JPH05250286A - Dynamic managing method for address space - Google Patents

Abstract

PURPOSE:To perform retrieval at high speed by reducing memory resources. CONSTITUTION:This method is provided with a high-order address managing table 1 to statically manage addresses with the address of high-order 8 bits by dividing the address space of 16 bits, for example, by half when realizing plural sessions with the address of 16 bits by using one physical communication path between computers, and low-order address managing table 2 to dynamically manage the address space with the address of low-order 8 bits and although the high-order address managing table 1 is composed of a leading address (1) of the low-order address managing table 2 and a flag (F) (2) to display whether the low-order address managing table 2 is valid or invalid, and is made statically existent, the low-order address managing table 2 is composed of an information area address (3) to hold information required for forming the sessions and a header part (4) composed of bits to manage whether the information area address (3) is valid or invalid, and is made dynamically existent corresponding to the formation of the session (connection) with one physical communication path.

Description

Detailed Description of the Invention

[0001]

[Industrial field of use] In recent data communication, a logical connection called a plurality of sessions is made on a single physical line in order to efficiently use the line and improve serviceability. ..

In particular, recently, the number of intelligent terminals on the computer side where the data communication is carried out is increasing, and the wave of pluralization is insufficient in the conventional 8-bit address space and the 16-bit address space. Are coming to demand.

Since an enormous memory space is required to manage such an address space, a method for managing the address space that does not require the enormous memory resource is required.

[0004]

2. Description of the Related Art FIG. 6 is a diagram for explaining a conventional address space management method, in which (a) shows a configuration example of a data processing system and (b) shows a conventional address space management method. There is.

The data processing system on which the present invention is based is a system in which computers 1 are connected using a single physical communication path as shown in FIG. The path is provided with a communication protocol that logically realizes a plurality of connections (called sessions) by using, for example, a 1-byte address.

In this case, when one logical communication path is formed, a forward or random 1-byte address is generated, and information of the generated address (00 to FF: hexadecimal address) Information necessary for the communication, such as priority, communication speed, communication name (name of partner system), etc., is held in the area, and the address of the information area is set to the 00-FF address (16
The address management table 3 consisting of

In the conventional management of the address space, it is sufficient to manage at most 1 byte (256 lines) as described above.
As shown in (b) of this figure, on the address management table 3,
Even if the above information was statically held, there was no problem in terms of memory resources.

[0008]

However, as described above, if a 2-byte address space (65536 connections) is provided to realize a plurality of communication paths, it becomes static as in the conventional case. However, if the information and the address of the information area address are paired and each element has 6 bytes, a huge memory area of 384 Kbytes is required.

In view of the above-mentioned conventional drawbacks, the present invention is a computer 1
In a system in which two physical sessions are connected using a single physical communication path, multiple sessions are formed on the physical communication path for communication, but the persistence of the sessions is not so long. Another object of the present invention is to provide a method of dynamically managing an address space for identifying the session, focusing on the fact that the session itself is dynamic.

[0010]

FIG. 1 illustrates the principle of the present invention. The above problem is solved by the dynamic management method of the address space configured as follows.

A method for managing an address space when a plurality of connections (sessions) are realized with an n-bit address for connecting computers using one communication line. Is divided into a high-order a bit and a low-order b bit (a + b = n), and a statically existing high-order address management table 1 and a dynamically existing low-order address management table 2 Address management table 1
Is composed of the start address of the lower address management table 2 and a flag (F) indicating valid / invalid of the lower address management table 2, and the lower address management table 2 is connected to the connection (session). ), The address of the information area holding the information, and the header section consisting of the valid / invalid management bits of the information area address.
When a bit address is given, the upper a bits
When the upper address management table 1 is searched and the flag (F) is “OFF”, the area of the lower address management table 2 is acquired, and the corresponding area designated by the lower b bits is n The address of the information area holding the information necessary for communication with the bit address is stored, and the corresponding bit of the valid / invalid management bit of the header section indicated by the b bit is set to "ON", and If the flag (F) of the upper address management table 1 is set to "ON" and the flag (F) is "ON" in the search of the upper address management table 1, the lower b bits are
The information area address is stored in a corresponding area designated by the lower b bits of the lower address management table 2 and the relevant bit designated by the b bits of the header section is turned "on" to make the connection. When releasing the (session), the upper address management table 1 is searched with the upper a bits of the n bits, and based on the address of the lower address management table 2 of the corresponding area indicated by the a bits, The lower address management table 2
Is configured to open the lower address management table 2 when all the "0" s in the header part are detected by turning off the corresponding bit indicated by the b bit. ..

[0012]

That is, according to the present invention, when connecting a computer using one physical communication path, for example, when forming a plurality of sessions with a 16-bit address, the 16-bit address space Upper address management table that divides into half and statically manages with the upper 8 bits address 1
And a lower address management table 2 that is dynamically managed by the lower 8 bit address. The upper address management table 1 includes the start address of the lower address management table 2 and the lower address management table 2 It is configured statically with a flag (F) indicating whether the session is valid or invalid, but the lower address management table 2 has an information area address that holds information necessary for forming a session and the information area It is composed of a header part consisting of valid / invalid management bits of an address, and is made to dynamically exist in response to the formation of a session on one physical communication path.

Specifically, the upper address management table
When there is at least one valid lower address corresponding to each address of 1, the bit corresponding to the lower address in the header part of the lower address management table 2 is at least 1 When there is one, the lower address management table 2 is formed, and when there is no valid lower address for the upper address, the lower address management table 2 is released from the memory.

Therefore, since the session actually existing on one physical communication path is dynamic, the lower address management table 2 is dynamically generated in response to the existence of the session. When the release is performed and the address space of all sessions on the communication path, for example, a 16-byte address, as described above, a relatively small memory space is actually used as compared with the address management space of 65536 × 6 bytes. It is possible to manage the address space by forming a lower address management table corresponding to the session in which communication is being performed.

[0015]

Embodiments of the present invention will now be described in detail with reference to the drawings. The above-mentioned FIG. 1 is an explanatory view of the principle of the present invention.
FIG. 5 is a diagram showing an embodiment of the present invention, FIG. 2 is a flow chart showing a process of creating a lower address management table, and FIG. 3 is a flow chart showing a process of releasing a lower address management table. FIG. 4 and FIG. 5 schematically show the search process when generating the lower address management table.

According to the present invention, when a session is generated and a corresponding address is generated on one communication path between computers, the generated n-bit address space is defined by the upper a bits and the lower b bits ( a + b = n) and statically existing upper address management table 1
And a lower address management table 2 are provided. The upper address management table 1 includes a start address of the lower address management table 2 and a flag (F) indicating whether the lower address management table is valid or invalid. The lower-level address management table 2 that dynamically exists is composed of the address of the information area holding the information of the session and the header section of the valid / invalid management bit of the information area address. When the n-bit address is given, the upper address management table 1 is searched with the upper a bits, and if the flag (F) is “off”, the lower address management table is searched. The area 2 is acquired, and the address of the information area that holds the information necessary for communication at the address of the n bits is stored in the area indicated by the lower b bits and the above , The "on" the corresponding bit of invalid management bit (header portion),
The flag (F) in the upper address management table 1
Is set to "ON" and the flag (F) is set to "ON", the lower address management table 2 is searched and the information area address is stored in the corresponding area indicated by the lower b bits. Valid / invalid management bit (header)
When the n-bit address is released, the corresponding bit in the header section of the lower address management table 2 is set to "OFF", and the header section becomes all "0". A means for releasing the lower address management table 2 when it is detected is a means necessary for implementing the present invention. The same reference numerals denote the same objects throughout the drawings.

The address space dynamic management method of the present invention will be described below with reference to FIGS. 1 to 5 while referring to the data processing system shown in FIG. 6 (a). As shown in FIG. 6A, the data processing system on which the present invention is based presupposes that the physical communication paths are such that the computers 1 are connected using one physical communication path. For example, a communication protocol that logically realizes a plurality of connections (sessions) using a 2-byte address is provided.

In such a data processing system, for example, in a computer on the originating side, a request for a connection (session) is generated, and for example, a 16-bit address for forming the connection (session) is forwarded. ，
Or, if it is randomly generated, the memory area corresponding to the corresponding address (specifically, the lower address management table
In 2), information required when making the connection (session), for example, priority, communication speed, communication name
(Specifically, for example, the address of the information area holding the name of the partner system) is stored, and the information is released when the communication is terminated and the connection (session) is released.

2 and 3 are flow charts showing the process of creating and releasing the lower address management table 2 at this time. In the present embodiment, for example, the above 16-bit address space is divided into upper 8 bits and lower 8 bits (generally divided into upper a bits and lower b bits, where a + b = n) and corresponding to the upper address, as shown in FIG. 1, the upper address management table
1 is provided, and the lower address management table 2 is placed in the area indicated by the upper address of the upper address management table 1.
In order to link the lower address management table 2 and the top address of the lower address management table 2,
A flag (F) indicating whether or not is valid is provided.

This upper address management table 1 is made to exist statically regardless of whether or not the session has occurred.
The address information stored in the address management table 1 is
For example, if 4-byte information is used, the upper address management table 1 requires an area of 4 × 256 (= 1K) bytes.

The lower address management table 2 linked to the upper address management table 1 is dynamic.
If the header of the bitmap structure is used to determine whether the address in the above information area is valid at the beginning, 256 bits (32 bytes) are required for the bitmap memory area, so a total of 4 × 256 + 32 = An area of 1056 bytes is required, but this lower address management table 2
As described above, the memory resource is effectively used by configuring it to exist only dynamically.

That is, when a session occurs in the above-mentioned one physical communication path and at least one valid lower address exists corresponding to each address in the upper address management table 1, That is, when there is at least one bit corresponding to the lower address in the header part of the lower address management table 2, the lower address management table 2 has been generated, the session is released, When there is no valid lower-order address for the higher-order address, the lower-order address management table 2 is dynamically managed by releasing the lower-order address management table 2 from the memory. You can

The operation of generating and releasing the lower address management table 2 will be described more specifically below with reference to the flow charts of FIGS. 1 and 2 to 5. Process step 100: A session occurs on one physical communication path, and for example, a 16-bit address (0208 ₁₆ : "0208" in hexadecimal number, hereinafter omitted) occurs.

In this embodiment, as described above, the generated address is stored in the upper 8 bits (02 ₁₆ ) and the lower 8 bits.
It is divided into bits (08 ₁₆ ), and the upper address management table 1 and the lower address management table 2 are associated with each.

Process Steps 101, 102: Whether or not a valid upper address (02 ₁₆ ), that is, an upper address having the lower address management table 2 exists in the upper address management table 1 is checked by checking the flag (F). recognize. If the flag (F) is “ON”, the valid lower address management table 2 exists, so the start address of the lower address management table 2 stored in the corresponding address area. Point to the lower address management table 2. (Refer to FIG. 1) If the flag (F) is "off", it means that the effective lower-order address management table 2 does not exist, so that the process proceeds to step 105.

Process step 103: The lower address management table 2 pointed to is searched to find the lower address (08 ₁₆ ).
The address of the information area in which the information required for this communication (priority order, communication speed, communication name, etc.) is stored in the area indicated by.

Process step 104: The bit at the bit position corresponding to the lower address (08 ₁₆ ) in the header portion of the lower address management table 2 is turned "on". Processing step 105: on a memory area not shown,
The area of the lower address management table 2 is acquired, the leading address is stored in the corresponding area of the higher address management table 1, and the acquired lower address management table 2 is pointed to, and the above processing steps are performed. 103,104
Then, the address of the information area in which the information required for this communication is held is stored in the area designated by the lower address (08 ₁₆ ), and the lower address ( 08 ₁₆ ) Turn on the bit at the bit position corresponding to.

FIG. 4 and FIG. 5 schematically show the search processing when the above-mentioned address (0208 ₁₆ ) occurs. FIG. 4 shows the above flags in the upper address management table 1.
(F) shows the case of "ON", and recognizes that the flag (F) of the area corresponding to the corresponding higher address (02 ₁₆ ) of the higher address management table 1 is "ON". After that, the lower-order address management table 2 is obtained from the address information of the "lower-order address management table address storage area".

Next, the address of the information area in which the information required for the communication is stored is stored in the position "32 + 08 × 4 = 64" of the lower address management table 2, and The bit position corresponding to the lower address (08 ₁₆ ), specifically, the 8th bit is set to “ON”.

FIG. 5 shows the upper address management table 1
, The above flag (F) is “OFF”.
Corresponding upper address of the upper address management table 1
After recognizing that the flag (F) of the area corresponding to (02 ₁₆ ) is "OFF", the area of the lower address management table 2 is acquired and acquired in the memory area (not shown). Store the start address of the area in the corresponding address area of the upper address management table 1,
The above flag (F) is turned on.

Then, the information area address in which the information necessary for the communication is stored is stored in the position of "32 + 08 × 4 = 64" of the acquired lower address management table 2 and the header part is stored. , The bit position corresponding to the lower address (08 ₁₆ ) above, specifically, the 8th bit is “ON”
And

In this way, the lower address management table 2 is dynamically generated and managed in response to the occurrence of a session. Next, with reference to FIG. 3, a process of releasing the lower address management table 2 when the session is released after the communication is finished will be described.

Process step 110: The communication is ended, the session is released, and the address is released. Process step 111: The upper address management table 1 corresponding to the released address (0208 ₁₆ ) is searched, the upper address (02 ₁₆ ) is searched, and the lower address management table is searched.
2 is obtained, and the bit at the bit position corresponding to the lower address (08 ₁₆ ) in the header portion of the obtained lower address management table 2 is changed from “on” to “off”.

Process steps 112 and 113: Check whether the header part is all "0". If all the header parts are "0", it means that there is no valid lower address any more. Therefore, the lower address management table 2 Open up. (See FIG. 1) As described above, in the address space management method of the present invention, it is sufficient to make a one-time determination of all “0” s in the header portion (that is, all areas of the lower address management table 2 are searched). (Not necessary), so processing efficiency is good.

In the above processing, if the header portion is not all "0", there is still a valid lower address, and the lower address management table 2 cannot be released. The process ends.

Process step 114: The flag (F) of the area corresponding to the upper address (02 ₁₆ ) of the upper address management table 1 which points to the released lower address management table 2 is set to “off”. As a result, the upper address (02 ₁₆ ) is instructed that no valid lower address is present anymore.

As described above, according to the present invention, when there is at least one valid lower address corresponding to each address in the upper address management table 1, that is, in the lower address management table 2 described above. When there is at least one bit corresponding to the above lower address in the header section, the lower address management table 2 is formed, and there is at least one valid lower address for the higher address. If not (that is, all the above header parts are “0”), the lower address management table 2 is released from the memory to correspond to the session actually existing on one physical communication path. Then, the lower address management table is dynamically managed.

[0038]

As described above in detail, according to the dynamic management method of the address space of the present invention, a plurality of sessions are formed on one physical communication path between computers.
When the corresponding n-bit address is generated, the generated n-bit address space is divided into a higher-order a bit and a lower-order b bit (a + b = n), and the statically existing higher-order address management table is , The top address of the lower address management table and a flag (F) indicating valid / invalid of the lower address management table, and the dynamically existing lower address management table stores the information of the above session. It is composed of the address of the information area to be held and the header part of the valid / invalid management bit of the information area address. When an n-bit address is given by the occurrence of the session, the upper a bits and the upper When the address management table is searched and the flag (F) is "off", the lower address management table area is acquired, and the information is written in the corresponding area designated by the lower b bits. Area address is stored, the relevant bit of the valid / invalid management bit (header part) is turned on, the flag (F) of the upper address management table is turned on, and the above flag is set.
When (F) is “ON”, the lower address management table is searched, and the information necessary for communication at the n-bit address is held in the corresponding area indicated by the lower b bits. The address of the information area is stored, the relevant bit of the valid / invalid management bit (header section) is set to “ON”, the session is released, the n-bit address is released, and the lower address management table When the corresponding bits of the header part are turned off, when it is detected that all the header parts have become "0", the lower address management table is opened to manage the address space. Since the address space can be managed economically, and by dividing the address into the upper byte and the lower byte, for example, 1/256 can be searched for the upper address. Hit, after,
The address management table of the lower 256 elements relating to the lower address corresponding to the hit upper address may be searched with the lower byte, and the search result can be obtained faster than the search using 2 bytes directly. This is particularly noticeable when addresses generated at the time of forming a session are random. Further, when the lower address management table is opened, it is sufficient to determine that all the header parts that the bitmap format manages the validity and invalidity of all elements are all "0", so that the processing efficiency is good. There is.

[Brief description of drawings]

FIG. 1 is an explanatory diagram of the principle of the present invention.

FIG. 2 is a diagram showing an embodiment of the present invention (No. 1).

FIG. 3 is a diagram showing an embodiment of the present invention (part 2).

FIG. 4 is a diagram showing an embodiment of the present invention (part 3).

FIG. 5 is a diagram showing an embodiment of the present invention (No. 4).

FIG. 6 is a diagram illustrating a conventional address space management method.

[Explanation of symbols]

 1 Upper address management table 2 Lower address management table 100 to 105,110 to 114 Processing step Start address of lower address management table Flag (F) Information area address Header part

Claims (1)

[Claims] 1. A method of managing an address space when a plurality of connections (sessions) are realized with an n-bit address for connecting computers using one communication line. The address space is divided into upper a bits and lower b bits (a + b = n), and statically existing upper address management table (1) and dynamically existing lower address management table (2) In order to manage the address space, the upper address management table (1) sets the start address () of the lower address management table (2) and the valid / invalid of the lower address management table. Flags to display
(F) () and consists of the lower address management table above
(2) is the address () of the information area that holds the information of the connection (session) and the address of the information area ()
Header part () consisting of valid and invalid management bits of the above. When realizing the above-mentioned connection (session), when an n-bit address is given, the higher-order a-bit is used and the higher-order address management table (1 ) Search for the above flag
When (F) () is "OFF", the area of the lower address management table (2) is acquired, and the area of the lower bit b is used to communicate with the corresponding n-bit address. The address () of the information area that holds the necessary information is stored, and the relevant bit indicated by the b bit of the valid / invalid management bits of the header section () is set to "ON", and the upper address management table is set. Flag (F) of (1) ()
Is set to “ON”, and when the flag (F) () is “ON” in the search of the upper address management table (1), the lower b bits are
In the corresponding area indicated by the lower b bits of the lower address management table (2), the information area address ()
Is stored, the corresponding bit designated by the b bit of the header section () is turned “on”, and when the connection (session) is released, the upper a bit of the n bit is used to manage the upper address. The table (1) is searched, and the header part of the lower address management table (2) is searched based on the address of the lower address management table (2) of the corresponding area indicated by the a bit.
(), Turn off the corresponding bit indicated by the b bit, and open the lower address management table (2) when all "0" s in the header part () are detected. A method of dynamically managing an address space characterized by.