JPH04205039A - Exclusive control on shared files in a plurality of operating systems - Google Patents

Abstract

PURPOSE:To automatically carry out exclusive access control for shared files by providing an exclusive information management table that can be accessed from an access control module contained in a plurality of operating systems with information necessary for exclusive control of shared files. CONSTITUTION:In an exclusive information management table 7, a name of shared file 8, and a number of entries corresponding to the number of shared files 8 consisting of control flags, waiting times for exclusion are registered. The control flag 0 indicates no access, the control flag 1 indicates that information is being input in the table, the control flag 2 indicates that information is being output from the table, and the control flag 3 indicates that information is being updated. When an application program(AP) 3 on an operating system 1 issues a access request to the file 8, a module 5 references a corresponding entry control flag for an external file name on table 7. If the entry control flag indicates 0, it is understood that no access is carried out from AP4 on operating system 2 to file 8. Accordingly, the control flag is changed to 1, 2, or to 3 in accordance with type of access to make operating system 1 execute access from AP3 on operating system 1 to file 8.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a shared file exclusive control method in multiple O3s (operating systems), and in particular, the present invention relates to a shared file exclusive control method in multiple O3s (operating systems), and in particular, a shared file on a disk from multiple OSs installed on the same computer system. The present invention relates to a shared file exclusive control method for multiple OSs that exclusively controls access to a shared file when accessing a shared file.

[Conventional technology]

Conventionally, in shared file access methods for multiple OSs installed on the same computer system, exclusive control of access to shared files has not been performed because the OSs have different access methods for shared files.

[Problem to be solved by the invention]

In the conventional shared file access method for multiple O3s described above, exclusive control of access to shared files was not performed due to differences in the OS access methods for shared files. Since it is necessary to prevent access, and manual intervention is required, there is a drawback that great care is required when executing data update processing by an application program.

In addition, since it requires human intervention, the application program cannot be executed automatically, and update errors and data omissions may occur, which may seriously impede the operation of the application program. be.

In view of the above points, an object of the present invention is to automatically perform exclusive control of access to shared files, enable automatic execution of application programs, and eliminate errors during processing due to operator intervention. The purpose of the present invention is to provide a shared file exclusive control method for multiple OSs.

[Means to solve the problem]

The shared file exclusive control method for multiple OSs of the present invention is applicable to multiple OSs installed on the same computer system.
In the shared file exclusive control method in multiple O3s that exclusively controls access to the shared file when accessing the shared file on the disk from 3. An exclusive information management table that stores information, and an access control module that refers to the exclusive information management table, determines whether access is possible according to the type of access to the shared file, and waits for access if access is not possible. have

[Effect]

In the shared file exclusive control method for multiple OSs of the present invention, an exclusive information management table is commonly accessible from multiple OSes and stores information necessary for exclusive control, and the access control module refers to the exclusive information management table and It is determined whether or not access is possible according to the type of access to, and if access is not possible, it waits for access.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a shared file exclusive control method in multiple OSs according to an embodiment of the present invention. (not shown) installed on the 1081st and 2032nd SI, the application program 3 running on the 10th SI, and the 203rd SI.
Application program 4 running on 2 and
The access control module 5 included in 051 and the 20th
The access control module 6 included in 82 and the 10th S
Exclusive information management table 7 created on a disk that can be accessed in common from I and 2082nd, and also from 1st
081 and 2032, and one or more shared files 8 based on the common logic of application programs 4 and 5 created on a disk that can be accessed in common from 081 and 2032.

Referring to FIG. 2, the exclusive information management table 7 contains external file names (names of shared files 8).

An entry corresponding to the number of shared files 8 is registered, consisting of a control flag and a waiting time for exclusive use. , "2" indicates that output (writing) is in progress, and "3" indicates that updating (reading and writing) is in progress.

Next, the operation of the shared file exclusive control method in the multiple OSs of this embodiment configured as described above will be explained.

When the application program 3 on the 10th sI issues an access request to the shared file 8, the access control module 5 refers to the control flag of the entry of the corresponding external file name in the exclusive information management table 7, and sets it to "O". When this happens, it can be seen that the same shared file 8 is not being accessed from the application program 4 on the 2032nd, so the control flag is set to "l" according to the type of access 1s (input, output, or update).
”, “2” or “3” to allow the application program 3 on the 10th Sl to access the shared file 8.

While the application program 3 on the 1051st is accessing the shared file 8, the application program 3 on the 20th
When an access request to the same shared file 8 is issued from the application program 4 on 82, the access control module 6 refers to the control flag of the entry of the corresponding external file name in the exclusive information management table 7 and sets it to "1". ”, it can be seen that the input is being made as an access to the shared file 8 from the application program 3 on the 10th Sl, so if the access from the application program 4 on the 2082nd is also an input, then the access from the application program 4 on the 2082nd Access to the shared file 8 from the application program 4 is also executed. On the other hand, application program 4 on the 20th S2
If the access from is other than input (i.e. output or update), the access control module 6
Access to the shared file 8 from the above application program 4 is made to wait.

Also, refer to the control flag of the entry of the corresponding external file name in the exclusive information management table 7, and set it to “2” or “
3”, the access control module 6
Since it can be seen that the application program 3 on the sI is accessing and outputting or updating the shared file 8, the access to the shared file 8 from the application program 4 on the 2032nd is made to wait.

When access to the shared file 8 by the application program 3 on the 10th SI ends while the access to the shared file 8 from the application program 4 on the 2082nd SI is made to wait by the access control module 6, the access control module 5: The control flag of the entry of the corresponding external file name in the exclusive information management table 7 is rewritten to "0". Therefore, the access control module 6 that had been waiting to access the shared file 8 refers to the control flag of the entry of the corresponding external file name in the exclusive information management table 7 and
0", and changes the control flag to "2" or "3" depending on the type of access (output or update) that has been kept waiting from the application program 4 on the 2082nd, Access to the shared file 8 from the 2082nd application program 4 is executed.

Note that in the above embodiment, the exclusive information management table 7 is
Although the case has been described in which the exclusive information management table 7 is formed on a disk that is commonly accessible from the 1051st and 2032nd nodes, the exclusive information management table 7 may be formed on a main memory that is commonly accessible from the 1051st and 2032nd nodes.

Further, in the above embodiment, the case where there are two OSs installed on the same computer system, 1031st and 2032nd, was explained as an example, but three or more ○Ss are installed on the same computer system. There may be.

〔Effect of the invention〕

As explained above, the present invention provides exclusive access to shared files by having information necessary for exclusive control of files on an exclusive information management table that can be commonly accessed from access control modules included in the OS. This has the advantage that control can be performed automatically.

Furthermore, since there is no need for human intervention, application programs can be automatically executed, and errors during processing due to operator intervention can be eliminated.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of a coexistence file exclusive control method in multiple OSs according to an embodiment of the present invention, and FIG. 2 is a diagram showing the contents of the exclusive information management table in FIG. 1. In the figure, 1... 1st O3, 2... 2nd O3, 3. 4. Application program, 5.6. Access control module, 7. Exclusive information management table, 8. Shared file.

Claims (1)

[Claims] Multiple OSs installed on the same computer system
In a shared file exclusive control method for multiple OSs that exclusively controls access to a shared file on a disk when accessing a shared file from a disk, information that is commonly accessible from the multiple OSes and necessary for exclusive control is provided. and an access control module that refers to the exclusive information management table, determines whether or not access is possible according to the type of access to the shared file, and waits for access if access is not possible. A shared file exclusive control method for multiple OSs, which is characterized by: