JP5975419B2 - Information processing apparatus, information processing method, and program - Google Patents

Description

  Some embodiments according to the present invention relate to an information processing apparatus, an information processing method, and a program.

  In recent years, various methods of using data referred to in transaction processing have been studied (for example, see Patent Document 1).

  Patent Document 1 discloses information that allows a program to be designed without being aware of the relationship between a shared area and a process by dynamically allocating a shared area from a generated transaction and releasing the shared area when it is no longer needed. A processing apparatus scheme is disclosed.

Japanese Patent Laid-Open No. 10-049430

  By the way, when updating the data in the shared memory area referred to by the transaction, in order to ensure the consistency of the data, the data update process is executed exclusively from the process after the transaction process is completed. There are many cases.

  However, when the shared memory area reference process and the update process are exclusively controlled, the next transaction cannot be executed until the update process is completed, which may cause a processing speed delay.

  Further, the method described in Patent Document 1 only considers processing between transactions, and does not take into account the relationship between the reference processing and the update processing.

  Some aspects of the present invention have been made in view of the above-described problems. An information processing apparatus, an information processing method, and a program capable of processing data reference and update in a shared memory area in parallel are provided. One of the purposes is to provide it.

  An information processing apparatus according to the present invention includes a first storage unit that stores first position information related to a position on a storage medium in which first data is stored, and the first storage unit that is stored in the first storage unit. The first processing means for processing the first transaction with reference to the first data based on the position information of the first data, and the second data obtained by updating the first data are the first data Update means for recording at different positions on the storage medium, second storage means for storing second position information relating to positions on the storage medium where the second data is recorded, and the first storage When the first position information stored in the means is different from the second position information stored in the second storage means, the second position information is recorded in the first storage means. Position information updating means.

  The information processing method according to the present invention includes a step of recording first position information relating to a position on a storage medium in which first data is stored in a first storage unit, and the first storage unit stores the first position information. The step of processing the first transaction with reference to the first data based on the first position information, and the second data updated from the first data are different from the first data. A step of recording at a position on a storage medium, a step of recording second position information on the position on the storage medium where the second data is recorded in the second storage means, and the first storage When the first position information stored in the means is different from the second position information stored in the second storage means, the second position information is stored in the first storage means. Recording in the updating means; Provided.

  The program according to the present invention includes a step of recording, in the information processing apparatus, first position information related to a position on a storage medium in which first data is stored in a first storage unit; Based on the stored first position information, processing the first transaction with reference to the first data, and the second data updated from the first data, the first data and Recording at a different location on the storage medium, recording second location information on the location on the storage medium where the second data is recorded, on the second storage means, When the first position information stored in the first storage unit is different from the second position information stored in the second storage unit, the second position information is stored in the first storage unit. Is recorded in the location information update means To perform the steps that.

  In the present invention, “unit” and “means” do not simply mean physical means, but also include cases where the functions of the “part” and “means” are realized by software. In addition, even if the function of one “unit” or “means” is realized by two or more physical means or devices, the function of two or more “units” or “means” can be one physical means or It may be realized by an apparatus.

  ADVANTAGE OF THE INVENTION According to this invention, the information processing apparatus, the information processing method, and program which can process the reference and update of the data of a shared memory area in parallel can be provided.

It is a figure for demonstrating the structure of the information processing apparatus in Embodiment 1 of this invention. 3 is a flowchart illustrating a processing flow of the information processing apparatus illustrated in FIG. 1. 3 is a flowchart illustrating a processing flow of the information processing apparatus illustrated in FIG. 1. 3 is a flowchart illustrating a processing flow of the information processing apparatus illustrated in FIG. 1. It is a figure for demonstrating the specific example of a process of the information processing apparatus shown in FIG.

Embodiments of the present invention will be described below. In the following description and the description of the drawings to be referred to, the same or similar components are denoted by the same or similar reference numerals.
(Embodiment)

  1 to 5 are diagrams for explaining an embodiment of the present invention. Hereinafter, the present embodiment will be described along the following flow with reference to these drawings. First, “1” indicates an overview of the entire embodiment. Then, “2” describes the system configuration, and “3” describes the processing flow. In “4”, the processing flow of the present embodiment will be described with a specific example. Finally, the effects and the like according to the present embodiment will be described after “5”.

(1 Overview)
There is a technique called a shared memory that can access the same data in parallel from a plurality of programs. In this embodiment, a case is considered in which data in the shared memory is referred to by a transaction and the same data is updated by an update command related to a process different from the transaction.
The processing of such a system can be broken down into the following processing.

(A) As the data is updated, the area on the shared memory that the transaction should refer to (the location where the data is stored, hereinafter also referred to as “shared memory area”) is changed from time to time and is no longer referenced by the transaction. Data in the shared memory area (data before update) is deleted.
(B) Updating and deleting data on the shared memory is executed by a process different from the transaction process.
(C) During transaction processing, even if data on the shared memory is updated, the shared memory area referred to by the transaction is not changed.
(D) When the data on the shared memory is updated, the process in which the transaction is executed changes the shared memory area to be referred to by the transaction.

In such a system, in addition to transaction processing, when data is updated, processing for changing the shared memory area referred to by the transaction is required. For example, the following two threads are prepared, and these two threads are prepared. Exclusive control will be performed.
(1) Thread that executes a transaction (2) Thread that receives a data update, changes the shared memory area to be referenced in the transaction, and releases the shared memory area that is no longer referenced

  Here, when the above two threads are exclusively controlled, it is possible to prevent misreference of the shared memory area and memory leak due to data change and to maintain data consistency.

  However, if such a method is performed in a system with a large number of CPUs (Central Processing Units), this process becomes a critical section, so a waiting occurs, and the CPU performance cannot be fully exhibited, and the performance reaches its peak. .

  Therefore, the information processing apparatus 1 of the present embodiment has a configuration as shown in FIG. In the system of the information processing apparatus 1, the shared memory 100, the process 200 for referring to and updating the shared memory 100, the shared memory update command 300 for updating the shared memory 100, and the threads included in the process 200 are referenced and updated. A shared memory reference table 400.

  In the example of FIG. 1, the process 200 and the shared memory update command 300 are each a program executed on the CPU or a part of the program, and the process 200 and the shared memory update command 300 are stored in the data on the shared memory 100. , Accessible in parallel. That is, the shared memory update command 300 may update the same data while the process 200 refers to the data on the shared memory 100.

  The process 200 includes a transaction thread 210, a change thread 220, and a shared memory area release thread 230. The transaction thread 210, the change thread 220, and the shared memory area release thread 230 refer to the shared memory reference table 400, respectively, and update data (information).

  The shared memory reference table 400 is an information management table managed on a storage medium (not shown), and manages the transaction reference memory area information 410, the next transaction reference memory area information 420, and the referenced memory area information 430.

  The transaction reference memory area information 410 stores an address of the shared memory area 120 on the shared memory 100 that is referred to by a transaction processed by the transaction thread 210.

  The next transaction reference memory area information 420 stores the address of the shared memory area 120 to be referred to by the transaction executed next to the transaction executed by the transaction thread 210 at the present time or immediately before.

  The referenced memory area information 430 stores the address of the shared memory area 120 that has been referenced by the transaction that the transaction thread 210 previously processed (that is, that is not currently referenced).

  By managing the shared memory reference table 400 as described above, the information processing apparatus 1 avoids exclusion between the transaction thread 210 that executes the transaction and the thread related to the shared memory 100 update by the shared memory update command 300. .

  When the shared memory 100 is updated during a transaction by the transaction thread 210 (when the data referred to by the transaction thread 210 is updated), first, the updated data is the shared memory in which the data before the update is stored. It is stored in a shared memory area 120 different from the area 120.

  The transaction reference memory area information 410 keeps storing the address of the shared memory area 120 where the data before update is stored (that is, at least until the end of the transaction is not updated), and the next transaction reference memory area information 420 contains Stores the address of the shared memory area 120 in which updated data (latest data) is stored. As a result, even if the shared memory 100 is updated during the transaction, the pre-update data is referred to in the current transaction, and the shared memory area 120 in which the latest data is stored is referred to in the next transaction. Will be able to.

  Also, at the start of execution of the next transaction or before (for example, at the end of the previous transaction), the address of the shared memory area 120 of the latest data stored in the next transaction reference memory area information 420 is set. In addition to being stored in the transaction reference memory area information 410, the address of the shared memory area 120 related to the data before update that has been stored in the transaction reference memory area information 410 until then is stored in the referenced memory area information 430. The shared memory area releasing thread 230 prevents memory leak by periodically releasing (deleting) the shared memory area 120 that is no longer referred to and whose address is stored in the referenced memory area information 430.

  With such processing, it is possible to process the reference of the shared memory 100 by a transaction and the update of the shared memory 100 by the shared memory update command 300 without performing exclusive control. It becomes possible to prevent.

(2 System configuration)
Hereinafter, the configuration of the information processing apparatus 1 will be described with reference to FIG. As described above, the system of the information processing apparatus 1 is referred to by the shared memory 100, the process 200 that references and updates the shared memory, the shared memory update command 300 that updates the shared memory 100, and each thread included in the process 200. And the shared memory reference table 400 to be updated.

The shared memory 100 is a storage medium (or a part of the storage medium) that can be accessed concurrently by processes including the process 200 and the shared memory update command 300 and other processes. In the shared memory 100, the generation number 110 is managed and a shared memory area 120 is secured.
The generation number 110 is a number that is added (or subtracted) every time a new shared memory area 120 is secured by the shared memory update command 300. The value of the generation number 110 matches the memory number 121 of the shared memory area 120 in which the latest data is stored.

  The shared memory area 120 is a storage area secured on the shared memory 100 for storing the data when the data is recorded or updated by the shared memory update command 300. Here, a memory number 121 is managed in the shared memory area 120. The memory number 121 is a number that serves as an identifier for identifying each shared memory area 120.

  In the description of the present embodiment, when the individual areas such as the shared memory areas 120A and 120B are not referred to, they are collectively referred to as “shared memory area 120”. This also applies to the memory number 121.

  The process 200 includes a transaction thread 210, a change thread 220, and a shared memory area release thread 230. The transaction thread 210, the change thread 220, and the shared memory area release thread 230 refer to and update information in the shared memory reference table 400, respectively.

  The transaction thread 210 is a thread of a transaction executed while referring to (data stored in the shared memory 100). The transaction thread 210 includes a transaction start unit 211 and a transaction end unit 213.

  Here, the transaction start unit 211 starts the transaction thread 210. In this start process, the transaction start unit 211 confirms the transaction reference memory area information 410 and the next transaction reference memory area information 420 in the shared memory reference table 400. When the addresses of the shared memory areas 120 set in both are different, the transaction start unit 211 stores the address of the shared memory area 120 set in the next transaction reference memory area information 420 in the transaction reference memory area information 410. At the same time, the address of the shared memory area 120 previously stored in the transaction reference memory area information 410 is stored (added) in the referenced memory area information 430.

  The transaction end unit 213 ends the transaction thread 210. In this termination process, the transaction termination unit 213 confirms the transaction reference memory area information 410 and the next transaction reference memory area information 420 in the shared memory reference table 400, similarly to the transaction start unit 211. When the addresses of the shared memory areas 120 set in both are different, the transaction end unit 213 stores the address of the shared memory area 120 set in the next transaction reference memory area information 420 in the transaction reference memory area information 410. At the same time, the address of the shared memory area 120 previously stored in the transaction reference memory area information 410 is stored (added) in the referenced memory area information 430.

  In this embodiment, both the transaction start unit 211 and the transaction end unit 213 check the transaction reference memory area information 410 and the next transaction reference memory area information 420 in the shared memory reference table 400, and the difference is the same. In some cases, information is updated, but this is not a limitation. Specifically, for example, only the transaction start unit 211 may be provided and executed at the start of the transaction.

  The change thread 220 is a thread for setting the address of the shared memory area 120 in which the latest data is stored, and includes a shared memory setting unit 221. When the shared memory setting unit 221 is notified of the new creation of the shared memory area 120 from the shared memory update unit 310, the shared memory setting unit 221 reads the generation number 110 from the shared memory 100 and has the same number as the generation number 110. The address of the shared memory area 120 is set in the next transaction reference memory area information 420 in the shared memory reference table 400.

  The shared memory area release thread 230 is a thread for securing the shared memory area 120 secured on the shared memory 100 in which data that is no longer referenced is stored, and includes a shared memory release means 231.

  The shared memory releasing unit 231 deletes old data that is no longer referenced by releasing the shared memory area 120 whose address is set in the referenced memory area information 430 at regular intervals. Further, the shared memory releasing unit 231 changes (rewrites) the referenced memory area information 430 to an unset after this releasing process.

  The shared memory update command 300 is an instruction for updating data in the shared memory 100 and includes a shared memory update unit 310. The shared memory update unit 310 newly creates the shared memory area 120 and adds 1 to the generation number 110. Also, the shared memory update command 300 stores the added generation number 110 as the memory number 121 in the newly created shared memory area 120.

  The shared memory reference table 400 manages the transaction reference memory area information 410, the next transaction reference memory area information 420, and the referenced memory area information 430. The address of each shared memory area 120 is stored in at least one of the transaction reference memory area information 410, the next transaction reference memory area information 420, and the referenced memory area information 430.

  The transaction reference memory area information 410 stores the address of the shared memory area 120 on the shared memory 100 that is referred to by the transaction thread 210.

  The next transaction reference memory area information 420 stores the address of the shared memory area 120 (the shared memory area 120 to be referred to by the next executed transaction) in which the latest data is stored.

  The referenced memory area information 430 stores the address of the shared memory area 120 that has been referenced by the transaction that the transaction thread 210 previously processed (that is, that is not currently referenced). The referenced memory area information 430 can store the addresses of a plurality of shared memory areas 120.

(3 Process flow)
Next, the flow of processing by the information processing apparatus 1 will be described with reference to FIGS. Hereinafter, the flow of processing at the time of updating data to the shared memory 100 will be described with “3.1”, and the flow of processing at the start or end of a transaction will be described with “3.2”.

(3.1 Flow of processing when updating data)
With reference to FIGS. 2 and 3, the flow of processing when data is updated (created) in the shared memory 100 will be described. 2 and 3 are flowcharts for explaining the flow of processing of the shared memory updating unit 310 and the shared memory setting unit 221 when data is updated (created) in the shared memory 100, respectively.

  In order to update the data in the shared memory 100, the shared memory update unit 310 first secures a new shared memory area 120 in the free area of the shared memory 100 and stores the data (S201). Next, the shared memory update unit 310 updates (adds 1) the generation number 110 (S203), and sets the updated generation number 110 as the memory number 121 of the newly secured shared memory area 120 (S205). ).

  When these processes are completed, the shared memory update unit 310 notifies the shared memory setting unit 221 of an event indicating that the shared memory area 120 has been newly created (S207).

When the shared memory setting unit 221 receives an event indicating that the shared memory area 120 has been created from the shared memory update unit 310 (S301), the shared memory setting unit 221 accesses the shared memory 100 and acquires the current generation number 110 (S303). Then, the shared memory setting unit 221 searches for the shared memory area 120 having the memory number 121 having the same number as the generation number 110, and uses the address of the shared memory area 120 as the next transaction reference memory area information 420. (S305).
Thus, the update process of the shared memory 100 is completed.

(3.2 Process flow at the start or end of a transaction)
Next, the flow of processing at the start or end of a transaction will be described with reference to FIG. In this embodiment, the transaction start unit 211 and the transaction end unit 213 perform the same processing shown in FIG. 4 at the start and end of a transaction, respectively, but here, the processing will be described as the process of the transaction start unit 211.

  The transaction start unit 211 starts the transaction process by the transaction thread 210 and the address of the shared memory area 120 set in the transaction reference memory area information 410 and the shared memory area 120 set in the next transaction reference memory area information 420. It is confirmed whether the address is the same or different (S401). When the set addresses are different (when the reference destination shared memory area 120 is different; Yes in S401), the transaction start unit 211 uses the address of the shared memory area 120 set in the transaction reference memory area information 410 as It is set (added) to the referenced memory area information 430 (S403). Then, the transaction start unit 211 sets the address of the shared memory area 120 set in the next transaction reference memory area information 420 in the transaction reference memory area information 410 (S405).

  As a result, even if the position of the shared memory area 120 in which the latest data is stored has been changed before the transaction execution (including the time of the previous transaction execution), the transaction thread 210 has the latest data. Can be referred to.

(4 Description of specific examples)
Hereinafter, a specific example of processing of the information processing apparatus 1 according to the present embodiment will be described with reference to FIG. FIG. 5 is a diagram for explaining a specific example of a flow of processing related to data update and release of the shared memory 100. Hereinafter, description will be made while paying attention to state transitions of the shared memory 100 and the shared memory reference table 400.

  Before the transaction by the transaction thread 210 is started, the shared memory reference table 400 includes “shared memory area A” (address of the shared memory area 120A) in the transaction reference memory area information 410 and the next transaction reference memory area information 420. “Shared memory area B” (similarly, the address of the shared memory area 120B) is set. Nothing is set in the referenced memory area information 430 (not set).

  In the shared memory 100, shared memory areas 120A and 120B are secured and data is stored, and “1” and “2” are set in the respective memory numbers 121A and 121B. The generation number 110 is set to “2” that matches the largest value in the current memory number 121 (the shared memory area 120B in which the latest data is stored).

  When the transaction start unit 211 of the transaction thread 210 starts a transaction, the transaction start unit 211 first checks the transaction reference memory area information 410 and the next transaction reference memory area information 420 as described with reference to FIG. Then, it is confirmed whether or not the addresses of the shared memory area 120 set for both coincide.

In the example of FIG. 5, “shared memory area A” is set in the transaction reference memory area information 410, and “shared memory area B” is set in the next transaction reference memory area information 420. That is, since the two are different, the transaction start unit 211 sets the “shared memory area A” (address of the shared memory area 120A) set in the transaction reference memory area information 410 to the referenced memory area information 430, and next time. The “shared memory area B” (address of the shared memory area 120B) set in the transaction reference memory area information 420 is stored in the transaction reference memory area information 410.
Next, consider a case where the shared memory update command 300 updates the shared memory 100 during a transaction by the transaction thread 210.

The shared memory update unit 310 of the shared memory update command 300 secures a new shared memory area 120C (“shared memory area C”) in the shared memory 100 and adds “1” to the generation number 110 to generate “3”. The number 110 is set, and “3”, which is the same value as the generation number 110, is set in the memory number 121C of the shared memory area 120C.
After these processes are completed, the shared memory update unit 310 notifies the shared memory setting unit 221 of the change thread 220 to that effect.

  When the shared memory setting unit 221 receives an event indicating that a new shared memory area 120C has been created, the shared memory setting unit 221 refers to the generation number 110 of the shared memory 100 and knows that the latest memory number 121 is “3”. , The address of the shared memory area 120C having “3” as the memory number 121C (“shared memory area C”) is stored in the next transaction reference memory area information 420.

  In the example of FIG. 5, after the shared memory setting unit 221 changes the next transaction reference memory area information 420, the transaction end unit 213 of the transaction thread 210 ends the transaction. At this time, the transaction end means 213 first checks the transaction reference memory area information 410 and the next transaction reference memory area information 420, and checks whether or not the addresses of the shared memory area 120 set in both match. .

  In this example, “shared memory area B” is set in the transaction reference memory area information 410, and “shared memory area C” is set in the next transaction reference memory area information 420. That is, since they are different, the transaction end unit 213 stores (adds) the “shared memory area B” (address of the shared memory area 120B) set in the transaction reference memory area information 410 in the referenced memory area information 430. At the same time, the “shared memory area C” (address of the shared memory area 120C) set in the next transaction reference memory area information 420 is stored in the transaction reference memory area information 410.

  In the example of FIG. 5, after the transaction of the transaction thread 210 ends, the shared memory releasing unit 231 that operates at regular intervals performs a releasing process of the shared memory area 120 that is not used. Specifically, the shared memory releasing unit 231 first refers to the referenced memory area information 430 of the shared memory reference table 400, and the shared memory area 120A (“shared memory area A”) and shared memory that are not currently referenced. The address of the area 120B (“shared memory area B”) is acquired. Then, the shared memory releasing unit 231 releases the shared memory areas 120A and 120B, and deletes data stored in these areas. After completion of the deletion, the shared memory releasing unit 231 changes the referenced memory area information 430 of the shared memory reference table 400 to “unset”.

(5 Effects of this embodiment)
As described above, the information processing apparatus 1 according to the present embodiment stores the information of the shared memory area 120 created by the shared memory update command 300 in the next transaction reference memory area information 420, and starts or ends a transaction. Information of the next transaction reference memory area information 420 is set in the transaction reference memory area information 410. As a result, even during a transaction, the shared memory 100 can be updated without performing exclusive control with reference processing by the transaction and without erroneous reference.

  Further, by saving the information of the referenced shared memory area 120 in the referenced memory area information 430, the shared memory releasing unit 231 releases the shared memory area 120 that is no longer referenced at regular intervals, and a memory leak. Can be prevented.

(5 Additional notes)
Note that the configurations of the above-described embodiments may be combined or some of the components may be replaced. The configuration of the present invention is not limited to the above-described embodiment, and various modifications may be made without departing from the scope of the present invention.
Further, a part or all of each of the above-described embodiments can be described as in the following supplementary notes, but is not limited thereto.

(Appendix 1)
First storage means for storing first position information relating to a position on a storage medium in which first data is stored, and first information based on the first position information stored in the first storage means. The first processing means for processing the first transaction with reference to the data and the second data obtained by updating the first data are recorded at a position on the storage medium different from the first data. Updating means, second storage means for storing second position information relating to the position on the storage medium in which the second data is recorded, and the first storage means stored in the first storage means. Information processing comprising position information update means for recording the second position information in the first storage means when the position information is different from the second position information stored in the second storage means apparatus.

(Appendix 2)
The information according to appendix 1, wherein the location information update unit records the second location information in the first storage unit with the start of a second transaction executed next to the first transaction. Processing equipment.

(Appendix 3)
The information processing apparatus according to appendix 1 or appendix 2, wherein the location information update unit records the second location information in the first storage unit upon completion of the first transaction.

(Appendix 4)
When the position information update unit records the second storage information in the first storage unit, a third storage in which the first position information stored in the first storage unit is recorded. The information processing apparatus according to appendix 1 to appendix 3, further comprising means.

(Appendix 5)
The information processing apparatus according to appendix 4, further comprising a deletion unit that deletes the first position information stored in the third storage unit and the first data corresponding to the first position information.

(Appendix 6)
Based on the step of recording the first position information on the position on the storage medium storing the first data in the first storage means, and the first position information stored in the first storage means, Processing the first transaction with reference to the first data, and recording the second data updated from the first data at a location on the storage medium different from the first data. Recording the second position information on the position on the storage medium in which the second data is recorded in the second storage means; and the first information stored in the first storage means A step of recording the second position information in the first storage means in the position information update means when the position information is different from the second position information stored in the second storage means. Information processing method.

(Appendix 7)
A step of recording, in the information processing apparatus, first position information relating to a position on a storage medium storing the first data in a first storage means; and the first information stored in the first storage means Based on the position information, referring to the first data, processing the first transaction, and updating the second data updated on the first data on the storage medium different from the first data A step of recording in the position, a step of recording second position information on the position on the storage medium where the second data is recorded in the second storage unit, and a step of storing in the first storage unit. If the first position information is different from the second position information stored in the second storage means, the second position information is recorded in the first storage means in the position information update means. Step to perform Because of the program.

  DESCRIPTION OF SYMBOLS 1 ... Information processing apparatus, 100 ... Shared memory, 110 ... Generation number, 120 ... Shared memory area, 121 ... Memory number, 200 ... Process, 210 ... Transaction thread, 211 ... transaction start means, 213 ... transaction end means, 220 ... change thread, 221 ... shared memory setting means, 230 ... shared memory area release thread, 231 ... shared memory release means , 300 ... Shared memory update command, 310 ... Shared memory update means, 400 ... Shared memory reference table, 410 ... Transaction reference memory area information, 420 ... Next transaction reference memory area information, 430 ... Referenced memory area information

Claims (7)

First storage means for storing first position information relating to a position having a first memory number on a storage medium in which first data is stored;
Means for managing the first memory number as generation information;
A first processing means for processing the stored in said first storage means based on the first position information, first transaction by referring to the first data,
The second data updated from the first data is recorded at a position having a second memory number on the storage medium different from the first data, and the second memory number is registered in the generation information. and updating means for,
Second storage means for storing second position information related to the position having the second memory number on the storage medium on which the second data is recorded by referring to the generation information ;
When the first position information stored in the first storage means is different from the second position information stored in the second storage means, the second information is stored in the first storage means. An information processing apparatus comprising position information update means for recording position information. The location information update unit records the second location information in the first storage unit with the start of a second transaction executed next to the first transaction.
The information processing apparatus according to claim 1. The location information update unit records the second location information in the first storage unit when the first transaction ends.
The information processing apparatus according to claim 1 or 2. When the position information update unit records the second storage information in the first storage unit, a third storage in which the first position information stored in the first storage unit is recorded. The information processing apparatus according to claim 1, further comprising means. The information processing apparatus according to claim 4, further comprising a deletion unit that deletes the first position information stored in the third storage unit and the first data corresponding to the first position information. . Recording first position information on a position having a first memory number on the storage medium storing the first data in the first storage means;
Means for managing the first memory number as generation information;
Processing said stored in said first storage means based on the first position information, first transaction by referring to the first data,
The second data updated from the first data is recorded at a position having a second memory number on the storage medium different from the first data, and the second memory number is registered in the generation information. And steps to
Recording the second location information on the location having the second memory number on the storage medium in which the second data is recorded by referring to the generation information in the second storage means;
When the first position information stored in the first storage means is different from the second position information stored in the second storage means, the second information is stored in the first storage means. An information processing method comprising: recording position information in a position information update unit. In the information processing device,
Recording first position information on a position having a first memory number on the storage medium storing the first data in the first storage means;
Managing the first memory number as generation information;
Processing said stored in said first storage means based on the first position information, first transaction by referring to the first data,
The second data updated from the first data is recorded at a position having a second memory number on the storage medium different from the first data, and the second memory number is registered in the generation information. And steps to
Recording the second location information on the location having the second memory number on the storage medium in which the second data is recorded by referring to the generation information in the second storage means;
When the first position information stored in the first storage means is different from the second position information stored in the second storage means, the second information is stored in the first storage means. A program for executing the step of recording the position information in the position information update means.

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