JPH0365574B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a roll-in/roll-out control method that expands the range of memory space subject to roll-in/roll-out.

A roll-in/roll-out method is known as a long-term memory load control method. In the traditional roll-in/roll-out method, the task being executed is long-term.
When the WAIT state is entered, for example when a manual operation is requested, the memory space specific to that task is evacuated (rolled out) to a secondary storage medium,
When the WAIT state is released, the contents saved to the secondary storage medium are reloaded into memory (roll-in).
It is something to do. However, although buffers for inter-task communication are secured in the system shared space, and each inter-task communication buffer is used only by one specific task at a certain point in time, In the conventional roll-in/roll-out control method, the system shared space is
It had the disadvantage that it was not subject to roll-out, and the effect of roll-in/roll-out could not be fully demonstrated.

The present invention eliminates the above-mentioned drawbacks, and also manages buffer users (tasks) regarding buffers secured in the system shared space, and also rolls the system shared space when performing roll-in and roll-out. It is an object of the present invention to provide a roll-in/roll-out control method that can improve the effect of roll-in/roll-out by making it a target of in-roll-out. Therefore, the roll-in/roll-out control method of the present invention provides a task control table and a buffer control table in order to manage the system shared space, and when a task is created, the task name is entered in the entry of the task control table. At the same time as registration, the entry points to one buffer control table, and when task A secures buffer BUF-A on the system shared space, the buffer control table of task A is
BCT-A points to the buffer BUF-A, and when task A requests processing to another task B by specifying buffer BUF-A on the system shared space, buffer BUF-A points to the buffer BUF-A. The pointer is changed so that it points to B's buffer control table, and when another task B completes the above request process and reports this to task A, buffer BUF-A points to task A's buffer control table. When rolling out the contents of the memory space allocated to a task by changing the pointer so that The contents of the buffer saved in the external storage device are also saved to an external storage device, and when roll-in is performed, the contents of the task-specific space and the contents of the buffer saved in the external storage device are restored to their original positions. It is something to do. Hereinafter, the present invention will be explained with reference to the drawings.

FIG. 1 shows one embodiment of the present invention, where TCT is a task control table, BCT is a buffer control table, BUF is a buffer, DISP is a display device, and OP is an operator.

The memory load control program is a program for performing roll-in/roll-out. The system shared space is used for inter-task communication buffers and I/O
It is used for baths, etc. The system shared space also includes a task control table TCT, buffer control table BCT, etc.
The task control table TCT points to the buffer control table BCT, and the task control table TCT points to the buffer control table BCT.
BCT points to Batsuhua BUF. A task-specific space is assigned to a task.

Next, the roll-in/roll-out control of the present invention will be explained with reference to the drawings.

A program running on task A inputs data to the terminal user.

When a data input request is made, the system waits for data input, and at this time a rollout request is made to the memory load control program.

In the memory load control program, the contents of the task-specific space allocated to task A and the contents of buffers 1 and 2 used by task A in the system shared space are stored in an external storage device.
Save to DASD and release these memory spaces.

When data input processing is completed, a roll-in request is made to the memory control program.

In the memory load control program, task A is executed based on the contents saved on the external storage device DASD.
Restore memory information.

The program running on task A resumes execution when the roll-in is completed.

FIGS. 2 and 3 are diagrams illustrating a memory management method for the system shared space.

In the initial state, as shown in Figure 3A,
Assume that task A does not use any buffer, and only task B secures buffer 1.

When there is a request from task A to secure a buffer for inter-task communication, buffer 2 is secured and a point is made from the buffer control table BCT of task A. This state is shown in FIG. 3B.

' When a processing request is made to task B using the buffer secured from task A, buffer 2 is replaced with task B's buffer control table BCT. This state is shown in FIG. 3C.

Task A waits for task B to complete its processing.

Task B performs processing, and upon completion of processing, notifies task A of completion of processing. Then, the pointer of buffer 2 is changed to the buffer control table of task A. This state is shown in FIG. 3D.

FIG. 4 is a diagram illustrating memory space garbage processing when task A terminates abnormally and aport processing is performed. When an abnormality occurs during the execution of the program on task A and the port processing is executed, garbage processing of the system shared space and garbage processing of the self-task-specific space are performed. When garbage processing the system shared space, the task control table
TCT and the buffer control table BCT are looked up to find the buffers used by task A (buffers 1 and 2 in the illustrated example), and these buffers are determined to be usable buffers.

As is clear from the above description, according to the present invention, the system shared space is also subject to roll-in/roll-out, so the effect of memory load control by the roll-in/roll-out control method is improved accordingly.

[Brief explanation of drawings]

FIG. 1 is a diagram showing an embodiment of the present invention, FIGS. 2 and 3 are diagrams explaining the memory management method of the system shared space, and FIG. FIG. 3 is a diagram illustrating garbage processing of memory space. TCT...Task control table, BCT...Buffer control table, BUF...Buffer, DASD
...External storage device.

Claims (1)

[Claims] 1 In order to manage the system shared space, a task control table and a buffer control table are provided, and when a task is created, the task name is registered in the entry in the task control table, and the entry points to one buffer control table. When task A secures buffer BUF-A on the system shared space,
Buffer control table BCT-A for the task A
points to the buffer BUF-A, and when task A requests processing from another task B by specifying buffer BUF-A on the system shared space, buffer BUF-A points to the buffer BUF-A of other task B. The pointer is changed so that it points to the control table, and when another task B completes the above request processing and reports this to task A, buffer BUF-A is pointed to in task A's buffer control table. When rolling out the contents of the memory space allocated to a task by changing the pointer as shown in FIG. The roll-in is characterized in that the contents of the task-specific space and buffer contents that have been saved in the external storage device are restored to their original positions when roll-in is performed.・Rollout control method.