JP2713079B2 - Recovery assistance method when memory is insufficient - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to an application program which proceeds with processing while sequentially securing a memory area from a main memory of an information processing apparatus when a memory shortage is encountered. A recovery assisting method in the event of a memory shortage, so that the application program can reliably use the allocated memory to perform a recovery process such as saving data being created to an external storage medium. .

[0002]

2. Description of the Related Art In an information processing apparatus including a central processing unit, a main memory (memory), and the like, there is a physical upper limit to the capacity of the main memory. Therefore, countermeasures against a memory shortage under various circumstances as described below have conventionally been taken.

Conventional method (1) When there is a command to start a program, the amount of memory necessary for executing the program and the amount of memory currently available are checked. By not starting up, it is possible to prevent a memory shortage during execution and abnormal termination (see, for example, JP-A-2-260049).

Conventional method (2) In a program which has a relationship of calling and being called, a main memory has a memory capacity for loading a calling program when a calling program that calls a certain program calls another program. When there is no such program, an unnecessary program among the programs that have already been called is canceled to create an empty area, and the program can be called (for example, see Japanese Patent Application Laid-Open No. 1-173233).

[0005]

By the way, if an application program that creates data on the main memory of the information processing apparatus consumes a large amount of memory and encounters a shortage of memory during execution, the processing is continued. Not only is it not possible, but in general, when performing recovery processing such as saving data in memory to an external storage medium such as a magnetic disk, a new memory area is required for it, so even recovery processing cannot be performed. The created data is wasted.

[0006] Such a situation does not lead to the effective use of the information processing apparatus, so that some countermeasures are necessary.
In the case where the application program is a program that performs processing while sequentially securing memory areas required in the course of processing, it is not clear how much memory is finally required. It is difficult to accurately determine whether the program has been started or not, and the program is executed when the amount of memory originally required for execution of the program cannot be secured. Problem.

In the conventional method (2), a memory area for executing an application program is positively secured by canceling another program. In the case of an application program for which it is unclear how much memory space is required, there is a problem that the program is executed even though the memory space originally required for executing the program cannot be secured.

The present invention has been made in view of such circumstances, and it is based on the premise that in the case of an application program which performs processing while sequentially securing a memory area, it is inevitable that a memory shortage will be encountered. If a memory shortage occurs, only a memory area that can perform the recovery process should be able to be secured, and the application program starts the recovery process when the memory is insufficient, so that the application process can not even perform the recovery process. The purpose is to prevent the program from ending.

[0009]

According to the present invention, there is provided a method for assisting recovery in the event of a memory shortage, in order to achieve the above object, as shown in a principle explanatory diagram of FIG. Program AP
And run in parallel in advance while securing a defined amount of memory the low memory notification from the application program AP is issued own program by being activated
The application program AP issues a memory shortage notification to the recovery assistance program B when the securing of the memory area has failed in the course of processing, by executing the recovery assistance program B for releasing the secured memory by ending the processing . Reallocating memory after a predetermined time has elapsed
Or try to allocate memory several times.
If the memory area is secured by the attempt,
Externally store data in memory using the saved memory area
A recovery process for saving the data on a medium is performed.

Also, the present invention checks whether or not a certain amount of memory can be secured after the completion of the recovery assistance program B, and restarts the recovery assistance program B when a certain amount of memory can be secured. The program C is executed.

[0011]

When the recovery assisting program B is started, a predetermined amount of memory is secured through the operating system of the information processing apparatus. After starting, the application program AP sequentially secures a memory area required for processing through an operating system and performs processing such as data creation. Application program AP
Requests the operating system to allocate memory, and if there is not enough free memory, securing the memory area will fail. At this time, the application program AP issues a memory shortage notification to the recovery assistance program B. The recovery assistance program B
Releases the memory area allocated by the program itself,
Free memory space increases. Therefore, when the application program AP subsequently tries to secure memory again,
A memory area can be secured, and a recovery process such as saving created data in an auxiliary storage medium can be performed using the secured memory area.

Further, if the application program AP uses the memory area released by the recovery assistance program B, it will not be possible to cope with another similar application program when it encounters a memory shortage. After completion of the recovery assistance program B, it is checked whether or not a predetermined amount of memory exceeding the amount of memory released by the recovery assistance program B can be secured, and if it can be secured, the recovery assistance program B is restarted. Thus, it is possible to cope with an environment in which a plurality of application programs AP are executed.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, embodiments of the present invention will be described in detail with reference to the drawings.

FIG. 2 is a block diagram showing an example of an information processing apparatus for implementing the recovery assisting method in the case of a memory shortage according to the present invention. The information processing apparatus includes a CPU 1, a main memory (memory) 3 connected to a bus 2, and a magnetic disk. A control unit 4 and an input / output interface unit 5, a program file 6 and a data file 7 connected to the magnetic disk control unit 4,
It comprises a CRT 8 and a keyboard 9 connected to the input / output interface unit 5.

The program file 6 stores various programs executed by the information processing apparatus. In the case of the present embodiment, a plurality of data processing application programs AP1 and AP2, a recovery assistance program B, and a recovery assistance activation program C are stored. Is loaded into the main memory 3 as shown in FIG.

The OS in the main memory 3 is an operating system such as UNIX, and manages and controls the entire system such as memory area management of the main memory 3.

Application programs AP1, AP
Reference numeral 2 denotes a C-language-based program which advances processing such as data creation while securing a working memory area. As shown in FIG. 3, for example, as shown in FIG. If the reservation fails when the reservation is performed, processing such as S1 to S7 is performed.

The recovery assistance program B is, for example, an application program of the C language system which secures a predetermined amount of memory when activated. The amount of memory to be secured here is such that one application program AP1 or AP2 can sufficiently perform the recovery processing, and is, for example, 1 Mbyte in this embodiment. Further, when the memory shortage notification is issued from the application programs AP1 and AP2, the recovery assistance program B releases its memory by terminating its own program.
FIG. 4 shows an example of the processing of the recovery assistance program B.

The recovery assistance activation program C is, for example, a C-language application program for performing the initial activation of the recovery assistance program B and restarting after the termination, and performs, for example, processing as shown in FIG.

The operation of this embodiment will be described below.

[0021] The user can use the application program A
When activating P1 and AP2, the recovery assistance activation program C is activated by operating the keyboard 9 or the like prior to the activation.

The actual activation is performed by the operating system OS. That is, the operating system OS loads the recovery assistance start program C from the program file 6 into the main memory 3 and transfers control to the program.

When the recovery assistance activation program C is activated, as shown in FIG. 5, it checks whether or not a predetermined amount of memory can be secured by inquiring of the operating system OS about the amount of free memory (S21).
Here, the predetermined amount of memory is the size of the recovery assistance program B and the memory area secured by it (1 in this example).
(M bytes), which is larger than the sum α, for example, 2 M bytes of memory. This is Recovery Aid Program B
And before the application program secures the memory area released by the recovery assistance program B as described later, the recovery assistance program B is started again to use the once released memory area again. This is to prevent that.

When the recovery assistance activation program C determines that a predetermined amount of memory can be secured (YES in S21),
It requests the operating system OS to start the recovery assistance program B (S22), and then waits for the recovery assistance program B to end (S22).
23). If a predetermined amount of memory area cannot be secured (NO in S21), a wait for a predetermined time is performed (S21).
24) Then, the process returns to step S21 to repeat the above-described processing.

Now, assuming that a predetermined amount of memory area can be secured, the recovery assisting program B is requested to be started from the recovery assisting program C by the operating system OS.
Is loaded from the program file 6 into the main memory 3 and control is passed to it.

When the recovery assisting program B is started, it requests the operating system OS to secure a certain amount (1 Mbytes in this example) of a memory area as shown in FIG.

The operating system OS centrally manages the memory area of the main memory 3. If there is a free area corresponding to the requested size in the main memory 3, the operating system OS replaces the memory area of the requested size with a recovery assistance program. Assign to B. The memory area DE in FIG. 2 indicates the memory area allocated to the recovery assistance program B in such a manner.

When the memory area DE is secured (YES in S12), the recovery assistance program B waits for a memory shortage notification (S13). If it is failed to secure a certain amount of memory area (NO in S12), in the present embodiment, the own program is terminated (S1).
5).

The user starts the recovery assistance starting program C
Is completed, the application programs AP1 and AP2 are started by operating the keyboard 9 or the like. As a result, the application programs AP1 and AP2 are operated by the operating system OS.
2 from the program file 6 to the main memory 3 under the control of FIG.
And control is passed to them.

Application programs AP1, AP
2 is activated, and performs predetermined data processing such as updating data stored in the data file 7. At this time, when a memory area is required for data processing, a request is made to the operating system OS to secure the memory area, and the data processing proceeds while using the secured memory area.

Now, the application program AP
1 and AP2, for example, application program A
When P1 requests the operating system OS to secure a memory area, it is assumed that the operating system OS returns a message that the memory area cannot be secured because the free area is insufficient in the main memory 3 at that time. The application program AP1 outputs a memory shortage notification to the recovery assistance program B as shown in FIG. 3 (S1).

When the recovery assistance program B receives the memory shortage notification from the application program AP1 in step S13 in FIG. 4, it checks whether the format of the notification is correct or not, and ignores it if it is not correct ( If it is correct (NO in S14), the program is terminated (S15).

When the recovery assistance program B ends,
The operating system OS releases the memory area in which the recovery assistance program B has been loaded and the memory area DE secured by the recovery assistance program B. As a result, the free area of the main memory 3 increases.

After outputting the memory shortage notification, the application program AP1 waits for a predetermined time (S2), and then requests the memory reservation again (S2).
3).

As described above, the recovery assistance program B is terminated by the memory shortage notification, and the memory area occupied by the recovery assistance program B is released, so that the memory reservation request issued in the processing S3 from the application program AP1 is almost successful. (YES in S4), and the application program AP1 performs a recovery process such as saving the created data in the data file 7 using the memory area secured by the request in the process S3 (S5). And then,
An error message is displayed on the CRT 8 indicating that data has been saved due to memory shortage, etc., and an unnecessary memory area is released.

If the memory reservation request in step S3 fails for some reason (NO in S4), the memory reservation request is retried (YES in S6). If the retry is not successful even after several retries (NO in S6),
In the present embodiment, an error message indicating that a memory shortage was encountered and the recovery process could not be performed is output to the CRT 8 (S7).

On the other hand, when the recovery assistance program B ends, the operating system OS returns control to the recovery assistance activation program C, which is the activation source. As a result, the recovery assistance activation program C proceeds from the processing S23 in FIG. 5 to the processing S24, waits for a predetermined time, and then proceeds to the processing S21, and determines whether a predetermined amount of memory (2 Mbytes in this example) can be secured. It is checked whether it is possible or not, and if it can be secured, the recovery assistance program B is started again in step S22. If a predetermined amount of memory cannot be secured, the process proceeds to step S24, and the above-described process is repeated.

Therefore, the application program AP
1, when the free space of the main memory 3 reaches a predetermined amount due to the termination of its own program after the recovery processing, or the termination of another program (not shown), the recovery assistance start program C once terminates the recovery assistance program B
Will then be automatically restarted.

When the recovery assistance program B is restarted, the processing shown in FIG. 4 is executed again. This allows
Again, a fixed amount of memory area is secured. Therefore, even when the remaining application program AP2 encounters a memory shortage, a recovery process can be performed.

In the example of FIG. 3, the application program AP1 outputs a memory shortage notification and then issues a memory reservation request after waiting for a predetermined period of time. This is because the time until the release of the memory is taken into consideration. However, in a configuration in which the memory allocation is attempted several times, a configuration may be adopted in which the memory allocation request is sent immediately after the memory shortage notification is output.

[0041]

As described above, according to the present invention,
The following effects can be obtained.

When the application program fails to secure the memory area, the application program issues a memory shortage notification. When the recovery assistance program receives the memory shortage notification, the application program releases the memory area secured by itself. Attempting to secure the memory area again after the output makes it possible to secure the memory area. Using this, it is possible to perform recovery processing such as saving the created data in an external storage medium, thereby increasing the reliability of the application program.

For example, in a configuration in which a spare memory area is reserved on the operating system side and the spare memory area is allocated when the memory is insufficient,
Significant modification of the operating system is required, but the present invention does not cause such a problem.

For example, in a configuration in which a memory area for recovery processing is secured in advance on the application program side, when a plurality of application programs of the same type are operated, a memory area for recovery processing is secured for each individual application program. Therefore, the memory area required for the original processing is excessively reduced, but such a problem does not occur in the present invention.

After the memory of the recovery assistance program is released, the recovery assistance startup program that restarts the recovery assistance program automatically re-allocates the memory area for the recovery processing. Can handle the environment in which it runs.

[Brief description of the drawings]

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

FIG. 2 is a block diagram illustrating an example of an information processing apparatus that implements the present invention.

FIG. 3 is a flowchart illustrating an example of processing of an application program.

FIG. 4 is a flowchart illustrating an example of processing of a recovery assistance program.

FIG. 5 is a flowchart illustrating an example of processing of a recovery assistance start program.

[Explanation of symbols]

 AP, AP1, AP2 ... Application program B ... Recovery assistance program C ... Recovery assistance activation program 7 Data file 8 CRT 9 Keyboard

Claims (4)

(57) [Claims] [Claim 1] In parallel with the execution of the application program to proceed with processing while ensuring the memory region, the memory shortage report is issued from the application program while securing the amount of memory that has been predetermined by being activated A recovery assistance program that releases the secured memory by terminating its own program is executed, and the application program issues a memory shortage notification to the recovery assistance program when it fails to secure a memory area in the course of processing. After a predetermined time has elapsed.
Attempt to secure memory, and the memory area is confirmed by the attempt.
If it is kept, it will be stored in memory using the secured memory area.
A recovery process for storing a shortage of data in an external storage medium . 2. The process proceeds while securing a memory area.
In parallel with the execution of the application program,
To secure a predetermined amount of memory
In both cases, the application program reports a memory shortage.
When the knowledge is issued, by ending the program,
Run a recovery aid program to release the allocated memory.
The application program is executed in the process
When securing the memory area fails, the recovery
After issuing a memory shortage notification to the program, secure the memory.
Try several times, and secure memory area
In the event that the
Perform recovery processing to save data to external storage media.
Recovery assistance method in case of memory shortage characterized by
Law. 3. A process according to claim 1, characterized in that to perform the recovery assistance start program to restart the recovery assistance program after completion of the recovery assistance programs or
Or the recovery assisting method at the time of memory shortage described in 2 . Wherein said recovery assistance launcher claim 3, characterized in that to check whether it is possible to secure a certain amount of memory, activates the recovery assistance program if it can ensure a certain amount of memory The recovery assistance method at the time of memory shortage described.