JPS61151755A - File revision system - Google Patents

Abstract

PURPOSE:To avoid dead lock generation by means of application software by arranging a file updating request from plural program in the order of first-in first-out, taking over the control to an updating-exclusive program in the order of arrangement to update the file. CONSTITUTION:Programs A, B output an updating request and updating data to plural common files 20 to a first-in first-out (FIFO) buffer 30. The buffer 30 transmits the updating request and updating data inputted according to the FIFO to a total file updating program 40. The program 40 extracts sequentially the updating request and updating data, updates the relating file in files 1, 2-n according to the command content and when the updating is finished, other file is updated until the content of the buffer 30 is lost. When the buffer 30 is idle, the updating program 40 is brought into the stand-by state. Thus, the competition of the programs A, B to the file 20 is avoided.

Description

DETAILED DESCRIPTION OF THE INVENTION Technical Field of the Invention The present invention relates to a file update method related to an application software system in which data is simultaneously read and updated from a plurality of terminal devices to a common file.

[Technical Background of the Invention] Conventionally, in application software systems that read or update data from multiple terminal devices at the same time, timing conflicts occur between the terminal devices when updating the same name. It has been designed with this in mind.

FIG. 2 is a block diagram showing an example of a conventional application software system of this type. Program A uses the data input from the terminal device 10A to create files 1.2 and 1.2.
. . . The contents of n are displayed on the screen of the terminal device 10A and updated again. Program B operates independently of program A, and displays or updates the contents of files 1, 2°, . . . , n on the screen of terminal device iOB based on data input from terminal device 10B. In such a system, multiple programs do not access the same file at the same time, and therefore control is performed so that only either program A or program B can access the same file. ing.

[Problems with weight technology] In the above system, program A now accesses file 1, program B accesses file 2,
Then, without letting go of this file 2, file 1.
Suppose you are trying to access . At the same time, if program A attempts to access file 2 without releasing file 1, program A will be unable to access file 2, program B will be unable to access file 1, and both programs will be unable to access the intended file. This has the drawback of causing a so-called deadlock situation in which access becomes inaccessible and the system stops working.

[Object of the Invention] In view of the above drawbacks, an object of the present invention is to provide a file update method that does not cause a deadlock state in application software.

[Summary of the Invention] The present invention provides, in a system in which a plurality of programs access a common file, a file update request organizing means that receives and organizes the file update requests from each program in a first-in, first-out order; By applying a file update method comprising a partial file update program that extracts the file update requests in the order organized by the file update request organizing means and updates the files sequentially, the above purpose is achieved. It is something to be achieved.

[Embodiment of the Invention] An embodiment of the present invention will be described below with reference to the drawings, using the same reference numerals for the same parts as in the conventional example. FIG. 1 is a block diagram showing an embodiment of an application software system to which the file update method of the present invention is applied. Program A, B
performs only reading from the common files 20 (in the figure, they are written as two separate files for convenience, but in reality they are multiple common files), and sends the read data to the respective terminal devices 10A and 10B. Perform processing such as display. Programs A and B are FIFO (first in, first out)
The FIFO buffer 30 outputs update requests and update data for the above-mentioned files (this data is input from the terminal device 10A and IOB) to the buffer 30. The request and update data are partially sent to the file update program 40.

Batch file update program 40 is FIFO buffer 3
Sequentially extracts update requests and update data from 0, updates related files in files 1, 2--n according to the instruction contents, and when the series of file updates is completed,
Other files are updated until the FIFO buffer 30 is empty. When the contents of the FIFO buffer 30 become empty, the batch file update program 40 becomes held. Although the files 1, 2, . . . n are part of the files 20 described above, they are shown separately in the figure for convenience.

In this embodiment, programs A and B are stored in FIFO buffer 3.
If you output the update request and update data to 0, the rest is FIF
Since the O buffer 30 organizes updates in the order of first input and first output, and then control is passed to the partial file update program 30 dedicated to file updates to update files in an orderly manner, the program A , B with respect to the file 20 is avoided, so-called deadlock conditions are eliminated, and the system can always operate smoothly.

[Effect of the invention] As described above, according to the file update method of the present invention,
After organizing file update requests from multiple programs in first-in, first-out order, update them in this organized order! By passing control to a specific program to update files, it is possible to avoid a put-lock state in the application software system, and to keep the system running smoothly at all times.

[Brief explanation of drawings]

Figure 1 is a block diagram showing an embodiment of an application software system to which the file update method of the present invention is applied;
The figure is a block diagram showing an example of a conventional application software system. 10A, IOB...Terminal device 20...File 30...FIFO buffer 7 40...Batch file history new program A, B...Program

Claims (1)

[Claims] In a system in which a plurality of programs access a common file, a file update request organizing means receives and organizes the file update requests from each program in a first-in, first-out order, and an order in which the file update requests are arranged by the file update request organizing means. A file update method comprising: a batch file update program that extracts the file update requests at a time and sequentially updates the files.