JPH04217048A - memory management device - Google Patents

Abstract

PURPOSE:To offer the memory management system which can use effectively a void area of various sizes. CONSTITUTION:A memory management processing means provided with a user, a memory management processing means, and an OS(operating system) is constituted so that the next block address, a block size, and a head free area address are entered in a block being under its own management, and also, in the case there if a void area in the block, the next void area address, and a void area size are entered in the void area concerned, and when an area obtaining request for designating the minimum size is received from a user, in the case the void area exceeding a request size exists in the block being under its own management, the void area concerned is delivered to the user, and in the case said area does not exist, an area obtaining request is outputted to the OS, the area delivered from the OS is delivered to the user, and also, the area concerned is connected to a chain of the block as the block.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to improvements in memory management methods.

0002

2. Description of the Related Art In conventional memory management, it is necessary to specify the required size and issue an area acquisition request.

0003

[Problem to be solved by the invention] When acquiring a memory area,
Although it may be divided, there are cases where it is desired to make the area as continuous as possible, or where the required size as a whole is unknown at the time of acquisition. For example, this is the case when it is necessary to have a fixed management area for each divided area or when an area used for storing program translation results is acquired.

[0004] In conventional processing, it is necessary to specify the acquisition size even in such a case, so if a larger size is acquired, a small empty area will be wasted, and if a smaller size is specified, the area will be subdivided and the area will be wasted. This resulted in the contradiction that the number of management areas increased. It is an object of the present invention to provide a memory management method that solves the above-mentioned contradictions and makes it possible to effectively use empty areas of various sizes.

[0005]

[Means for Solving the Problems] FIG. 1 is a diagram illustrating the principle of the present invention. The memory management method of the present invention includes a user, a memory management processing means, and an operating system, and the memory management processing means stores the next block address, block address, etc. in the blocks under its own management. In addition to filling in the size and start free area address, if there is an empty area in the block, write the next empty area address and empty area size in the empty area, and use an area acquisition request with the minimum size specified. When received from the user, it is checked whether there is an empty area larger than the requested size in the block under its control, and if it exists, the corresponding empty area is passed to the user, and if it does not exist, it is The system is characterized in that it issues an area acquisition request to the operating system, passes the area passed from the operating system to the user, and connects the area as a block to a chain of blocks. be.

[0006]

[Operation] The memory management processing means blocks-manages the area under its own management. The next block address, block size, and first free area address are written in each block, and if a free area exists, the next free area address and free area size are written in the empty area. .

[0007] The user requests the memory management processing means to
Minimum size specification information can be added when issuing an area acquisition request. What is an area acquisition request with a minimum size specification?
For example, it requests acquisition of an area of at least size 5 or more.

[0008] When the memory management processing means receives an area acquisition request specifying a minimum size of size=5, it finds an empty area of size 5 or more from among the blocks under its own management, and provides this empty area to the user. hand over. If there is no empty area of size 5 or more in the block under its own management, the memory management processing means issues an area acquisition request to the operating system and uses the area passed from the operating system. give it to someone.

[0009] The user uses the necessary portion of the area passed from the memory management processing means, and if there is any remaining area, returns the excess area to the memory management processing means.

The operating system described here manages all the areas in the system, and in response to requests for acquiring and releasing areas, it cuts out and extracts the areas it manages.
It shall have a collection function. Furthermore, this operating system usually has functions such as allocating areas among multiple users and recovering areas when a user program terminates abnormally.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 2 is a diagram showing the structure of blocks under the control of the memory management program of the present invention. A block under the control of the memory management program has a next block address, a block size, a block end address, and a leading empty area address. Also, if there is an empty area in the block, the next empty area address,
The empty area size is filled in. The block size is greater than or equal to the basic block size (eg, 8K bytes). This size should be sufficiently larger than the user's normal request size so that the operating system does not receive frequent requests to acquire space.

The memory management program of the present invention: ■ Acquires an area by specifying a requested size ■ Acquires an area by specifying a minimum size ■ Returns the remaining area after acquiring it ■ Releases the acquired area by specifying an address ■ All areas at once It has the function of liberation.

FIG. 3 is a diagram illustrating the processing of the memory management program when an area acquisition request specifying the minimum size is received. For space acquisition requests with minimum size specified,
Information indicating that the minimum size is specified is added.

[0014] In step S1, the next (the first one for the first time)
Get the block pointer. If the pointer to the corresponding block does not exist, the process advances to S6. In step S2, the next (the first empty area pointer for the first time) is obtained. If the empty area pointer does not exist, the process returns to S1; if the empty area pointer does exist, the process proceeds to S3. In step S3, the empty area size and the requested size are compared. If empty area size<required size, the process returns to S1, and if empty area size≧requested size, the process proceeds to S4. In step S4, empty areas are removed from the chain. In step S5, the empty area pointer and empty area size are notified to the requesting program. In step S6,
Compare basic block size to requested size. If basic block size<request size, proceed to S7; if basic block size≧required size, proceed to S1
Go to 0. In step S7, the system (
Issues an area acquisition request to the virtual memory management program. In step S8, the pointer of the acquired block is placed in the previous block. In step S9, the pointer and size of the acquired area are notified to the requesting program. In step S10, an area acquisition request is issued to the system using the basic block size. Next, proceed to S8.

FIG. 4 is a diagram illustrating the processing of the memory management program when it receives an area acquisition request specifying the requested size. For an area acquisition request with a specified request size,
Information indicating that the requested size is specified is added.

[0016] In step S1, the next (the first one for the first time)
Get the block pointer. If it exists, the process advances to S2; if it does not exist, the process advances to S6. In step S2, the next (the first empty area pointer for the first time) is obtained. If it exists, the process advances to S3; if it does not exist, it returns to S1. In step S3, the empty area size and the requested size are compared. If empty area<required size, the process returns to S1, and if empty area≧requested size, the process proceeds to S4. Step S4
Now, the part obtained by removing the requested size from the beginning of the empty area is set as an empty area, and is connected to the previous empty area. In step S5,
Notify the requesting program of the area pointer. In step S6, the basic block size and the requested size are compared. S if requested block size < requested size
The process proceeds to step 7, and if the requested block size≧required size, the process proceeds to step S10. In step S7, an area acquisition request is issued to the system with the requested size. In step S8, the pointer of the acquired block is placed in the previous block. In step S9, the pointer and size of the acquired area are notified to the requesting program. In step S10, an area acquisition request is issued to the system using the basic block size. In step S11, the remaining portion of the block is set as the empty area at the beginning of the block. Next, the process advances to step S8.

FIG. 5 is a diagram showing the processing for returning the remainder area. The requesting program uses the necessary portion of the allocated area, issues an area return request to the memory management program, and returns the remaining area. When the memory management program receives an area return request, it performs the following processing.

In step S1, the acquired area pointer, acquired area size, and used size added to the area return request are fetched. In step S2, the start address of the remainder area is obtained. This start address can be obtained by adding the used size to the acquired area pointer. Step S3
Now, get the remainder size. The remainder size is obtained by subtracting the used size from the acquired area size. In step S4, the blocks are traced to find the block to which the target sky area belongs. In step S5, it is checked whether the next (in the first time, the first) free area exists. If it exists, the process advances to S6; if it does not exist, the process advances to S10. In step S6, the next empty area pointer is obtained. In step S7, the free area pointer and the remaining area start address are compared. If the empty area pointer is less than the first address of the remainder area, the process returns to S5, and if the empty area pointer≧the first address of the remaining area, the process goes to S8. In step S8, it is determined whether the remaining area and the empty area are adjacent to each other. If they are adjacent, the process advances to S9; if they are not adjacent, the process advances to S11. In step S9, the remaining area and the empty area are combined into one empty area. In step S10, the remaining area is set as the leading empty area. In step S11, the next area pointer of the previous empty area is set as the remainder area start address, and the empty area address is entered at the remainder area start.

FIG. 6 is a diagram showing an example of area return according to the present invention. 6A corresponds to the process S11 in FIG. 5, and FIG. 6B corresponds to the process S9 in FIG.

FIG. 7 is a diagram showing the entire area release process in the memory management program of the present invention. The following processing is performed in the all area release processing. In step S1, a pointer to the first block is obtained. In step S2, a next block pointer within the block is obtained. In step S3, a block release request is issued to the system. Step S
4, it is checked whether the next block pointer is 0 or not. If the next block pointer is 0, the process ends, and if it is not 0, the process returns to S1.

FIG. 8 is a diagram showing the designated area release process in the memory management program of the present invention. Information indicating an empty area pointer is added to the specified area release request. The following processing is performed to release the specified area. In step S1, the blocks are traced to find the block to which the target sky area belongs. In step S2, the next (the first empty area for the first time) is determined. In step S3, it is checked whether the pointer is equal to a specified pointer. If they are equal, the process advances to S4; if they are different, the process returns to S2. In step S4, it is checked whether the sky area is adjacent to the sky area above or below, and if they are adjacent, it is treated as one sky area.

FIG. 9 is a diagram showing an example of a processing procedure of a user program, FIG. 10 is a diagram showing an example of a data structure, and FIG. 11 is a diagram explaining an example of area acquisition according to the present invention. As shown in FIG. 10, it is assumed that there is a data structure called management area + block. In the illustrated example, the management area size is 3 and the block size is 2. It is assumed that the empty area is as shown in FIG. 11(a). If you want to create 10 blocks, if you use the conventional area acquisition method that specifies the size, you can: ■ Create 5 blocks at a time ■ Create them all at once, but in either case, you will end up wasting space and creating empty space. Dispersion occurs.

According to the present invention, as shown in FIG. 11(b), it is possible to successfully pack seven pieces into an empty area of size 17 and three pieces into an empty area of size 11. The procedure is shown in FIG. In step S1, a minimum size of 5 is specified and an acquisition request is issued. In step S2, a pointer to an area of size 17 is returned, so seven blocks are created here. In step S3, a minimum size of 5 is further specified and an acquisition request is issued. In step S4, a pointer to an area of size 11 is returned, so three blocks are created here. In step S5, the remaining area of size 2 is returned.

[0024]

[Effects of the Invention] As is clear from the above explanation, according to the present invention, the minimum size can be specified when making an acquisition request, so there is no need to acquire more memory area than necessary, and if acquisition is not possible, the minimum size can be specified. There is no need for control such as requesting re-acquisition of the data. In addition, since allocation first searches for empty areas and, if they exist, allocation is made from there, effective use of resources and high-speed allocation are possible.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the principle of the present invention.

FIG. 2 is a diagram showing the structure of blocks under the management of the memory management program of the present invention.

FIG. 3 is a diagram illustrating area acquisition processing by specifying a minimum size in the present invention.

FIG. 4 is a diagram illustrating area acquisition processing based on size specification in the present invention.

FIG. 5 is a diagram illustrating a surplus area return process in the present invention.

FIG. 6 is a diagram illustrating an example of area return according to the present invention.

FIG. 7 is a diagram illustrating a process for releasing all areas according to the present invention.

FIG. 8 is a diagram illustrating designated area release processing in the present invention.

FIG. 9 is a diagram illustrating an example of a previously used processing procedure for acquiring an area.

FIG. 10 is a diagram showing an example of a data structure.

FIG. 11 is a diagram illustrating an example of area acquisition according to the present invention.

Claims (1)

[Scope of Claims] [Claim Number 1] The memory management processing means includes a user, a memory management processing means, and an operating system, and the memory management processing means selects the next block among the blocks under its own management.・Enter the address, block size, and first free area address, and if there is an empty area in the block, enter the next empty area address and empty area size in the empty area, and specify the minimum size. When receiving an area acquisition request from a user, it checks whether there is an empty area larger than the requested size in the block under its own management, and if it exists, it passes the corresponding empty area to the user, If it does not exist, issue an area acquisition request to the operating system, pass the area passed from the operating system to the user, and confirm that the area is configured to be connected to a chain of blocks as a block. Characteristic memory management method.