JPH05268291A - Data buffer management system - Google Patents

Abstract

PURPOSE:To change the number of buffers for every line without causing the occurrence of buffer busy due to the occupation of the buffer by a specified protocol line, and at that time, to give no influence upon a line during communication. CONSTITUTION:A resource management processor 120 and a shared memory 14 to execute the assignment and the management of a data buffer resource include a transmitted data buffer 141 to execute the dynamic assignment of a resource in accordance with the kind of a designated protocol and a buffer management information area 143 for realizing buffer management.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a data buffer management system and a data buffer management method in a communication control device for accommodating a plurality of communication lines and transmitting and receiving data, and more particularly to a communication which is different for each line. The present invention relates to a protocol, a data buffer management system and a data buffer management method suitable for performing communication at different line speeds.

[0002]

2. Description of the Related Art A communication control device is used as a device for controlling communication when performing communication between host computers or between a host computer and a terminal. This communication control device has a memory that constitutes a buffer for temporarily storing communication data.

By the way, in recent years, a communication control device has come to control communication of a plurality of lines and a plurality of protocols within the same device. In this type of communication control device, it is necessary to allocate a buffer for storing data during communication. Conventionally, this type of buffer allocation is described in, for example, Japanese Patent Publication No. 1-48574.

According to this conventional technique, Japanese Patent Publication No. 1-4857.
As described in Japanese Patent No. 4, the number of usable buffers is set according to the request source of the buffer. In this method, the transmission buffer is hunted from the common buffer pool and used when the transmission in the high level procedure and the transmission in the basic procedure are simultaneously performed. Therefore, it is possible that the high-level procedure side continuously transmits a plurality of frames and temporarily uses up the buffer resource while waiting for the delivery confirmation. In such a case, if the basic procedure side tries to hunt the transmission buffer, the transmission buffer may be in a busy state and smooth communication may not be performed.

[0005]

As described above, in the prior art, since the buffer resource is shared by the high level procedure and the basic procedure, the above-mentioned is caused by the load on the communication line of the high level procedure. Occurrence of such a transmission buffer busy cannot be avoided. In addition, if a buffer resource is assigned to each communication line, it is possible to avoid the load on a specific line from affecting the control of other lines, but the amount of memory required for the transmission buffer used in the high-level procedure is very large. There is a problem that it will increase.

In order to solve the above problems, the present invention acquires the optimum number of buffers according to the protocol type at the time of defining a line and uses a small amount of memory.
An object of the present invention is to provide a data buffer management system and a data buffer management method capable of performing smooth communication without waiting time due to buffer busy.

[0007]

In order to achieve the above object, according to one aspect of the present invention, a plurality of lines are used to control transmission from a host device to a line and control from a line to a host device. A data buffer management system in a communication control device for performing, comprising a memory that constitutes a buffer for temporarily storing communication data, and a resource management processor that controls the allocation of the buffer configured in this memory to each line, The memory includes a transmission buffer for storing transmission data, a reception buffer for storing reception data,
The resource management processor has a buffer management information area for storing information for managing the buffer, and the buffer management information area has a resource management table for each protocol, and these management tables include at least a transmission buffer. The table group including the management table group that manages the transmission buffer is
Defines a buffer group that is fixedly allocated for at least one type of applied protocol, a buffer group that is allocated line-correspondingly, and a pool buffer group that is not allocated to any of the other types of applied protocol. Information and buffer pool management information for additionally managing the pool buffer group to the fixedly allocated buffer group and for returning the pool buffer group are described. A management system is provided.

Here, as the protocol types to be applied, for example, a high-level procedure (including HDLC and the like) adapted to the layer concept of the OSI basic reference model, and a medium-low speed protocol in which the layer concept is ambiguous There can be two basic procedures (a SYN synchronization procedure and the like are included in the procedure).

According to another aspect of the present invention, data is temporarily stored in a communication control device that controls transmission from a host device to a line and reception from the line to a host device using a plurality of lines. A data buffer management method in a memory, wherein a data storage area of the memory is divided into a plurality of buffer areas, and at least an area for storing transmission data is fixedly allocated to a plurality of predetermined surfaces for a high-level procedure. , For the basic procedure, divide the number of planes predetermined for each line, pool those that cannot be allocated to any of them as a pool buffer, and share the buffer area allocated for the high-level procedure with each line. Use the pool buffer for the shortfall and secure it as an additional buffer area, and return it to the pool buffer at the end of communication. The data buffer management method of the symptoms is provided.

That is, the present invention employs the following means in order to perform buffer management for each protocol.

(1) A management table is provided for buffer management according to the protocol type.

(2) A data storing optimum number of buffers corresponding to parameters such as line speed and maximum transmission data length.
Provide a bull.

(3) Register the buffer address hunted from the buffer pool in the buffer management table according to the protocol type at the time of defining the line and deleting the definition according to the instruction from the host computer. , Or, or the registered buffer is returned to the buffer pool.

In the present invention, for the high level procedure,
Since the buffers are commonly assigned to the lines, the number of buffers can be changed for each line. This change can be set even while another line is communicating.

When the protocol is single, the optimum buffer can be allocated only by the line speed or the maximum transmission data length.

The allocation of the number of transmission / reception buffers can be performed by searching the table in the memory according to the protocol type and the line speed or the maximum transmission data length.

[0017]

In the present invention, the buffers are allocated according to the protocol type, that is, divided into the high level procedure buffer and the basic procedure buffer. This ensures the buffer for the basic procedure. Conventionally, the problem that the buffer for the basic procedure is difficult to hunt due to the load on the communication line of the high level procedure is solved.

Further, the high-level procedure buffer is not shared for each line but is commonly reserved for each line. Therefore, each line sequentially uses the buffer. It then grabs (hunts) the required number of buffers from the pool buffer and makes them additional high-level procedure buffers. This allows
Even if the buffer for the high-level procedure runs out, the buffer area can be expanded as needed. Further, when the communication ends, the secured high level procedure buffer is released (freed). The buffer hunted from the pool buffer is returned to the pool buffer. This allows the buffer to be used for other communications. Therefore, it is possible to omit preparing a large number of buffers for the line.

Further, according to the present invention, the following effects can be expected.

(1) Since the transmission buffer is managed for each protocol, the transmission buffer is occupied by the line of the specific protocol, and the buffer busy does not occur in the line of the other protocol.

(2) Since transmission / reception buffer allocation and return are performed at the time of line definition, it is possible to change the number of buffers for each line without affecting other lines in communication.

(3) Transmission / reception buffer hunt and free
At times, double hunting and double free of the buffer due to a program failure or the like is detected by checking information that identifies whether the buffer has already been hunted and freed.

In the present invention, the amount of memory in the table can be reduced by classifying the protocol types into only two types, a high level procedure and a basic procedure.

[0024]

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 shows an example of the configuration of a communication control device to which an embodiment of the present invention is applied. In FIG. 1, the communication control device 100 controls communication between the host computer 200 and other host computers or terminals by channel-connecting with the host computer 200 and connecting with various communication lines 160.

The communication control device 100 allocates line resources and data buffer resources in response to an instruction from the host protocol control processor 110 that performs host interface control and layer 3 control of the OSI basic reference model, and the host computer 200. , A resource management processor 120 for managing, a lower level protocol control processor 130 for performing a unique protocol processing according to a protocol type for communication, a line controller 150, and access from the respective processors 110, 120 and 130. The shared memory 140 is included as a component.

The shared memory 140 is a transmission data buffer 141 and a reception data buffer 142 which are buffer resources for performing allocation according to a designated protocol type.
And a buffer management information area 143 for realizing control and management of transmission / reception data buffer allocation according to the protocol type.

FIG. 2 shows the correspondence between the protocol hierarchy of the high level procedure and the basic procedure and the OSI basic reference model lower layer 310.

In the preferred embodiment, the high level procedure is the OS
Circuit physical interface control 320 corresponding to layer 1 (physical layer) of the I basic reference model, data link control 330 corresponding to layer 2 (data link layer), and network control 34 corresponding to layer 3 (network layer)
0 is performed by the communication control device 100, and control of layers 4 and above is performed by the host computer 200. That is, in the high-level procedure, the communication control device 1 controls the layer resources such as line resource allocation, data delivery confirmation, and retransmission control.
00.

In the basic procedure, since there is no layer concept corresponding to the OSI basic reference model, the communication physical interface control 320 and the character unit control are performed by the communication control unit 100, and the host computer 200 controls the text unit or more. .. That is, in the basic procedure, the host computer 200 directly controls the line unit and the text unit.

As described above, by supporting the two types of interfaces corresponding to the protocol types having different control levels between the host computer 200 and the communication control device 100, the transmission efficiency can be improved. The boundary of the function sharing between the communication control device 100 and the host computer 200 is indicated by a dashed line 350.

When performing communication of protocol types having different control levels between the host computer 200 and the communication control device 100, it is necessary to allocate buffers efficiently. In this embodiment, the buffer state is managed by the buffer resource management table, and the resource management processor 120 uses this buffer resource management table to execute resource management.

First, regarding the management of the transmission buffer, FIG.
~ It demonstrates with reference to FIG.

FIG. 3 shows a management table for managing buffer resources according to the protocol type, and the relationship between the management table and the transmission buffer. These management tables are stored in the buffer management information area 14 of FIG.
Exists within 3. Further, the transmission buffer 450 is in the transmission data buffer 141 of FIG.

Of these management tables, a high level buffer address table 410 (hereinafter, HBAT) is provided as a table for managing the buffers allocated for the high level procedure. The HBAT 410 is a continuous area on the memory in units of one side composed of the busy flag 411 and the transmission buffer address 412, and is used cyclically from the beginning of the area.
The HBAT 410 sets one surface of the transmission buffer allocated for the high level. In this embodiment, the HBAT 410 is provided on 1400 surfaces.

In order to refer to this HBAT410, H
A BAT pointer 440 (hereinafter, HBATP) is provided. The HBATP 440 is composed of the following three pointers. A buffer address table header pointer 441 that gives the start address on the memory area of the HBAT 410, a buffer address table tail pointer 442 that gives an address of the final surface on the memory area of the HBAT 410, and a buffer address table A buffer address table return pointer 443 for giving an address.

A basic buffer address table 460 (hereinafter referred to as BBAT) is provided as an address table for referring to the buffer allocated for the basic procedure. BBAT460 is 1 per line
It is a table in which six areas for buffer addresses are provided. The buffer address is stored in this area when the buffer is actually allocated.

A basic buffer management table 430 (hereinafter, BBMT) is provided as a table for managing the buffer allocated for the basic procedure. BB
The MT 430 is provided on each side corresponding to each line.
The configuration of one side includes a buffer side number 431 and a BBAT address 432 corresponding to the line.

A transmission buffer pool management table 420 (hereinafter, BPMT) is provided in order to manage the buffer before allocation according to the protocol type. This table 420 is composed of the following elements. A pool buffer header pointer 421 that gives the start address of the pool buffer before allocation, a pool buffer tail pointer 422 that gives the address of the last surface of the pool buffer, a pool buffer number 423, and a pool buffer number regulation value 424.
And.

When the shared memory is initialized after the program is loaded, a predetermined number of transmission buffers are allocated to the high level procedure. As a result, the high-level fixed allocation buffer 4 is partially provided in the transmission buffer 450.
54 is provided. A certain number of HBATs 410
Turn off the busy flag and set the assigned transmit buffer address. The remaining HBATs 410 turn on the busy flag and clear the buffer address area. The return pointer 443 of the HBATP 440 sets the address of the final surface of the HBAT 410 to which the buffer is allocated.

At this time, the remaining buffers not allocated to the high level procedure are pool buffers 455 and B
Register with PMT420. At this time, the number of pool buffers is set to the number 423 of pool buffers and the regulation value 424 of number of pool buffers. Management table 430 for basic
With regard to, the initial state is a cleared state, that is, a state in which no buffer is allocated.

As described above, by providing the two types of buffer management tables for the high level procedure and the basic procedure, it becomes possible to perform the buffer management according to the protocol type.

One side of each transmission buffer is a control information area 452 for storing control information about each data buffer.
And a data area 453. The control information area 452 includes a buffer status code 451 that is a code for identifying that the buffer is in the hunted or freed state.

Next, how the tables of the buffer resource management table are associated with each other when the high level line is defined will be described with reference to the table relation diagram shown in FIG.

When defining the high level procedure, how much the high level buffer is allocated can be determined according to the line speed. Therefore, using the line speed code as an index, a high-level buffer plane number table 530 (hereinafter, referred to as HBC)
T) is provided.

When a high-level procedure definition instruction is given to the line resource from the host computer 200,
The resource management processor 120 obtains the optimum number of transmission buffers for the line speed by searching the HBCT 530 using the line speed code as an index. Hunt this number of send buffers from the pool buffer and
Update MT 420. At this time, the number of hunted pool buffers is subtracted from the pool buffer regulation value 424. The hunted buffer is already additionally registered in the HBAT 410 by connecting to the buffer allocated for high level at the time of initial setting, and the buffer address table return pointer 443 of the HBATP 440 is updated.

For each high level line definition, a number of buffers corresponding to the line speed are connected to the buffer resources allocated for the high level. This buffer resource is
It is not managed separately for each line, but shared between lines defined at a high level. This makes it possible to realize this with a small amount of memory even when performing a high-level procedure that requires a large number of buffer resources for high line speed and continuous frame transmission with a plurality of lines.

When the host computer 200 instructs the line defined for high level to delete the definition, the resource management processor 120 returns the buffer additionally registered at the time of defining the line to the buffer pool,
Update the BPMT 420. At this time, the number of buffers to be returned is added to the pool buffer number regulation value 424.
When the deletion of the definition for the line defined for high level is instructed, another line temporarily occupies a large number of buffers, and the assigned number of buffers for the definition of the line is If it cannot be returned, the number that can actually be returned is returned, but the number given at the time of line definition is added to the pool buffer number regulation value 424.

Next, how the tables of the buffer resource management table are associated with each other when defining the basic line will be described with reference to the table relation diagram shown in FIG.

In order to give the optimum number of transmission buffers when defining the basic procedure, the basic buffer plane number table 610 (hereinafter, BB) which defines the number of basic buffer planes by using the maximum transmission frame length code as an index.
CT) is provided.

When a basic procedure definition instruction is received for a line resource, the resource management processor 120
Searches the BBC 610 using the maximum transmission frame length code simultaneously instructed as an index,
Get the optimal number of send buffers. Hunt a predetermined number of transmit buffers from the pool buffer 455 to allow the BPMT420
To update. The number of buffer surfaces 431 is registered in the BBMT 430 of the line, and the buffer address is set to BBAT 460.

In the basic procedure, medium and low line speed,
Since a relatively short frame length is transmitted, the buffer resource amount does not matter even if a buffer hunted from the buffer pool for each line definition is difficult to handle for each line. As a result, busy management of each buffer can be omitted and buffer control can be simplified.

For the line defined for basic,
When the deletion of the definition is instructed, the resource management processor 120 returns the buffer allocated to the relevant line to the buffer pool. BBMT430 corresponding to the line
The buffer face number 431 of is cleared and the BPMT 420 is updated.

The definition of the line resource and the deletion of the definition are instructed from the host computer 200 on a line-by-line basis. Therefore, the number of buffers can be changed for each line or while another line is communicating.

Next, the operation at the time of transmission in the high level procedure will be described with reference to FIG. 6 showing the data transmission sequence in the high level procedure.

When receiving a transmission instruction (611) from the host computer 200, the communication control device 100 hunts the buffer resource for high level (612), and if a buffer with a sufficient number for data transmission can be secured, transmission is performed. The host computer 200 is notified of the completion of preparation (613). When the buffer cannot be secured, the buffer busy is notified and the host computer 200 waits for a retry.

The host computer 200 having received the transmission preparation completion 613 transmits the data to be transmitted to the communication control device 100.
(614). The communication control device 100 stores the transmission data in the hunted buffer (615), notifies the host computer 200 of the transmission completion (616), and transmits the data to the partner station (617). Thereafter, the communication control device 100 analyzes the received data (618) from the partner station, and if this is a normal response to the previous transmission (617), frees the buffer storing the previous transmission data. (619)

At this time, the buffers are once returned to the buffer pool, and the number of buffers exceeding the pool buffer number regulation value is registered again in the HBAT 410. In this way
If a certain line temporarily occupies a large number of buffers during communication and cannot delete the assigned number of buffers for the deletion of definitions for other lines, the buffer will be released at the end of transmission when the buffer is free. Adjust the number.

When the normal response to the transmission (617) cannot be received, the communication control device 100 retransmits the data in the buffer.

Next, an operation at the time of transmission in the basic procedure will be described with reference to FIG. 7 showing a data transmission sequence in the basic procedure.

When receiving a transmission instruction (711) from the host computer 200, the communication control device 100 is ready for transmission (71) if the transmission instruction can be accepted.
2) is notified to the host computer 200. The host computer 200 which has received the transmission preparation completion (712)
Transfer data to be transmitted to the communication control device 100 (713)
To do. The communication control device 100 stores this transmission data in the buffer allocated at the time of defining the line (714), and then transmits the data to the partner station (715). After the data transmission (715) ends, the communication control device 100 notifies the host computer 200 of the transmission completion (716).

Next, buffer management of the reception buffer will be described with reference to FIGS. FIG. 8 shows a management table for managing the reception buffer resource and the relationship between the management table and the reception buffer.

These management tables exist in the buffer management information area 143 of FIG. The management table of the reception buffer is not divided according to the protocol type but uses a common table. A reception buffer address table 820 (hereinafter, RBAT) is provided for each reception buffer. The RBAT 820 includes a busy flag 821 and a reception buffer address 822.

In the case of reception, the buffer is managed for each communication line even in the high level procedure. When the host computer 200 instructs the line definition, the buffer hunted from the buffer pool is registered in the reception buffer registration table 810 (hereinafter, RBST). RB
The configuration of the first surface of ST810 is as follows: RBAT address 811, which stores the RBAT of the hunted head buffer, data length 812 in the buffer, and R, which stores the number of hunted buffers.
It is composed of 813 BAT numbers.

In order to manage the reception buffer pool, a reception buffer pool management table 840 (hereinafter, RPM
T) is provided. This table consists of the following elements. A pool buffer header pointer 841 that gives the start address of the pool buffer before allocation, a pool buffer tail pointer 822 that gives the address of the last surface of the pool buffer, the number of pool buffers 843, and a pool buffer number regulation value 844.

When a line is defined in the high level procedure, a reception buffer plane number table 830 (hereinafter, RBCT) is provided to use the line speed code as an index to obtain the optimum number of reception buffers for the line speed.
For reception, the basic procedure allocates a fixed number of buffers for each line.

Next, the operation at the time of reception in the high level procedure will be described with reference to FIG. 9 showing the data reception sequence in the high level procedure.

When data is received from the partner station (911), the communication control device 100 stores the received data in the buffer (912), and the reception buffer is further expanded from the buffer pool by the number of buffer planes used in this reception. Hunt (913). In this way, even when the line speed is high and data is continuously received, a constant number of buffers is secured in preparation for the next reception in order to avoid overrun due to buffer busy.

Thereafter, the communication control device 100 notifies the host computer 200 of the reception completion (914).
To do. After receiving the reception preparation completion notification (915) from the host computer 200, the communication control device 100 transfers the reception data (916), then releases the reception buffer (917) and returns it to the buffer pool.

Next, the operation at the time of reception in the basic procedure will be described with reference to FIG. 10 showing the data reception sequence in the basic procedure.

After receiving the reception instruction (1011) from the host computer 200, the communication control device 100 stores the received data in the buffer (1013) in response to the data reception 1012 from the partner station and uses the received data. Turn on the busy flag for the buffer. After that, the reception completion notification (1014) is sent to the host computer 200, and then the received data is transferred (1015).

After that, the communication control device 100 turns off (1016) the busy flag of the reception buffer that has been used. In the basic procedure, basically, one text data is received in response to one instruction from the host computer. In addition, reception is mainly done with medium to low line speeds and relatively short data lengths. As a result, the reception buffer management can be simplified by using the busy flag to manage and use the fixed reception buffer allocated at the time of line definition without hunting or freeing the reception buffer.

In the above embodiment, the resource management processor 120 checks the buffer status code 451 in the buffer when hunting and freeing the send / receive buffer. Further, when the hunt and the free state are performed, the buffer status code 451 is rewritten. As a result, it is possible to prevent double hunting and double freeing of the buffer due to defective programming or the like.

In the above-described embodiments, two types of protocols, a high level procedure and a basic procedure, have been described. However, the present invention is not limited to these two types. It is also applicable to other protocols. It is also applicable when three or more protocols are used. In that case, for example, the buffers may be assigned to the types.

[0075]

The present invention has the following effects.

(1) Since the transmission buffer is managed for each protocol, the transmission buffer is occupied by the line of the specific protocol, and the communication of the other protocol is performed smoothly without waiting time due to the occurrence of buffer busy. You can

(2) Since the number of buffers is allocated to the transmission / reception buffers according to the characteristics of the protocol, the amount of memory required for the buffers can be reduced.

(3) Since transmission / reception buffer allocation and return are performed at the time of line definition, it is possible to change the number of buffers for each line, and at this time, other communication lines are not affected.

(4) During transmission / reception buffer hunt and free, by checking the information for identifying whether the buffer has already been hunted and freed, double hunting and double freeing of the buffer due to a defective program or the like are detected.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of an example of a communication control device for realizing an embodiment of a data buffer management system of the present invention.

FIG. 2 is an explanatory diagram showing a hierarchy of protocols.

FIG. 3 is a table related diagram of a transmission buffer resource management table.

FIG. 4 is a diagram relating to a transmission buffer management table when a high level line is defined.

FIG. 5 is a diagram relating to a transmission buffer management table when defining a basic line.

FIG. 6 is a data transmission sequence diagram in a high level procedure.

FIG. 7 is a data transmission sequence diagram in the basic procedure.

FIG. 8 is a table related diagram of a reception buffer resource management table.

FIG. 9 is a data reception sequence diagram in a high level procedure.

FIG. 10 is a data reception sequence diagram in the basic procedure.

[Explanation of symbols]

100 ... Communication control device, 120 ... Resource management processor, 140 ... Shared memory, 143 ... Buffer management information area, 200 ... Host computer, 410 ... High-level buffer address table (HBAT), 460 ...
Basic buffer address table (BBAT).

Claims (2)

[Claims] 1. A data buffer management system in a communication control device for controlling transmission from a higher-level device to a line and reception from a higher-level device using a plurality of lines, comprising a buffer for temporarily storing communication data. The memory includes a constituent memory, and a resource management processor that controls allocation of a buffer configured in the memory to each line. The memory includes a transmission buffer that stores transmission data, a reception buffer that stores reception data, and The resource management processor has a buffer management information area for storing information for managing the buffer, and the buffer management information area has a resource management table for each protocol, and these management tables include at least a transmission buffer. Including management table group to manage,
The group of tables for managing the transmission buffer is a group of buffers that are fixedly allocated to at least one type of applied protocol, and a group of buffers that are allocated line-correspondingly to other types of applied protocol. And information that defines a pool buffer group that cannot be allocated to any of them, and buffer pool management information that additionally manages the pool buffer group to the buffer group that is fixedly allocated and that returns the pool buffer management information. A data buffer management system characterized by being described. 2. A data buffer management method in a memory for temporarily storing data in a communication control device for controlling transmission from a host device to a line and reception from a line to a host device by using a plurality of lines. Divide the data storage area of the memory into multiple buffer areas, and at least the area to store the transmission data, fixedly allocate multiple predetermined areas for the high-level procedure, and make a line correspondence for the basic procedure. A predetermined number of faces is divided, pools that cannot be allocated to any of them are pooled, and the buffer area allocated for high-level procedures is shared by each line and used. Data buffer management method that secures it as an additional buffer area and returns it to the pool buffer at the end of communication .