JPS60110053A - File controller - Google Patents

Abstract

PURPOSE:To attain an exclusive control while confirming that a deadlock state is never produced by providing a deadlock state detecting means to a file controller which gives an exclusive control to a shared file group for each block. CONSTITUTION:Data processors 1-1-1-n deliver a lock block command to a file controller 3, then use exclusively the blocks of shared files within file devices 2-1-2-m. Then the processors deliver an unlock block command immediately before said exclusive use of the blocks and ends this exclusive use. A processing control circuit 3-3 refers to a block using state table 3-4 for exclusive control as well as to a block waiting state table 21 for detection of deadlock to detect a deadlock state. This prevents completely a fact that plural tasks are set under a block waiting state respectively and the exclusive control has no end forever.

Description

DETAILED DESCRIPTION OF THE INVENTION (1) Technical field to which the invention pertains The invention relates to a file control processing device applied to a multiple data processing system in which a plurality of data processing devices share a file device.

(2) Prior Art Conventionally, in this type of multiple data processing system, the patent application No. 57-191783 1-File Control Processing Device"
As seen in Figure 2, although there is a function to perform block-by-block exclusive control of a group of shared files using commands issued by individual tasks running on multiple data processing devices, deadlock conditions occur during exclusive control. However, it is impossible to detect it. Therefore, there is a drawback that there is a possibility that the firing of exclusive control will not be completed no matter how long a plurality of tasks wait.

(3) Purpose of the Invention The purpose of the invention is to eliminate the drawbacks of the prior art described above, and to ensure that files are shared between multiple tasks on multiple data processing devices in block units while ensuring that deadlock does not occur. An object of the present invention is to provide a file control processing device that can perform exclusive control of files.

(4) Structure of the Invention The file control processing device according to the invention includes a plurality of cheaters that are composed of a plurality of data processing devices and at least one file device containing a file group that is shared by the plurality of data processing devices. In a file control processing device in a processing system, receiving means for receiving commands issued from individual tasks running on the plurality of data processing devices.

a storage means for storing the issuer of the command; a processing control means for analyzing the command and controlling processing based on the command; a management means for managing each block constituting a file, a transmission means for transmitting the processing result of the command to the issuer of the command, and a detection means for detecting the occurrence of a ted l work state between a plurality of tasks. The feature is that by providing this, exclusive control is performed on a block-by-block basis for shared files while making sure that a locked state does not occur.

(6) Embodiment of the invention Next, let's discuss an embodiment of the invention with reference to the drawings.
This will be explained in III.

Referring to FIG. 1, one embodiment of the non-invention is
-191783 r It is basically the same as the overall configuration diagram of the file control processing device. That is, - the example is n
data processing devices l-1 to l-n, m file devices 2-1 to 2-m, shared files 21 and 22. One block 211 and 22 each in the shared file
1 degree and a file system 1 (1 processing device 3).

Referring to FIG. 2, the file control processing device 3 includes a human output control circuit 3-11 a human output control memory 3-2. Processing control a41 times wr3-3. Block usage status table for exclusive control 3-4. and block waiting state tables 3 to 5 for detecting block lock. Note that each file device includes a plurality of shared files, and each of these shared files is composed of a plurality of blocks. In this system, if a task wants to exclusively use a block in a shared file, it sends a lock block (LOCK ELPCK) command to the file control processing unit to request exclusive use before starting use. It is necessary to issue. When the exclusive use of that block is to be terminated, an unlock block (UNLOCKBLOCK) command indicating the termination of 4J and other use is to be issued to the file control processing device immediately before the use is terminated. .

In such a multiple data processing system, a certain task (hereinafter referred to as Tl) on the data processing device ]-2 processes the block 21 of the shared file 21 in the file device 2-2.
In the case of exclusive use of 1, the overall operation will be explained with reference to the money side. For example, in order for the task Tl on the data processing device 1-2 to update each of the blocks 211,
This corresponds to a case where it is necessary to use block 211 exclusively. First, a lock pro command is issued from the data processing device ]-2 to the file control processing device 3. In this directive.

Identifier of data processing device 1-2 that issued the command.

The identifier of the issuing task T1, the identifier of the shared file 21 to be used exclusively, and the block 2 in the file
Control information such as 11 identifiers are included.

The lock block command issued from the data processing device 1-2 is first processed by the file control processing device 30 output control circuit 3-.
1 will be missed. This input/output control circuit 3-1 issues a lock block command, and after recording both the identifiers of the data processing table 1-2 and the task T1 in the human output control memory 3-2, the processing control circuit 3-1 Transfer the lock block command and control information to 3. When the processing control circuits 3-3f receive all of this information, they analyze the command control information. The result is shared file 21 block 2 in file
When it is determined that the exclusive 1 change fee is for 11, the processing control circuit 3-3 enters the following processing for exclusive control and ted lock detection based on the above analysis result.

The process 1till side 1 circuit 3-3 first looks at the block usage state table 3-4 for exclusive control,
This has the configuration shown in Figure 3. Here, B
i (i=l, 2...) is an identifier that uniquely represents a block within the multiple data processing system, and Tj (j=
x, 2. Similarly, =-> is an identifier that uniquely represents a task within the multiple data processing system. The block usage status table 3-4 shows the usage status Tp)Ak of all blocks existing in the system, and if a task identifier is displayed in the corresponding block column, that block is exclusively used by the task represented by that identifier. Indicates that the If nothing is written, it indicates that the block is not exclusively used by any task. In the above example, the task T1 wants to use block 211 (B211) exclusively, but when the processing control circuit 3-3 refers to the block usage state table 3-4 for exclusive control, as shown in FIG. In the column 8211, T2 is written. If nothing is directed, block 211 by task T1
However, in this case, this is not the case.
In other words, this lock block command is used exclusively by task T2 or task T2.
When the exclusive use of block 211 by block 211 ends in step 1, the block 2110 is in this state waiting for unlocking (block wait).

However, block 211 due to task T
If you don't make sure that waiting for a block does not result in a deadlock state, there is a possibility that a deadlock will occur and the VC will end up in a professional or tsuku waiting state. Therefore, the processing control circuit 3-3 needs to also refer to the block waiting state table 3-5 that manages the block waiting state of the valley task and perform lrk i+gτ for this purpose. The block waiting status 16-table, as shown in FIG. 4, shows the block waiting status of valley tasks in the system.

If the task is waiting, the block's identifier will be sworn, so F:J, it will be blank. In the above case, task T! I would like to write the identifier 3211 of block 211 in the column 211, but when I return to FIG. 3 and look at the column 211, I see that block 211 is being used exclusively by task T2. Next, when looking at S of tie ``1'' and ``2'' in FIG. 4, task IP2 is in a state of waiting for all of block 2 (not running on the data processing device).

Furthermore, looking at the column for block 2 in FIG. 3, block 2 is being used by task T5 for exclusive 1 change. and,
Looking at the column for task T5 in FIG. 4, task T5 is waiting for block 221. Furthermore, looking at the column of block 221 in FIG. 3, the original task T1 is in exclusive use.

That is, as shown in FIG. 5, if task T1 decides to wait for block 211, task '1. 'l,
T2. It is known that Ta has a mutually beneficial relationship, that is, a tedlock situation. If the relationship of mutual waiting τ is 11d as described above, the third
In the case where 9 Kiri j occurs in the diagram or in Figure 4, the mutual waiting relationship shown in Figure 5 does not become a closed loop. In other words, there is no need to fall into a deadlock state.

As described above, the processing control circuit 3-3 can check whether a deadlock condition will occur when a block wait occurs due to a task. According to the present invention, when a deadlock occurs as described above, the processing control circuit 3-3 does not allow the original task to wait for a block, but instead executes the original lock block command by the sled task. It is determined that the task T on the data processing device l-2 is
Notify 1. On the other hand, if a deadlock does not occur, the original task is allowed to wait for the block, and the original lock block command is sent to the input/output control circuit 3-1 to indicate that the task is waiting. Then, the task T1 on the data processing device 1-2 is notified. -f. When the processing control circuit U-3 first consults the block usage status table purple in Figure 3, if block 211 (13211)
If the field is blank, the request for exclusive use of the block 211 by the task Tl is accepted, and this fact is sent to the task T on the data processing device 1-2 through the input/output control circuit 3-1.

A lock block command issued from a task on a data processing device to a block within a shared file is naturally notified. The operation of the file control processing device 3 in the case of an unlock block command for completely terminating the exclusive use of blocks in a shared file is basically the same as in the case of the above-mentioned Japanese Patent Application No. 1917-83 ``File Control Processing Device''. Therefore, the complete explanation will be omitted here.

(7) Effects of the Invention The non-inventive feature is the addition of means for detecting the occurrence of a tedlock state regarding exclusive use of a block between multiple tasks to the configuration of the "R File Control Processing Device" disclosed in Japanese Patent Application No. 57-191783. This has the effect of completely avoiding the situation where a plurality of tasks are each placed in a block wait state and the exclusive control remains indefinitely without photons.

[Brief explanation of the drawing]

Figure 1 is a diagram showing the configuration of one embodiment of non-invention, Figure 2
The figure shows the specific configuration of the file control processing device in one embodiment of Figure 1, Figure 3 shows the block usage state table for exclusive control, and Figure 4 shows the block wait for deadlock detection. FIG. 5 is a diagram illustrating the mutual waiting relationships among a plurality of tasks. In the figure, 1-1 to 1-n are data processing devices. 2-1 to 2-m are file devices, 3 is a file control processing device, 3-1 is an input/output control circuit, and 3-2 is an input/output control memo! J, 3-3 is a processing control circuit, and 3-4 is a block usage state table for exclusive control. 3-5 is a block wait state table for detecting Tedlock, 21.1! :22 is a shared file% 211 and heart 2
Figure 5 Figure 4 Figure S

Claims (1)

Claims: A file control processing device in a plurality of data processing systems comprising a plurality of data processing devices and at least one file device containing a file group shared by the plurality of data processing devices. receiving means for receiving all commands issued from individual tasks running on the mantissa data processing device; a storage means for storing the issuer of the command; a processing control means for analyzing the command and controlling processing based on the command; and a processing control means for classifying various file identifiers specified by the command, management means for managing each constituent block. Detection means for detecting the occurrence of a deadlock state regarding exclusive use of a block between 6L tasks; and transmission means for transmitting the processing result of the command to a specific task on a specific data processing device that has issued the command. File control is characterized in that it performs exclusive control on a block-by-block basis for a group of shared files while making sure that commands issued by the plurality of data processing devices do not result in a locked state. Processing equipment.