JPH01282646A - Fixing memory access system for segment base register - Google Patents

Abstract

PURPOSE:To delete a use memory by copying a task corresponding segment table on a memory assigned at the time of preparing a task to a segment table area on the memory assigned to a system uniquely. CONSTITUTION:The title system has a task corresponding segment table preparing mean 1 to execute the preparing processs of the task corresponding segment table at the time of preparing a task and a segment table transferring means 2, and the task corresponding segment table on the memory assigned at the time of preparing the task is copied to a segment table area on the memory assigned to the system uniquely. Consequently, since an area for controlling a system space from an entry 1 of a segment table necessary for a task up to an entry 8 may be the system unique segment table only at the control system to change a segment base register, the use memory can be deleted. Since the segment base register is not changed, the system down can be deleted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a memory access method for segment-based registers, and particularly to task management that performs processing during task creation and processing during task dispatch.

[Conventional technology]

The conventional memory access method stores a segment table (ST) for tasks in a segment base register (SBR).
Control was performed to set the real address of the address.

[Problem to be solved by the invention]

For this reason, the system space segment table, which originally only needs to exist, is required for each task, and a large amount of memory is used.

In task dispatch processing, which switches running tasks, job execution by tasks is controlled by setting the segment table address for the own task stored in the task to be dispatched in the segment base register. If the segment table address stored in the task is destroyed due to destruction, an abnormal value will be set in the segment base register and the system will go down.

[Means to solve the problem]

According to the present invention, the present invention includes a task-corresponding segment table creation means for creating a task-corresponding segment table at the time of task generation, and a segment table transfer means, and the task-corresponding segment table on the memory allocated at the time of task generation. , a fixed memory access method for segment-based registers is obtained, which is characterized by copying to a segment table area in memory that is uniquely allocated to the system.

〔Example〕

Next, the present invention will be explained in more detail with reference to the drawings showing one embodiment of the present invention.

Referring to FIG. 1, one embodiment of the present invention includes task-compatible segment table creation means 1 that creates a segment table for job space management corresponding to a task, and transfers data to a corresponding area of the segment table for job space management corresponding to a task. Alternatively, the segment table transfer means 2 is configured to transfer job space management of a unique segment table (segment table entry 9 to segment table entry 16) to a segment table storage area corresponding to a task.

FIG. 2 shows the processing contents of the task corresponding segment creation means 1, and shows the task control block (TC).
It consists of the securing process 21 of B) and the initializing process 22 of all segment table entries in the task control block.

FIG. 3 shows the contents of the segment table transfer means 2, in which a process 31 acquires whether the run is to start or end from the input information, a process 32 determines whether to start or end the run, and a task for the start task It consists of a process 33 for transferring the segment table information in the control block to the system-unique segment table area, and a process 34 for transferring the task-corresponding segment table information in the system-unique segment table area to the segment table storage area of the running end task.

Next, the operation of the present invention will be explained.

(1) The task corresponding segment creation means 1 operates as part of the task generation process activated by the Sv''C command, and secures an area for the task control block in process 21, and generates the task control block area secured in process 22. Performs initialization processing for all segment table entries in the block.

(2) The segment table transfer means 2 is called and operates when a running task abandons the CPU and enters a wait state, or when a task dispatcher transfers to a running task in a ready state waiting for the CPU. In process 31, information on whether to start or end running is acquired from the input information, and in process 32, processing is performed based on the information obtained in process 31. The job space information from segment entry 9 to segment entry 16, which is the segment table information in the task control block of the start task, is transferred to the corresponding area of the system-unique segment table area. At the end of the run, in step 34, the job space management information from segment entry 9 to segment entry 16 of the system-unique segment table information is transferred to the segment table information storage area in the task control block of the task to be placed in a wait state.

By using the segment table transfer method described above, the system-unique segment table can be changed without changing the contents of the segment base register, and the system-unique segment table can be changed. The division of control performs control.

〔Effect of the invention〕

As explained above, according to the present invention, in the control method that changes the segment base register, the area for system space management from entry 1 to entry 8 of the segment table required for each task is allocated only to the system unique segment table. , so the memory usage can be reduced. Furthermore, since the segment base register is not changed, the segment base register is not destroyed, which has the effect of reducing system downtime.

[Brief explanation of the drawing]

FIG. 1 is an overall configuration diagram of an embodiment of the present invention, FIG. 2 is a diagram showing the processing contents of the task-corresponding segment table creation means, FIG. 3 is a diagram showing the processing contents of the segment table transfer means, and FIG. 4 is a diagram showing the processing contents of the segment table transfer means. 1 is an overall configuration diagram showing a conventional memory access method by changing segment registers; FIG. 1: Task-compatible segment table creation means, 2: Segment table transfer means, Patent attorney Uchihara Otokiku Z diagram

Claims (1)

[Claims] task-compatible segment table creation means for creating a task-compatible segment table when a task is generated;
Fixing of a segment base register comprising a segment table transfer means and copying a task-corresponding segment table in memory allocated at the time of task generation to a segment table area in memory uniquely allocated in the system. memory access method.