task to be determined is a task that is currently being executed. It is conceivable that the set priority P is acquired by an OS subroutine call.
Next, priorities PA, PB, and PC corresponding to the control data A, B, and C to be processed are acquired (S710). This is stored in the storage area 13c described above. At this time, it is conceivable to obtain the highest priority among the three priorities PA, PB, and PC. Further, all of the three priorities PA, PB, and PC may be acquired.
[0073]
Then, the priorities acquired in S700 and S710 are compared to determine whether the priority P is relatively low (S720). If any of the three priorities PA, PB, PC exceeds the priority P, an affirmative determination is made here. If the priority P is relatively low (S720: YES), the task being executed is determined as a lower task (S730). On the other hand, if the priority P is not relatively low (S720: NO), it is being executed. The task is determined as an upper task (S740).
[0074]
As a result, when calculating the control data U with reference to the control data A, B, C in a certain task, if there is a possibility that the control data A, B, C is updated in another task, the above-mentioned By executing the determination process in advance, the lower task process shown in FIG. 3 or the upper task process shown in FIG. 8 can be selectively executed.
[0075]
Similarly, when the control data A, B, and C are calculated by a certain task and the control data A, B, and C are updated, the control data A, B, and C may be referred to by another task. For example, by executing the above-described determination process in advance, the lower task process shown in FIG. 7 or the upper task process shown in FIG. 5 can be selectively executed.
[0076]
This is advantageous in that each task becomes more versatile.
In such a configuration, the RAM 13 included in the microcomputer 10 corresponds to the “priority storage unit”, and the determination process illustrated in FIG. 10 corresponds to the “determination process”.
Here, as shown in FIG. 9, information on the priority is stored for each of the three control data A, B, and C. On the other hand, global variables such as control data that require concurrency are grouped together, and only the highest priority set for tasks that may reference or update global variables is stored. You may make it do. Even in this case, the lower or upper task process can be selectively executed by executing the same determination process as in FIG.
[0077]
In the above embodiment, the present invention is embodied as the ECU 1 that performs the engine control process. However, the present invention is not limited to the engine control of the vehicle, and the information processing apparatus generally performs an interrupt process that should ensure real-time performance. Needless to say, the present invention is applicable.
[Brief description of the drawings]
FIG. 1 is a block diagram illustrating a configuration of an ECU according to an embodiment.
FIG. 2 is an explanatory diagram showing a storage area for area setting information and control data;
[Fig. 3] ] Real It is a flowchart which shows the low-order task process of an Example.
FIG. 4 is a flowchart showing a reference process.
FIG. ] Real It is a flowchart which shows the high-order task process of an Example.
FIG. 6 is a flowchart showing an update process.
[Fig. 7] reference It is a flowchart which shows the low-order task process of an example.
[Fig. 8] reference It is a flowchart which shows the high-order task process of an example.
FIG. 9 is an explanatory diagram showing a priority recording area;
FIG. 10 is a flowchart showing a determination process.
[Explanation of symbols]
1 ... ECU 10 ... Microcomputer
11 ... CPU 12 ... ROM
13 ... RAM 13a ... storage area
13b: Storage area 13c: Storage area
14 ... I / O 21 ... Input circuit
22 ... Output circuit 30 ... Sensor
40 ... Actuator

Claims (8)

In an information processing apparatus that realizes a series of functions by executing a plurality of processing programs as execution units based on a priority set for each processing program,
A global variable used in common between the lower program having a relatively low priority and the higher program having a relatively high priority is stored in two areas overlappingly, and one of the areas is a public area Set the other as the work area,
For the first case in which the global variable may be updated by the upper program in the middle of referring to the global variable by the lower program,
In the upper program, the upper update process for updating the global variable using the work area is executed,
On the other hand, in the lower program, when the lower reference process that refers to the global variable using the public area and the reference of the global variable by the lower reference process is completed, the work area is newly set as the public area. An information processing apparatus characterized in that an area switching process for newly setting the public area as a work area is executed. In an information processing apparatus that realizes a series of functions by executing a plurality of processing programs as execution units based on a priority set for each processing program,
A global variable used in common between the lower program having a relatively low priority and the higher program having a relatively high priority is stored in two areas overlappingly, and one of the areas is a public area Set the other as the work area,
For the first case in which the global variable may be updated by the upper program in the middle of referring to the global variable by the lower program,
In the upper program, the upper update process for updating the global variable using the work area is executed,
On the other hand, in the lower program, when the lower reference process that refers to the global variable using the public area and the reference of the global variable by the lower reference process is completed, the work area is newly set as the public area. At the same time, an area switching process for newly setting the public area as a work area is executed.
Furthermore, for the second case in which the global variable may be referred to by the upper program during the update of the global variable by the lower program,
In the upper program, an upper reference process that refers to the global variable using the public area is executed,
On the other hand, in the subordinate program, when the subordinate update process for updating the global variable using the work area and the update of the global variable by the subordinate update process are completed, the work area is newly set as a public area. An information processing apparatus characterized in that an area switching process for newly setting the public area as a work area is executed. The information processing apparatus according to claim 2 ,
In each processing program, based on the priority of another processing program that performs reference or update of the global variable, a determination process is performed to determine which of the lower processing program and the upper processing program corresponds, An information processing apparatus characterized in that the corresponding process is executed based on a determination result of the determination process. The information processing apparatus according to claim 3 .
A priority storage means for storing the highest priority among the priorities of the processing program for referring to or updating the global variable;
The information processing apparatus according to claim 1, wherein the determination process is performed by comparing a priority stored in the priority storage unit with a priority set in a processing program to be determined. The information processing apparatus according to claim 3 .
The information processing apparatus according to claim 1, wherein the determination processing is based on a priority of another processing program that performs reference or update for a global variable to be processed in the processing program to be determined. The information processing apparatus according to claim 5 ,
For each global variable, comprising a priority storage means for storing the highest priority among the priorities of the processing program for referring to or updating the global variable,
The determination process is performed by comparing the priority corresponding to the global variable to be processed stored in the priority storage unit and the priority set in the processing program to be determined. An information processing apparatus characterized by being. In the information processing apparatus according to any one of claims 1 to 6 ,
The information processing apparatus further comprises an area information storage unit for storing setting information for setting an area as the public area or the work area. The information processing apparatus according to claim 7 ,
In the area switching process, the work area is newly set as a public area and the public area is newly set as a work area by updating the setting information stored in the area information storage unit. An information processing apparatus characterized by

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