JPH0567057A - Exclusive file control system - Google Patents

Abstract

PURPOSE:To operate a file sharing for a file having an occasion of an updating by operating an exclusive control so as not to simultaneously operate the update from two central processing units for a file in a shared external storage device. CONSTITUTION:An update request 31 for a file 11 is outputted from an application software 4 of a central processing unit 1 of a main system to a logic input and output control software 6. The control software 6 delivers the update request 31 to an exclusive control software 8 by a processing 32. The exclusive control software 8 checks whether or not a central processing unit 2 of a conventional system uses the file 11 by a processing 33, and when the file 11 is not used by the central processing unit 2, it is communicated by a processing 34. The exclusive control software 8 operates the actual update 35 for the file 11, and stores the update history in an update history storage part 12 by a processing 36. When an update request 37 is outputted from an application software 5 of the conventional system to the same file 11, the information that the file 11 is not used is communicated by a processing 30 in the same way.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an information processing system in which a central processing unit is duplicated so as not to cause a contradiction in updating a file in an external storage device shared by both central processing units. Regarding exclusive control method of file.

[0002]

2. Description of the Related Art As conventional file exclusion control, a plurality of programs make update requests to the same file in an information processing system with one central processing unit.

In FIG. 3, the exclusive control software 1 responds to a file update request 108 from the program 102.
04 refers to the exclusive control information section 105, and as a result, if the requested file 107 is not in use, the actual update 1
11 is performed on the file 107 of the external storage device unit 106.

At this point, when the program 103 issues an update request 112 to the same file 107, the exclusive control software 104 refers to the exclusive control information section 105, and as a result, the program 102 has already made a request. Since the file 107 is in use, the update request is waited for and the execution of the program 103 is suspended. Alternatively, for the program 103, another program 10
In step 2, the fact that the file 107 is already in use is notified.

Further, in a dual system or a duplex system in which the central processing unit is duplicated, only an input request without updating is possible so that no contradiction occurs due to simultaneous updating of files from both systems.

[0006]

The above-mentioned conventional exclusive control is based on the simplex system and cannot be used in a dual system or a duplex system in which the central processing unit is duplicated.

Further, in the conventional dual system or duplex system, the files in the external storage device shared by the two central processing units can be updated simultaneously because only those input requests that do not involve updating can be performed. The files accompanied by must be held individually for each central processing unit.

[0008]

According to the file exclusion control method of the present invention, a communication path for performing mutual communication between central processing units, application software operating in each central processing unit, and each of the above The logical input / output control software operating in the central processing unit, the exclusive control software operating in the central processing unit of the main system (master), the exclusive control information section managed by the exclusive control software, and the two units It has an external storage device shared between the central processing units, a file existing in the storage device, and an update history storage unit of the file existing in the external storage device.

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of a file exclusive control system of the present invention. The information processing system has two central processing units 1 and 2 which form a duplex system, and comprises a central processing unit 1 of a main system (master) and a central processing unit 2 of a slave system (slave). A communication path 3 for exchanging data between the devices 1 and 2, application software 4 and 5 operating on the central processing units 1 and 2, and logical input / output control operating on the central processing units 1 and 2. Software 6 and 7, and exclusive control software 8 that operates in the central processing unit 1 of the main system
And an exclusive control information section 9 existing in the central device 1 of the main system,
External storage device 1 shared between two central processing units 1 and 2
0, and a file 11 existing in the external storage device 10,
It is composed of an update history storage unit 12 existing in the external storage device 10.

FIG. 2 is a diagram showing the concept of the operation of the present invention. The master application software 4 issues an update request 31 for the file 11 to the logical input / output control software 6. The logical input / output control software passes the update request 31 to the exclusive control software 8 by 32. The exclusive control software 8 checks by 33 whether or not the file 11 is being used by the subordinate central processing unit 2, and if it is not being used, then 34
Notify by. The exclusive control software 8 that has received the unused notification of the file 11 performs the actual update 35 on the file 11 and stores the update history in the update history storage unit 12 by 36. Next, when an update request 37 is issued from the slave application software 4 to the same file 11, the slave logical I / O control software 7 that has received the request sends the update request 37 to the communication path 3
The update request is transferred to the exclusive control software 8 of the main system via 38 via. Exclusive control software 8 is 39
Checks whether the file 11 is being used by the central processing unit 1 of the main system, and if it is being used, 30 is notified to that effect. At this point, the update request from the slave system waits or notifies the logical input / output control software 7 of the slave system via the communication path 3 that the update request is in use.

When the order of update requests from the master system and the slave system is reversed, the update request of the master system is kept waiting.

When a failure occurs in the central processing unit 1 of the main system and the central processing unit 2 cannot function as the main system, the central processing unit 2 which has been the sub system until then functions as the main system. The control software 8 and the exclusive control information section 9 are also transferred to the central processing unit 2 which has been a slave. Further, the contents of the shared file at the time of failure occurrence are restored to the latest state by the information in the update history storage unit 12.

The exclusive control of the present invention works only when updating a shared file, and does not work for reference requests that do not involve updating. That is, the two central processing units 1 and 2 can simultaneously refer to each other.

[0015]

As described above, according to the present invention, in the dual system / duplex system in which the central processing units are duplicated, the files in the shared external storage device can be simultaneously updated from the two central processing units. By performing exclusive control so as not to be performed, it becomes possible to share a file with an update.

As a result, efficient data sharing in the duplex system and data takeover at the time of failure can be easily performed.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing an embodiment of a file exclusive control system of the present invention.

FIG. 2 is a diagram showing the concept of the operation of the present embodiment.

FIG. 3 is a diagram showing a concept of conventional exclusive control operation.

[Explanation of symbols]

 1 central processing unit 2 slave central processing unit 3 communication path between central processing units 4 master application software 5 slave application software 6 master logical I / O control software 7 slave logical input / output Control software 8 Exclusive control software 9 Exclusive control information section 10 External storage device 11 File 12 Update history storage section

Claims (1)

[Claims] 1. In a system having dual central processing units, a communication path for performing mutual communication between the central processing units, application software operating in each of the central processing units, and in each of the central processing units. Between the two central processing units, the logical input / output control software operating in the main processing unit, the exclusive control software operating in the central processing unit of the main system (master), the exclusive control information unit managed by the exclusive control software, An exclusive control system for a file, comprising: an external storage device shared by a storage device, a file existing in the storage device, and an update history storage unit for the file existing in the external storage device.