JPS6265137A - Control system for priority of user task - Google Patents

Abstract

PURPOSE:To control the priority with high efficiency by increasing temporarily the priority level of its own user task which is being used to the resources for which other user tasks are waiting. CONSTITUTION:A key control part 3 performs the key control for user tasks 1A-1C of users A-I respectively according to the information given from an exclusive control part 2 which gives the exclusive control to the use of resources. Here a priority control part 4 increases temporarily the priority level of the task 1C compared with the task corresponding to a user K in response to the control contents of the part 3 in such a case where the user I uses the resources X and the user K is waiting for use of the resources X. In the same way, the priority level of the task 1C is increased temporarily compared with the task 1A via the part 4 in case the task 1A request the use of the resources X and is set under a waiting state. When the use of the resources X is promoted and through, the priority level of the task 1C is set back to its original level by the part 4. Thus the priority levels of user tasks can be controlled appropriately with high efficiency.

Description

[Detailed Description of the Invention] [) Already Required] 1. In a data processing device where exclusive control is exercised regarding resource usage among multiple user tasks.
When another user's task becomes in a standby state regarding the resource being used by the own user's task, the priority of both user tasks will be raised to the higher level of the priority level.
It is disclosed that the priority of the self-user task is increased so that processing can be performed efficiently.

[Industrial application field]

The present invention is a user task priority control method.

In particular, when other second user tasks are in a standby state due to the presence of a first user task that is currently using a resource, the priority of the first user task can be efficiently increased. This invention relates to a priority control method for user tasks.

[Conventional technology]

In a data processing apparatus in which multiple user tasks access a common resource while adopting an exclusive control method, a resource currently being used by a first user task is conventionally accessed by another second user. When a task issues a usage request and the second user task is placed in a standby state because the first user task is in use, the following actions may be taken. That is, the priority of the first user task is temporarily set to the highest level allowed by the system, so that the waiting state of the second user task is released early.

Even if increasing the priority may cause the first user task to further conflict with a third party user task for resource usage.

The first user task will be given priority in acquiring the resource, and the processing of the first user task will be completed earlier, resulting in the resource requested by the second user task being The aim is to make it available for use as soon as possible.

[Problem that the invention seeks to solve]

Conventionally, the above-mentioned processing has been carried out, but because of this, there are problems in the system in which tasks that should normally be processed with the highest level of priority are moved to the next level, and tasks that are temporarily processed as described above are There are problems such as when and how to return the priority of the first task, which has been set to the highest level, to its original level.

[Means for solving problems]

The present invention solves the above-mentioned problems, and FIG. 1 shows a basic configuration diagram of the present invention.

In FIG. 1, 1 is a user task, and 2 is an exclusive control unit. The exclusive control unit 2 controls each of the users 1A, IB, .
In response to resource use requests and resource use release requests from ..., the availability of resource use is controlled using an exclusive control method.

3 is a queue control unit that stores, for each resource, for example resource Bx, the name of the user task (user) currently using it and the name of the user task (requester) that is waiting to request its use. cue and control. Reference numeral 4 denotes a priority control unit, and regarding exclusive control, when a new user task that enters a standby state occurs or a user task currently in use releases the use of resources, the exclusive control unit 2 I have been notified by. Then, when a new user task that enters the standby state occurs.

The priority of the user task currently in use.

A) The priority of the user task currently in use, and B) The priority of the user task that has newly entered the standby state.

control is performed to increase the priority of the user task currently in use to the higher priority.

[Effect]

Assume that each user task is proceeding with processing while acquiring resources under exclusive control.

The state shown in Figure 1 is that for resource X, user task (1) is in use, user task (K) is on standby, and user task (A) is now on standby. shown as something.

In this case, when user task (K) becomes waiting, the priority of user task (1) currently in use is set to the higher level of task (1) or (K). It has been placed. Then, when the user (A) is newly placed on standby, the priority of the user task (1) is placed at a higher level than that of the user (A). Then, user task (1) is enabled to release resource X early.

When user task (1) releases resource 1x.

If there is another resource, for example Y, being used by the user task (1), the same procedure is taken with respect to the resource Y so that the user task (+) can release the resource Y at an early stage. And under the condition that there are no other tasks in the 3 waiting state.

The priority of the user task (I) is returned to its original level.

〔Example〕

FIG. 2 shows the configuration of an embodiment of the present invention.

Reference numbers 1A, IB, . . . , 2, 3.4 in the figure correspond to those in FIG. Resource name registration processing unit.

Reference numeral 2-12 represents a resource use/waiting processing section, 2-21 a waiting requester index processing section, and 2-22 a resource name deletion processing section. Also, ■, ■, . . . represent the flow of control.

Now, suppose that the user task (-■) issues a usage request for resource 1x (■), the resource name registration processing unit 2-11 notifies the queue control unit 3 (■), and the queue control unit 3 requests the use of the resource 1x (■). +) on the queue for resource X. Thereafter, as shown in FIG.

Assume that a user task K (not shown) has issued a request for resource Hx and is in a standby state, and that a user task (A) has issued a request for use of resource X.

At this time, the resource use/wait processing section 2-12 notifies the queue control section 3 (2), and the queue control section 3 registers the name of the user task (A) on the queue. The resource use/waiting processing unit 2-12 also notifies the priority control unit 4 of this fact. The priority control unit 4 includes a priority level index unit 5
The content of the queue control unit 3 is indexed via level to the user task (1)■.

When the user task (1) issues a release request (2) for resource X, the waiting requester index processing section 2-21 notifies the queue control section 3 of this fact.

The user task (1) notifies the priority control unit 4 that resource X has been released [phase]. The priority control unit 4 indexes the contents of the queue control unit 3 via the priority level index unit 5, and if the user task (1) is using or waiting for another resource Y, the user task (1) 1) @ to control the priority. Also, if there is no other task waiting for user task (1), the priority of user task (I) is returned to the original level. 2-22 deletes the name of user task (1) with regard to ax [Effect of the invention] As explained above, according to the present invention Regarding the priority of tasks, the higher priority is given to the task in use. For this.

The difficulties associated with reaching the highest level as in the past are eliminated. Of course, the effects expected in the conventional case can be enjoyed. Furthermore, the process of restoring the priority to the original level can be performed efficiently.

[Brief explanation of drawings]

FIG. 1 shows the basic configuration of the present invention, and FIG. 2 shows the configuration of an embodiment of the present invention. In the figure, 1 is a user task, and 2 is an exclusive control unit. 3 represents a queue control section, 4 a priority control section, and 5 a priority level index section.

Claims (1)

[Scope of Claims] A plurality of user tasks (1) are configured to proceed with processing while accessing a common resource, and an exclusive control unit ( 2)
and a queue control unit (3) that performs queue control regarding a user task (1) in a standby state by exclusive control, in which a first user task (1C) is currently exclusively controlling a resource. During use, the second user task (1A) issues a request to use the resource, and the second user task (1A) issues a request to use the resource.
When the task (1A) is placed in a standby state and when the first user task (1C) in use releases the resource, the exclusive control unit (2) performs priority control to this effect. Department (
4), and the priority control unit (4) sets the priority control unit (4) to the level of the higher priority of the first user (1C) and the second user (1A). The first user task (1C) is configured to dynamically set the priority of the first user task (1C), and while the other user task (1A) is waiting for the resource in use by the self user task (1C). A user task priority control method characterized in that the priority of a user task (1C) can be temporarily raised to a predetermined level.