JPH03265948A - Buffer pool controller - Google Patents

Abstract

PURPOSE:To use the system resources with no waste by securing and releasing dynamically a buffer inquiring an application program as a memory space of an optimum size. CONSTITUTION:When a buffer release request is received from an application program 1, a request is given to an unused buffer control means 3 to change a logical chain to the unused buffer control from the busy buffer control for the corresponding buffer. The means 3 collects the buffers set before and after the relevant buffer and controls them as a buffer of a large continuous memory space as long as those buffer are not used yet. At the same time, request is given to a segment reduction means 7 to reduce the memory space when the memory space for the final unused buffer stored in the memory space is reduced less than a fixed size. Furthermore, a request is given to a segment release means 5 to release the memory space when the entire memory space is not used yet. Thus, the system resources can be used with no waste.

Description

[Detailed description of the invention] [Industrial application field] The present invention relates to a buffer pool control device.

[Conventional technology]

Conventional buffer pool control devices utilize resources (memory space) secured in advance to provide a fixed length and fixed number of buffers.

[Problem to be solved by the invention]

The conventional buffer pool management device described above provides a buffer with a fixed capacity to an application program that requests it, so the length or number of buffers required by the application program may be insufficient. In order to prevent this from happening, resources (memory space) with more than the required capacity must be secured in advance, which has the disadvantage of creating dead memory space.

[Means to solve the problem]

The buffer pool control device of the present invention includes a used buffer management means for managing the number and length of buffers in use, an unused buffer management means for managing the number and length of unused buffers, and a memory space secured. The segment securing and releasing management means manages the release of memory space that is no longer needed or is deleted, and the segment expansion/reduction management means manages the expansion/reduction of the memory space.

〔Example〕

Next, the present invention will be explained with reference to the drawings.

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

In the figure, 1 is an application program, 2 is a used buffer control means, 3 is an unused buffer control means, 4 is a segment reservation control means, 5 is a segment release control means, and 6
7 represents a segment expansion control means, 7 represents a segment reduction control means, and 8 represents an operating system.

Next, the functions of this embodiment will be explained using FIG.

In this embodiment, the application program 1 can secure a necessary buffer when it becomes necessary for processing, and release it when it becomes unnecessary.

The in-use buffer control means 2 manages the number of buffers provided to the application program 1 and the length of each buffer. Here, the relationship between the buffers in use and the application programs 1 is established by attaching a logical chain to each buffer and associating them with the application programs 1 in use.

Further, when a buffer release request is received from the application program 1, a request is made to the unused buffer control means 3 to change the logical chain of the buffer from using buffer control to unused buffer control.

If the buffers before and after the requested buffer are unused, the unused buffer control means 3 combines them into one buffer and manages them as one large continuous memory space buffer.

Furthermore, when the memory space for the last unused buffer in the memory space becomes less than a certain size, the segment reduction means 7 is requested to reduce the memory space. When all of the memory space is unused, a request is made to the segment release means 5 to release the memory space.

When a buffer reservation request is made from the application program 1 and there is a memory space that satisfies the requested buffer length of 1, a memory space larger than the requested buffer length is searched from the unused memory space,
The address of the available memory space is notified to the application program 1 as a buffer address. Then, the extra memory space is managed by the logic check 2 of the unused memory space, and the in-use buffer control means 2 is requested to manage the buffer provided to the application program 1.

Conversely, if the application program 1 makes a buffer reservation request and there is no free memory space that can satisfy the request, a memory space expansion request is sent to the segment expansion control means 6, and the memory space expansion is requested, but no response is taken. If this is not possible, to secure new memory space,
The segment reservation control means 4 is requested to secure a new memory space.

Segment securing control means 4. Segment release control means 5
．． The segment expansion control means 6 and the segment reduction control means 7 utilize the virtual memory management function of the operating system 8 to realize their functions. This feature is
Although it provides management and functions related to securing, releasing, expanding, and contracting segments, it is not concerned with how the segments are used.

FIG. 2 is a diagram showing how buffers in the memory space are secured.

In the figure, 9 is a memory space, 10 is a segment header, 11 is a buffer in use, 12 is an unused buffer, 13 is a segment logic chain, 14 is an unused buffer logic chain, 1
5 each represents a buffer logic chain in use.

Next, using FIG. 2, a description will be given of how buffers in the memory space are secured.

A segment header 10 is set in the segment managed by the present invention in the memory space 9. In the segment header 10, the segment logic chain 13. Unused buffer logic chain 14 and used buffer logic chain 1
5, respectively the address and length of the next segment,
It manages the addresses of the intra-segment unused buffers 12 and the addresses of the intra-segment used buffers 11.

At the head of the in-use buffer 11, the next in-use buffer logic chain 15 and the length of the buffer are managed. Furthermore, at the beginning of the unused buffer 12, the unused buffer logical chain 14 is transferred to the next unused buffer 12.
and manages the buffer length.

〔Effect of the invention〕

As described above, the present invention has the advantage that system resources can be used without wasting them because the application program dynamically allocates and releases necessary buffers as memory spaces of optimal size.

DESCRIPTION OF SYMBOLS 1...Application program, 2...Used buffer control means, 3...Unused buffer control means,
4... Segment reservation control means, 5... Segment release control means, 6... Segment expansion control means, 7.
... Segment reduction control means, 8. Operating system, 9. Memory space, 10. Segment header, 11. Buffer in use, 12. Unused buffer, 13. Segment logic. Chen, 14.
...Unused buffer logic chain, 15...Used buffer logic chain.

Claims (1)

[Claims] In-use buffer management means for managing the number and length of buffers in use; unused buffer management means for managing the number and length of unused buffers; and securing memory space and releasing memory space that is no longer needed. 1. A buffer pool control device comprising: segment securing/releasing management means for managing memory space expansion/reduction management means; and segment expansion/reduction management means for managing expansion/reduction of memory space.