JPS61279955A - List processing system - Google Patents

Abstract

PURPOSE:To increase an effective applicable range of a memory compared with the half of an original area by providing an exclusive copy area to a memory control system which contains plural memory areas and collects discarded copies. CONSTITUTION:A memory includes an exclusive copy area C in addition to memory areas 1-n. The size of the area C is not smaller than each of memories 1-n. When the memory area 1, for example, is used up, only the valid data within the area 1 is copied on the area C. Then the valid data in the area C is copied again on the area 1. Thus it is not needed for each memory area to have a copy area. Therefore, the valid area occupied by the valid data can have an area larger than the half of the entire area.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a list processing method, and relates to a processing method suitable for effective use of memory when copying and collecting unnecessary items from a plurality of memory areas within 1%.

[Background of the invention]

When the list processing method is used to collect unnecessary items using the conventional copying method, there is a drawback that the effective area in each memory area is halved in order to reserve an area for copying. When applied as is when there are multiple memory areas, only half of each area can be used effectively.

[Purpose of the invention]

SUMMARY OF THE INVENTION An object of the present invention is to provide a function that makes the area that can be effectively used as memory larger than half of the original area even in the case of copying and collecting unnecessary items for multiple memory areas.

[Summary of the invention]

In copy method waste collection with multiple memory areas,
Focusing on the fact that multiple collections of unnecessary items cannot be performed at the same time, we set up one copy-only area in common in each memory area, perform copying in this copy-only area, and then restore the original memory area. By performing copying, each memory area does not have an internal area for copying, and the area that can be effectively used in the memory can be expanded.

[Embodiments of the invention]

Hereinafter, one embodiment of the present invention will be described while comparing it with a conventional example.

FIG. 1 shows a conventional memory management system using a copying method and collection of unnecessary materials. When you perform list processing.

Some things like 2-7 will be made. Among them, 2.
3. Alternatively, there will be items such as 6 and 7 that can be traced from the management table 1, and items such as 4 and 5 that cannot be traced from the management table 1. The former is called valid data, and the latter is called invalid data. Continuing with list processing.

Eventually, the memory will be used up and no more list processing will be possible. The copy method waste collection method divides the memory into two parts, 8 and 9, and on the other hand, for example, when 8 is used up, valid data that can be traced from management table 1 2.3.6.7
Copy it to the other memory part.

At this time, invalid data 4 and 5 are left as they are.

In the memory portion 9, an extra free space is created for the invalid data 4 and 5 in 8, and the list processing can be continued again. On the other hand, when the area 9 is full, in this method of copying valid data to the area 8, the size of the valid area occupied by the valid data is at most half of the entire area.

FIG. 2 shows the conventional method. This is an embodiment of the copying method for collecting unnecessary items, and shows an example in which there are multiple memory areas. The memory is divided into n areas from 1 to n, and each area further has an I
It is divided into halves, such as A and IB, 2A and 28, ... IImA and nB. For example, when half IA of one memory area is used up, only valid data is copied to IBK. In this way, in each of the n regions,
Make copies.

FIG. 3 shows an embodiment of the present invention. Memory is 1
In addition to the memory areas from n to n, there is a copy-only area C. The size of C is set to K so that it is not smaller than any of the memory areas. Any memory area, for example area 1
and when it is used up.

Copy only valid data in 1 to C. After that, the valid data in %C is copied to area 1 again. According to this embodiment, there is no need for each memory area to have a copying area, and there is an effect that the size of the effective area occupied by valid data is more than half of the total.

〔Effect of the invention〕

In the conventional example, the size of each memory area is tl, t2°・
..., t, then half of each, that is, t t /'
2 tt2/2. ..., t, /2 L or memory cannot be stored at maximum, so the total memory size is 1 (=
l t + l-2+...+1. ), the maximum size of memory that can be effectively used is L/2 (= l
-1/2 +12/2+...+t, /2).

On the other hand, in an embodiment according to the present invention, let the sizes of each memory area be tl', t2', . . . , t,'.

The size Lo of the copy-only area C is max(tH', t2
'1... 1. /). The total memory size is t
′, the maximum size that can be effectively used is A I' +
lz'+t,', that is, t'-t. t=
Let's say t'.

For example, tl'=t2'=...=tl(=t'/
(n+1)), t'-to=-t.

n + 1 When n=9, up to 90% can be used effectively.

[Brief explanation of the drawing]

Figure 1 shows the copying method memory allocation diagram in the conventional example, and the second
The figure shows a memory allocation diagram of a copying method in a conventional example having a plurality of memory areas, and FIG. 3 shows a memory allocation diagram of a copying method having a plurality of memory areas according to an embodiment of the present invention. Tomi 1 Ward

Claims (1)

[Claims] A list processing method characterized by providing a copy-only area in a memory management system having a plurality of memory areas and performing copy-based waste collection.