JPH01125643A - Control system for divided transmission/reception of message - Google Patents

Abstract

PURPOSE:To avoid the deadlocks due to the buffer waiting state caused by the shortage of buffers at a high load by opening an uncompleted message buffing buffer to positively cope with the shortage of buffers at the transaction processing of a computer system. CONSTITUTION:The input/output of transaction messages are controlled by the transmission/reception control means 5 of a computer system and the transaction messages are processed by a processing program 6 in response to the start of the means 5. At the same time, the contents of messages are changed by reference to a terminal control table 1 consisting of the entries corresponding to each terminal and storing the message transmission/reception control information. Then the buffing actions of the output messages received from the program 6 into a buffer pool 3 and the divided transmission of those messages to terminals are controlled by a buffing control means 7. The transaction messages received from the means 5 are received by a terminal program 4 and a buffer control table 2 storing buffers is opened at the shortage of buffers. Thus no deadlock is produced.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a message division transmission/reception control method in a transaction processing system on a computer system and a communication program on a terminal.

[Conventional technology]

In a conventional message transmission control system in a transaction processing system, a transaction message processing program makes multiple buffering requests and holds unfinished messages in a buffer until the output message is completed.

In addition, in the message reception control method of the terminal program,
Completed messages were now received all at once.

[Problem that the invention seeks to solve]

In the conventional transmission/reception control method in the transaction processing system and terminal program described above, in response to the occurrence of a buffer shortage in the transaction processing system, the buffer holding the unfinished message is allocated to another buffer and the output message is completed. will not be released until

When a buffer shortage occurs under high load, most of the buffers are used for output messages, so even if there are other ways to release buffers, they are not very effective, and deadlocks of the transaction processing system due to waiting for buffers may occur. The problem was that it was easy.

[Means for solving problems]

The message division transmission/reception control method in the transaction processing system and terminal program of the present invention consists of terminal management table means (hereinafter referred to as terminal management tape storage) that stores message transmission control information, which is composed of entries corresponding to each terminal, and is configured from multiple buffers of the same size. A buffer pool means (hereinafter referred to as a buffer pool), a buffer management table means (hereinafter referred to as a buffer management table) that stores management information of the buffer usage status of this buffer pool, and a transaction message processing program that controls input/output of transaction messages. a transmission/reception control means to be activated; a buffering control means for controlling the terminal management table and controlling output of the processing program, buffering of the message, and divided transmission; It includes terminal program means (hereinafter referred to as terminal program) that performs specialized message reception control.

〔Example〕

The present invention will be explained in detail with reference to the drawings.

Referring to FIG. 1, one embodiment of the present invention includes a terminal management table 1 that includes entries corresponding to each terminal and stores message transmission control information, a buffer pool 3 that stores a plurality of buffers of the same size, A buffer management table 2 that stores management information indicating the usage status of the buffers stored in the buffer pool 3, a transmission/reception control means 5 that controls input/output of transaction messages, and a transmission/reception control means 5 that responds to activation of the transmission/reception control means 5. A processing program 6 that processes transaction messages, and a buffering control that refers to the terminal management table l, updates the contents, and controls buffering of output messages from the processing program 6 to the buffer pool 3 and divided transmission to terminals. and a terminal program 4 which is specialized for transaction processing and receives transaction messages from the transmission/reception control means 5 in a terminal communicating with the transaction processing system.

Referring to FIG. 2, the terminal management table 1 is made up of entries corresponding to each terminal, and each entry is made up of a terminal identification name field, a terminal status field, a divided transmission field, and a buffer pointer field. The terminal status field stores the value "0" when the terminal is normal, and stores the value "1" when the terminal is abnormal (failure occurrence or disconnection). The value "0" is stored in the divided transmission flag field for terminals that have not performed divided transmission, and the value "1" is stored for terminals that have started divided transmission.

The buffer pointer field contains the buffer chain information of the buffer in which the output message is buffered, and if no buffering is being performed, the value is “0-”.
” is stored.

Referring to FIG. 3, the buffer management table 2 is composed of a total number of buffers field, a number of allocated buffers field, and a threshold number of allocated buffers field. The total number of buffers field stores the total number of buffers on the buffer pool 3, and the allocated buffer number field stores the number of buffers in use at each point in time. As the allocated buffer number threshold, the number of in-use buffers that is a criterion for recognizing a buffer shortage is set for each transaction processing system from the viewpoint of system management.

When the number of allocated buffers is equal to or greater than this value, the transaction system recognizes a buffer shortage.

Referring to FIG. 4, each buffer of the same size in buffer pool 3 of FIG. 1 is comprised of a message type field and a message buffer field.

The message type field has meaning only in the first buffer of the multiple buffers that make up each message. As shown in Figure 5, the value "0" is stored in the case of a message output that only displays a message, and the value "1" is stored in the case of a message display and message output waiting for input, and a buffering request is stored. In the case of time division transmission, the value "2" is stored. The message data body is placed in the message buffering field.

Referring to FIG. 6, the first
A general processing flow of the processing program 6 shown in the figure is shown. The processing program 6 completes the output message by repeating the buffering request several times, issues a message output request, repeats this several times until there are no more output messages, and then ends the process.

Next, in one embodiment of the present invention, FIG.
This will be explained in detail with reference to FIGS. 8, 9, 10, and 11.

First, the buffering processing control method of the buffer control means 7 will be explained with reference to FIG.

Referring to FIG. 7, in the buffering process, it is called when a buffering request is made from the processing program 6, and control is returned to the processing program 6 in response to the completion of the process.

In the buffering process, divided output is performed when there is a buffer shortage and at a terminal that has started divided transmission, and in other cases, normal buffering is performed. When there is a buffer shortage, the divided transmission flag of the terminal in the terminal management table l shown in FIG. 2 is set to the value "1" prior to the divided transmission processing.
be made into

Buffering is performed in response to a previous buffering request, and if there is no buffered message in buffer Boolean 3 in Figure 1, a buffer is secured, the buffer is initialized (cleared to 0), and the buffer is cleared. The message will be embedded in the empty area. If the l buffer is insufficient in size, a new buffer is allocated and the continuation of the message is embedded, and the same process is repeated until all the messages are embedded.

For divided output, normal buffering is performed, the message type of the first buffer of the combined divided messages is set to the value "2", and immediate transmission processing is called.

Next, the message output processing control method of the transmission/reception control means 5 will be explained with reference to FIG.

Referring to FIG. 8, the message output process is called when a message output is requested from the processing program, and control is returned to the processing program in response to the completion of the process. When requesting message output, either display only or display and then wait for input is selected by the processing program and notified.

In message output processing, divided output is performed when there is a buffer shortage or at a terminal that has started divided transmission, and normal output is performed in other cases.

For normal output, the message type of the buffer at the head of the output message is set to "0" or "l" according to the selection instruction of display only or wait for input after display, and immediate transmission processing is called. For split output, secure a buffer, initialize the buffer (clear it to 0), set the value "2" to the message type of the buffer, and immediately send the message data without embedding the message data other than the message type. call

Next, a method of controlling the processing program start-up process of the transmission/reception control means 5 shown in FIG. 1 will be explained with reference to FIG. 9.

Referring to FIG. 9, the processing program activation waiting process is activated when a transaction message is received.

In the processing program startup waiting process, the disassembly transmission flag corresponding to the terminal is set to "0".

Next, the immediate output processing control method of the transmission/reception control means 5 is changed to the first one.
This will be explained with reference to FIG.

Referring to FIG. 10, the immediate output process is called from the buffering process of the buffer control means and the message output process of the transmission/reception control means.

Immediate output processing can be performed by multiple servers if the terminal status is normal.

If it is a file, the buffers are taken out in order from the first buffer, and an input/output (hereinafter referred to as l10) request is output to the terminal, and after the processing in response to the request is completed, all buffers are released.

The I10 request is controlled as shown in FIG. 5 depending on the type of message in the first buffer. That is, if the message type is "0" or "2", all buffers are continuously transmitted. If the message type is "1", continuous transmission is performed except for the last buffer, and then the last buffer performs reception-waiting transmission.

If the terminal status is abnormal or if the processing result of the I10 request is detected before the transmission of all buffers is completed, all buffers are released without transmitting the message. I1
0 If an abnormality is detected, the terminal status of the terminal is set to "1".

Next, a message reception processing control method in the terminal program 4 will be explained with reference to FIG.

In message reception processing, if the communication result is normal, processing is performed according to the message type of the received message. If the message type is "2", the received message is buffered as a divided message in preparation for receiving the next message. If the message type is "0" or "1", the message is displayed on the screen or printer. At this time, if the divided message is buffered, the received message is combined with the buffered message and displayed, and after the display is completed, the buffer contents are initialized.

If the communication result is abnormal, the communication abnormality is displayed on the screen or printer, and then the buffer contents are initialized.

〔Effect of the invention〕

Abnormality As mentioned above, the present invention proactively deals with a buffer shortage in a transaction processing system by releasing the buffer for unfinished message buffering. This is an effective means to avoid deadlocks caused by waiting. Furthermore, the present invention has the effect of not imposing an unnecessary burden on communication control when the transaction processing system is under low load.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing an embodiment of the present invention, FIG. 2 is a diagram showing the configuration of the terminal management table 1 in FIG. 1, and FIG. 3 is a diagram showing the configuration of the buffer management table 2 in FIG. 1. Figure 4 is the first
5 is a diagram illustrating the control of message types and immediate output processing; FIG. 6 is a diagram illustrating the processing flow of the processing program 6 of FIG. 1; 7 is a diagram for explaining the operation of the buffering means 7 of FIG. 1, FIGS. 8, 9, and 10 are diagrams for explaining the operation of the transmission/reception control means 5 of FIG. 1 in detail. and FIG. 11 are diagrams for explaining the message reception processing control system of the terminal program 4 of FIG. 1. In the figure, 1...terminal management table, 2...
... Buffer management table, 3 ... Buffer pool, 4 ... Terminal program, 5 ...
...transmission/reception control means, 6...processing program,
7... Buffering control means. Agent Patent Attorney Otoji Uchihara 2 Figure 3 Figure 6 @

Claims (1)

[Scope of Claims] Terminal management table means for storing message transmission control information consisting of entries corresponding to each terminal; buffer pool means for storing a plurality of buffers; A message division transmission/reception control system comprising: buffering control means for buffering output messages in the buffer pool means and controlling division transmission to the terminals.