JPH1173364A - Memory buffer management system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent a memory area in use from being released. SOLUTION: A memory buffer securing means 12 secures memory areas in a memory buffer 21 in accordance with a request from a user program 11. When data of which memory releasing time exceeds current time exist in a memory buffer management data, a memory buffer delay releasing means 13 requests the release of a memory area corresponding to the management data. A memory buffer releasing means 14 releases the memory area in accordance with the request from the means 13. A use time reset means 15 resets the use time of the specified memory area in accordance with the request from the program 11 to extend the use time.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of managing a memory area of a computer system, and more particularly to a method of managing a memory buffer shared by a plurality of programs.

[0002]

2. Description of the Related Art In a computer system, when executing a program, it is necessary to secure a memory area. However, if an unnecessary memory area is kept held due to forgetting to release the secured memory area, a normal operation cannot be performed due to a shortage of the memory area or the like. Therefore, a method of managing a memory buffer that automatically releases a memory area by monitoring time has been proposed (Japanese Patent Laid-Open No. 3-271842).

FIG. 4 is a block diagram of a computer system to which a conventional memory buffer management system is applied. The user program 42 requests the memory buffer allocating means 43 to allocate a memory area. At this time, the user program 42 specifies a time for using the memory area. After this usage time,
If the release of the memory area is not requested, the memory buffer delay release means 45 detects the use time excess, and requests the memory buffer release means 44 to release the memory area. As a result, the memory area that has exceeded the used time is automatically released.

[0004]

However, according to the management method disclosed in Japanese Patent Application Laid-Open No. 3-271842, even if the reserved memory area is still used by the user program, it is determined that the memory area has been set in advance. If the time is exceeded, there is a problem that the memory area is automatically released. The reason is that the usage time is set by estimating how long the usage time of the memory area allocated by the user program should be used. This can happen. SUMMARY OF THE INVENTION The present invention has been made to solve the above-described problem. In a memory buffer in which a memory area is released by time monitoring, it is possible to automatically release a used memory area due to an excessive use time. It is an object of the present invention to provide a management method of a memory buffer that can be prevented beforehand.

[0005]

According to the present invention, there is provided a memory buffer securing means for securing a memory area in response to a request from a user program, and a memory buffer securing means for securing a memory area in each secured memory area. When there is a memory area exceeding the preset use time, a memory buffer delay releasing unit requesting release of this memory area, and a memory designated in response to a request from the user program or the memory buffer delay releasing unit. It has memory buffer releasing means for releasing an area and use time resetting means for resetting the use time. In this way, when the user program requests the reset of the use time of the memory area, the use time resetting means re-registers the memory area as an object to be released based on the specified new use time. . Further, as set forth in claim 2, the memory has a management data storage area in which a use time corresponding to each memory area is stored, and the memory buffer delay releasing means stores the management time in the management data storage area. The use time resetting means resets the use time stored in the management data storage area based on the determined use time. Things.

[0006]

Next, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram of a computer system to which a memory buffer management system according to an embodiment of the present invention is applied. This computer system includes a processing device 1 that operates under program control.
And a storage device 2 for storing information.

The processing device 1 includes a user program 11, a memory buffer securing means 12 for securing a memory area in the storage device 2 in response to a request from the user program 11, and a preset memory area in each secured memory area. When there is a memory area that has exceeded the usage time, the specified memory area is deleted in response to a request from the memory buffer delay release unit 13, the user program 11, or the memory buffer delay release unit 13 requesting release of this memory area. It comprises a memory buffer releasing means 14 for releasing and a use time resetting means 15 for resetting the use time.

[0008] The storage device 2 has a memory buffer 2
1, delay release queue header 22, management data storage area 2
3-1 to 23-n. The memory buffer 21 is a memory area shared by a plurality of user programs 11, and the user program 11 secures a part of this memory area by a secure request.

In the management data storage areas 23-1 to 23-n, memory buffer management data respectively corresponding to the respective memory areas secured by the plurality of user programs 11 are stored. The memory buffer management data includes a head address of a corresponding memory area, a size of the memory area, a memory release time indicating a time at which the memory area should be released, a bidirectional queue node for connecting to a delay release queue, and the like. The delay release queue connects the management data storage areas 23-1 to 23-n in ascending order of the memory release time in the management data, and a delay release queue header 22 is added to the head of these.

The delay release queue header 22 includes a delay release timer value indicating the current time, a bidirectional queue node, and the like. The bidirectional queue nodes stored in the delay release queue header 22 and the management data storage areas 23-1 to 23-n are used to assemble the delay release queue by connecting them, and the head addresses of the preceding and succeeding elements are stored. Have been.

For example, the head address of the management data storage area 23-1 connected to the header 22 is stored in the bidirectional queue node of the delay release queue header 22, and the bidirectional queue node of the management data storage area 23-1. In
Start address of header 22 and management data storage area 23-
2 (not shown) are stored. The same applies to other bidirectional queue nodes. In this way, the delay release queue can be assembled, and if the delay release queue header 22 is accessed, the management data storage areas 23-1 to 23-n behind it can be traced by the bidirectional queue node. I have.

Next, the operation of the above system will be described. The memory buffer securing unit 12 secures a memory area of a designated size in the memory buffer 21 according to a request from the user program 11. At this time, the memory buffer allocating unit 12 calculates the memory release time obtained by adding the head address of the allocated memory area, the size of this memory area, and the current delay release timer value to the use time of the memory area specified by the program 11. Then, memory buffer management data corresponding to the secured memory area is created.

The memory buffer securing means 12
The management data storage area storing the newly created memory buffer management data and the existing management data storage area are reconnected in ascending memory release time order. Therefore, existing management data whose release time is later than the memory release time of the newly created management data is connected after the newly created management data.

For example, as shown in FIG. 2A, the delay release queue header 22, the management data storage areas 23-1 and 23-2,
When the delay release queue is assembled by connecting 3-2 (t1 <t2), the memory release time t3 is set to t1 <
When the memory buffer management data satisfying t3 <t2 is newly created, the existing management data storage area 23-
The management data storage area 23-3 storing the newly created management data and the management data 1, 23-2 is reconnected as shown in FIG. These reconnections can be realized by resetting the bidirectional queue header.

The memory buffer delay release means 13 operates periodically, and updates the delay release timer value by adding the period to the delay release timer value at regular intervals. Thus, the value of the delay release timer stored in the delay release queue header 22 is constantly updated as time passes.

In parallel with this, the memory buffer delay release means 13 determines whether the memory release time in each management data stored in the management data storage areas 23-1 to 23-n exceeds the delay release timer value. It is checked whether there is any memory buffer management data whose memory release time exceeds the delay release timer value, and requests the memory buffer release means 14 to release the memory area corresponding to this management data.

The memory buffer releasing unit 14 is provided with the user program 11 or the memory buffer delay releasing unit 13.
Releases the specified memory area as requested by. At this time, the memory buffer releasing unit 14 removes the memory buffer management data corresponding to the memory area to be released from the delay release queue.

Therefore, if another management data exists after the management data to be removed from the delay release queue, the reconnection is performed in the reverse of the above. For example, FIG.
As shown in (b), when the delay release queue header 22 and the management data storage areas 23-1, 23-3, and 23-2 are connected to form a delay release queue (t1).
<T3 <t2), when the management data storage area 21-1 is to be removed, the management data storage areas 23-3 and 23-2 are not shown in FIG.
The connection is made again as shown in FIG. This reconnection can also be realized by resetting the bidirectional queue header.

Next, the operation of the use time resetting means 15 will be described. FIG. 3 is a flowchart for explaining the operation of the use time resetting means 15. The usage time resetting means 15 resets the usage time of the specified memory area in accordance with a request from the user program 11.

That is, the use time resetting means 15 temporarily removes the memory buffer management data corresponding to the specified memory area from the delay release queue (step 101), and resets the use time specified by the current delay release timer value. The added value is set as a new memory release time, and this memory release time is reset to the management data removed from the delay release queue (step 102).

Subsequently, the use time resetting means 15 compares the management data storage area storing the management data with the memory release time reset and the other management data storage area connected to the delay release queue with the memory release time. The connection is made again in the early order (step 103). This is the same as the process described with reference to FIG. As described above, in this embodiment, when there is a concern that the usage time of the memory area will be exceeded, the usage time is extended by requesting the user program 11 to reset the usage time of the memory area. Can be.

[0022]

According to the present invention, since the use time of the memory area can be extended by providing the use time resetting means, the used memory area is automatically released when the use time is exceeded. Can be prevented beforehand.

[Brief description of the drawings]

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

FIG. 2 is a diagram for explaining reorganization of a delayed release queue.

FIG. 3 is a flowchart for explaining the operation of a use time resetting means.

FIG. 4 is a block diagram of a computer system to which a conventional memory buffer management method is applied.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Processing apparatus, 2 ... Storage device, 11 ... User program, 12 ... Memory buffer securing means, 13 ... Memory buffer delay release means, 14 ... Memory buffer release means, 1
5: use time resetting means, 21: memory buffer, 22
... Delayed release queue header, 23-1, 23-2, 23-
3, 23-n... Management data storage area.

Claims (2)

[Claims] 1. A memory buffer securing means for securing a memory area in response to a request from a user program, and when a memory area exceeding a preset use time exists in each of the secured memory areas, Memory buffer delay releasing means for requesting release of a memory area, memory buffer releasing means for releasing a specified memory area in response to a request from a user program or a memory buffer delay releasing means, and resetting the use time A memory buffer management method, comprising a use time resetting means. 2. The memory buffer management method according to claim 1, further comprising: a management data storage area in which a use time corresponding to each memory area is stored in the memory; Based on the usage time stored in the management data storage area, it is determined whether or not there is a memory area that has exceeded the usage time, and the usage time resetting means is configured to store the memory area in the management data storage area. A memory buffer management method for resetting the use time.