JPS63211032A - Shared resource control system - Google Patents

Abstract

PURPOSE:To finely protect shared resources by permitting the access when information included in a descriptor generated by the request of resource reservation is matched to the key and the identification number of the access request. CONSTITUTION:When resource reservation is requested from a process, intra- resource block position discrimination information and related information are taken out from an idle resource chain 2 where shared resources are divided into blocks and the registered, and an identification number is added to generate an access descriptor 16, and this descriptor 16 is registered in the table 17, and it is released by a release request. When the access to a shared resource is requested from the process with intra-resource block position discrimination information and specific related information as the key, the access descriptor 16 is searched in the table 17, and the access is permitted when information included in the descriptor 16 is matched to specific related information and the identification number of the request from the process.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention is applied in the field of information processing technology to securing and releasing common resources shared by multiple processes in response to requests from individual processes. The present invention also relates to a common resource control method that enables access to reserved resources.

Here, a process is a job also called a task, and a common resource refers to programs and data on memory and files that are commonly secured, released, referenced, and updated by multiple processes.

In other words, in a common resource accessed by multiple processes, the present invention limits the access range and access method, and allows access only to processes that have been given access rights in advance.
It relates to technology for fine-grained protection of common resources on a process-by-process basis, ranging from fields that do not require real-time performance to fields such as exchange processing that requires real-time multiprocessing, and control of various industrial processes. This invention relates to a common resource control method suitable for protecting common resources in a wide range of technical fields.

[Conventional technology]

Conventionally, resources are divided into areas called segments, and a segment descriptor (SD
) is created and registered in a table (this is called the segment descriptor table SDT), and a segment number (SGN) indicating the registration position on the table (SDT) is created.
) and the intra-segment offset as keys, the segment number (SG
N) to the corresponding segment descriptor (SD)
, the size in the segment descriptor (SD) is larger than the offset, and the access method of the execution instruction that requested access is the segment descriptor (SD).
A segment method is known in which resources are protected by permitting access only when the access method matches the access method in the SD.

In this segment method, for each individual area, a segment descriptor table (SDT) is created for each process.
By providing a Segment Descriptor Table (SDT), illegal access from other processes to which access is not permitted is prohibited, and for common areas, one common Segment Descriptor Table (SDT) is provided that allows access from all processes. There is.

[Problem that the invention seeks to solve]

Therefore, in order to restrict access to the common area for each process, it is necessary to set up a separate management table and check this table every time the common area is accessed to see if there is an access right. occurs. Also, when securing or releasing resources for a specific process, processing for rewriting the management table is required. Although it is necessary to implement such processing using software, this results in a decrease in processing speed, making it difficult to apply the conventional segmentation method to an environment where real-time performance is strict.

An object of the present invention is to provide a common resource control method that enables fine-grained protection of common resources on a process-by-process basis, does not cause a decrease in processing speed, and is applicable even to environments with severe real-time performance. It's about doing.

[Means for solving problems]

To achieve the above object, the present invention provides a common resource control method that secures and releases common resources shared by multiple processes in response to requests from individual processes, or allows access to the secured resources. , the common resource is divided into blocks that serve as units for securing, releasing, or accessing the common resource, and the block position identification information and related information within the resource for each block are classified and registered with a predetermined order of retrieval. the access descriptor table; and means for checking whether there is a match between the information contained in the descriptor searched from the table and the information serving as the key of the access request.

[Effect]

In a common resource control method that secures, releases, or allows access to a common resource shared by multiple processes in response to a request from an individual process, the common resource is secured, released, or accessed. Divide into blocks, which serve as units for access, and classify the block position identification information and related information within the resource for each block, assign a predetermined order of retrieval, and register in the registration means, so that resources can be secured from the process. When there is a request, extract block position identification information and related information in the resource of one block from the registration means according to a predetermined order of extraction,
An access descriptor as a series of information is created by assigning the identification number of the process that made the request to secure the resource, and it is registered in a table. The access descriptor containing the identification number is searched for in the table and released by deleting it from the table, and a process requests access to a common resource using the block position identification information within the resource of a specific block and specific related information as keys. In this case, an access descriptor including the resource block position identification information is searched from the table, and when the information included in the descriptor matches the specific related information and the identification number of the process that made the access request, access is granted. I'll do what I do.

〔Example〕

Next, an embodiment of the present invention will be described with reference to the drawings.

FIG. 1 is an explanatory diagram showing an allocation method in which common resources are divided into pools and blocks, and each block is registered and sequentially allocated to a process that requests it, in an embodiment of the present invention. It is.

FIG. 2 is an explanatory diagram of the securing operation when a common resource is allocated and secured to a process using a block when a request is received from a process in an embodiment of the present invention.

FIG. 3 is an explanatory diagram showing an access method when accessing a common resource secured by a block in an embodiment of the present invention.

First, with reference to FIG. 1, an allocation method will be described in which common resources are divided into pools and blocks, each block is registered, and each block is sequentially allocated to a process that requests it.

In FIG. 1, 1 is a common resource to be protected, and in this case, common resource 1 is Boolean 15 and Boolean 1 for each resource type.
It is divided into 5′. Letting Boolean 15 be Boolean 1, the area of Boolean 1 is from address 1000 to address 1999, and this area is further divided into a certain plurality of blocks 14 from blocks 1 to 10. In this example, block 1 is 1
From address 000 to address 1099, block 2 from address 1100 to address 1199, and so on, block 10:
Addresses 1900 to 1999 are assigned.

In other words, the block size of each block is 100, meaning that it can accommodate 100 addresses. This block becomes a unit when securing or releasing common resources. Letting Boolean 15' be Boolean 2, this also has a similar configuration.

2 is called a free resource chain for Boolean 1, and its contents include a ladder 3 and a plurality of block headers 4 (4a, 4b) to the free resource chain.

"4c). A plurality of block ladders 4 are provided so as to correspond to each block in the Boolean 15 in the common resource 1.

In the free resource chain header 3, common information within the Boolean 15 is registered as resource management information, and in each block header 4, different information for each block is registered,
This avoids duplicate registration of the same information in each block. In the free resource chain header 3, 5 is a head pointer that points to the first block ladder 4a, and the next pointer 11 of the block ladder 4a further points to the next block ladder 4b, and so on. A chain is constructed.

In order to be able to recognize which block header is the last block header (4c in this case), 6 in free resource chain header 3 is used as the final pointer to identify the last block header 4C.
is pointing to. The number of blocks constituting the chain is managed by a registration counter 7 in the free resource chain header 3. In addition to these, the free resource chain header 3 also registers the block size of each block as 8, the access method as 9, and the Boolean identification name as 10.

In each block header 4, in addition to the pointer 11, a block identification name 12 and a block base pointer 13 are registered.

To summarize the above, in Lada 3 to the free resource chain, 1
Pool identification name 1 indicates that 0 is Boolean 1, and R indicates that the access method is read or write in 9.
/W is registered, 8 is registered with 100 representing the block size, and 7 is registered with the total number of blocks, 10. In addition, each block header 4 (for example, 4a) has a block identification name (block number) 01 as 12, and 1000 representing a block base pointer (address 1000) as 13.
Each is registered.

When requested by a process, block headers 4a, 4b
, . . . The corresponding blocks in the chain order of 4C are block l, block 2 . . . . They are allocated in order like block lO.

Next, with reference to FIG. 2, the securing operation when a certain process requests to secure a common resource will be described.

As already explained, the common resources are divided into pools and blocks and registered in the free resource chain 2, so we extract various information about the block to be secured from the chain 2, and use the information about the block to be secured. By creating an access descriptor as a series of information from the process identification name and registering it in the table, the reservation is completed.

See Figure 2. The case where common resources are secured from Boolean 1 will be explained. f1 pool identification name register 36
After setting the name of the current execution process (name of the process requesting reservation) to the execution process register 18 and making a request to secure the common resource by a method not shown, the pool identification name 10 will be changed to “Find a 1° free resource chain 2, extract one block (48 in this case) from the beginning of the chain, and create an access descriptor 16 as a series of information using the registration information related to the block.

That is, this access descriptor 16 is the name of the currently executing process stored in the register 18.
' in position 20, and '1° registered in 10 of ladder 3 to the free resource chain as the pool identification name in position 21.
'01' registered in 12 of the block header 4a as the block identifier is placed in position 22, i o o o' registered in 13 of the block header 4a as the block base pointer is placed in position 23, and the free block size is set as the block size. "10" registered in resource chain header 3-8
0" in position 24, and °R/W' registered in free resource chain header 3-9 as the access method in position 25.
It is created by copying each.

This created access descriptor 16 is registered in the access descriptor table 17.

At the same time, in order to delete 7da4 (4a in this case) from the block where "01' is registered in the block identifier 12 as it has already been allocated, change the value of the start pointer 5 in the free resource chain header 3. , change the block identifier 12 so that it points to the block header 4 of 02° next, and also decrease the registration value °10° of the registration counter 7 by 1 to 9", and at the same time, change the value of the secured process side. The registered numerical value of a certain resource identification name 26 from the pool identification name 21 and block identification name 22 is stored in the resource identification name register 19.
101' and cents.

This completes the securing operation.

Next, a method for accessing the secured common resource will be explained with reference to FIG.

In FIG. 3, the access descriptor table 17 is searched using the current execution process name '5' stored in the execution process register 18 and '101° set in the resource identification name register 19 as keys. Header, base pointer 23 from column a to the corresponding block
Obtain the value "1000" and set this pointer value "1000" to the value "20" set in the offset register 27.
By adding them in the adder 29, the actual access pointer "1020'" is obtained in the register 32.

If the corresponding pointer does not exist during this search, access becomes impossible. Also, at the same time as the actual pointer is determined, the offset register 27 (direct ``20'' and block size position 2
The access range is checked using the value ``100'' of 4, and the access method is checked using the instruction ``JP'' set in the instruction register 28 and R/W' at the access method position 25.

The access range is checked using the value of the offset register 27.
This is performed based on whether 20° is smaller than the value 100° of the size position 24, and if it is smaller, access is permitted. To check the access method, if the access method 35 obtained by searching the instruction access method correspondence table 33 from JP' of the instruction register 28 is "EXEC", this and "R/W" at the access method position 25 are checked. This is done by comparing whether or not they match, but in the current case, they do not match, so access is prohibited.

Next, the operation when transferring the access rights held by a certain process to another process is shown in FIG. The case of transferring to a process with process identification name "3°" will be explained as an example.

In this case, the corresponding access descriptor (Table 1
After changing the process identification name 20 in column a of Table 17 from the process identification name "5°" currently being executed to the process identification name "3" to be transferred, the process identification name 20 is registered in column C of the same table 17. As a result, the resource identifier "101" becomes accessible while the process with the process identifier "3°" is being executed. This operation
This is possible only for access descriptors in which the process identification name 20 is equal to the execution process name 18.

To release a resource whose resource identifier 19 is "101',""101" is deleted from all the corresponding access descriptors aa and C in the access descriptor table 17 in FIG. 3, and the pool identifier 21 of the corresponding access descriptor is is "1", select the pool whose pool identification name 1'0 in the free resource chain header 3 in Figure 1 is "1", and insert the block header of the corresponding resource into the access descriptor at the end of the free chain. Block identification name 22 in Table 17) Generate and add from the block base pointer 23, and rewrite the next pointer 11 in the previous final block header 4 to a pointer to the block header, and add the ladder 3 to the free resource chain.
The final pointer 6 inside is also rewritten at the same time. At this time again,
Increase the value of registration counter 7 by 1.

〔Effect of the invention〕

As explained above, according to the present invention, illegal access to common resources from a process that does not have access rights to common resources, illegal modification of access rights, access outside the range of common resources to be accessed, Access by unauthorized access methods can be prevented, fine-grained control regarding access to common resources can be realized, and reliability during software execution can be improved.

Further, the above control can be realized without requiring any software procedure, and can be realized without significantly impairing the execution speed. It is particularly effective to apply associative memory to access descriptor tables.

In the embodiment described, common resources are managed using a free chain method for each pool, but other methods can also be used. Furthermore, although one access descriptor table is used and accessible process names are registered in the access descriptor table, it is also possible to separate access descriptor tables for each accessible process.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram showing an allocation method in which common resources are divided into pools and blocks, and each block is registered and sequentially allocated to a process that requests it, in an embodiment of the present invention. , FIG. 2 is an explanatory diagram of the securing operation when a common resource is allocated and secured by a block to a process in response to a request from a process in the first embodiment of the present invention, and FIG. , an explanatory diagram showing an access method when accessing a common resource secured by a block in an embodiment of the present invention;
It is. Explanation of symbols

Claims (1)

[Scope of Claims] 1) A common resource control method that secures and releases common resources shared by a plurality of processes in response to requests from individual processes, or enables access to the secured resources, comprising: Divide the common resource into blocks that serve as units for securing, releasing, or accessing the common resource, and registering in-resource block position identification information and related information for each block in the registration means with a predetermined order of retrieval for each block. When there is a request to secure a resource from the process, extract block position identification information within the resource and related information of one block according to a predetermined extraction order from the registration means,
An access descriptor as a series of information is created by assigning the identification number of the process that made the request to secure the resource, and it is registered in a table. a step of searching for an access descriptor including an identification number in the table and releasing it by deleting it from the table; and a process requesting access to the common resource using the block position identification information in the resource of the specific block and the specific related information as keys. If there is an access descriptor that includes the block position identification information within the resource, the access descriptor is searched from the table, and when the information included in the descriptor matches the specific related information and the identification number of the process that made the access request, the access descriptor is A common resource control method comprising: an access permission step for permitting; 2) In the common resource control method described in claim 1, when a process that has an access right to a certain common resource transfers that access right to another process (or when the access method is changed) , a common resource control method characterized in that the descriptor is copied (or the descriptor is changed) for a process to be transferred.