JPH01295346A - Data destruction preventing system - Google Patents

Abstract

PURPOSE:To process data with no erasion nor destruction by storing the next data into a buffer memory part as the dummy record in case the record length stored in the buffer memory part is equal to 1 physical record to secure the record length larger than 2 physical records. CONSTITUTION:When the data read out of a buffer memory part and to undergo a prescribed process through a data processing part is equal to 1 physical record length, both subroutines A and B deliver a series of subsequent process instructions to a common routine 7. Based on the instruction of the routine 7, a common processing part 8 calculates the short record length to satisfy >=2 physical record lengths via a file device 6. This calculated record length is read and stored in the buffer memory part. Thus the data length stored in the buffer memory part has >=2 physical records and the replacement data is written into the device 6. Thus it is possible to process the data read out and written into the device 6 with no erasion nor destruction.

Description

[Detailed Description of the Invention] [Summary] It relates to a data processing system having a file in which data is read/written in units of physical records including at least one logical record, and in particular, the length of the physical record, which is a unit of processing, etc. Regarding the data destruction prevention method when updating data length shorter than that, when updating data with one physical record length, the relative number of the physical record including the logical record where the data was updated is recognized, and the data is updated after the update. The purpose of this method is to provide a data destruction prevention method in which data in a buffer memory held in a channel is updated on a storage medium such as a file by dummy reading a logical record other than the previously updated physical record number. , When the data in the buffer memory section for performing prescribed processing in data processing is one physical record length, the common processing section transfers two files from the file device based on the instructions of the common routine.
The system is configured to calculate and read the record length that is insufficient because it is longer than the physical record length, and additionally stores it in the buffer memory section.

[Industrial application field]

The present invention relates to a data processing system having a file that reads/writes data in units of physical records including at least one logical record, and in particular updates data lengths that are equal to or less than the length of a physical record, which is a unit of processing. Regarding data destruction prevention methods when

When a single external storage device is shared and data is processed by accessing the external storage device from multiple subroutines within a given processor, one method is to process data in units of physical record length, which includes one or more logical records. There is.

In such a method, if data that is less than the physical record length is updated, the updated data is not guaranteed on the external storage device, so a simple method is required that guarantees the updated data on the external storage device on the user side. Ru.

[Conventional technology]

Figure 5 is a diagram explaining the conventional example, Figure 6 is a diagram explaining the configuration of data processing, Figure 7 is a diagram explaining the data storage situation in a file, and Figure 8 is a diagram explaining the relationship between physical records and logical records. Diagrams for explanation are shown respectively.

The conventional subroutine AI (1) shown in FIG.
It performs a predetermined reception process on the data read from the file device 6 and instructs a series of processes to write to the same location in the file device 6.

On the other hand, subroutine Bl(2) executes the buffer memory section 4.
Instructs a series of processing to perform predetermined processing (for example, update processing) on data stored in .

Further, the data reception processing unit 2 receives instructions from subroutine Al(1) and performs a predetermined reception process (
data formatting processing, etc.).

Then, the data is stored in the buffer memory unit 4, and the processed data is written to the same location where it was read, and the data processing unit 3 updates the data stored in the buffer memory unit 4. Perform processing.

Furthermore, subroutine At (1) and subroutine Bl
(2) is provided in the processor l, and sends and receives a completion signal and a confirmation signal when each instruction is completed, and sends and receives a completion signal and a confirmation signal to the subroutine At(1) and subroutine Bl.
(2) Processing in between is handed over.

Further, the read/write control device 5 controls data read and write operations for the file device 6, and operates upon access from the data reception processing section 2 or the data processing section 3.

Further, a data reception processing section 2. The data processing unit 3 and buffer memory unit 4 are operated by subroutine A shown in FIG. 6(A).
It is assumed that it is installed in A channel 2 (1) and daily channel 2 (2) corresponding to I (1) and Bl (2).

As shown in FIG. 7, the data stored in the file device 6 consists of N records with a fixed logical record length of N bytes (
(corresponding to N pointers) forms one data file.

Furthermore, data is read/written to the file device 6 sequentially starting from the first code, and any record can be read/written by specifying a record number (that is, by specifying a record pointer).

Further, the relationship between the above-mentioned logical records and physical records is as shown in FIG. That is, a logical record is defined by the length of a code having a sequential number, and a physical record is defined by the minimum length that the file device 6 actually reads/writes.

Further, it is assumed that the processing of the data reception processing section 2 has a higher processing priority than the processing of the data processing processing section 3.

Next, parallel processing of data communication will be explained based on FIGS. 5 and 6.

Now, a case will be described in which two subroutines At(1) and Bl(2) operating in parallel read/write the same record of the same file.

In addition, there are two subroutines AI (1) and subroutine Bl.
(2) assumes that data is exchanged through the file device 6 as shown in FIG. 6(A).

Furthermore, the data reception processing unit 2 and the data processing processing unit 3 execute processing in a series of flows as shown in FIG. 6(B), and the processing time is the minimum cycle time t of received data and the processing time T. Execute with.

Next, subroutine AI(1), subroutine Bl(2)
) declares the use of the file device 6, it starts the read/write control unit 5 via the assigned channels 2(1) and 2(2), and the read/write control unit 5
The file device 6 is accessed via.

Note that channels 2 (1) and 2 (2) contain the corresponding subroutine AI (1) and subroutine B1 (
2) holds in the buffer memory unit 4 the physical record number, logical record number, and data in the physical record number that was accessed immediately before.

Then, when subroutine AI (1) reads logical record (n+1) shown in FIG.
At the same time that the contents of the (n+1) record are notified to I (1), the contents of the physical record N are held in the corresponding internal buffer memory section 4 of channel 2 (1).

Also, when subroutine Bl(2) reads logical record (n+5) shown in FIG.
At the same time that the contents of the (n+5) record are notified to the corresponding channel 2 (2), the contents of the physical record (N+1) are held in the buffer memory section 4 in the corresponding channel 2 (2).

When the subroutine At (1) changes the data of the (n+1) record and issues a write command to the file device 6, the buffer memory section 4 in channel 2 (1) simply writes the data in the buffer memory because the change is in the same physical record. Part 4
It only updates the contents of , and does not issue a write command to the read/write control device 5.

Next, subroutine Bl(2) is subroutine Al
Upon receiving the data update end from (1), the corresponding record (n+
1) from the file device 6 and record (n+1
) is notified to subroutine B1(2).

' However, at this point, record (n+1) on the file device 6 has not been updated, and the old data is notified to subroutine Bl(2).

[Problem to be solved by the invention]

As mentioned above, multiple subroutines AI (1).

When subroutine Bl(2) operates in parallel and sends and receives data by sharing one file device 6, data updating (rewriting and addition) is performed by subroutine AI(1),
When subroutine Bl(2) is executed, subroutine A
If the physical record length is smaller than or equal to the buffer memory capacity length in channels 2(1) and 2(2) corresponding to I(1) and subroutine Bl(2), it will not be updated on the file device 6, so the following If this data is read from the file device 6 in step, the old data will be notified and the updated new data will be destroyed and lost.

When updating data with a length of one physical record, the present invention recognizes the relative number of the physical record that includes the logical record where the data was updated, and after the update, the logical record other than the previously updated physical record number is processed. An object of the present invention is to provide a data destruction prevention method in which data in a buffer memory held in a channel is updated on a storage medium such as a file by dummy reading the data.

[Means to solve the problem]

FIG. 1 shows a detailed illustration of the invention.

7 in the principle diagram of the present invention shown in FIG. 1 receives the instruction contents of subroutine A and subroutine B when the data stored in the buffer memory section to be processed based on the instructions of subroutine B is one physical record. This is a common routine that instructs a series of procedures, and 8 is the logical record length of data to be stored in the buffer memory section in order to read multiple records belonging to other physical records from the file device based on the instructions of the common routine 7. , a status storage area that stores status information including the physical record length and maximum number of records, a data storage area that stores data in the record, and a logical record that is added to the buffer memory section from the status storage area and data storage area. It is a common processing unit that has an arithmetic processing area that calculates numbers, and when the data in the buffer memory unit for performing predetermined processing in data processing is one physical record length, it performs common processing based on the instructions of common routine 7. File device 6 in section 8
This problem is solved by configuring the system to calculate and read the record length that is insufficient because it becomes two physical record lengths or more, and to additionally store it in the buffer memory section.

[For production]

When the data to be read from the buffer memory section and subjected to predetermined processing in the data processing section has a length of one physical record, subroutine A and subroutine B pass a series of subsequent processing instructions to common routine 7; Based on this, the common processing unit 8 calculates the insufficient record length from the file 6 to exceed one physical record length, reads the record, and stores it in the buffer memory unit. The updated data is guaranteed, and the data read/written from the file device 6 can be processed without being lost or destroyed.

〔Example〕

The gist of the present invention will be specifically explained below with reference to embodiments shown in FIGS. 2 to 4.

Fig. 2 is a diagram explaining the present invention in detail, Fig. 3 is a diagram explaining the data processing situation in the embodiment of the present invention, and Fig. 4 is a processing flowchart of data destruction prevention processing in the embodiment of the present invention. Figures are shown for each. Note that the same reference numerals indicate the same objects throughout the figures.

The embodiment of the present invention shown in FIG. 2 is a data processing system in which two subroutines Al(1) and Bl(2) in a processor 10 access a file device 6 which is a shared external storage device. It is assumed that the read/write control device 5 and the file device 6 have the same contents as explained in FIG.

Also, channels 20 (1) and 20 (2) according to the present invention
) have the same contents, and the contents are the same as those explained in FIG. 5. Number of records, record number.

From a common processing unit 8 consisting of a state storage area 81 for storing physical record length, logical record length, and channel number, a data storage area 82 for storing data in records, and an arithmetic processing area 83 for performing various logical calculation processes. This is an example of a configuration.

Further, the processor IO executes the subroutine A explained in FIG.
1 (1), Bl (2), and a common routine 7 that instructs a series of procedures of the common processing section 8.

This common routine 7 is activated by access after the data processing section 3 updates the data stored in the buffer memory section 4, and is accessed by the data reception processing section 2 and the data processing section 3 for subsequent processing. Control is passed.

At this time, an area for storing the logical record length, physical record length, record number (pointer), maximum record number, channel number, and data in the record is provided from the data reception processing unit 2 and data processing unit 3 to Ll-L5. ．． Dl, and stores this in the state storage area 81 and data storage area 82 in the common processing unit 8.

The arithmetic processing area 83 then executes the processing shown in FIG. That is, the number S of logical records to be skipped is determined from Ll (logical record length) and L2 (physical record length) as the integer part of S' = (L2/Ll) + 1, and this number S of logical records to be skipped and the record number (pointer )
Accordingly, the dummy read pointer R (=S+L3) is obtained and compared with the maximum record number L4. If the condition of R≧L4 is not satisfied, R=L3-3 is set.

Using the dummy read pointer R obtained in this way, data is stored in the buffer memory section 4 from the data file of channel number L5 and read/read via the data processing section 3.
Instructs the light control device 5.

As a result, the data length stored in the buffer memory unit 4 becomes equal to or greater than the length of two physical records, and the update data is written to the file device 6, and the process then moves on to the next process.

The above series of processing is shown in FIG. That is, when processing l physical record length in the data reception processing unit 2, when the data read from the file device 6 is received and formatted, the 4th
The flow moves to the data destruction prevention process shown in the figure.

Then, when the flow of data destruction prevention processing shown in FIG. It is retained in the memory section 4.

Next, in the process of the data processing section 3, the number of unprocessed cases of the processing of the data reception processing section 2 is constantly monitored, and when the number of unprocessed cases≠0, the flow similarly shifts to the data destruction prevention process.

Similarly, when the flow of the data destruction prevention process is completed, the process returns to the original process, reads the data written to the file device 6, processes it, and after the process is completed, sets the number of unprocessed items to -1 and returns to subroutine A1 (1). Notice.

In this way, when data of one physical record length is stored in the buffer memory section 4, subroutine Bl (2) is started and the data stored in the buffer memory section 4 is transferred to the data via subroutine Al (1). It is sent to the reception processing section 2, starts the read/write control section 5, and sends it to the file device 6.
Rewrite the data to the same location.

As mentioned above, when the record length stored in the buffer memory section 4 is one physical record length, the next data is stored as a dummy record in the Batza memory section 4, and only when the length becomes two physical record length or more. , the updated record is written to the file device 6, and the data in the file device 6 is also guaranteed as updated data.

〔Effect of the invention〕

According to the present invention as described above, it is possible to realize a data destruction prevention method that can perform read/write and processing processing without data loss or destruction in large-capacity data processing.

[Brief explanation of the drawing]

FIG. 1 is a diagram explaining the present invention in detail. FIG. 2 is a diagram explaining the present invention in detail. FIG. 3 is a diagram explaining the data processing situation of the embodiment of the present invention. FIG. 4 is a diagram explaining the present invention. Figure 5 is a diagram explaining a conventional example, Figure 6 is a diagram explaining the configuration of data processing, and Figure 7 is a diagram explaining the data storage situation in a file. Figure 8 is a diagram explaining the relationship between physical records and logical records. In the figure, 1.10 is the processor, 1(1) is the subroutine A
, 1 (2) is subroutine B, 2 is data reception processing section,
2 (IL2(2), 20(1), 20(2) are channels, 3 is a data processing unit, 4 is a buffer memory unit,
5 is a read/write control device, 6 is a file device, 7 is a common routine, 8 is a common processing section, 81 is a state storage area, 82 is a data storage area, and 83 is an arithmetic processing area. Figure 1 Detailed explanation of the present invention Figure 2 Figure 5 (B)

Claims (1)

[Scope of Claims] A file device (6) that stores data in units of physical records including at least one logical record, and receives and processes data read from the file device (6) in parallel. In a data processing system having a plurality of subroutines for processing, data read from the file device (6) is transferred to a buffer memory based on instructions from subroutine A, which incorporates a series of procedures for data reception processing. When data processing is performed based on the instructions of subroutine B, which includes a series of procedures for processing the data stored in the buffer memory section, the processing is performed based on the instructions of subroutine B. a common routine (7) that receives instructions from the subroutine A and subroutine B and instructs a series of subsequent procedures when the data to be stored in the buffer memory section has a length of one physical record; A state including the logical record length, physical record length, and maximum number of records of data to be stored in the buffer memory section in order to read multiple records belonging to other physical records from the file device (6) based on instructions from a state storage area (81) for storing information;
Data storage area (82) for storing data in records
, the state storage area (81) and the data storage area (82).
) for calculating the number of logical records to be added to the buffer memory section, and a common processing section (8) having an arithmetic processing area (83) for calculating the number of logical records to be added to the buffer memory section, and for performing predetermined processing in the data processing. When the data in the buffer memory is one physical record length,
Based on the instructions of the common routine (7), the common processing unit (8) calculates and reads the insufficient record length from the file device (6) due to the length of two or more physical records, and reads the record length from the file device (6). A data destruction prevention method characterized by additional storage.