JPH0642673B2 - Transmission buffer pool management method for communication controller - Google Patents

Description

The present invention relates to a data link buffer for storing data to be transferred from a central processing unit to a plurality of terminal control units connected via a local area network (LAN). Regarding the management method of the pool.

(Prior Art) Conventionally, this type of data link buffer pool management method uses one transfer data for all terminal control device transfers.
It was stored in the data link buffer pool of one communication control unit. Further, the buffer pool for data link is used each time there is a data transfer request from the central processing unit.

(Problems to be Solved by the Invention) In the conventional data link buffer pool management method described above, the transfer data for all terminal control device transfers is set to 1
Since it is stored in the data link buffer pool of one communication control device, when the transfer data for one terminal control device is large and occupies most of the data link buffer pool, the transfer data for the other terminal control device is stored. There is a problem that the storage time becomes longer and the hold time becomes longer.

Also, even if multiple transfer data for the same terminal control device are stored in the data link buffer pool, subsequent transfer data remains stored in the data link buffer pool unless the previous transfer data is transferred. Therefore, there is a similar problem.

(Means for Solving the Problems) In order to solve the above-mentioned problems, a buffer pool management system for a data link of a communication control apparatus provided by the present invention is connected to a central processing unit to transfer data from the central processing unit. In a communication control device for transferring to a plurality of terminal control devices via a local area network, data link control means for controlling a data link between the communication control device and the terminal control device, and the data link control means used in the data link control means, A data link buffer pool for storing transfer data from a central processing unit, and a method for managing the data link buffer pool, wherein the transfer data stored in the data link buffer pool is Continuous transmission buffer number specifying means for specifying the number of buffers for continuous transmission to the terminal control device, In response to a data transfer request from the central processing unit to the data link control means of the communication control device, when the buffer of the continuous transmission buffer number designated by the continuous transmission buffer number designating means becomes full, the buffer busy A buffer busy notifying means for notifying the central processing unit of the state, and a buffer busy cancellation notifying means for notifying the central processing unit that the buffer has become empty due to completion of data transfer to the terminal control device. When the buffer of the continuous transmission buffer number designated by the continuous transmission buffer number designating means is full, the data transfer to the corresponding terminal control device is suspended by the notification by the buffer busy notifying means, The buffer busy cancellation notification means notifies the data transfer becomes possible. , And performs data transfer to the other terminal control devices.

(Example) Hereinafter, one example of the present invention will be described with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of a data link buffer pool management system of a communication control apparatus according to an embodiment of the present invention.

In FIG. 1, the data link buffer pool management system of the communication control device of the present embodiment comprises a continuous communication buffer number designation means 1, a data link control means 2, a buffer busy notification means 3, and a buffer busy cancellation notification means 4. I have it.

The data link control means 2 includes a transfer control unit 21, a transmission buffer free space management control unit 22, and a terminal control transmission buffer control unit 23.
And a transmission control unit 24.

FIG. 2 is a schematic configuration diagram of a system to which this embodiment is applied.

In FIG. 2, the central processing unit 6 is connected to the LAN via the communication control unit 7 and communicates with the terminals 10, 11 and 12 under the control of the terminal control units 8 and 9 via the LAN.

Next, the operation of this embodiment will be described.

First, when the communication control device 7 is activated, the continuous transmission buffer number specifying means 1 specifies the number of buffers to be continuously transmitted for each of the terminal control devices 8 and 9 connected to the LAN. The designated continuous transmission buffer number is loaded into the control memory unit in the communication control device 7.

When there is a data transfer request from the central processing unit 6 to the communication control unit 7 to the terminal control units 8 and 9, the data link control means 2 in the communication control unit 7 causes the central processing unit 6 to operate.
The transfer control unit 21 that controls data transfer and control information exchange with the The transfer control unit 21 makes a buffer take-out request to the transmission buffer free space management control unit 22 in order to obtain a buffer for storing transfer data from the data link buffer pool.

The transmission buffer empty management control unit 22 obtains an empty buffer by referring to the transmission buffer management table.

FIG. 3 is a diagram showing the structure of the transmission buffer management table.

If the number of free buffers in the send buffer management table is 1 or more, there is a free buffer, so the free send buffer management control unit 22 obtains the buffer from the leading free link pointer. At this time, the number of empty buffers is decremented by 1 and the leading empty link pointer is replaced with the next buffer. For example, in FIG. 3, the leading free link pointer points to buffer a, buffer b, and buffer c.
The last empty link points to the buffer c in the order of. That is, the number of empty buffers is 3. After taking out the empty buffer a in such a state, the leading empty link pointer points to the buffer b and is linked in the order of the buffer c.

Next, the transfer control unit 21 transfers the transfer data from the central processing unit 6 to the buffer acquired from the transmission buffer free space management control unit 22. When the buffer takeout request is made to the transmission buffer free space management control unit 22, if the number of free buffers in the transmission buffer management table is 1, this buffer becomes the last available buffer, and therefore the central processing unit. The all transmission buffer busy notification flag, which means that the next data transfer from 6 cannot be performed, is turned on.

Next, the terminal control transmission buffer control unit 23 for controlling the number of continuous transmission buffers for each of the terminal control devices 8 and 9 is activated.
The terminal control transmission buffer control unit 23 includes the terminal control device 8,
The queuing process of the buffer storing the data to be transmitted is performed for each 9. That is, the buffer processed by the transfer control unit 21 is linked to the final link pointer of the terminal control buffer management table, and the number of untransmitted buffers is incremented by 1.

FIG. 4 is a diagram showing the structure of the terminal control buffer management table.

For example, as shown in FIG. 4, when the number of untransmitted buffers = 0, the first link pointer and the last pointer are NUL.
L (state with no link). At this time, if the buffer storing the transfer data for the terminal control devices 8 and 9 is queued, the number of untransmitted buffers = 1
Therefore, the head link pointer and the last pointer point to the buffer.

The terminal control transmission buffer control unit 23 determines the value of the number of untransmitted buffers when the number of untransmitted buffers is incremented by 1 in the queuing process of the data link buffer and the continuous transmission buffer number designating unit 1. When the value of the number of transmission buffers becomes equal, it becomes the last buffer that can be used for data transfer to the terminal control devices 8 and 9, so that the central processing unit 6 transfers the data to the terminal control devices 8 and 9. The transmission buffer busy notification flag, which means that data transfer cannot be performed, is turned on.

For example, referring to the terminal control device identification name a in FIG. 4, the number of continuous transmission buffers = 3, the number of untransmitted buffers =
The state is 2, and at this time, when there is a queuing request for the buffer, the number of untransmitted buffers = 3 and the buffer is in a busy state.

Further, when the buffer queuing process for each of the terminal control devices 8 and 9 is completed, the terminal control transmission buffer control unit 23 determines the transmission buffer busy notification flag, and determines the total transmission buffer busy notification flag and the terminal control device 8. When any of the transmission buffer busy notification flags for each 9 is turned on, control is passed to the buffer busy notification means 3.

The buffer busy notification means 3 generates buffer busy notification information according to the buffer busy state, that is, the total transmission buffer busy or the buffer busy status of each of the terminal control devices 8 and 9, and the buffer busy notification information is sent to the transfer control unit 21 of the data link control means 2. Transfer busy notification information. The transfer control unit 21 transfers the received buffer busy notification information to the central processing unit 6.

When the central processing unit 6 receives the buffer busy notification information, if it is the buffer busy notification for each of the terminal control devices 8 and 9, it temporarily suspends the data transfer to the terminal control devices 8 and 9, and the other terminal control devices. Data transfer to 8 and 9 is performed.
If it is the all-transmission buffer busy notification, the data transfer to the communication control device 7 is suspended until the data transfer trigger is obtained again by the busy cancellation notification.

On the other hand, the data link control means 2 activates the transmission control unit 24 which sends the data link frame to the LAN. In the case of the connection-type data link procedure, the data link frame is sent normally when the transmission confirmation for the data link frame is received after the data link frame is sent normally, and in the case of the connectionless data link procedure, the data link frame is sent normally. When the terminal control device 8 or 9
The number of untransmitted buffers in the terminal control buffer management table is decremented by 1 and the head link pointer is replaced. Also, when the transmission buffer busy notification flag of the terminal control buffer management table for the terminal control devices 8 and 9 is on, this is turned off and the transmission buffer busy cancellation notification flag is turned on.

In this way, since the buffer becomes an empty buffer, the data link control means 2 makes a buffer return request to the transmission buffer empty management control unit 22. The transmission buffer free space management control unit 22 links the buffer to the last pointer in the transmission buffer management table and counts up the number of free buffers by one. After this, the transmission buffer busy cancellation notification flag is determined, and if the transmission buffer busy cancellation notification flag is on, control is passed to the buffer busy cancellation notification means 4.

The buffer busy cancellation notification means 4 generates buffer busy cancellation notification information, and turns off all the transmission buffer busy notification flags and the transmission buffer busy notification flags of the terminal control devices 8 and 9. Further, the buffer busy cancellation notification information is transferred to the transfer control unit 21 of the data link control means 2,
Turn off the buffer busy cancellation notification flag. The transfer control unit 21 that has received the buffer busy cancellation notification information notifies the central processing unit 6 of this.

Upon receiving the buffer busy cancellation notification information, the central processing unit 6 restarts the suspended data transfer triggered by this.

(Effects of the Invention) As described above, the present invention specifies the number of buffers that can be continuously transmitted for each terminal control device that transfers data in the data link buffer pool of the communication control device. When the number of buffers of data transferred to the device reaches the designated continuous transmission buffer number, a buffer busy notification is sent to the central processing unit. Also, when the data transfer to the terminal control device is completed and the buffer for continuous transmission becomes available, the buffer busy cancellation notification is sent to the central processing unit.

Therefore, when transferring data to a plurality of terminal control devices via the LAN, there is an effect that a buffer for storing transfer data can be efficiently used.

Further, since the buffer busy notification is sent out for each terminal control device, the data transfer to the terminal control device in the buffer busy state can be put on hold immediately, and the data transfer service of the other terminal control devices can be efficiently performed. I can do it.

Further, to the terminal control device in the buffer busy state, when the link level response is obtained, the transmission buffer becomes empty, and the buffer busy cancellation notification is sent, so that an opportunity to restart the data transfer can be obtained. .

[Brief description of drawings]

FIG. 1 is a block diagram showing the configuration of a data link buffer pool management system of a communication control device according to an embodiment of the present invention,
2 is a schematic configuration diagram of a system to which this embodiment is applied, FIG. 3 is a diagram showing a configuration of a transmission buffer management table, and FIG.
The figure is a diagram showing the structure of a terminal control buffer management table. 1 ... Continuous communication buffer number designation means, 2 ... Data link control means, 3 ... Buffer busy notification means, 4 ... Buffer busy cancellation notification means, 6 ... Central processing unit, 7 ...
… Communication control device, 8, 9 …… Terminal control device, 10, 11, 12
...... Terminal, 21 ...... Transfer control unit, 22 ...... Sending buffer empty management control unit, 23 ...... Sending buffer control unit for terminal control, 24
...... Transmission control unit.

Claims (1)

[Claims] 1. A communication control device which is connected to a central processing unit and transfers transfer data from the central processing unit to a plurality of terminal control devices via a local area network, the communication control device and the terminal control device. It has a data link control means for controlling the data link, and a data link buffer pool used by the data link control means for storing transfer data from the central processing unit, and manages the data link buffer pool. A continuous transmission buffer number designating means for designating the number of buffers for continuously transmitting the transfer data stored in the data link buffer pool to the terminal control device, and the central processing unit to connect the communication control device to the communication control device. In response to the data transfer request to the data link control means, the continuous transmission buffer number designation When the number of continuous transmission buffers designated by the above is full, a buffer busy notifying unit for notifying the central processing unit of a buffer busy state, and by completing data transfer to the terminal control unit, A buffer busy cancellation notifying unit for notifying the central processing unit that the buffer is empty, and when the buffer of the continuous transmission buffer number designated by the continuous transmission buffer number designating unit is full, the buffer The data transfer to the corresponding terminal control device is suspended by the notification by the busy notification means, and the data transfer is performed to another terminal control device until the buffer busy cancellation notification means notifies the data transfer. A transmission buffer pool management method for a communication control device.