JPH04148259A - Communication processing system - Google Patents

Abstract

PURPOSE:To reduce the waiting time of a data signal generated in a communication process, and to improve the efficiency of a file transfer by processing a received data block while receiving the next data block from another computer. CONSTITUTION:Data from another computer C2 are received at every block through a communication line 11, and before processing the received data block, an affirmation response is transmitted to the computer C2 to have transmitted the data. And the received data block is outputted to the output devices such as a data memory unit 6, a printer 7, a video display terminal equipment 8 and a magnetic tape unit 9, and the last of file data is discriminated then the communication process is finished. Thus, while receiving the next data block, the process of the already received data block can be executed at the same time, and the efficiency of the data transfer can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention is used for data transfer between computers. The present invention relates to a communication processing method for conversational communication in which data is transferred between combinators.

〔overview〕

The present invention is a communication processing method for conversational communication in which data is transferred between computers.Data reception is achieved by processing an already received data block in parallel while receiving the next data block from another computer. This is designed to reduce waiting time and improve file transfer efficiency.

[Conventional technology]

Conventionally, this type of communication processing has consisted of repeating three processes: data reception processing, received data processing, and acknowledgment transmission, as shown in FIG.

[Problem that the invention seeks to solve]

In the conventional communication processing method described above, after a response is returned to the communication partner, there is a waiting period until the next data block is received, resulting in wasted time, which has the disadvantage of reducing the efficiency of data reception. .

SUMMARY OF THE INVENTION An object of the present invention is to provide a communication processing method that can solve these problems, reduce data reception waiting time, and improve file transfer efficiency.

[Means for solving problems]

The present invention is a communication processing system that transmits an acknowledgment to another computer connected via a communication line to transmit the next data block, and processes the received data block by block. When one data block is received, an acknowledgment is sent to the communication line before executing the above processing, and the next data block is received in parallel with the processing of the received data block, and the processing of the received data block is performed. The system is characterized in that when an error or failure is discovered during the process, failure recovery processing is executed.

Failure recovery processing is a process that sends a negative response to the communication line in response to a protocol error, and failure recovery processing is a process that requests retransmission of a data block in response to an output failure of received data. be.

[Effect]

It receives data block by block from other computers via a communication line, and sends an acknowledgment to the computer that sent the data before processing the received data block. Also, the received data block is stored in the data memory device.
The data is output to an output device such as a printer, a video display terminal device, or a magnetic tape device, and the end of the file data is identified to end the communication process.

When an error is discovered in the protocol of a received data block, or when an input/output failure occurs during data output, recovery processing for the error and input/output failure is performed.

As described above, since it is extremely rare for data block protocol errors or input/output failures to occur during normal communication processing, it is possible to process previously received data blocks in parallel while receiving the next data block. This makes it possible to improve data transfer efficiency.

In the recovery process, if there is a protocol error that can be recognized before sending an acknowledgment, a negative response is sent instead of an acknowledgment. For output failures that are discovered later in time, a separate command is sent requesting retransmission of the data block.

〔Example〕

Next, an example of an apparatus implementing the present invention will be described with reference to the drawings. FIG. 1 is a block diagram showing the configuration of an apparatus implementing the present invention. computer C1 and computer C2
are connected via a communication line 11. computer C1
includes a data receiving means 1 for receiving a data block, a response transmitting means 2 for transmitting an acknowledgment before processing the received data block, and a received data output for outputting the data block received by the data receiving means 1 to an output device. means 3, end processing means 4 for identifying the end of file data and terminating the communication process, and when a protocol error in the data block received by response sending means 2 is discovered, and data outputting by received data output means 3. It also includes an input/output failure recovery means 5 that performs failure recovery when an input/output failure occurs. The received data output means 3 also includes a data memory unit (DMU) 6, a printer 7, a video display terminal (VDT) 8, and a magnetic tape unit (MTU) 9.
is connected.

Next, taking file data reception as an example, data receiving means 1,
Regarding the response transmission means 2, received data output means 3, termination processing means 4, and input/output failure recovery means 5, the second
This will be explained with reference to FIGS.

FIG. 2 is a flowchart of the data receiving means 1. The data receiving means 1 receives data blocks transmitted from the computer C2 via the communication line 11. The data block received in the reception process in step 21 is sent to the response sending means 2. If there is no received data block from computer C2 by the time t and the start of step 21, the process waits in step 21 until a data block is received from computer C2. The details of the means for waiting for received data blocks will be omitted since they are not directly related to the present invention.

FIG. 3 is a flowchart of the response sending means 2. The response transmitting means 2 determines whether the protocol of the data block received from the computer C2 is correct in step 31. For example, a protocol error such as a data block being changed due to a failure in the communication line 11 or a data block being dropped is detected. If the judgment is correct, step 3
2, and if it is not correct, it is output to the input/output failure recovery means 5.

In step 32, it is determined whether or not an acknowledgment may be sent before processing the received data block. In this embodiment, it is determined only whether it is the end of the file data. This means that if the end of the file data is received and a positive response is returned before processing the received data block, computer C2 will determine that the file transmission has ended normally and delete the file data from computer C2. This is done because there are times when you end up doing something wrong.

In this case, when an output failure occurs while computer C1 is outputting the last data block to the output device, even if computer C2 is instructed to retransmit the last data block,
This means that there is no more file data in computer C2, and the last data block of the file disappears. Therefore, an acknowledgment for the last data block of a file is performed after the processing of the received data block is normally completed. If it is the last data block as determined in step 32, it is output to the received data output means 3, and if it is not the last data block, the process moves to step 33, where an acknowledgment is sent to the computer C2 and then sent to the received data output means 3. Output.

FIG. 4 is a flowchart of the received data output means 3. The received data output means 3 determines the output device in step 41, and outputs a data block to each output device: a data memory device in step 42, a printer in step 43, a video display device in step 44, and a magnetic tape device in step 45. Next, in step 46, the output result is determined. If the output is normal, the process goes to the termination processing means 4, and if the output is not normal, the output is sent to the input/output failure recovery means 5.

FIG. 5 is a flowchart of the termination processing means 4. The termination processing means 4 determines whether the file data is the last in step 51, and if it is the last, transmits an affirmative response to the computer C2 in step 52 and ends the communication process; if it is not the last, the data receiving means - Send to 1.

FIG. 6 is a flowchart of the input/output failure recovery means 5. The input/output failure recovery means 5 determines a failure in step 61, performs protocol error recovery processing such as sending a negative response to the computer C2 in step 62 in the case of a protocol error, and performs protocol error recovery processing such as sending a negative response to the computer C2 in the case of a data output failure. At step 63, a command is sent to the computer C2 to perform data output recovery processing such as instructing retransmission of several data from before. after that,
When the recovery from the failure is completed, the process moves to the data receiving means 1.

Next, the overall operation of the embodiment of the present invention will be specifically explained with reference to FIGS. 7, 8, and 9.

FIG. 7 shows an example of normal file data reception. Computer C1 repeats the data receiving operation until it receives data 1 from computer C2. When the data 1 is received, the response sending means 2 determines the protocol and whether it is the last data, and sends an affirmative response 1 to the computer C2. Thereafter, the received data output means 3 outputs the received data 1 to the data memory group W (DMU) 6, and the end processing means 4 determines whether or not it is the end of the file data, and the process returns to the data reception means 1. The above process is repeated until the last data of the file data is received. When the data receiving means 1 receives the last data m of the file data, the response transmitting means 2 determines the protocol and whether it is the last data.

Since data m is the last data, no acknowledgment is sent. The received data output means 3 outputs a data memory device (DMU).
)6, the data m is outputted, the termination processing means 4 determines whether or not it is the end of the file data, and an affirmative response m is transmitted, thereby terminating the communication processing of the present invention.

FIG. 8 shows an example where the data block received from computer C2 has a protocol error. The data receiving means 1 receives data l from the computer C2, and the response transmitting means 2 determines whether the protocol is correct or not. If the result of the determination is that data 1 is a protocol error, the input/output failure recovery means 5 transmits a negative response to the combinator C2 and instructs it to retransmit the data 1;
Return to data receiving means 1.

FIG. 9 shows an example where an output failure occurs when data received from the computer C2 is output to the data memory unit (DMU) 6. When data k received from the computer C2 by the data receiving means 1 was output to the data memory unit (DMU) 6 by the received data output means 3, an output failure occurred, so the input/output failure recovery means 5 sent a command to the computer C2. It instructs retransmission from data k and returns to data receiving means 1. If the data receiving means receives the data l, the response transmitting means 2 determines the protocol to be incorrect, and the input/output failure recovery means 5 discards the data l.

〔Effect of the invention〕

As explained above, according to the present invention, by processing a received data block while receiving the next data block from another computer, it is possible to reduce the data reception waiting time that occurs in communication processing compared to the conventional method. This has the effect of improving the efficiency of file transfer.

[Brief explanation of drawings]

FIG. 1 is a block diagram showing the overall configuration of an embodiment of the present invention. FIG. 2 is a flowchart of the data receiving means 1 shown in FIG. FIG. 3 is a flowchart of the response transmitting means 2 shown in FIG. FIG. 4 is a flowchart of the received data output means 3 shown in FIG. 1. FIG. 5 is a flowchart of the termination processing means 4 shown in FIG. FIG. 6 is a flowchart of the input/output failure recovery means 5 shown in FIG. 1. FIG. 7 is a time chart of file data reception. FIG. 8 is a time chart when a protocol error occurs. FIG. 9 is a time chart when an output failure occurs. FIG. 10 is a conventional time chart. CLC2: Computer, 1: Data receiving means, 2: Response transmitting means, 3: Received data output means, 4: Termination processing means, 5: Input/output failure recovery means, 6 ...Data memory unit (DMU), 7...Printer, 8...Video display terminal device (VDT), 9
...Magnetic tape unit (MTU), 11...Communication line.

Claims (1)

[Claims] 1. Communication that causes another computer connected via a communication line to transmit the next data block by transmitting an acknowledgment, and processes the received data block by block. In the processing method, when one data block is received, an acknowledgment is sent to the communication line before executing the above processing, and the next data block is received in parallel with the processing of the received data block, and the received data block is processed. A communication processing method characterized in that when an error or failure is discovered during processing, failure recovery processing is executed. 2. The communication processing method according to claim 1, wherein the failure recovery process is a process of transmitting a negative response to the communication line in response to a protocol error. 3. The communication processing method according to claim 1, wherein the failure recovery process is a process of requesting retransmission of a data block in response to an output failure of received data.