JPS62278660A - Access control system - Google Patents

Abstract

PURPOSE:To attain the reference to the data having the low frequency of renewing without inputting data through a shared file, by using the data on the shared file to obtain the data up-dated by each processor among these processors with each other. CONSTITUTION:An updating register list (R1 record) 3 for processors is always stored in the record resident buffer 2 of each processor. A record input/output service program 4a performs the exclusive control of a shared file 1 by an access start request given to the file 1. Then the program 4a supplies the R1 record 5 of the file 1. The record 3a stored in the buffer 2a is compared with the R1 record supplied from the file 1 to obtain the number of a record which is under updating. In such a way, the processing time can be shortened by using the list 3 for comparison/reference processing compared with a case where data are read out directly of the file 1 in such a case the replacement frequency is not so high.

Description

[Detailed Description of the Invention] 3. Detailed Description of the Invention [Field of Industrial Application] The present invention relates to access control to a shared file in which data is shared by a plurality of processing devices, and in particular to exclusive control of the shared file. The present invention relates to an access control method suitable for speeding up input/output processing by preventing discrepancies between data in a shared file and data in memory held by each processing device due to data updating.

[Conventional technology]

In the Combiator, the input/output processing speed (Cl10 processing) is significantly slower than the CPU processing speed (reducing the I10 processing speed is extremely effective in speeding up computer processing. Therefore, as a means of reducing the I10 processing speed, input It is common practice to save the obtained data in memory in order to reduce the number of I10 times.

but,? When Ja's processing device accesses the data of the shared file, when the first processing device accesses the data of the shared file and updates the data, the Ike's processing device accesses the data of the shared file. If the other processing device accesses the old data, it means that the other processing device has accessed the old data, and there will be a mismatch between the updated data and the new data.

As a means of solving this problem, when a plurality of processing devices access a shared file, exclusive control is generally used to prevent access by other processing devices when one processing device is accessing the file.

Furthermore, in order to reduce I10 processing speed, there are multiple processes that hold data in memory and update data in a shared file (in this case, each processing unit updates the data it needs in memory). If there is data, it is used to process information, but even if data in memory is used, if another processing device has already updated the same data in the shared 7 isles, the memory A discrepancy occurs between the data in the shared file and the data in the shared file. Such data discrepancies reduce the reliability of the computer.

A related example is the interactive data processing system shared file update control method described in Japanese Unexamined Patent Publication No. 58-50043. In an interactive data processing system in which a user exclusively occupies a shared file from a terminal device and performs update processing, this method minimizes the time that the shared file is occupied and reduces the waiting time for other users (all the time). (, so to speak, only the results executed during the tentative update execution are logged (), and if the results match the results executed during the actual update execution, the desired resource is found between the tentative update execution and the actual update execution. This is a shared file update control method in which it is assumed that the shared file has not been substantially changed in an undesired manner, and processing 7 proceeds.

In other words, the user retrieves data from the shared file on the terminal device, causes the processing device to perform temporary data processing,
If the user approves the processing result, exclusive control is performed,
Access the shared file, perform actual processing, update the file only when the saved temporary processing result and the actual processing result match, and select the exclusive side? i! This is to cancel io.

[Problem that the invention seeks to solve]

Although the above conventional technology assumes multiple terminal devices,
Written assuming I number of processing devices @! Even if multiple processing devices were incorporated into the above conventional technology, 1
There is no way to tell other processing devices the data updated by one processing device; the only option is to perform exclusive control and directly access the updated data in the shared file.

Therefore, when another processing device performs processing using the data in its own memory in order to reduce the number of I10 operations, if the data has been updated, the data in the memory and the data in the shared file will be There was a problem with the reliability of the processing equipment due to discrepancies.

Is the purpose of the invention updated data? : Provides job-specific information to other processing devices, and if data that has not been updated based on this information exists in memory, it is used as is; if it does not exist in memory, it is used as a shared file. By accessing the shared file and retrieving the necessary data, and by accessing the shared file and retrieving the necessary data for updated data, the reliability of the information processing system is ensured, and at the same time, the I10 processing speed is improved. An object of the present invention is to provide an access control method that reduces the number of requests and speeds up computer processing.

[Means for solving problems]

The above purpose is to create a register that holds information related to data updates (update information) in a shared file, create a register that holds update information related to multiple processing devices, and update information within both registered thicknesses. When both update information matches, the data in memory is accessed, and when both update information does not match, the data on the shared file is read into memory and accessed 7 times. This is achieved using an access control method that discards old data and updates new updates.

[Effect]

In the access control method of the present invention, one of each processing device is
When performing processing work using data in a shared file, after applying exclusive control to the shared file, the data update information held by the shared file is referred to, and if the required data has not been updated and is If the required data exists in memory, the data in memory is used for processing, and if the required data has not been updated but the required data does not exist in memory, the required data is processed from the shared file. is retrieved to memory and processed, and if the required data has been updated and the required data exists on the memory, the data in memory is discarded and the required data is newly retrieved from the shared file. If the required data has been updated and the required data does not exist in memory, the required data is retrieved from the shared file to memory and processed, and any processing The result (updated data) is also stored in the memory, and updated information is stored and updated to update the data in the shared file, release exclusive control, and end data processing.

〔Example〕

Hereinafter, one embodiment of the invention will be described with reference to FIGS. 1 and 2.

FIG. 1 is a diagram showing an example of a configuration to which the present invention is applied. A plurality of processing devices (processors), for example processor A, processor B, and processor i, each have record resident buffers 2a+2b and 2i, and perform access control such as data (record) input/output. It is provided with record person output service programs 4a, 4b, and 4s. ! Ta,
In the shared file 1 of the external storage, various records are stored from Ordinary 2 to Rn11, and in addition to these, an R1 record of updated code registration 5 for the shared file is also stored. The shared file update code registration number 5 is a register in which the number of the updated record is recorded in the fixed position record 1 in the shared file 1.Furthermore, a similar register is created for each process. This is for the process (fr record registration thin 5a + 5ba 5
It's called i.

Next, the operation of this system will be explained. Record input/output service to one of the processors! Ram 4
a stores the records of the shared file 1 in the record resident buffer 2a, and when there is a record input request, it searches the record resident buffer 2a and uses the necessary record if it is found. If the record does not exist, the shared file 1 is accessed, the record is retrieved and processed, thereby reducing the number of record inputs I10. A processor update record (hereinafter referred to as R1 record) 3 is always stored in the record resident buffer 2 of every processor. Next, the explanation will be centered on the processor At. The record input/output service program 4a responds to a request to start accessing the shared file 1.
The shared file 1 is subjected to exclusive control (■ in Figure 2), and the security code 5 of the shared file 1 is input (■ in Figure 2).

Compare the R1 record 5a stored in the record resident buffer 2a with the general code input from the shared file 1 and find out the updated record number (record updated by another processor) (Fig. 2) ). If a record with the updated record number exists in record resident buffer 2, that record is truncated (Fig. 2 ■)
. As for the R1 record 3a, there is no time difference in the update time between the latest general code input from the shared file 1 and the R1 record of the processor update record registration card 3a that has been compared and truncated. Therefore, records in the record resident buffer 2a that are not equal to records in file 1 are eliminated.

If a record with the requested number exists in the record resident buffer 2a after the processor update code registration card 3a in the record resident buffer 2a is newly updated, that record is passed to the request source. . If it does not exist, a record is input from shared file 1. , the input records are accumulated in the record resident buffer 2a (Fig. 2).

When the record resident buffer 2a becomes full, records are replaced according to the LAU algorithm.

When a record output request is received, the record to be output is written to file 1 and stored in record resident buffer 2a.
Records are stored in (Figure 2 ■■).

In the access termination request, update the updated record number for the processor, update the code registration code 3a and the shared file, register it in the code registration code 50, write it to file 1, and remove the exclusive control of the file (Figure 8g2 ■ @ ).

As is clear from the above explanation, in the present invention, the update record number of a file shared by multiple processors is written in the file (thereby, the update record number can be known from other processors, so the number of updates can be reduced). In rare cases, it is better to compare and refer to the register and perform the above processing than to read data directly from the shared file.
This results in a considerable reduction in time, reduces I10 processing speed, speeds up processing, and prevents discrepancies between records in record resident buffer 3 and records in shared file 1. This also has the effect of improving the reliability of the device.

In the above embodiment, as a means of knowing updated records, the updated record register is held by both the process side and the shared file side and compared. (For example, by setting up a table in a shared file that stores the number of updates for each record number, each process can search the table to check if the record it needs has been updated.) It is also possible to provide means for determining whether or not the

〔Effect of the invention〕

According to the present invention, the processing devices can mutually know the data updated by each processing device using the data on the shared file, so that there is no mismatch between the data stored in the memory and the data in the shared file. Throw away only what you have,
Since the remaining data can be utilized, data that is updated infrequently continues to live in memory, and data can be referenced without inputting it from a shared file, improving the reliability of the information processing system and improving input/output processing. This is effective in speeding up the process.

[Brief explanation of drawings]

FIG. 1 is a schematic diagram of the configuration of an embodiment of the present invention, and FIG. 2 is a flowchart showing the flow of processing. 1... Shared file, 2a+ 2b, 2 T-record resident buffer, 5
a, 3b, 3i... Update for process and register code (
Record 1), 4al 4b+4t...Record input/output service program, 5...Updated code registration for shared file.゛・Kono

Claims (1)

[Claims] (1) In an information processing system that includes a plurality of processing devices that have a memory that temporarily stores data and that accesses and processes the data, and a shared file that the plurality of processing devices share data, the shared file A register is provided for storing data updates, and the plurality of processing devices also include:
A register is provided for storing updates of data stored in at least each memory, and each said processing device has:
When accessing data, if the required data is not present in each memory, the data is read from the shared file, and if the required data exists in the memory, the shared file is registered. Compare the update record of the register with the update record of the register in the memory, and if they do not match, access the data in the memory, and if they do not match, read the data from the shared file, The access control method further comprises updating the shared file and the register in the memory.