JPH05127926A - Task controller - Google Patents

Abstract

PURPOSE:To reduce overhead required for task switching by grouping tasks by means of a common characteristic and exchanging the register of a peculiar part without exchanging the register of a common part at the time of switching the tasks. CONSTITUTION:A task control information extraction part 5 extracts task control information which is inputted from a task input interface 1 with the tasks and which provides information on the state of the tasks and on priority, and they are stored in a task control information storage part 6. A task control part 7 exchanges the tasks by information on a task storage peculiar register part 14, a task storage common register part 15 and a task control information storage part 6 through CPU and a task input/output interface 8. When the next task is in the same group as the present task, the common part is left as it is and the task of the peculiar part is exchanged.

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention is used for computer multitasking. In particular, it relates to task switching technology.

[0002]

2. Description of the Related Art In an operating system operating by a plurality of tasks, when assigning a register for each task to be executed and switching the task in the dispatch processing, the contents of the register of the current task (the task that has been executed up to now) Was saved in a specific storage area, and the content of the register of the next task (the task to be executed next) was read from the specific storage area.

A conventional example will be described with reference to FIGS. 4 and 5. FIG. 4 is a block diagram of a conventional example. FIG. 5 is a flowchart showing the operation of the task control unit 7 of the conventional example.

The task input from the task input interface 1 is given a task identification number by an integer for task control in the task identification number giving section 2. The task-specific register address designation unit 3 stores the task in the task storage register unit 4 according to the task identification number.

Other task control information input together with the task is extracted by the task control information extracting section 5, and data such as task status and priority order is stored in the task control information storing section 6.

The task control section 7 performs task control as shown in the flowchart of FIG. The next task to be executed next to the current task currently being executed by the CPU is determined by referring to the task control information in the task control information storage unit 6, and it is determined whether the task is the same as the current task. As a result, if the next task is the same as the current task, task switching is not executed and the next task is similarly verified. If the next task is different from the current task, the current task is stored in the task storage register unit 4
Then, the next task is read from the task storage register unit 4. In this way, this operation is repeated until all tasks have been performed.

Further, in a certain type of operating system, when a certain register is exchanged by the operating system for a certain register, the contents may be excluded from the target for exchanging the contents and may be shared by all the tasks.

[0008]

In the method in which the contents of a certain register are excluded from the target of exchanging the contents when the operating system switches the task and the contents are shared by all the tasks, the task allocates the register to the computer resource. Seeing that, resource management has to be done and it is not efficient.

Further, the conventional method of simply exchanging the contents of the registers when switching tasks has the following problems.

First, there is a problem that the overhead of register replacement accompanying task switching becomes large.

In recent microprocessors, the overhead of exchanging the contents of registers in one microprocessor is increasing due to the expansion of the bit length of the registers and the increase in the number of registers. For example, the conventional μPD70116 (V30) manufactured by NEC Corporation had eight 16-bit registers for performing processing such as calculation, but the recent μPD70616 (V6)
In 0), there are 32 32-bit registers,
The amount of information that needs to be replaced is eight times larger.

Further, in order to perform high-precision floating-point calculation and high-dimensional matrix calculation, the function of the microprocessor is expanded by adding one or more coprocessors. Some coprocessors also have built-in registers, which increases the overhead of exchanging the contents of registers. For example, the floating point arithmetic coprocessor μPD72691 (FPP) for the μPD70616 (V60) has 32 registers each having an 80-bit length, and the amount of information to be exchanged is 24 times.

Next, there is a problem that the overhead associated with communication between tasks becomes large.

For example, a specific task is caused to perform arithmetic processing such as floating point arithmetic, and another specific task is caused to perform its control processing, and the result of the arithmetic processing is communicated between tasks such as shared memory or message. By means of the means for notifying the task of the control processing from the task of the arithmetic processing and the means for synchronizing the tasks, a certain processing may be performed as a whole. In such software, when performing floating point arithmetic with a coprocessor that has dedicated registers,
The task that performs the control process does not use these registers for floating point arithmetic, and the notification of the result by the inter-task communication means is basically useless and becomes a large overhead.

The present invention has been made against such a background. By grouping a plurality of tasks and designating the registers to be swapped at the time of task switching for each group, the overhead accompanying the swapping of registers is minimized. It is an object of the present invention to provide an apparatus that suppresses the temperature and forms an efficient multitask environment.

[0016]

The present invention provides a task input interface for inputting a task, a task identification number assigning section for assigning a task identification number to a task input from the task input interface, and this task identification number assigning section. Task-specific register address designating section for designating the address of the register to be stored in each task assigned with the identification number, and a task storage register section for storing each task at the address designated by the task-specific register address designating section A task control information extraction unit that extracts task control information input together with a task via the task input interface; and a task control information storage unit that stores the task control information extracted from the task control information extraction unit, The task control information stored in this task control information storage In a task control device having a task control unit for controlling tasks according to the above, task groups classified by assigning the identification number to each task into similar groups Means is provided, and the task storage register section includes means for storing each task belonging to this classified one group by dividing it into a unique part and a shared part, and the task control section has an input / output interface. When the task to be executed by the connected CPU is switched, when the currently executing task and the task to be executed next belong to the same group, a means for switching the unique part of the task is included.

[0017]

The task input from the task input interface is assigned an integer task identification number by the task identification number assigning section.

The task group classification unit classifies tasks by the task identification number into groups having similar contents and operations, and the task group identification number assigning unit assigns an integer task group identification number to each of the classified task groups. Granted.

In the course of this group classification, the unique part and shared part of each task have been clarified, and this unique part is stored in the task storing peculiar register part at the address specified by the task-specific peculiar register address specifying part. To be done. Similarly, the common part is stored in the task storage shared register part at the address designated by the task-specific shared register addressing part.

The task control information input from the task input interface together with the task and providing information such as the status and priority of the task is extracted by the task control information extraction unit and stored in the task control information storage unit.

The task control unit switches the task via the CPU and the task input / output interface according to the information of the task storage specific register unit, the task storage shared register unit and the task control information storage unit.

At this time, the feature of the present invention is that when the next task is the same task group as the current task,
The task is to switch the task of the unique part while leaving the common part as it is.

[0023]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The configuration of an apparatus according to an embodiment of the present invention will be described with reference to FIG. FIG. 1 is a view showing the arrangement of an apparatus according to the present invention.

The present invention is a task input interface 1 for inputting a task, and the task input interface 1
Task identification number assigning section 2 that assigns a task identification number to the task input from the task identification register, and a task-specific register that specifies the address of the register that is stored in each task that has been assigned an identification number by the task identification number assigning section 2. An address designation unit 3, a task storage register unit 4 for storing each task at an address designated by the task-specific register address designation unit 3, and a task input interface 1
Task control information extraction unit 5 that extracts task control information input together with a task via the task, task control information storage unit 6 that stores the task control information extracted from this task control information extraction unit 5, and this task control In a task control device including a task control unit 7 that controls a task according to the task control information stored in the information storage unit 6, each task assigned with the identification number is classified into groups for each similar task. A group categorizing means is provided to the task-specific register address designating section 3, and the task storing register section 4 includes means for storing each task belonging to the one categorized group by dividing it into a unique part and a shared part. , The task control unit 7 has a function for switching the task executed by the CPU connected to the task input / output interface 8 when When executing task and the execution plan to the next task belongs to the same group, characterized in that it comprises a means for switching a specific part of the task.

Next, the operation of the apparatus of the present invention will be described with reference to FIGS. FIG. 2 is a diagram showing a unique part and a shared part of a task.

The task input from the task input interface 1 is assigned an integer task identification number by the task identification number assigning section 2.

The task group classification unit 10 classifies the tasks by the task identification number into groups having similar contents and operations, and the task group identification number by an integer is assigned to each of the classified task groups. It is given by 11.

As shown in FIG. 2, the unique parts 20 and 21 and the common part 22 of each task are clarified in the process of the group classification, and the unique parts 20 and 2 are shown.
1 is an address designated by the task-specific peculiar register address designating section 12 and is stored in the task storage peculiar register section 14. Similarly, the common portion is the address designated by the task-specific shared register address designating unit 13,
It is stored in the task storage shared register unit 15.

The task control information, which is input from the task input interface 1 together with the task and provides information such as the status and priority of the task, is the task control information extraction unit 5.
And is stored in the task control information storage unit 6.

The task control unit 7 switches tasks via the CPU and the task input / output interface 8 according to the information in the task storage specific register unit 14, the task storage shared register unit 15, and the task control information storage unit 6.

At this time, the feature of the present invention is that when the next task is the same task group as the current task,
The task is switched to the unique portion while leaving the common portion as it is. This operation will be described with reference to FIG.
FIG. 3 is a flow chart showing the operation of the task control unit of the apparatus of the present invention.

The task control section 7 is a task control information storage section 6
The next task is decided based on the information. It is determined whether the task is the same as the current task, and if the task is the same, the next next task is verified. At this time, if the current task and the next task are different, the task group is verified from the task group identification number to which this task belongs, and it is determined whether the task groups are the same. If this is also different, there is no shared part between the current task and the next task, so all registers of the current task are replaced with the next task. As a procedure, first, a portion which is a shared portion in the first group classification is stored in the task storage shared register unit 15 and saved. Next, a portion corresponding to the shared portion of the next task is read from the task storage shared register unit 15 and stored in the register on the CPU side. Subsequently, the part that is the unique part of the current task is stored in the task storage unique register unit 14 and saved. Next, a portion corresponding to the unique portion of the next task is read from the task storage unique register unit 14 and stored in the CPU side register, and all the registers are replaced.

Next, the task switching procedure for the same group, which is a feature of the apparatus of the present invention, will be described. The current task and the next task having the same task group identification number can share the shared part. Therefore, the part that needs to be replaced is a unique part. First, the peculiar part of the current task is stored in the task storage peculiar register unit 14 and saved. Next, the peculiar part of the next task is read from the task storing peculiar register unit 14 and stored in the register on the CPU side. In this way, the next task is input to the CPU and executed without replacing all registers.

[0034]

By classifying the tasks into the shared part and the unique part by grouping the tasks, the registers of the shared part can be shared without being exchanged, and the task switching overhead can be reduced.

[Brief description of drawings]

FIG. 1 is a block diagram of an apparatus according to an embodiment of the present invention.

FIG. 2 is a diagram showing a unique part and a shared part of a task.

FIG. 3 is a flowchart showing the operation of the task control unit of the device of the present invention.

FIG. 4 is a block diagram of a conventional example.

FIG. 5 is a flowchart showing the operation of a task control unit of a conventional example.

[Explanation of symbols]

 1 task input interface 2 task identification number assignment unit 3 task-specific register address designation unit 4 task storage register unit 5 task control information extraction unit 6 task control information storage unit 7 task control unit 8 task input / output interface 10 task group classification unit 11 tasks Group identification number assigning unit 12 Task-specific peculiar register address designation unit 13 Task-specific shared register address designation unit 14 Task storage unique register unit 15 Task storage shared register unit 20, 21 Unique portion 22 Shared portion

Claims (1)

[Claims] 1. A task input interface for inputting a task, a task identification number assigning unit for assigning a task identification number to a task input from this task input interface, and an identification number assigned by this task identification number assigning unit. A task-specific register address specification unit that specifies the address of the register stored in each task,
A task storage register unit for storing each task at an address designated by the task-specific register address designation unit, a task control information extraction unit for extracting task control information input together with the task via the task input interface, Task control including a task control information storage unit that stores task control information extracted from the task control information extraction unit, and a task control unit that controls a task according to the task control information stored in the task control information storage unit The apparatus is provided with task group classification means for classifying each task assigned with the identification number into groups for each similar task, and giving the task-specific register address designation section to the task storage register section. Each task belonging to another group is divided into its unique part and shared part. Includes means for separately storing, on the task control unit, when switching the tasks performed by the CPU connected to the input-output interface,
A task control device comprising means for switching a unique part of a task when a task currently being executed and a task to be executed next belong to the same group.