JPH10171666A - Task control block management mechanism and its managing method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To quickly retrieve an inserting position into a task control block queue in an operating system. SOLUTION: Each task control block 200 corresponding to each of plural tasks managed by the operating system includes a priority queue pointer 210 constituting a priority queue. A management data area 100 in the operating system includes an overall end pointer 110 indicating the leading element of the priority queue and plural priority end pointers 120 indicating the final task control blocks of respective priority elements in the priority queue. The inserting position of a task control block to be inserted is determined by referring to the priority end pointer 120 based on the priority of the task control block.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a task control block management mechanism for managing a task control block, which is a data structure for controlling a task in an operating system, and a management method thereof. And a method for managing a queue as a queue.

[0002]

2. Description of the Related Art Conventionally, in this type of technology, a queue of task control blocks is formed in order of priority, and a queue for connecting a head task control block of each priority is separately formed.

For example, Japanese Patent Laid-Open No. 4-101233 discloses a task management method using a two-level queue structure. This conventional method will be described with reference to FIG.
Referring to FIG. 6, each task in the operating system is managed as a task control block 900, and a priority queue is configured by connecting each task control block 900 by a priority queue pointer 910. Also, a dedicated queue is formed by connecting only the first task of each priority by the dedicated queue pointer 920.

In this prior art, in order to schedule tasks in an executable state in order of priority, task control blocks are inserted in a queue in order of task priority and connected. At this time, the insertion position is determined by comparing the priority of the task to be inserted with the task priority of each task control block connected to the dedicated queue.
That is, the search of the insertion position is performed without comparing with other tasks of the same priority.

[0005]

However, in the above-mentioned prior art, there is a problem that the insertion position cannot be searched unless the first task of each priority is traced in order, and it takes time to perform the processing for that.

An object of the present invention is to solve such a problem of the prior art, and an object of the present invention is to provide a mechanism for quickly searching a task control block insertion position with a simple configuration.

[0007]

According to the present invention, there is provided a task control block management mechanism for managing a queue of task control blocks, which is a data structure for controlling a task in an operating system. A block management mechanism, comprising: an entire end pointer for holding a pointer to a task control block at an entire end of the queue of the task control blocks; and a task control block at an end for each priority in the queue of the task control blocks. A priority end pointer for holding a pointer to the new task control block in the management data area outside the task control block, and the task control block indicated by the priority end pointer corresponding to the priority of the new task control block. Means for inserting a control block and the priority end pointer And means for updating as a control block.

Another task control block management mechanism of the present invention is a task control block management mechanism for managing a queue of task control blocks, which is a data structure for controlling a task in an operating system. A whole end pointer that holds a pointer to a task control block at the entire end of the control block queue; and a priority end that holds a pointer to a task control block at the end of each priority in the task control block queue. A pointer is included in the management data area outside the task control block, and corresponds to the priority when a task control block having the same priority as the priority of the new task control block is in the queue of the task control block. Next to the task control block indicated by the priority end pointer First inserting means for inserting a new task control block, and a first updating means for updating the priority end pointer to indicate the new task control block when the new task control block is inserted by the first inserting means. Updating means, and when a task control block having the same priority as the priority of the new task control block is not in the queue of the task control block, the task control block corresponding to the closest priority higher than the priority Second insertion means for inserting the new task control block next to the task control block indicated by the priority end pointer, and the priority end pointer when the new task control block is inserted by the second insertion means. And second updating means for updating to indicate the new task control block.

In another task control block management mechanism of the present invention, the entire end is a head element of a queue of the task control block, and the end for each priority is an end of a queue of the task control block. This is the end of each priority.

In the task control block management method according to the present invention, an entire end pointer for holding a pointer to the task control block at the entire end of the queue of the task control block; and a priority of the task control block in the queue. A priority end pointer that holds a pointer to a task control block at each end in the management data area outside the task control block, and the task control block having the same priority as the priority of the new task control block is If the task control block is in the queue, the new task control block is inserted next to the task control block indicated by the priority end pointer corresponding to the priority, and the priority end pointer is set to the new task control. Blocks having the same priority as that of the new task control block. When the task control block is not in the task control block queue, the new task control block is inserted next to the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority. Above, the priority end pointer points to the new task control block.

In another task control block management method according to the present invention, an entire end pointer for holding a pointer to a task control block at the entire end of a queue of task control blocks; A task control block having a priority end pointer holding a pointer to a task control block at the end of each priority in a management data area outside the task control block, and having the same priority as the priority of the new task control block When the new task control block is in the task control block queue, the new task control block is inserted next to the task control block indicated by the priority end pointer corresponding to the highest priority higher than the priority, and the new task control block is inserted. The task control block having the same priority as the priority of the task control block is the task control block. When not in the queue, after inserting the new task control block next to the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority, the priority end pointer is Indicate a new task control block.

In another task control block management method according to the present invention, the whole end is a head element of a queue of the task control block, and the end for each priority is an end of a queue of the task control block. This is the end of each priority.

[0013]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the task control block management mechanism of the present invention will be described in detail with reference to the drawings.

Referring to FIG. 1, an embodiment of the task control block management mechanism of the present invention manages a task control block 200 provided for each of the tasks managed by the operating system. The task control block 200 includes a priority queue pointer 210
Priority queues are configured by connecting the respective task control blocks 200 by the priority queue pointer 210. In this priority queue,
For example, task control blocks are connected in order from the task with the highest priority, and an identifier (for example, a “null pointer”) indicating the last element is set in the priority queue pointer 210 of the task with the lowest priority. Is done.

[0015] In the priority queue, the order of task control blocks within the same priority follows a predetermined management method. For example, when performing first-in first-out (FIFO) management, a task control block to be newly inserted is inserted as the last element in the corresponding priority.
If last-in-first-out (LIFO) management is performed, a task control block to be newly inserted is inserted as a head element at a corresponding priority.

The task control block 200 further includes task control information 220. The operating system controls the execution state of the task based on the task control information 220. In the task control information 220, for example, a task name, a value of a program counter, a pointer to a stack area, a value of a register, and the like are saved, and when the task is restarted, these information are restored to the processing device.

The management data area 100 includes an overall end pointer 110 indicating an end element (for example, a head element) as a whole of the priority queue, and an end element (for example, a tail end) of each priority in the priority queue. ) Includes the priority end pointer 120 indicating the task control block. Priority end pointer 120
Are provided corresponding to each of the priorities. If there is no task control block corresponding to the priority, the priority end pointer 120 is set with an identifier indicating that it is empty (for example, a “null pointer”).

Next, the operation of the embodiment of the task control block management mechanism of the present invention will be described with reference to the drawings. Here, the overall end pointer 110 indicates the head element of the priority queue, and the priority end pointer 120 indicates the last task control block of each priority in the priority queue.

Referring to FIG. 2, when a new task control block is inserted by first-in first-out management, the dispatcher of the operating system sets the priority of the newly inserted task to a variable X (step S3).
01). Then, it is checked whether or not the task control block of the priority X is in the priority queue (step S30).
2). If it is determined in step S302 that the task control block with the priority X is not in the priority queue, the insertion processing in step S400 is performed.

In step S302, when it is determined that the task control block of the priority X is in the priority queue, the task immediately before the task to be inserted (hereinafter, referred to as an insertion task) (hereinafter, immediately before). The last task with the priority X is selected as a task (refer to step S303). The selection of the last task can be easily obtained from the priority end pointer 120 in the management data area 100.

Next, the priority queue pointer 210 of the immediately preceding task is added to the priority queue pointer 210 of the inserted task.
0 is copied (step S304). Then, a pointer to the inserted task is set in the priority queue pointer 210 of the immediately preceding task (step S305). Then, a pointer to the insertion task is set as the priority end pointer 120 of the priority X (step S306).

Referring to FIG. 3, step S in FIG.
The operation results from 303 to S306 are shown. That is,
3A illustrates a state after execution of step S303, FIG. 3B illustrates a state after execution of step S304, and FIG. 3C illustrates a state after execution of steps S305 and S306. . Through this series of processing, the task control block relating to the insertion task is inserted into the priority queue.

Next, referring to FIG. 4, the insertion processing in step S400 in FIG. 2 is performed as follows. First, the dispatcher of the operating system sets the priority of the insertion task to the variable Y (step S40).
1). Then, the value of the variable Y is reduced by one (step S40).
2) It is checked whether a task control block of priority Y is in the priority queue for the new variable Y (step S403). However, in the present application, the priority is the highest and the priority decreases as this value increases.

If it is determined in step S403 that the task control block with the priority Y is not in the priority queue, it is further checked whether the priority Y is the highest priority that can be managed by the operating system (step S403). Step S404), if not the highest priority, step S402
Return to

If it is determined in step S404 that the priority Y is the highest priority, the following operation is performed. First, the priority queue pointer 210 of the insertion task
Then, the entire end pointer 110 is copied (step S40).
5). Then, a pointer to the insertion task is set as the entire end pointer 110 (step S406). afterwards,
The pointer to the insertion task is set as the priority end pointer 120 of the priority X (step S410).

If it is determined in step 403 that the task control block of priority Y is in the priority queue, the last task of priority Y is selected as the immediately preceding task (step S407). Then, the priority queue pointer 210 of the immediately preceding task is copied to the priority queue pointer 210 of the inserted task (step S408), and a pointer to the inserted task is set as the priority queue pointer 210 of the immediately preceding task (step S409). ). Thereafter, a pointer to the insertion task is set as the priority end pointer 120 of the priority X (step S410).

Referring now to FIG. 5, when a new task control block is inserted by last-in first-out management,
The dispatcher of the operating system sets the priority of the insertion task to the variable X (step S50).
1). Then, it is checked whether or not the task control block of the priority X is in the priority queue (step S50).
2). If it is determined in step S302 that the task control block with the priority X is not in the priority queue, the insertion processing in step S600 is performed. The insertion processing in step S600 is the same as the insertion processing in FIG.

If it is determined in step S502 that the task control block of the priority X is in the priority queue, the priority of the inserted task is set to the variable Z (step S503). Then, the value of the variable Z is decremented by one (step S504), and it is checked whether or not the task control block of the priority Z is in the priority queue for the new variable Z (step S505).

If it is determined in step S505 that the task control block of the priority Z is not in the priority queue, it is further checked whether or not the priority Z is the highest priority that can be managed by the operating system (step S505). Step S506), if not the highest priority, step S504
Return to

If it is determined in step S506 that the priority Z is the highest priority, the following operation is performed. First, the priority queue pointer 210 of the insertion task
Then, the entire end pointer 110 is copied (step S50).
7). Then, a pointer to the insertion task is set as the entire end pointer 110 (step S508).

If it is determined in step 505 that the task control block having the priority Z is in the priority queue, the last task having the priority Z is selected as the immediately preceding task (step S509). Then, the priority queue pointer 210 of the immediately preceding task is copied to the priority queue pointer 210 of the inserted task (step S510), and a pointer to the inserted task is set as the priority queue pointer 210 of the immediately preceding task (step S511). ).

As described above, according to the task control block management mechanism of one embodiment of the present invention, the priority end pointer 120 for each priority is provided in the management data area 100 of the operating system. The insertion position of the task control block can be searched without tracing the first task in sequence, and the task control block can be managed at high speed with a simple configuration.

[0033]

As apparent from the above description, according to the present invention, the insertion position of the task control block can be searched at high speed with a simple configuration, and efficient task control block management can be realized.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of an embodiment of a task control block management mechanism of the present invention.

FIG. 2 is a diagram illustrating an operation of a first-in first-out insertion process of a task control block in the task control block management mechanism of one embodiment of the present invention.

FIG. 3 is a diagram illustrating a procedure for inserting a task control block in a task control block management mechanism according to an embodiment of the present invention.

FIG. 4 is a diagram illustrating an operation of a task control block insertion process in the task control block management mechanism of one embodiment of the present invention.

FIG. 5 is a diagram illustrating an operation of a last-in first-out insertion process of the task control block in the task control block management mechanism of one embodiment of the present invention.

FIG. 6 is a block diagram showing a configuration of a conventional task control block management mechanism.

[Description of Signs] 100 management data area 110 first element pointer 120 last pointer 200 task control block 210 priority queue pointer 220 task control information

Claims (7)

[Claims] 1. A task control block management mechanism for managing a queue of task control blocks, which is a data structure for controlling tasks in an operating system, comprising: a task control unit for controlling an entire end of the queue of the task control blocks. A management data area outside the task control block, including a whole end pointer holding a pointer to the block and a priority end pointer holding a pointer to a task control block at the end of each priority in the queue of the task control block. Means for inserting the new task control block next to the task control block indicated by the priority end pointer corresponding to the priority of the new task control block; and wherein the priority end pointer indicates the new task control block. Means for updating the task control block. Click management mechanism. 2. A task control block management mechanism for managing a queue of task control blocks, which is a data structure for controlling tasks in an operating system, comprising: a task control unit for controlling an entire end of the queue of the task control blocks. A management data area outside the task control block, including a whole end pointer holding a pointer to the block and a priority end pointer holding a pointer to a task control block at the end of each priority in the queue of the task control block. In the case where a task control block having the same priority as the priority of the new task control block is in the queue of the task control block, the task control block indicated by the priority end pointer corresponding to the priority Next, first insertion means for inserting the new task control block, First updating means for updating the priority end pointer to indicate the new task control block when the new task control block is inserted by the first insertion means; and the priority of the new task control block. If there is no task control block having the same priority in the task control block queue, the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority and the new task control block is added to the new task control block. A second inserting means for inserting a task control block; and a second updating means for updating the priority end pointer so as to indicate the new task control block when the new task control block is inserted by the second inserting means. A task control block management mechanism. 3. The task control block according to claim 1, wherein the entire end is a head element of a queue of the task control block, and the end of each priority is a tail end of the task control block in a queue of each priority. 2. The task control block management mechanism according to claim 1, wherein: 4. An entire end pointer for holding a pointer to a task control block at an end of a queue of task control blocks, which is a data structure for controlling a task in an operating system; and a queue of the task control block. And a priority end pointer holding a pointer to a task control block at the end of each priority in the management data area outside the task control block, and the task control having the same priority as the priority of the new task control block When a block is in the task control block queue, the new task control block is inserted next to the task control block indicated by the priority end pointer corresponding to the priority, and the priority end pointer is A new task control block is indicated, and the superiority of the new task control block is indicated. If there is no task control block having the same priority as the task control block in the queue of the task control block, the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority is next A task control block management method, wherein the priority end pointer indicates the new task control block after inserting the new task control block. 5. The task control block according to claim 5, wherein the entire end is a head element of a queue of the task control block, and the end of each priority is a tail end of the task control block in a queue. 4. The task control block management method according to claim 3, wherein: 6. An entire end pointer for holding a pointer to a task control block at an end of a queue of task control blocks, which is a data structure for controlling a task in an operating system; and a queue for the task control block. And a priority end pointer holding a pointer to a task control block at the end of each priority in the management data area outside the task control block, and the task control having the same priority as the priority of the new task control block If the block is in the task control block queue, insert the new task control block next to the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority, A task control block that has the same priority as the priority of the new task control block If the task control block is not in the queue, the new task control block is inserted next to the task control block indicated by the priority end pointer corresponding to the closest priority higher than the priority, and A task control block management method, wherein an initial pointer indicates the new task control block. 7. The task control block according to claim 1, wherein the whole end is a head element of a queue of the task control block, and the end of each priority is a tail end of a queue of the task control block for each priority. 6. The task control block management method according to claim 5, wherein: