JP2003131938A - Method and system for managing memory - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a method and a system for managing memory, which can effectively utilize the unutilized capacity of more than a half of the memory during the execution of an application program when the memory is reserved and guaranteed for executing the application program run on a computer system. SOLUTION: A method and a device for managing memory comprise a memory reservation unit 10 that adds the quantity of memory to the standard quantity of reservation memory Rx when an application program reserves the capacity of the memory, and specifies the capacity limit for the memory Lx to be acquired according to the capacity of the memory not utilized for the execution of the application program. A memory acquisition unit 20, then, acquires a memory region up to the capacity limit for the memory Lx to be acquired if there exists the enough memory being not utilized even though the acquisition unit 20 receives a new demand for acquiring the memory region under a condition of the total capacity of the memory utilized for the application program is beyond the capacity of the reservation memory Rx.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a memory management device and a memory management method for managing memory in a computer system.

[0002]

2. Description of the Related Art Conventionally, an operating system (O
A system program called S) is resident, and the OS centrally manages the hardware resources of the computer system.
Each application program (hereinafter, “application”) operates using resources managed by the OS. One of the main roles of the OS is memory management for effectively utilizing limited memory resources.

There are the following two types of memories to be subject to memory management. One is a first memory area used for storing and executing arithmetic processing for an application running on the OS. The other is a second control block that stores management information for functions that dynamically generate software resources during execution, such as semaphore exclusive control functions, interprocess communication functions, and memory management functions.
Memory area.

The OS acquires the first memory area in the main memory each time the OS receives a request to start a process or task that is an execution unit of an application, and releases it at the end. At the time of acquisition, the OS determines whether acquisition is possible based on the memory capacity included in the request and the free memory capacity in the main memory managed by itself. Further, the second memory area is also acquired in response to the request to start the function execution, and similarly, the availability of the acquisition is determined from the block capacity and the free memory capacity.

When memory is acquired by such a method,
Since the capacity of the main memory is limited, when a plurality of applications each acquire memory, the memory area of the requested capacity cannot always be acquired. For example, when an application AP1 that wants to guarantee a memory acquisition operation (high priority) and an application AP2 that is less important and has a lower priority coexist, the application AP1 has acquired a large amount of memory first, and thus the application AP1 A situation occurs in which the memory requested by is unable to be obtained.

Therefore, as a conventional technique, for obtaining a memory area of an application, the specification of the service call cre_mpl in μITRON (“μITRON
As described in "3.0 Standard Handbook" (edited by TRON Association, Personal Media Co., Ltd.), a memory area with a capacity expected to be used is reserved before execution, and the reserved memory area is used. There is a method of sequentially acquiring memory at the timing of task execution.

[0007]

However, in the above reservation method, the reserved capacity may be the upper limit of the memory capacity that can be acquired by the application, and the memory resources on the system may not be efficiently used. It can happen. This is because even when there is a lot of free memory in the system when the application is executed, the application cannot acquire more memory than the reserved capacity.
In addition, the reserved memory capacity tends to be the minimum necessary considering the influence on other applications. In other words, if you use a little more memory area in addition to the reserved amount, you can expect to improve the processing efficiency of the application,
Moreover, there is a possibility that the free memory is not used even though the free memory area is actually available.

In view of the above problems, the present invention not only secures a memory area required for application execution and a function management block in advance, but also makes it possible for an application to efficiently use a free memory area on the system at the time of execution. An object of the present invention is to provide a memory management device and a memory management method for acquiring a memory.

[0009]

In order to solve the above problems, the present invention is a memory management device for managing a memory area used when an application is executed on a computer system in which the application operates. A reservation accepting unit that accepts a reservation of a reserved memory capacity that is guaranteed in advance for the application before execution, and an execution memory area used by the application for execution of processing after the execution of the application is used as the reserved memory capacity. Reserved memory acquisition means for acquiring within the range of, and free memory management means for managing the amount of free memory that has not been reserved or acquired for an application with respect to the memory resources on the computer system; Memory area beyond memory capacity An additional memory acquisition unit for acquiring an additional memory area from the free memory according to the free memory capacity when the user intends to use the free memory. Has become.

According to this, for the application,
The application reserves the amount of memory for the reservation because it reserves the minimum required memory area as the reserved memory capacity and also adds the memory capacity that can be acquired according to the free memory status on the system at the time of execution. It is possible to use the free memory on the system efficiently after ensuring the area.

[0011]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of a memory management device of the present invention will be described below with reference to the drawings. (Configuration) First, the configuration of the memory management device according to the present embodiment will be described. The memory management device according to the present embodiment performs a process related to memory management of a main storage device used for executing an application on an OS in a small computer system operating on a personal computer, a mobile terminal, or the like. In this memory management device, the application can not only reserve a memory area of a required capacity, but also obtain and use a memory area exceeding the reserved amount if there is a free memory on the system at the time of execution. However, for the memory capacity that can be acquired beyond the reserved amount, an upper limit is set at the time of memory reservation.

FIG. 1 shows the configuration of a memory management device 1 according to this embodiment. The memory management device 1 is roughly divided into a memory reservation unit 10 that reserves a memory area for each application, and a memory acquisition unit that actually acquires a memory area for an application according to the contents of the memory reservation when the application is executed. It consists of 20. The memory reservation unit 10 and the memory acquisition unit 20 are both activated by the application in the form of a function call, and return the contents of the reservation / acquisition processing result to the application in the form of a function return. The configuration will be described below in the order of the memory reservation unit 10 and the memory acquisition unit 20. (Configuration of the memory reservation unit 10) Of these, the memory reservation unit 1
0 is a reservation request receiving unit 11 that receives a reservation request for a memory required for execution from an application on the system.
And a reservation availability determination unit 12 that determines whether the requested memory reservation can be executed, a reservation failure notification unit 13 and a reservation success notification unit 14 that notify the application of the results of the execution availability of the requested memory reservation, and the memory reservation Reservation information registration unit 1 for generating reservation management information for managing contents
5, a reservation information storage unit 16 that holds the reservation management information in a referable form, and a free memory management unit 17 that manages information regarding the memory capacity and memory usage state of the main storage device that is the reservation target.

The reservation request acceptance unit 11 accepts a memory reservation request from an application on the system, and informs the reservation permission / inhibition judgment unit 12 of the content thereof. For memory reservation request,
The "reserved memory capacity Rx", which is the memory capacity estimated to be the minimum required for executing the application, is the desired memory capacity for comfortably executing the application, and indicates the upper limit value that does not require any more memory. Two parameters "acquisition limit memory capacity Lx" are added. The reservation request receiving unit 11 is linked with an application in the form of a function call having the above two parameters, and is realized in the form of a system library that activates a system program by interrupt processing.

The reservation approval / disapproval determination unit 12 is a reservation request reception unit 1
1 for the reservation request for the memory area, the requested reserved memory capacity Rx and the system free memory capacity E
(Held by the free memory management unit 17) is compared to determine whether the requested memory reservation is possible. The free memory refers to a portion of the memory of the main storage device on the system that is not used at the time of determination and is not reserved for any application.

The reservation availability determination unit 12 is a reservation request reception unit 1
The reserved memory capacity Rx obtained from 1 is compared with the free memory capacity E. When the result of the comparison is “Rx> E”, that is, the memory capacity requested to be newly reserved is
When the currently reservable memory capacity is smaller, the reservation availability determination unit 12 determines that the reservation cannot be executed, passes the identification information of the request source application to the reservation failure notification unit 13, and notifies the request source application of the identification information. Notify that the memory reservation has failed. On the other hand, when the comparison result is “Rx ≦ E”, that is, when the capacity of the currently reservable memory is equal to or larger than the capacity of the memory for which a new reservation is requested, the reservation availability determination unit 12 The "reserved memory capacity Rx", "acquisition limit memory capacity Lx", and identification information of the request issuing application are passed to the reservation information registration unit 15 to instruct execution of a specific process of memory reservation.

The reservation information registration unit 15 includes a reservation availability determination unit 1
In response to the reservation request determined as No. 2, reservation management information for managing the reservation content is generated and stored in the reservation information table held by the reservation information storage unit 16. FIG. 2 is a diagram showing a reservation management information table 200 in which the reservation management information generated by the reservation information registration unit 15 is stored. The reservation management information in the reservation management information table 200 includes a reserved memory ID column 210 that stores a reserved memory identifier that is identification information and a reserved memory capacity column 2 that stores the value of the reserved memory capacity Rx.
20, the acquisition limit memory capacity column 230 in which the value of the acquisition limit memory capacity Lx, which is the upper limit of the memory capacity when acquiring the memory of the reserved memory capacity Rx or more according to the state of the free memory, is executed by the reservation source application. The acquired memory capacity column 240 stores the acquired memory capacity Gx, which is the total value of the acquired memory area capacities.

The reservation information registration unit 15 stores the value of the "reserved memory capacity Rx" added to the reservation request in the "reserved memory capacity column 220" of the reservation management information and the "acquired limit memory capacity column 230". , The value of the “acquired limit memory capacity Lx” added to the reservation request is set in the “acquired memory capacity column 24
The initial value "0" is set to "0" (the value in this column is set by the memory acquisition unit 20 when the application is executed). Then, a unique reserved memory identifier Ix is generated and set in the "reserved memory ID column 210".

Further, the reservation information registration unit 15 reduces the value of the free memory capacity E managed by the free memory management unit 17 by the amount of the newly reserved memory area. Specifically, it is assumed that “free memory capacity E after update = free memory capacity E-Rx before update”. Then, the reservation information registration unit 15
Sends the generated reserved memory identifier Ix and the identification information of the request source application to the reservation success notifying unit 14 to notify the request source application of the reservation success.

The reservation success notifying unit 14 notifies the requesting application that the memory reservation has succeeded. At the same time, the reservation information registration unit 15 returns the reserved memory identifier Ix given to the reserved memory to the application. As a concrete method of the success notification performed by the reservation success notification unit 14, a specific non-negative error code is returned together with the reservation memory identifier in response to the function call to the reservation request reception unit 11 described above. Can be considered.

The reservation failure notifying unit 13 notifies the requesting application of the failure of the memory reservation with respect to the reservation request judged by the reservation possibility judging unit 12 to be unexecutable. As a concrete method of the failure notification performed by the reservation failure notification unit 13, it is conceivable to return a specific negative error code in response to the function call to the reservation request reception unit 11 described above. The reservation failure notification sent by the reservation failure notification unit 13 to the application is also shown to the administrator or the user via the OS, and prompts a response such as a reduction in the number of applications on the system and a review of the system configuration.

The free memory management unit 17 holds information such as the capacity E and the address of the free memory on the main storage device of the system. (Configuration of Memory Acquisition Unit 20) The memory acquisition unit 20 includes an acquisition request reception unit 21 that receives a memory acquisition request from an application on the system for each task of an execution unit.
An acquisition availability determination unit 22 that determines whether the requested memory acquisition is executable, an acquisition failure notification unit 23 and an acquisition success notification unit 24 that notify the application of the results of whether the requested memory reservation is executable, It has a memory acquisition processing unit 25 for acquiring a memory area in the main memory according to the determined acquisition request.

The acquisition request receiving unit 21 receives a memory acquisition request from an application running on the system,
The content is transmitted to the acquisition propriety determination unit 22. The application issues a request each time the task, which is a processing unit, starts executing. For the memory acquisition request, the “acquisition request memory capacity S” which is the capacity of the memory area required for the task to be executed, and the “reservation” given to the memory area reserved for the request source application by the memory reservation device 10. Two parameters "memory identifier Ix (see FIG. 2)" are added. Acquisition request reception unit 21
Is realized in the form of a system library that is linked with an application in the form of a function call having the above parameters and that activates a system program by interrupt processing.

The acquisition propriety determination unit 22 is an acquisition request reception unit 2
Regarding the memory acquisition request received by the first request, whether or not to execute can be determined based on the reservation management information of the memory reserved for the request source application and the information of the free memory capacity E held by the free memory management unit 17. . Acquisition propriety determination unit 2
In the second step, first, in the determination of the first stage (acquisition of reserved memory), based on the remaining amount of reserved memory (“reserved memory capacity Rx−acquired memory capacity Gx”), the memory of the newly requested capacity is determined. It is determined whether the reserved memory remaining amount can be acquired. When the reserved memory is used up and the acquisition request cannot be satisfied, the acquisition availability determination unit 22 determines whether the requested memory area can be acquired from the free memory of the system as the determination of the second step (additional memory acquisition). judge. Hereinafter, it will be described more specifically.

The acquisition availability determination unit 22 first reads the reservation management information corresponding to the reservation memory identifier Ix obtained from the acquisition request reception unit 21 from the reservation management information table 200 in the reservation information storage unit 16. Then, the sum of the “acquisition request memory capacity S” obtained from the acquisition request receiving unit 21 and the “value (Gx) of the acquired memory capacity column 240” of the reservation management information is the “reservation” of the reservation management information. Memory capacity column 22
0 value (Rx) ”. If “S + Gx ≦ Rx”, even if a memory area of the capacity S is newly acquired, it will fall within the range of the reserved memory capacity Rx. Therefore, the acquisition availability determination unit 2
2 determines that the memory acquisition request is executable, passes the reservation management information and the acquisition request memory capacity S to the memory acquisition processing unit 25, and instructs the memory acquisition processing unit 25 to execute the area acquisition process.

In the above comparison judgment, if "S + Gx>Rx", this means that if the memory area of the requested capacity S is newly acquired, it exceeds the reserved memory capacity Rx. The determination unit 22 determines whether or not the required memory area can be acquired by using the free memory on the system. However, since the memory area that can be acquired more than the reserved amount by using the free memory is limited by the “value (Lx) of the acquisition limit memory capacity column 230” of the reservation management information for each application, the acquisition availability determination unit 22 First, a check is performed based on this limit value. In particular,
The sum of the acquisition request memory capacity S and the acquired memory capacity Gx is compared with the acquisition limit memory capacity Lx. "S + Gx> L
In the case of “x”, if the memory area of the capacity S is acquired according to the acquisition request, the limit value will be exceeded. Therefore, the acquisition availability determination unit 22 executes the memory acquisition request even if the free memory is used. It is determined that it is impossible to do. Then, it instructs the acquisition failure notification unit 23 to notify the request source application of the area acquisition failure.

On the contrary, in the above comparison judgment, "S + Gx≤L"
In the case of “x”, this means that even if the memory area of the capacity S is acquired according to the acquisition request, it is within the range of the limit value. In that case, the acquisition propriety determination unit 22 checks the free memory capacity E of the system. That is, the acquisition request memory capacity S is compared with the free memory capacity E. If “S> E”, the memory area of the requested capacity S cannot be acquired with the current free memory capacity. The identification information of the request source application is passed to and the area acquisition failure is notified. On the other hand, “S ≦
If it is “E”, the memory area of the requested capacity S can be acquired from the free memory on the system. Therefore, the acquisition permission / inhibition determination unit 22 notifies the memory acquisition processing unit 25 of the reservation management information and the acquisition request memory capacity S. To instruct execution of area acquisition processing.

The acquisition failure notifying section 23 is provided with the acquisition propriety judging section 2
Regarding the acquisition request determined to be unexecutable by 2, the request source application is notified of the memory acquisition failure.
As a specific method of the failure notification performed by the acquisition failure notification unit 23, it is conceivable to return a specific negative error code in response to the function call to the acquisition request reception unit 21 described above.

The memory acquisition processing section 25 actually acquires a memory area in the main memory of the system in accordance with the instruction from the acquisition possibility determination section 22. The memory acquisition processing unit 25 acquires “reservation management information” and “acquisition request memory capacity S” from the acquisition permission / inhibition determination unit 22, and reads the address of the memory area that can be acquired from the free memory management unit 17. When the memory area having the capacity indicated by the acquired memory capacity S is acquired, the start address of the acquired memory area is sent to the acquisition success notifying unit 23 as the designation information.

Next, the memory acquisition processing section 25 updates the reservation management information and the free memory capacity E according to the acquisition result. The value of the free memory capacity E is updated in the form of “capacity after update = capacity before update E−acquired memory capacity S”. Further, in the reservation management information, the “acquired memory capacity column 24
The value Gx of "0" is updated in the form of "Gx after update = Gx before update + acquired memory capacity S".

The acquisition success notifying unit 24 notifies the request source application notified from the memory acquisition processing unit 25 that the memory acquisition has succeeded. At the same time, the designation information (start address) of the acquisition area obtained from the memory acquisition processing unit 25 is returned to the application. As a concrete method of the success notification performed by the acquisition success notification unit 24, a specific non-negative error code is returned together with the specification information of the acquisition region in response to the function call to the acquisition request reception unit 21 described above. Can be considered. (Operation) Hereinafter, the memory management device 1 according to the present embodiment
The operation will be described with reference to the drawings. The operation for reserving the memory area for each application and the operation for actually acquiring the memory area for each task by the running application from the reserved memory area will be described separately.

(Reservation Operation) First, the memory reservation operation will be described. FIG. 3 is a flowchart showing the operation of the memory reservation process of the memory management device 1. The memory reservation is performed for an application on the system when the system including the memory management device 1 is started up, and when a new application is added to the system by installation or download, the additional application is added. Done against.

First, the reservation request receiving unit 11 receives a memory reservation request from one application (S30).
1). The reservation request receiving unit 11 receives the information (“reserved memory capacity Rx”, “acquisition limit memory capacity L”) added to the request.
x ”) is passed to the reservation availability determination unit 12 to instruct to determine whether or not the request can be executed. The reservability determination unit 12 obtains the value of the "free memory capacity E" at that time from the free memory management unit 17 and compares this with the reserved memory capacity Rx (S302).

When the comparison result is "Rx>E",
In other words, if the currently reservable free memory capacity is smaller than the newly reserved memory area capacity (S303: No), the reservation availability determination unit 12 instructs the reservation failure notification unit 13. Then, the request source application is notified of the memory reservation failure (S307). On the contrary, when the comparison result is “Rx ≦ E”, that is, when the currently reservable free memory capacity is equal to or larger than the newly reserved memory capacity S (S303: Yes), The reservation availability determination unit 12 instructs the reservation information registration unit 15 to execute a specific process of memory reservation.

First, the reservation information registration unit 15 generates the reservation management information for the reservation memory (see FIG. 2) and additionally stores it in the reservation management information table 200 held by the reservation information storage unit 16 (S304). . "Reserved memory capacity column 22
"0" indicates the "reserved memory capacity R added to the reservation request.
x ", the" acquisition limit memory capacity column 230 "is set with the value of the" acquisition limit memory capacity Lx "added to the reservation request, and the" acquired memory capacity column 240 "is set to the initial value. Set "0". Then, the unique reserved memory identifier Ix is set in the "reserved memory identifier column 210".

Further, the reservation information registration unit 15 updates the free memory capacity E managed by the free memory management unit 17 by the reserved memory capacity Rx (S305). "E after update = E-Rx before update". Finally, the reservation information registration unit 15 sends the reservation memory identifier Ix generated in step S304 to the reservation success notification unit 14. The reservation success notifying unit 14 sends a notification that the memory reservation has been successful to the request source application together with the reserved memory identifier Ix (S306).

Then, the above steps S301 to S30
The process of 7 is executed for all the applications for which the memory reservation is made (S308). (Operation at Acquisition) Next, the operation at memory acquisition will be described. FIG. 4 is a flowchart showing an operation performed by the memory management device 1 in response to one application requesting acquisition of a memory area in units of tasks.

First, the acquisition request receiving section 21 receives a memory acquisition request from a running application at a timing accompanying the start of execution of a task. The acquisition request reception unit 21 uses the “reserved memory identifier Ix” added to the request.
(The identifier of the reserved memory reserved by the requesting application) and the acquisition request memory capacity S are sent to the acquisition permission / inhibition determination unit 22 to instruct whether or not the memory area of the requested capacity S can be acquired (S401).

In response to this, the acquisition permission / inhibition decision unit 22 uses the reserved memory identifier Ix as a key to make a reservation regarding the reserved memory reserved by the requesting application from the reservation management information table 200 held in the reservation information storage unit 16. The management information is acquired (S402). Then, as a first determination process, the acquisition availability determination unit 22 compares the value obtained by adding the “acquired memory capacity Gx” to the “acquisition request memory capacity S” with the “reserved memory capacity Rx”. This is to determine whether or not the memory area reserved by the requesting application still has a sufficient memory area for the acquisition request memory capacity S.

When “S + Gx ≦ Rx”, that is, when the memory of the requested capacity S can be acquired from the remaining portion of the reserved memory capacity (S403: Yes), the acquisition availability determination unit 22 causes the memory acquisition processing unit 25 to perform the acquisition. Then, in step S40
Pass the reservation management information and the acquisition request memory capacity S obtained in 2,
Execute memory acquisition processing. The memory acquisition processing unit 25 first acquires an address of a memory area that can be acquired from the free memory management unit 17, and acquires a memory area having a capacity indicated by the acquisition memory capacity S from the area. Then, the acquired start address of the memory is sent to the acquisition success notification unit 24 (S407). The acquisition success notification unit 24 sends the start address of the received acquisition memory area to the request source application to notify that the memory acquisition has succeeded (S40).
8). After that, the memory acquisition processing unit 25 updates the value Gx of the “acquired memory capacity column 240” in the reservation management information. The content of the update is “Gx after update = Gx before update +
The acquired memory capacity is S ”(S409).

On the other hand, in the determination of step S403, "S + G
x> Rx ”, that is, when the memory area of the requested capacity S cannot be acquired within the reserved memory capacity range (S403: No), the acquisition availability determination unit 22 sets“ acquisition request memory capacity S ”. The value obtained by adding the “acquired memory capacity Gx” is further compared with the “acquired limit memory capacity Lx”.

When the comparison result is "S + Gx≤Lx" (S404: Yes), the memory of the requested capacity S is acquired only when the system has free memory exceeding the capacity S. It means that you can do it. Therefore, the acquisition availability determination unit 22 first acquires information on the free memory capacity E in the system from the free memory management unit 17. Then, the free memory capacity E is compared with the acquisition request memory capacity S (S405).

If “S ≦ E”, there is a free memory larger than the memory capacity S requested to be acquired in the system, and therefore the acquisition availability determination unit 22 causes the memory acquisition processing unit 25.
To execute the memory acquisition process shown in steps S407 to S409. In this case, the memory acquisition processing section 25 updates the value of the free memory capacity E before the processing of step S407 and returns the updated value to the free memory management section 17 (S406). The update process is “E after update = ES before update”.

As a result of the determination in step S404 or S405, if the memory of the requested capacity cannot be acquired, that is, the comparison result is "S +" in step S404.
Gx> Lx ”(S404: No) or the comparison result in step S405 is“ S> E ”(S405: No), the acquisition possibility determination unit 22 determines the acquisition failure notification unit 23. To notify the request source application of the acquisition failure (S410). In this case, the acquisition propriety determination unit 22 passes an error code indicating the cause of the acquisition failure (whether it is an error in S404 or an error in S405) to the acquisition failure notification unit 23. This is S405
The acquisition failure in is that the system has insufficient free memory,
The reason for this is that the acquisition failure in step S404 is due to the application making a memory request that exceeds the "limit value" assumed at the time of reservation, while it depends on the situation at the time of the determination. In the case of the former, it can be dealt with by terminating other applications that are running, but in the case of the latter, there is an error in the estimation of the memory demand for the application, or an excessive memory request occurs due to a failure such as a bug. Since it means that it has been issued, it is necessary to review the system. If the error code indicates which factor is the cause, the user or administrator will be able to take appropriate action.

The above steps S401 to S410 are repeated until the request source application is completed (S411). Although not shown in this figure,
In the middle of the above process, the task that was previously executed may be terminated and the memory acquired for the execution of the task may be released. At that time, the reserved memory management information (acquired memory capacity Gx) and the free memory capacity E are updated along with the release. This is performed by the memory acquisition processing unit 25, and the value is updated in such a manner as to increase by the capacity of the released memory area. (Summary) As described above, the memory management device according to the present embodiment determines the capacity of the memory area reserved by the application in addition to the reference reserved memory capacity Rx and the free memory capacity on the system at the time of execution. A memory capacity that can be acquired by adding the reserved memory capacity Rx is defined as an acquisition limit memory capacity Lx. When an application is executed and the total memory capacity used simultaneously by the applications exceeds the reserved memory capacity Rx, even if a new memory area acquisition request is received, if the system has sufficient free memory, the acquisition is performed. Limit memory capacity L
A memory area is acquired with x being the upper limit. Therefore, the application can reliably use the reserved memory area and can effectively use the free memory.

The memory management device can be implemented as a program here. Further, although the target of management has been described as the memory of the main storage device, it can be applied to other storage devices such as an auxiliary storage device. In the above explanation, the memory area required for executing the application was explained, but the reservation and acquisition of the memory area (memory area for control block etc.) required for the dynamic generation of software resources such as semaphores. The same configuration can be applied to the above. In this case, the main entity of the reservation is the application requesting the dynamic generation of the software resource, and the acquisition is performed at the timing when the application requests the dynamic generation at the execution.

Hereinafter, the memory management device 1 of the present embodiment
However, as an example of dynamic generation of software resources, a reservation for a memory area for a semaphore that has an exclusive control function,
The case of acquisition will be described. The only difference from the above description is that the acquired memory area is not used directly by the application but for the semaphore management block.

FIG. 5 is a diagram showing the memory management device 1 for acquiring the memory area for semaphore generation from the reserved memory area together with the semaphore generation device 30 which is the acquisition request source. The memory management device 1 has the same configuration as the memory reservation unit 1 shown in the embodiment, and the processing content of each component is basically the same. However, the acquisition request is not issued to the memory acquisition unit 20 from the application, but is issued to the memory acquisition unit 20 from the semaphore generation device 30 instructed by the application that is the main body of the semaphore generation.

When the semaphore generation device 30 receives a request for dynamic generation of a semaphore from any of the applications, the semaphore management device 1 requests the memory management device 1 to acquire a memory area for the semaphore management block, and manages the semaphore in the memory area. After setting the initial value of the information, the unique identification information (I
D) is returned to the requesting application. The semaphore generation device 30 includes a semaphore generation request reception unit 31, a semaphore generation failure notification unit 32, and a semaphore generation unit 33.

Upon receiving a new semaphore resource generation request from the application, the semaphore generation request reception unit 31 issues a memory acquisition request based on this request to the memory acquisition unit 2.
Issue to 0. A "reserved memory identifier Ix" for the request source application and an "acquired memory capacity S" (here, the memory area capacity for the control block of the semaphore in question) are added to the acquisition request. Semaphore generation request reception unit 31
The entity of is linked with the application in the form of a function call with the semaphore attribute and other information to be dynamically created and the reserved memory identifier Ix as an argument, and is in the form of a system library that activates the system program by interrupt processing. Can be achieved with.

In response to the memory area acquisition request issued by the semaphore generation request reception section 31, the semaphore generation failure notification section 32 sends a signal indicating that memory acquisition is impossible from the memory acquisition section 20 (acquisition failure notification section 23). In this case, the request source application is notified of the failure to dynamically create the semaphore resource. As the substance of the semaphore generation failure notifying unit 32, for example, the same one as the example of the semaphore generation request receiving unit 31 described above can be considered. However, here, a specific error code with a negative value (indicating failure) is returned to the function call.

The semaphore generator 33 has a memory acquisition unit 20.
When a memory acquisition notification is sent from the (acquisition success notification unit 24), the initial value of the semaphore management information is stored in the memory area indicated by the specified information (address) of the memory area sent together with the notification. Then, it notifies the request source application that dynamic generation of the semaphore resource has succeeded. Unique identification information of the management block is added to the notification. As the substance of the semaphore generation unit 33, for example, the same ones as those mentioned above in the semaphore generation request reception unit 31 can be considered. However, here, a specific non-negative error code (indicating success) is returned to the function call.

In the above description, the memory area for the semaphore management block is reserved together with other memory areas, but the memory area for the resource dynamic generation function such as the semaphore is reserved separately. It may be that. Although only the semaphore dynamic generation device has been described here, a dynamic generation mechanism for all software resources associated with the OS, such as processes and tasks that are execution units of applications, interprocess communication functions, and memory management functions, is also included. The same can be achieved by replacing the part of the semaphore dynamic generation device 30 with another object having substantially the same function.

The timing for reserving the memory area is
In the above description, the system is started up, but it may be performed for all applications when the system is constructed, or for each individual application each time a new application is started up on the system. Further, in the above-described embodiment, the upper limit value when allocating a memory area having a capacity exceeding the reserved memory capacity for an application is determined by the acquisition limit memory capacity set at the time of reservation on the application side.
It is also possible to determine the upper limit value on the memory management device side.
For example, it is conceivable that "half the free memory capacity", "a value obtained by dividing the free memory capacity by the number of running applications", and the like are set as the upper limit values.

Further, in the above embodiment, the memory reservation is made for each individual application, but it is also possible to make the memory reservation collectively for a plurality of applications. For example, an application that is executed only by being called by another application may be reserved together with the memory area for the calling application. Also, if there are multiple applications that may not be executed concurrently in parallel, these applications can share one reserved memory area.

Further, in the memory management processing of this embodiment, a modification in which the priority set for each application is used can be considered. For example, if a free memory shortage occurs when you try to reserve a memory area for a high-priority application, cancel the reservation for some or all of the memory areas already reserved for the low-priority application, and A processing method of executing a memory reservation of a high application can be considered. Alternatively, if the memory area required during the execution of a high-priority application does not fit within the reserved memory capacity and the free memory is insufficient, the reserved memory of the low-priority application A processing method of canceling reservations for some or all of them and executing memory acquisition for high-priority applications can be considered. By doing so, the application with high priority can reliably reserve and acquire the memory.

In the present embodiment, the case where one free memory is reserved and acquired is explained as an example, but it is also possible to reserve and acquire a memory area from a plurality of free memories. In that case, the free memory management unit of the present embodiment holds free memory management information by the number of free memories, and when requesting or responding to a memory reservation or memory acquisition,
The ID of the reserved and acquired free memory is added as a parameter.

[0057]

As is apparent from the above description, the memory management device of the present invention is a memory management device that manages a memory area used when an application is executed on a computer system in which the application operates. A reservation accepting unit that accepts a reservation of a reserved memory capacity that is guaranteed in advance for the application before execution, and an execution memory area used by the application for execution of processing after the execution of the application is used as the reserved memory capacity. Reserved memory acquisition means for acquiring within the range of, and free memory management means for managing the amount of free memory that has not been reserved or acquired for an application with respect to the memory resources on the computer system; The memory area is exceeded It refers to the capacity of the free memory when attempting to use, and having a a further portion memory acquisition means for acquiring additional memory area from the free memory in accordance with the capacity of the free memory.

According to this structure, the required memory area can be secured as the reserved memory capacity for the application, and the memory capacity that can be acquired according to the state of the free memory on the system at the time of execution can be added. Therefore, it is possible to efficiently use the memory resources on the system after securing the necessary memory area. In particular,
The effect is remarkable in a system that needs to perform processing using a limited capacity of main memory.

It should be noted that this effect is that, on the computer system in which the application operates, a reservation of the reserved memory capacity guaranteed in advance for the application is accepted before the application is executed, and the memory area is reserved when the application is executed. A memory management device for acquiring an execution memory area used by the application for execution of processing within a range of the reserved memory capacity, and a memory resource on the computer system. With regard to the above, regarding free memory management means for managing the amount of free memory that has not been reserved or acquired for an application, and the free memory capacity when the application tries to use a memory area exceeding the reserved memory capacity. Refer to, depending on the amount of free memory It is realized by the memory management device, characterized by having a a further portion memory acquisition means for acquiring additional memory area from the free memory.

Further, the reservation receiving means further receives the acquisition limit memory capacity, and the additional memory acquiring means acquires the memory area exceeding the reservation memory capacity within the acquisition limit memory capacity. Yes, you can. With this configuration, the total capacity of the memory area that can be acquired by one application is limited by the acquisition limit memory capacity, so that a situation in which a specific application does not exclusively use the free memory does not occur, Free memory can be effectively used.

It should be noted that the above effect is that, on the computer system in which the application operates, the reservation of the reserved memory capacity guaranteed for the application is accepted before the application is executed, and the memory is stored when the application is executed. A memory management device for acquiring an area, and a reserved memory capacity guaranteed in advance for the application before executing the application,
Reservation receiving means for receiving an acquisition limit memory capacity which is an upper limit value when the memory area is acquired beyond the reserved memory capacity within the range of free memory not reserved or acquired for the application, It can also be realized by a memory management device that operates.

Further, specifically, the memory area required for the processing of the application is the first memory area directly used by the application for executing the processing, and the software resource operation used by the application for executing the processing. It may be at least one of the second memory areas required for the dynamic generation device. According to this, the above effect can be achieved for the memory area directly used for executing the application as well as the memory area (memory area for the control block, etc.) necessary for dynamically generating software resources such as semaphores. Is obtained.

A similar effect is a memory management method for managing a memory area used at the time of executing an application on a computer system in which the application operates, and is guaranteed in advance for the application before the execution of the application. A reservation acceptance step of accepting a reservation of a reserved memory capacity to be reserved, and a reserved memory acquisition step of acquiring an execution memory area used by the application after the execution of the application for processing execution within the range of the reserved memory capacity. A free memory calculating step for calculating the amount of free memory that has not been reserved or acquired for an application with respect to the memory resources on the computer system; and the application tries to use a memory area exceeding the reserved memory capacity. When to The reference to the amount of free memory, the method characterized by having a a further portion memory acquisition step to acquire additional memory area from the free memory in accordance with the capacity of the free memory can be realized by.

[Brief description of drawings]

FIG. 1 is a diagram showing a configuration in an embodiment of a memory management device according to the present invention together with a related external configuration.

FIG. 2 is a diagram showing a configuration and contents of a reservation management information table according to the same embodiment.

FIG. 3 is a flowchart showing an operation at the time of memory reservation of the memory management device according to the same embodiment.

FIG. 4 is a flowchart showing an operation when a memory is acquired by the memory management device according to the same embodiment.

FIG. 5 is a diagram showing a configuration of the memory management device according to the embodiment when a memory area is acquired for a semaphore.

[Explanation of symbols]

1 Memory management device 10 Memory reservation section 11 Reservation request reception section 12 Reservation availability judgment section 13 Reservation failure notification section 14 Reservation success notification section 15 Reservation information registration section 16 Reservation information storage section 17 Free memory management unit 20 memory acquisition unit 21 Acquisition Request Reception Unit 22 Acquirability determination unit 23 Acquisition failure notification section 24 Acquisition success notification section 25 Memory acquisition processing unit 30 Semaphore generator 31 Semaphore generation request reception unit 32 Semaphore generation failure notification section 33 Semaphore generation success notification unit

   ─────────────────────────────────────────────────── ─── Continued front page    (72) Inventor Kiyoshi Owada             1006 Kadoma, Kadoma-shi, Osaka Matsushita Electric             Sangyo Co., Ltd. F-term (reference) 5B060 AA06 AA09 AC05

Claims (6)

[Claims] 1. A memory management device that manages a memory area used when an application is executed on a computer system in which the application runs, wherein a reserved memory capacity guaranteed in advance for the application before the application is executed. Reservation accepting means for accepting a reservation, and an execution memory area used by the application for execution of processing after the execution of the application is started,
A reserved memory acquisition unit that acquires within the reserved memory capacity range; an empty memory management unit that manages the amount of free memory that has not been reserved or acquired for an application with respect to the memory resources on the computer system; When the application tries to use the memory area beyond the reserved memory capacity, the free memory capacity is referred to, and an additional memory area is acquired from the free memory according to the free memory capacity. A memory management device comprising: 2. The reservation receiving means further receives an acquisition limit memory capacity, and the additional memory acquisition means acquires a memory area exceeding the reserved memory capacity within the acquisition limit memory capacity. The memory management device according to claim 1, wherein: 3. The memory area required for the processing of the application is a first memory area used directly by the application for processing execution, and a software resource dynamic generation device used by the application for processing execution. The memory management device according to claim 1 or 2, wherein the memory management device is at least one of the second memory areas required for the above. 4. A memory management method for managing a memory area used at the time of executing an application on a computer system in which the application operates, wherein a reserved memory capacity guaranteed in advance for the application before the application is executed. A reservation receiving step for receiving a reservation, and an execution memory area used by the application for execution of processing after the execution of the application is started,
A reserved memory acquisition step of acquiring within the reserved memory capacity range; a free memory calculation step of calculating a free memory capacity not reserved or acquired for an application with respect to the memory resources on the computer system; When the application tries to use the memory area beyond the reserved memory capacity, the free memory capacity is referred to, and an additional memory area is acquired from the free memory according to the free memory capacity. A memory management device, comprising: 5. A memory for accepting a reservation of a reserved memory capacity guaranteed in advance for the application before executing the application on a computer system in which the application runs and acquiring a memory area when the application is executed. A management apparatus, which comprises a reserved memory acquisition unit for acquiring an execution memory area used by the application in executing a process within a range of the reserved memory capacity, and a memory resource on the computer system for an application. A free memory management unit that manages a free memory capacity that is neither reserved nor acquired, and refers to the free memory capacity when the application tries to use a memory area exceeding the reserved memory capacity, Depending on the amount of free memory, the free memory And an additional memory acquisition unit for acquiring an additional memory area from the memory management device. 6. A memory which, on a computer system in which an application operates, accepts a reservation of a reserved memory capacity guaranteed in advance for the application before executing the application and acquires a memory area when the application is executed. The management device is a memory area that exceeds the reserved memory capacity within a range of a reserved memory capacity that is guaranteed in advance for the application before the execution of the application and a free memory that is neither reserved nor acquired for the application. A memory management method, comprising: a reservation reception unit that receives an acquisition limit memory capacity that is an upper limit value when acquiring.