JPH0416815B2 - - Google Patents

Description

[Detailed Description of the Invention] [Summary] An intersystem system in which data processing systems are connected to each other and when a communication control program prepares transmission data, a communication device transmits a plurality of pieces of transmission data at once. In the communication method,
In response to the completion of transmission of individual data, the channel program is configured to instruct whether or not to notify the completion by a program control interrupt (PCi interrupt), and by taking advantage of this,
It is disclosed that the communication control program is notified of the completion of transmission for a plurality of pieces of data that have already been transmitted, thereby making it possible to reduce the number of PCi interruptions to the communication control program.

[Industrial application field]

The present invention provides an intersystem communication method, particularly an intersystem communication method in which a plurality of pieces of transmission data are sequentially transmitted between a plurality of data processing systems. This invention relates to an intersystem communication method that can reduce the number of interrupts.

[Conventional technology]

The applicant had previously filed a patent application regarding an inter-system communication method as Japanese Patent Application No. 1982-226316 (Inter-system Communication Method). This application will be described later as a conventional technique with reference to FIGS. 3 to 6, but a communication control program prepares a plurality of pieces of transmission data and sequentially transmits the plurality of pieces of transmission data, so to speak. This allows the communication control program to reduce the number of input/output interrupts made to the transmission request source program.
The entire details of the earlier patent application will be described below, as this is the premise of the present invention.

FIG. 3 shows a configuration diagram of the conventional system, and the configuration of the present invention is substantially the same overall, especially with respect to the configuration of the communication device.

In the figure, 1 is a central processing unit (CPU), 2 is a channel device (CH), 3 is a main storage device, 4 is a queue pointer section, 5 is an enqueue pointer, 6 is a dequeue pointer, 7 is a transmission communication device, 8 is an I/O interface section, 9 is a queue pointer check section, 10 is a synchronization processing section, 11 is a data transfer section, 1
2 is a dequeue pointer management section, 13 is a communication control section, 14 is a central processing unit, 15 is a channel device,
16 is a main storage device, 17 is a queue pointer section, 1
8 is an enqueue pointer, 19 is a dequeue pointer, 20 is a reception communication device, 21 is an I/O interface section, 22 is a queue pointer check section, 23 is a synchronization processing section, 24 is a data reception section, 2
Reference numeral 5 represents a dequeue pointer management section, 26 a communication control section, and 27 a communication line.

The central processing units 1 and 14 are devices that fetch and execute instructions prepared in the main memories 3 and 16, respectively, and process data. The channel device 2 is a device that controls information transfer between the central processing unit 1 or the main storage device 3 and the transmission communication device 7. The channel device 15 is a device that controls information transmission between the central processing unit 14 or main storage device 16 and the reception communication device 20.

A queue pointer section 4 consisting of an enqueue pointer (ENQP) 5 and a dequeue pointer (DEQP) 6 is provided in the main storage device 3 for data transfer in intersystem communication. The enqueue pointer 5 is an information area that notifies the sending communication device 7 that the central processing unit 1 has completed preparation of the sending buffer in order to request data transfer processing, and has an initial value of 0, for example. It is treated as a counter. The dequeue pointer 6 is an information area that is updated when the transmission communication device 7 completes the transmission of one unit of data, and is treated as a counter with an initial value of "0", for example. The contents of the enqueue pointer 5 and the dequeue pointer 6 may be considered to represent a processing request identifier and a processed identifier, respectively.

Similarly, the main memory 16 includes an enqueue pointer 18 for receiving data for intersystem communication.
A queue pointer section 17 consisting of a queue pointer 19 and a queue pointer 19 is provided. enqueue pointer 18
is an information area in which the central processing unit 14 notifies the reception communication device 20 that the preparation of the reception buffer is completed in order to request processing for data reception. It is something that is treated. The dequeue pointer 19 is an information area that is updated when the reception communication device 20 completes reception of one unit of data, and is treated as a counter with an initial value of "0", for example.
The enqueue pointer 18 and the dequeue pointer 19 can be considered to represent a processing request identifier and a processed identifier, respectively, as in the case of transmission.

The transmission communication device 7 is a peripheral device that transfers data in intersystem communication. The I/O interface unit 8 is an interface circuit that sends and receives commands and data to and from the channel device 2. The queue pointer check section 9 recognizes that the transmission buffer is ready when the contents of the enqueue pointer 5 and the contents of the dequeue pointer 6 differ. Prior to data transfer, the synchronization processing unit 10 checks whether the receiving side system is ready for reception and synchronizes with the receiving side. The data transfer unit 11 transfers data using the function of the communication control unit 13 when synchronization with the receiving side is established. The dequeue pointer management section 12 counts up the dequeue pointer 6 when data transfer in units of one request is completed. The communication control unit 13 controls communication with other systems via the communication line 27. The communication line 27 may be a direct bus line or even a general communication line.

The reception communication device 20 is a peripheral device that receives data in intersystem communication. The I/O interface unit 21 is an interface circuit that sends and receives commands and data to and from the channel device 15. The queue pointer check section 22 is
When the contents of the enqueue pointer 18 and the contents of the dequeue pointer 19 differ, it is recognized that the reception buffer is ready. Prior to data reception, the synchronization processing unit 23 checks whether the sending system is ready for transmission and synchronizes with the sending side. Data receiving section 24
The data is received by the function of the communication control unit 26 when synchronization with the sending side is established. The dequeue pointer management section 25 counts up the dequeue pointer 19 when data reception for one request unit is completed. The communication control unit 26 controls communication with other systems via the communication line 27.

In order to start the transmitting communication device 7 and the receiving communication device 20, for example, a channel command as shown in FIG. 4 is prepared. SQ command C1 is
This command instructs the communication device to transfer information in the queue pointer section from the channel device and check the enqueue pointer (ENQP) and dequeue pointer (DEQP). The communication device responds to the channel device to execute the following TIC command if ENQP=DEQP.
If ENQP=DEQP, it responds to the channel device to execute the command following the TIC command. The TIC command C2 is a command that specifies the address of the channel command word (COW) to be executed next. W command C3 is a command for transmitting data. The RDQ command C4 is a command that increments the dequeue pointer information internally managed by the communication device by 1, transfers the contents to the channel device, and updates the DEQP on the main storage device. The WD command C5 is a command for synchronizing with data transfer instructions from the transmitting side. R command C6 is a command for receiving data.

By the above command, the channel program CP is executed on the transmitting side, as shown in FIG.
1, CP2, enqueue pointer 5 and dequeue pointer 6 are prepared, and on the receiving side, channel programs CP3, CP4, enqueue pointer 18 are prepared.
By preparing the dequeue pointer 19, it is possible to realize inter-system communication with extremely low CPU overhead.

The central processing unit 1 on the sending side specifies channel programs CP1 and CP2 as shown in FIG.
Issue a START I/O command. This I/O only needs to be activated once no matter how many pieces of data are to be transferred. Then, process as follows.

In order to transmit the first data, the address and count of the transmission buffer are set in the W command of the channel program CP1, and then the value of ENQP5 is incremented by 1.

In order to transmit the next data, the address and count of the transmission buffer are set in the W command of the channel program CP2, and then the value of ENQP5 is incremented by 1.

On the other hand, the central processing unit 14 on the receiving side specifies channel programs CP3 and CP4 as shown in FIG. 5 and issues a START I/O command in advance. This I/O only needs to be started once. Then, process as follows.

To receive the first data, after setting the receive buffer address and count in the R command of the channel program CP3, ENQP18 is set to +1.

To receive the next data, set the receive buffer address and count in the R command of channel program CP4, and then press ENQP18.
Set to 1.

Both of the above channel programs CP1, CP2 and CP3, CP4 are not limited to two programs, of course, but because they each loop, I/O is not completed. Therefore, data transfer is completed by each central processing unit 1, 14.
Check and recognize DEQP6 and 19 respectively. The channel program that completes each data transfer can be used for the next data transfer. Thereby, data transfer for intersystem communication can be realized on both the transmitting side and the receiving side without causing an input/output interrupt.

FIG. 6 shows the processing operations of the transmitting communication device 7 and the receiving communication device 20. When the transmitting communication device 7 is activated by the START I/O command, it first transmits ENQP as shown in FIG.
Periodically determine whether DEQP and DEQP are equal.
If ENQP and DEQP are not equal, it means that the transmission buffer is ready, and the process moves to the next step. In the next process, in order to synchronize with the receiving side, it is first determined whether the receiving side is ready. If the preparations are not completed, the sending side is notified that the preparations are complete, and the receiving side waits for the preparations to be completed. These synchronization processes can be considered to be the same as conventional ones. Once synchronization is achieved, a notification to start data transfer is given and the data is sent. When the data transmission is completed, 1 is added to DEQP and the process moves to the next data transmission.

When the reception communication device 20 is activated by the START I/O command, as shown in FIG.
First, it is periodically determined whether ENQP and DEQP are equal. When the central processing unit 14 on the reception side prepares the reception buffer, it increments ENQP by 1, so that ENQP and DEQP are no longer equal, and the process moves on to the next process. In the next process, in order to synchronize with the sending side, it is first determined whether the sending side is ready. If the preparation is complete, the receiving side is notified that the preparation is complete. If the preparations are not complete,
After notifying the receiving side that preparation is complete, wait for a notification of preparation completion from the transmitting side. Once synchronized with the sending side, it waits for a data transfer notification and receives the data. Once the data reception is complete,
Add 1 to DEQP and move on to the next data reception process.

ENQP5, 18 and DEQP6, 19 are set to return to 0 when an overflow occurs. The central processing units 1 and 14 can manage communication buffers using these pointers. That is,
For example, it is possible to provide a buffer area address management table having entries for the total number of ENQP counts, and use the value of ENQP or DEQP as an index to the communication buffer address registered in the address management table.

[Problem that the invention seeks to solve]

The applicant has proposed an inter-system communication method as previously explained with reference to FIGS. 3 to 6, and this enables processing at I/O startup and I/O interrupt processing, etc. This makes it possible to significantly reduce the overhead in the central processing unit 1.

However, considering the program configuration in the central processing unit 1, there is a transmission request source program that makes the above transmission request, and a communication control program that controls the actual transmission processing, and when the above I/O interrupt occurs, The process corresponds to the process in which the communication control program notifies the transmission requesting program of the completion of communication. Each time the transmitting communication device 7 shown in FIG. Notifications were made using interrupts (PCi interrupts).

The present invention aims to solve this problem, and uses the channel program CP shown in FIG.
The above-mentioned problem is attempted to be solved by instructing whether or not it is necessary to perform the above-mentioned PCi interrupt for each PCi interrupt.

[Means for solving problems]

FIG. 1 shows a block diagram of the principle of the present invention.

Codes 1, 2, 3, 4, 5, 6, 7, 27 in the diagram
corresponds to FIG. 3, and it can be considered that the other party's system exists at the other end of the communication line 27, similar to that shown in FIG. In addition, numeral 28 is a communication device,
29 is an area on the memory, 30 is the head of a queue for managing transmission data, 31-1, 31-2, . . . are transmission buffer sections, and 32-1, 32-2, . . . are channel programs, respectively. This corresponds to channel programs CP1 and CP2 shown in FIG. Furthermore, 33 represents a transmission request source program, and 34 represents a communication control program.

[Effect]

In the case of the present invention, as described with reference to FIGS. 3 to 6, the contents of the queue pointer section 17 are taken into account, and based on the channel programs 32-1, 32-2, . . . (Channel 2 side is channel program 32-1, 32-
2,...), transmits multiple pieces of transmission data prepared in each of the transmission buffer sections 31-1, 31-2,... as one batch, and executes the communication control program. 34 notifies the transmission requesting program 33 that the transmission has been completed by means of an I/O interrupt, and in this respect there is no difference from the previously filed patent application.

However, the present invention has the following configuration. That is, when the transmission request source program 33 requests transmission after preparing transmission data on the transmission buffer units 31-1, 31-2, . . . , the communication control program 34 transmits the contents of the transmission request. Depending on the determined result, a PCi interrupt instruction is issued or not issued to the channel programs 32-1, 32-2, . . . . In the case of the channel program 32-1 shown in FIG.
This is a state in which a PCi interrupt instruction is not being issued, and in the case of the channel program 32-2, a PCi interrupt instruction is being issued.

FLAG in the illustrated transmission buffer section 31-i
If the () flag is on, the flag is turned on or off immediately when the transmission of the relevant transmission data is completed.
This indicates that the data is of a type that reports the completion of transmission to the communication control program 34 using a PCi interrupt, and if the () flag is off, it is not necessary to immediately report the completion of transmission to the communication control program 34. This indicates that this is the type of data that only needs to be reported based on certain opportunities.

Further, in the transmission buffer section 31-i,
LENQP represents the contents of the enqueue pointer (ENQP) 5 as a result of the communication control program 34 receiving a transmission request and enqueuing the transmission buffer section.

In the case shown in Figure 1, it is assumed that the contents of the enqueue pointer (ENQP) and the dequeue pointer (DEQP) are each initial value "0", and when receiving the transmission request RQ1. , set "No PCi interrupt instruction" to the channel command 32-1, and set the transmission buffer section 31-1.
Then, with FLAG = OFF, LENQP = 1, and ENQP = 1 set on the enqueue pointer, a transmission request is made to channel 2, and () when the transmission request RQ2 is received, the dequeue pointer If the content of (DEQP) remains "0" (that is, if the transmission of the above request RQ1 has not yet been completed), the transmission buffer section 31- set by FLAG=ON and LENQP=2 2 will be prepared. At this time, since it is necessary to perform a PCi interrupt regarding the transmission data, "PCi interrupt instruction is present" is set in the channel program 32-2, and ENQP=2 is set on the enqueue pointer. These conditions are illustrated in FIG.

On the channel 2 side, when reading each of the channel programs 32-1, 32-2, . . . and transmitting the transmission data corresponding to the transmission buffers 31-1, 31-2, do the following. . That is, in the case of "no PCi interrupt instruction" as in the channel program 32-1, when the contents of the transmission buffer unit 31-1 are transmitted, a PCi interrupt is performed to the communication control program 34 and the corresponding Does not report completion of data transmission. and,
In the case of "PCi interrupt instruction provided" as in channel program 32-2, by PCi interrupt,
() At that point, if there is data that has been transmitted but has not yet been reported, it is reported, and () the completion of data transmission in the transmission buffer unit 31-2 is reported. .

Note that, as shown in the flowchart of the embodiment in FIG. 2, when the communication control program 34 receives a new data transmission request from the transmission request source program 33, the communication control program 34 performs a process in which the transmission has been completed before then. It is also possible to further add a function to check for data that has been reported but has not yet been reported, and to recognize this fact.

〔Example〕

FIG. 2 shows an embodiment flowchart of a portion of the communication control program that is directly related to the present invention. The illustrated flowchart of the communication control program is roughly divided into two parts.
That is, () Transmission reception (1) When a transmission request is accepted, it is checked whether there is data that has been transmitted and has not yet been reported. This check can be performed by checking whether there is a transmission request with LENQP<DEQP (processing A). Those that satisfy the conditions recognize that the corresponding data has been transmitted (processing B).

(2) Next, it is checked whether the request received is of the so-called "immediate type" (processing C). If it is an immediate type, as in the channel program 32-2 shown in FIG. 1, "PCi interrupt instruction present" is set (processing D).

(3) Next, the address and counter of the transmission buffer unit 31-i are displayed in the W command (processing E), and the enqueue pointer (ENQP) is updated (processing F).

Of course, based on this result, channel 2
side will operate.

() PCi interrupt (4) When the communication control program 34 receives a PCi interrupt from channel 2 as described above, it checks whether there is data that has been transmitted and has not yet been reported (processing G). .

(5) As described above, if the condition LENQP<DEQP is satisfied, the transmission is recognized as complete (processing H).

〔Effect of the invention〕

As explained above, according to the present invention, it is also possible to reduce the number of PCi interrupts to the communication control program.

[Brief explanation of drawings]

FIG. 1 is a block diagram of the principle of the present invention, FIG. 2 is a flowchart of the main part of a communication control program, FIG. 3 is a block diagram of a conventional system, and FIGS. 4 to 6 are explanatory diagrams of the conventional system. In the figure, 1 is a central processing unit, 2 is a channel device,
3 is a main storage device, 4 is a queue pointer unit, 5 is an enqueue pointer, 6 is a dequeue pointer, 28 is a communication device, 31 is a transmission buffer unit, 3
2 represents a channel program, 33 represents a transmission request source program, and 34 represents a communication control program.

Claims (1)

[Claims] 1. Respectively independent processors 1, 14, main storage devices 3, 16, channels 2, 15, and communication devices 7, 2
At least two data processing systems equipped with When the preparation of the transmission buffers 31-1, 31-2, . In an inter-system communication method configured to transmit data and data all at once, a channel program 32- is transferred by the communication control program 34 to the channel 2 in response to a transmission request from the transmission request source program 33.
1, 32-2, ..., a program control interrupt instruction indicating whether or not channel 2 should issue a program control interrupt to the communication control program 34 at the time when the transmission of the transmission data is completed. The channel 2 is configured as described by the control program 34, and when the channel 2 detects the program control interrupt instruction, it notifies the communication control program 34 of the completion of transmission of the transmission data with the instruction. In addition, if there is transmission data that has been completed at the time of detection but has not yet been notified of the completion of transmission, it is also configured to notify the completion of transmission of each transmission data. An inter-system communication method characterized by: 2 Independent processors 1, 14, main storage devices 3, 16, channels 2, 15, and communication devices 7, 2
At least two data processing systems equipped with When the preparation of the transmission buffers 31-1, 31-2, . In an inter-system communication method configured to transmit data and data all at once, a channel program 32- is transferred by the communication control program 34 to the channel 2 in response to a transmission request from the transmission request source program 33.
1, 32-2, ..., a program control interrupt instruction indicating whether or not channel 2 should issue a program control interrupt to the communication control program 34 at the time when the transmission of the transmission data is completed. When the channel 2 detects the program control interrupt instruction, the channel 2 notifies the communication control program 34 of the completion of transmission of the transmission data with the instruction. , if there is transmission data corresponding to the presence or absence of transmission data for which transmission has been completed at the time of detection and the transmission completion has not yet been notified, the transmission completion of each transmission data is also notified; When the communication control program 34 receives an instruction from the transmission request source program 33 to perform new data transmission, the communication control program 34 determines whether or not there is any transmission that has been completed at that time and for which the completion of the transmission has not yet been notified. An inter-system communication method, characterized in that, if there is corresponding transmission data, it is configured to check the completion of transmission of each transmission data.