JPH06214874A - Memory managing system - Google Patents

Abstract

PURPOSE:To provide a memory managing system which improves the efficiency of the use by compressing invalid areas as much as possible while securing and releasing information storage areas on a memory as needed. CONSTITUTION:Corresponding to the secure request of information (x), a memory allocation controller 2 secures an empty area B on a memory 6 from the retrieved result of memory managing information 52 generated by a retrieving device 3, stores the address and the secured amount in memory managing information (y) corresponding to the information (x) on memory allocation managing information 51, sets a relevant flag under use, erases the address and the secured amount of memory managing information (b) corresponding to certain information (a) concerning the release request of this information (a) and sets the relevant flag to non-use. On the other hand, corresponding to a memory compaction request, this device 2 copies contents in the storage area settled in the relevant area to the empty area on the memory recognized through the retrieving device 3 by using a memory content copying device 4, and the address on memory managing information 52 is reloaded with the address of the copy destination.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention secures an area for storing information necessary for providing a service in a memory when the information is needed and stores the area when the information is no longer needed. The present invention relates to a dynamic memory management method for releasing the above from the above memory.

[0002]

2. Description of the Related Art As a memory management system for storing information necessary for providing a certain service in a memory, static storage in which a storage area for all information corresponding to a service to be provided is secured in advance in advance. A management method and a memory area with a certain storage capacity are prepared, a necessary area is secured in the memory area when a service is provided, and the corresponding storage area is released when it is no longer needed. A dynamic memory management system is known.

Of these, in the static storage management system, since all necessary areas are secured in advance from the beginning, the absolute memory capacity increases, and even if the service is not used, the memory capacity is increased. As a result of being secured, a decrease in memory usage efficiency cannot be avoided. On the contrary,
The dynamic storage management method is overwhelmingly advantageous in terms of memory utilization efficiency because it is a method of repeatedly securing and releasing a storage area on a memory having a certain storage capacity.

However, in this dynamic storage management system, by repeatedly securing and releasing storage areas having different capacities, areas in use and unused areas appear discontinuously, and areas between the areas in use are in use. Fragmentation, in which a small free area appears, is unavoidable, which hinders the improvement of memory utilization efficiency. In other words, when fragmentation occurs, a small empty area between the areas in use intervenes in the memory as an area with no utility value, which promotes waste of memory and the required area cannot be secured, thus providing services. It may be impossible.

Therefore, in order to solve the denial of service situation caused by this fragmentation, so-called memory compaction for moving a used area on a memory to an unused area and creating a larger unused area is indispensable. Become. However, when carrying out this memory compaction, it is necessary to grasp the address or capacity relationship between the empty area and the storage area on the memory.

In this regard, in the conventional dynamic memory management system, when allocating a memory, it is not managed which information for providing which service is allocated to which area, and the above-mentioned memory use condition is grasped. The only way to do this is to access the memory directly and refer to the address of the area secured in the memory.

Therefore, in the conventional memory management system of this type, the compaction of the memory can be performed only when the secured area is released, and the fragmentation tends to increase. Therefore, due to the existence of an invalid area having a very small storage capacity, there is a limit in improving the utilization efficiency of the memory, the requested area cannot be secured, and the service cannot be provided due to lack of memory.

[0008]

As described above, the dynamic memory management system is excellent in memory utilization efficiency, but by repeatedly securing and releasing storage areas having different capacities, the areas in use and unused areas are not used. Areas appear discontinuously,
Inevitably the occurrence of fragmentation, where small empty areas appear between the areas in use. Since this fragmentation increases the invalid area and causes the situation where the required area required cannot be secured, if the memory efficiency is to be further improved, the used area is moved to the unused area, and The key is how to efficiently perform the compaction of the memory that creates a large unused area.

In the conventional dynamic storage management system of this type, when the storage area of the information in the memory is secured, it is not managed which information is allocated to which storage area, but is directly secured in the memory. Since the memory usage status is grasped by referring to the address of the reserved area, the memory can be compacted only at the time of releasing the reserved storage area, and the requested area is secured by the incomplete arrangement of fragmentation. There was a problem that it was not possible to do so, and there were not a few cases where the service could not be provided due to lack of memory.

The present invention eliminates the above problems, and when the memory is dynamically managed while securing and releasing a certain information storage area on the memory as necessary, the fragmentation is completely arranged, It is an object of the present invention to provide a memory management system which has a higher usage efficiency by compressing invalid areas as much as possible.

[0011]

SUMMARY OF THE INVENTION The present invention secures a storage area for a certain piece of information in a memory at the time when the certain information is needed, and from the memory when the certain information becomes unnecessary. In a memory management system for dynamically managing the memory while releasing the storage area of the management memory, management information storage means for storing management information for managing which storage area on the memory is reserved for which information, At the time of securing the storage area, at least the address of the storage area and the secured amount are recorded on the management information, and at the time of releasing the storage area, the management information corresponding to the storage area is updated to an unused state. And a searching unit for searching the use status of the storage area in the memory with reference to the management information in the management information storage unit. To secure or release the storage area of the information to the memory, characterized by being adapted to implement based on the search result of the management information by the search means.

Preferably, the present invention further comprises a copying means for copying the contents of a certain area in the memory to another area, and in response to a predetermined memory compaction request, the contents of the memory are stored in the memory based on the search result of the searching means. The contents of each storage area are copied to an unused area so that each storage area becomes continuous, and the address on the memory management information corresponding to the copied storage area is rewritten to the copy destination address. It is characterized by

[0013]

According to the present invention, management information for managing which storage area on the memory is reserved for which information is used, and securing or releasing of the storage area for certain information on the memory is performed according to the management information. It is designed to be processed.

Further, according to the present invention, when a memory compaction request is received, the capacity relationship between the free area of the memory and the secured storage area is grasped based on the management information, and the capacity within the free area of the memory is accommodated. Copying the contents of another storage area with, and then rewriting the address in the management information corresponding to the copied storage area to the copy destination address until the storage area becomes continuous Is.

The management information is, for example, memory management information including an address of a storage area reserved on the memory, a reserved capacity and a flag indicating a used state, and information required to reserve the storage area. Each of them is composed of memory allocation management information indicating which information of the memory management information corresponds.

According to the present invention, when allocating a memory,
It is possible to manage which service is provided in which storage area in the memory by accessing the management information without referring to the address secured in the memory as in the conventional device. Therefore, it is possible to speed up memory allocation and reduce fragmentation.

Further, conventionally, it can be performed only at the time of releasing the memory by utilizing the fact that which information is assigned to which area can be managed without directly using the address of the area secured on the memory. Memory compaction can be performed not only at the time when the memory is released, but also at the time when the information is not accessed, such as when the system starts up. While compressing, it is possible to significantly reduce the situation where the service becomes unavailable due to lack of unused area in the memory.

[0018]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail below with reference to the accompanying drawings. FIG. 1 is a block diagram showing an embodiment of a memory control system to which the memory management system of the present invention is applied, and a control target thereof is, for example, a memory 6 prepared in a switching system. As a peripheral device for controlling the process of securing or releasing the information storage area on the memory 6, 1 is a CP for controlling the whole.
U and 2 are a memory allocation control device that controls a memory allocation process of information necessary for providing each service on the memory 6, and 3 is a search device that searches a free area on the memory 6 by using memory management information described later, Reference numeral 4 is a memory content copying device for copying the contents of a designated storage area on the memory 6 to a designated unused area, and 5 is a device specific to the present invention used for managing the securing or releasing of the information storage area in the memory 6. It is a management information memory for storing memory management information and memory allocation management information.

This memory control system secures a storage area of the information in the memory 6 when a certain information is required and stores the storage area of the information in the memory 6 when the certain information becomes unnecessary. It is operated by a memory management system that dynamically manages the memory 6 while releasing the
In the memory control system, the management information memory 5 holds the memory management information and the memory allocation management information as control parameters for the memory management.

FIG. 2 shows a conceptual configuration of the memory control system shown in FIG. 1. In FIG.
-1, 51-2 are memory allocation management information prepared for each information required for providing a service, and 52 is a memory management that can be searched using the memory allocation management information 51-1, 51-2 as an index. Information.

Further, FIG. 3 shows an example of the structure of the memory management information, and shows whether the corresponding area of the memory 6 is reserved (in use) or released (unused). It has at least three pieces of information, which are a flag, a memory reservation amount of a storage area reserved on the memory 6 based on a request, and an address of each storage area on the memory 6, as its constituent elements.

Next, the basic processing operation of the memory management system in this memory control system will be described in detail with reference to FIG. First, when a request to secure the information x necessary for providing a certain service is made, the search device 3 that has received the request via the CPU 1 searches the memory management information 52 for a free area. As a result of this search, when an unused memory area G is secured, the memory allocation control device 2 that receives the search result receives the memory area G from the requested memory area H and the remaining memory area. The former is secured after being divided into the area I, and the address of the secured memory area H and the secured capacity thereof are recorded in the address information and memory reserved amount columns of the memory management information y corresponding to the memory reserved request information x, respectively. At the same time, the corresponding flag is set during use (see FIG. 3).

When a request for releasing the information a is made due to the interruption of the service provision, the memory allocating device 2 which has received the request via the CPU 1 secures the address and the memory management information b corresponding to the information a. The information a is erased from the corresponding storage area on the memory 6 using the amount as an index, and at the same time, the corresponding flag is set to unused.

As described above, by securing and releasing the storage area on the memory 6 in accordance with the area securing request and the releasing request, the use efficiency of the memory 6 can be dramatically increased even though the memory 6 is a relatively small amount. It is possible to realize highly improved operation. At this time, the required secured area size and the released area size are generally different, which allows the areas in use A and C on the memory 6, for example, as shown in FIG.
Small unused areas B and E appear between D, D, and F, and so-called fragmentation occurs.

Since a small empty area interposed between these in-use areas becomes an area of no use value and promotes the waste of memory, when such fragmentation occurs, it is normally used on the memory 6. A so-called memory compaction will be taken to move the area to an unused area and create a larger unused area.

Next, the memory compaction processing executed according to the memory management system of the present invention will be described with reference to FIG. Now, as a result of repeatedly executing the storage area securing and releasing processing according to the area securing request and the release request of different sizes as described above, a small free area is generated in the memory 6, and the memory 6 is being used. Since the area is continuous, memory compaction is required.

In the memory allocation control device 2 which has received this memory compaction request under the memory use condition as shown in FIG. 4A, the search device 3 is instructed to use the memory management information 52 and the unused memory 6 in the memory 6. Search for areas. As a result of this search, when the memory area B is searched as an empty area, the memory allocation control device 2 then searches for a used area whose capacity does not exceed the size of the memory area B after this memory area B. Search using 3.

When the memory area C is found as a result of this search, the CPU 1 activates the memory content copying device 4 to copy the contents of the memory area C to the memory area B,
The address information on the memory management information 52 is stored in the memory area C.
To the address of memory area B. FIG. 4 shows the usage status of the memory 6 when this process is repeated until the in-use area on the memory 6 becomes continuous.
It is (b). In the figure, a memory area J to a memory area M are collected as a continuous area in use, and the unused areas B, E, I shown in FIG. An unused area N corresponding to is newly secured.

Under the use condition of the memory 6, even when the small unused areas B, E, I, etc. are dispersed as shown in FIG. Memory area N that summarizes these
Can be dealt with, and the use efficiency of the memory 6 can be further improved.

As described above, according to the present invention, the address information indicating to which address on the memory the information necessary for providing the service is allocated, and the memory management information constituted by the required storage capacity and the like. , Which service is provided when a storage area is secured in the memory by using memory allocation management information for managing which information on the memory management information corresponds to each information required for providing the service It is possible to easily and accurately manage the area to which the information for allocation is assigned.

Further, according to the present invention, the address information secured by using the device for searching the memory allocation management information and the memory management information for the address on the memory secured according to the information necessary for providing the service. By knowing, it is possible to prevent the address of the area secured in the memory from being directly referenced, and moreover, the address change due to the movement of the memory area due to the memory compaction only needs to change the address information in the memory management information. Therefore, the effect of moving the memory area can be minimized.

Since the memory operation status can be grasped without directly referring to the address of the area secured in the memory, each information is accessed not only when the memory compaction is released but also when the secured area is released. All areas can be targeted even at the time of system startup, etc., and the efficiency of memory compaction makes it easy to avoid the situation in which service cannot be provided due to lack of unused areas.

[0033]

As described above, according to the memory management system of the present invention, the memory management information and the memory allocation management information are used, and when a certain information is required, the storage area of the information is managed as described above. The memory is secured according to the search result of information, and when a certain information becomes unnecessary, the storage area of the information is released from the memory and the memory is dynamically managed while updating the management information. Therefore, by referring to the above management information, the memory usage status can be grasped without directly referring to the address of the area secured in the memory, and the storage area of the desired information can be quickly stored in the memory. Therefore, the fragmentation at that time can be minimized to improve the memory utilization efficiency.

Further, according to the present invention, when the contents of other storage areas are copied to an empty area on the memory to perform compaction of unused areas scattered in the memory,
Since the above memory management information and memory allocation management information can be referred to at any time, the memory compaction can be performed not only at the time of releasing the secured storage area but also for the entire area, and the memory can be used by the efficient memory compaction. Can further improve efficiency,
Furthermore, it has an excellent advantage that the number of cases where service cannot be provided due to lack of unused areas can be greatly reduced.

[Brief description of drawings]

FIG. 1 is a block diagram showing an embodiment of a memory control system to which a memory management system according to the present invention is applied.

FIG. 2 is a diagram showing a conceptual configuration of the memory control system shown in FIG.

FIG. 3 is a diagram showing an example of memory management information used for memory control according to the memory management system of the present invention.

FIG. 4 is a conceptual memory configuration diagram for explaining a memory compaction process according to a memory management system of the present invention.

[Explanation of symbols]

 1 CPU 2 Memory Allocation Control Device 3 Search Device 4 Memory Content Copying Device 5 Management Information Memory 51-1, 51-2, ... Memory Allocation Management Information 52 Memory Management Information 6 Memory

Claims (3)

[Claims] 1. When a certain information is needed, a storage area for the information is secured in a memory, and when the certain information is no longer needed, the storage area for the information is released from the memory. In a memory management system that dynamically manages a memory, a management information storage unit that stores management information that manages which storage area on the memory is reserved for which information, and at least the storage area A management information update registration means for recording the address of the storage area and the reserved amount on the management information, and updating the management information corresponding to the storage area to an unused state when the storage area is released; Retrieval means for retrieving the use status of the storage area in the memory by referring to the management information in the means, and recording the information in the memory. A memory management system characterized in that the storage area is secured or released based on a search result of the management information by the search means. 2. A copy means for copying the contents of one area in the memory to another area is provided, and each storage area on the memory is consecutive based on the search result of the search means in response to a predetermined memory compaction request. The content of each storage area is copied to an unused area so that the address on the memory management information corresponding to the copied storage area is rewritten to the copy destination address. The memory management system according to item 1. 3. The management information includes memory management information composed of an address of a storage area secured on the memory, a flag indicating a secured amount and a usage state of the area, and the storage area needs to be secured. 3. The memory management system according to claim 1, further comprising: memory allocation management information for managing which information of the memory management information corresponds to each piece of information.