JPH11154132A - Server/client communication system - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide high reliability in transmission/reception of data and to realize exclusive control in inter-process communication without increasing the number of access times by permitting a reception side process to execute data reception processing after transmission from a transmission side process terminates and executes exclusive control in inter-process communication. SOLUTION: A process (A) changes/designs the exclusive control flag of a file in an inner storage part from '0' to '1'. The process (B) of a reception side recognizes the exclusive control flag '1' of the file in the inner storage part. The process (B) of the reception side is set to a waiting state for recognizing the exclusive control flag '1'. The process (A) executes a data transmission processing and the process (A) changes/sets the exclusive control flag of the file in the inner storage part from '1' to '0'. The process (B) of the reception side can receive data since the exclusive control flag of the file is '0' in such a state.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of processing data from a host computer by a server machine and displaying the processed data on a screen.
In addition, the present invention relates to a server / client communication system used for a local area network (LAN) or the like, which prints out with a printer and sends it to a client machine to display a screen. Server performs exclusive control in inter-process communication between a server process and a client process when a server requests a processing operation on a file through message communication with the server.
It relates to a client communication system.

[0002]

2. Description of the Related Art Conventionally, a server / client communication system has been used in a local area network employing a UNIX operation system (OS) which is widely used mainly for workstations. This server /
In a client communication system, data transmission and reception are performed between a server-side process and a client-side process by inter-process communication. In this case, the client-side process reads the data written by the server-side process before the end of the writing and recognizes the existence of the data. Therefore, only the data written so far is read.

As examples of performing such exclusive control, for example, a conventional example of Japanese Patent Application Laid-Open No. Hei 4-286044 "Server / Client Data Processing Device" and a conventional example of Japanese Patent Application Laid-Open No. Hei 6-19774 "File Server System" are known. Have been.
In the former conventional example, the number of message transmissions for exclusive control is reduced by using a nonvolatile memory, and the processing efficiency is increased. Further, in the latter conventional example, a data transfer unit on a line is determined in accordance with a transfer request for a file from an application program, and deterioration of transfer efficiency due to division of data transmission is suppressed. Furthermore, the update data is compressed to reduce the data transfer amount, thereby improving the throughput (data processing capacity).

[0004]

In such a conventional example, data transmission and reception are performed from a server-side process to a client-side process by inter-process communication. in this case,
Since the client-side process reads the data written by the server-side process before the end of the writing and recognizes the existence of the data, the client-side process may be able to read only the data written so far. That is,
Complete data transmission / reception cannot be performed at once, making it difficult to obtain high reliability in data transmission / reception and increasing the number of accesses. In other words, there is a disadvantage that exclusive control cannot be performed by highly reliable interprocess communication.

The present invention has been made to solve the above-mentioned problems in the prior art, and enables complete data transmission and reception at one time, high reliability in data transmission and reception can be obtained, and the number of access times can be improved. It is an object of the present invention to provide a server / client communication system capable of performing exclusive control in inter-process communication with high reliability without increasing the number of programs.

[0006]

In order to achieve the above object, a server / client communication system according to the first aspect of the present invention transmits and receives data between a server-side process and a client-side process by inter-process communication. At the time of the transmission, the receiving process performs data reception processing after transmission of the transmitting process is completed, and executes exclusive control in inter-process communication.

In the server / client communication system according to the second aspect, the transmitting-side process sets or releases an exclusive control flag, and the receiving-side process refers to the setting or releasing of the exclusive control flag, so that the inter-process can be set. It is configured to execute exclusive control in communication.

According to a third aspect of the present invention, the server / client communication system is configured to set or cancel the exclusive control flag by setting “0” or “1”.

According to a fourth aspect of the present invention, in the server / client communication system, the server-side process and the client-side process are configured as a single system of one data processing device having one internal storage file.

According to a fifth aspect of the present invention, in the server / client communication system, one of the server-side process and the client-side process has a file in a storage device, and the server and the client are connected via a network to perform inter-process communication. And execute exclusive control in inter-process communication by performing network file system processing.

In a server / client communication system according to a sixth aspect, the network is a local area network.

In a server / client communication system according to a seventh aspect, the server-side process and the client-side process repeatedly execute data processing, data transmission processing, and data reception processing.

The server / client communication system according to claim 8, wherein the data processing processes data, and then processes data transmission to a process on the other end.
It is configured to execute a process of receiving data from a process on the partner side.

According to a ninth aspect of the present invention, in the server / client communication system, the data transmission process sets an exclusive control flag in the file, then executes the data transmission process, and further releases the exclusive control flag in the file. It is configured to execute a setting process.

According to a tenth aspect of the present invention, in the server / client communication system, the data receiving process includes a process for confirming the data reception, a process for confirming the existence of the received data, and a process for setting an exclusive control flag for the file. With reference to the settings, the data reception process is executed thereafter.

The server / client communication system according to claim 11, wherein the server-side process is one, the client-side process side is a plurality, and the file in the internal storage unit of the server or the client includes the client-side process. The configuration is such that an address is assigned for each side process, and an exclusive control flag is set or released for each address to execute exclusive control in inter-process communication.

According to a twelfth aspect of the present invention, there is provided a server / client communication system for processing and distributing data from a host device, and an inter-process communication and network file system connected to the server machine via a local area network. A server machine that executes processing, the server machine executes exclusive control in inter-process communication as a single system, and a process between the server machine and another server machine as a server / client system is performed. It is configured to execute exclusive control in communication.

According to a thirteenth aspect of the present invention, in the server / client communication system, the server machine includes a control program execution unit serving as a server-side process and a display program execution unit for displaying data from a host device serving as a client-side process. And a display program execution unit serving as a client-side process that executes inter-process communication and a network file system process with a control program execution unit via a local area network in the other server machine.

In the server / client communication system according to the present invention, a printer for outputting a hard copy in which data from a host device is printed is connected to the control program execution unit, and the display program execution unit is connected to the control program execution unit. In addition to executing processing for displaying data on a screen, the display program execution unit includes a screen display unit.

In the server / client communication system having such a configuration, when data is transmitted and received by inter-process communication between the server-side process and the client-side process, the data is transmitted to the receiving-side process after the transmitting-side process has finished transmitting. The reception process is performed to execute exclusive control in inter-process communication.

In this exclusive control, the transmitting process sets or cancels the exclusive control flag in the file of the internal storage unit with "0" or "1", and sets or cancels the exclusive control flag on the receiving side. Exclusive control in inter-process communication is being executed by referring to the process.

The server-side process and the client-side process are a single system of one data processing device having one file in the internal storage unit, and the server-side process and the client-side process have one file in the storage device. The server and the client are connected via a network to perform inter-process communication and network file system (NFS) processing, and execute exclusive control in the inter-process communication.

The server-side process and the client-side process process and distribute data from the host device, and are connected to the server machine via a local area network to provide inter-process communication and a network file system. (NFS) processing and other server machines, and exclusive control in inter-process communication is executed as a single system using only the server machines. Also, a server / client system that connects a server machine to another server machine via a network such as a LAN executes exclusive control in inter-process communication.

As a result, complete data transmission / reception can be performed at once. Therefore, high reliability in data transmission / reception can be obtained, and exclusive control of inter-process communication (data transmission / reception) can be achieved without increasing the number of accesses.

[0025]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Next, an embodiment of the server / client communication system of the present invention will be described in detail with reference to the drawings. FIG. 1 is a block diagram showing a configuration of a data communication network to which a server / client communication system of the present invention is applied. This data communication network
A host device 1 such as a computer for transmitting data;
A server machine 2 for transmitting data from the host device 1 through inter-process communication, and a screen display unit 3 using a CRT (CRT) or a liquid crystal display (LCD) for displaying data from the server machine 2 on a screen.
And

The data communication network further includes a printer 4 for printing and outputting data from the server machine 2, a LAN connection control processing unit 7 for controlling connection of a local area network (LAN), and a server machine 2. A server machine 8 connected through the LAN connection control processing unit 7 and a C for displaying data from the server machine 8 on a screen
It has a screen display unit 9 using an RT (CRT), a liquid crystal display (LCD), or the like.

The server machine 2 sends data from the host device 1 to the printer 4 and executes a control program for performing inter-process communication with the server machine 8 through the LAN connection control processing unit 7. An execution unit 2a and a screen display program execution unit 2b for executing a program for displaying data from the control program execution unit 2a on the screen display unit 3 are provided. Also, the server machine 8 executes a program for displaying data from the control program execution unit 2a of the server machine 2 through the LAN connection control processing unit 7 on the screen display unit 9 by inter-process communication. 8a.

The control program execution unit 2a and the screen display program execution unit 2b in the server machine 2 are composed of, for example, a central processing unit (CPU) and a memory. Similarly, the screen display program execution unit 8a in the server machine 8 is also configured by a central processing unit (CPU) and a memory.

FIG. 2 is a block diagram showing a processing state of a single system for performing exclusive control in inter-process communication in FIG. 1 according to the first embodiment. This single system corresponds to the configuration of the control program execution unit 2a and the screen display program execution unit 2b in the server machine 2. This single system is a process (A) in the control program execution unit 2a.
And the process (B) in the screen display program execution unit 2b executes exclusive control in inter-process communication, and includes an internal storage unit (C) having a file.

FIG. 3 is a block diagram showing a processing state of a server / client system for performing exclusive control in inter-process communication in FIG. 1 according to the second embodiment. This server / client system corresponds to the configuration of the control program execution unit 2a of the server machine 2, the screen display program execution unit 8a of the server machine 8, and the LAN connection control processing unit 7 in FIG.

In the server / client system shown in FIG. 3, a process (A) in the control program execution unit 2a of the server machine 2 and a process (B) in the screen display program execution unit 8a of the server machine 8 are performed. Inter-process communication and network file system (NFS) processing are performed through the LAN connection control processing unit 7. Further, the control program execution unit 2a of the server machine 2 includes a disk device (D) having an exclusive control flag in the internal storage area of the file.

Next, the operation of this embodiment will be described. In the data communication network shown in FIG. 1, the server machine 2 transmits data from the host device 1 to the screen display unit 3, the printer 4, and the server machine 8 via the LAN connection control processing unit 7.
It is sent by inter-process communication through. In the server machine 2, the control program execution unit 2 a transmits data from the host device 1 to the printer 4 and the LAN connection control processing unit 7.
And executes a control program for inter-process communication sent to the server machine 8 through the server.

The screen display program execution unit 2b executes a program for displaying the data from the control program execution unit 2a on the screen, and displays the data on the screen display unit 3. Further, data from the control program execution unit 2a is printed by the printer 4, and a hard copy thereof is output. Furthermore,
Data from the control program execution unit 2a is processed by the screen display program execution unit 8a of the server machine 8 through the LAN connection control processing unit 7, and is displayed on the screen display unit 9.

Next, the exclusive control in the inter-process communication in the single system shown in FIG. 2 will be described. The single system shown in FIG. 2 having the configuration of the control program execution unit 2a and the screen display program execution unit 2b in the server machine 2 of FIG. 1 includes the process (A) in the control program execution unit 2a and the screen display program execution unit 2b. Process (B) executes exclusive control in inter-process communication.
In this exclusive control, when the process (A) and the process (B) perform data transmission / reception by inter-process communication, for example, the process (A) on the receiving side is terminated until the process (A) on the transmitting side ends data transmission. B) does not perform reception. In this single system, the internal storage (C)
File has an exclusive control flag (exclusive control flag), and the process (A) with the transmission side refers to the exclusive control flag in the disk device (D) before receiving data.

The process (A) on the transmission side sets the exclusive control flag value to "1", sets the exclusive control flag value to "0" after data transmission, and cancels the reception impossible by referring to the exclusive control flag. I do. As a result, even if the process (B) recognizes the existence of the reception data which is the transmission data from the process (A), the data reception of the exclusive control flag value is changed from “1” to “0” until the reception failure is canceled. Do not process. In other words, complete data transmission / reception can be performed at once, and exclusive control by inter-process communication that can obtain high reliability without increasing the number of accesses without increasing the reliability of data can be achieved.

Hereinafter, the exclusive control of the inter-process communication between the process (A) in the control program execution unit 2a and the process (B) in the screen display program execution unit 2b in this single system will be described in detail. Process (A) (B)
Repeatedly executes data processing, data transmission processing, and data reception processing.

FIG. 4 is a flowchart showing the processing procedure of the data processing of the processes (A) and (B). In this data processing, data processing is executed (step S41),
A process for transmitting data to the process (A or B) on the receiving side is executed (step S42). Next, a process of receiving data from the process (A or B) on the transmission side is executed (step S43).

FIG. 5 is a flowchart showing the procedure of the data transmission process in the processes (A) and (B). In this data transmission processing, the exclusive control flag is changed and set from “0” to “1” in the file in the internal storage unit (C) (Step S).
51) Then, a data transmission process is executed (Step S)
52). Further, the exclusive control flag is set from "1" to "0" in the file in the internal storage unit (C) to cancel the reception impossibility (step S53).

FIG. 6 is a flowchart showing the procedure of the data receiving process in the processes (A) and (B). In this data receiving process, a process for confirming data reception is executed (step S61), and then the existence of received data is confirmed (step S62). If the received data exists (S63: Yes), the setting of the exclusive control flag “1” of the file is determined (step S64), and if the exclusive control flag “1” is not set here (S64:
Yes), execute data reception processing (step S6)
5).

FIG. 7 is a diagram for explaining exclusive control in inter-process communication between the process (A) of the control program execution unit 2a and the process (B) of the screen display program execution unit 2b. When the process (A) is on the transmission side, first, the process (A) on the transmission side changes and sets the exclusive control flag of the file in the internal storage unit (C) from “0” to “1”. The process (B) on the receiving side checks the file exclusive control flag “1” in the internal storage unit (C). The process (B) on the receiving side has the exclusive control flag “1”.
Is set to wait for confirmation. The process (A) executes the data transmission process, and then the process (A) changes the exclusive control flag of the file in the internal storage unit (C) from “1” to “0”. In this state, the process (B) on the receiving side can perform data reception processing because the exclusive control flag of the file in the internal storage unit (C) is “0”.

That is, complete data transmission / reception is performed once in a single system. Therefore, the exclusive control of the inter-process communication (data transmission / reception) with high reliability is obtained without increasing the number of access times and the data reliability.

Next, the operation of the second embodiment will be described. The second embodiment operates similarly to the single system of the first embodiment shown in FIG. That is, the host device 1
Is sent from the server machine 2 to the screen display unit 3 and the printer 4. Further, the server machine 8 takes in data from the server machine 2 by inter-process communication through the LAN connection control processing unit 7. The control program execution unit 2a of the server machine 2 executes the control program. The screen display program execution unit 2b executes a program for displaying the data from the control program execution unit 2a on the screen, and displays the data on the screen display unit 3. Further, the data from the control program execution unit 2a is printed by the printer 4, and the data from the control program execution unit 2a is
The screen display program execution unit 8a of the server machine 8 processes through the AN connection control processing unit 7 and displays the screen on the screen display unit 9.

Next, exclusive control in inter-process communication in the server / client system shown in FIG. 3 will be described. In this server / client system, the process (A) in the control program execution unit 2a of the server machine 2 and the screen display program execution unit 8 in the server machine 8
The inter-process communication with the process (B) and the network file system (NFS) process in a are performed through the LAN connection control processing unit 7.

In the exclusive control of the process (A) in the control program execution unit 2a and the process (B) in the screen display program execution unit 8a of the server machine 8, the processes (A) and (B) When transmitting and receiving data by communication, the process (A) and the process (B) perform inter-process communication through the LAN connection control processing unit 7. And a network file system (NF
S) through the control program execution unit 2 of the server machine 2
The exclusive control in inter-process communication similar to the first embodiment is performed by referring to the exclusive control flag of the internal storage area of the file in the disk device (D) a.

In referring to the exclusive control flag, the process (A) in the control program execution unit 2a sets the exclusive control flag value to "1", and sets the exclusive control flag value to "0" after the subsequent data transmission. Change the setting and cancel the reception disabled.
As a result, even if the process (B) recognizes the existence of the received data, which is the transmission data from the process (A), the exclusive control flag value is changed from “1” to “0” until the reception disable is canceled. Does not perform data reception processing. That is, similarly to the first embodiment, the processing procedure of the data processing in the processes (A) and (B) shown in FIG. 4, the processing procedure of the data transmission processing shown in FIG. 5, and the processing procedure of the data reception processing shown in FIG. Execute

The exclusive control in the detailed inter-process communication is the same as the exclusive control in the process (A) in the control program execution unit 2a and the process (B) in the screen display program execution unit 8a of the server machine 8 shown in FIG. It is. That is, when the process (A) is on the transmission side, first,
The process (A) changes and sets the exclusive control flag of the file in the internal storage unit (C) from “0” to “1”. The process (B) on the receiving side checks the file exclusive control flag “1” in the internal storage unit (C). The process (B) on the receiving side is set to a wait state for confirming the exclusive control flag “1”. The process (A) executes the data transmission process, and then the process (A) changes the exclusive control flag of the file in the internal storage unit (C) from “1” to “0”. In this state, the process (B) on the receiving side can receive data because the exclusive control flag of the file in the internal storage unit (C) is “0”.

In the server / client system of the second embodiment, complete data transmission / reception is performed at one time as in the single system of the first embodiment. Therefore, the exclusive control of the inter-process communication (data transmission / reception) with high reliability is obtained without increasing the number of access times and the data reliability.

In the first and second embodiments, when the process (B) becomes the transmitting side, the exclusive control in the inter-process communication is performed in the same manner as in the case where the process (A) is the transmitting side. .

In the first and second embodiments,
Exclusive control in inter-process communication between processes (A) and (B) has been described. That is, the exclusive control in the inter-process communication of one client to one server has been described. However, the case where a plurality of clients are provided can be similarly handled. In this case, the exclusive control flag is set to “0” and the release is set to “1”, and an address for identifying each of a plurality of clients is assigned. Exclusive control in communication may be performed.

[0050]

As is apparent from the above description, according to the server / client communication system of the present invention, the transmitting process sets the exclusive control flag to "0" or "1" in the file of the internal storage unit. Then, the exclusive process in the inter-process communication is executed by referring to the setting or release of the exclusive control flag by the receiving process.

As a result, complete data transmission / reception can be performed at once. Therefore, high reliability in data transmission / reception can be obtained, and exclusive control of inter-process communication (data transmission / reception) with high reliability can be performed without increasing the number of accesses.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a configuration of a data communication network to which a server / client communication system of the present invention is applied.

FIG. 2 is a block diagram illustrating a processing state of a single system that performs exclusive control according to the first embodiment.

FIG. 3 illustrates a server that performs exclusive control according to the second embodiment.
FIG. 4 is a block diagram illustrating a processing state of the client system.

FIG. 4 is a flowchart illustrating a processing procedure of data processing in the embodiment.

FIG. 5 is a flowchart illustrating a processing procedure of a data transmission process in the embodiment.

FIG. 6 is a flowchart illustrating a processing procedure of a data receiving process in the embodiment.

FIG. 7 is a diagram for explaining exclusive control in inter-process communication according to the embodiment;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Host device 2, 8 Server machine 2a Control program execution part 2b Screen display program execution part 3, 9 Screen display part 4 Printer 7 LAN connection control processing part 8a Screen display program execution part 9 Screen display part

Claims (14)

[Claims] When transmitting and receiving data by inter-process communication between a server-side process and a client-side process, the reception-side process performs data reception processing after the transmission of the transmission-side process, and performs data reception processing. A server / client communication system for performing exclusive control. 2. The transmission-side process sets or releases an exclusive control flag, and the reception-side process refers to the setting or release of the exclusive control flag to execute exclusive control in inter-process communication. The server / client communication system according to claim 1, wherein 3. The method of setting or canceling the exclusive control flag,
3. The server / client communication system according to claim 2, wherein the communication is performed by setting "0" or "1". 4. The server / client communication system according to claim 1, wherein the server-side process and the client-side process are a single system of one data processing device having one file in an internal storage unit. . 5. The server-side process and the client-side process each include a file in a storage device, and the server and the client are connected via a network to perform inter-process communication and network file system processing. 2. The server / client communication system according to claim 1, wherein exclusive control in communication is performed. 6. The server / client communication system according to claim 5, wherein said network is a local area network. 7. The server-side process and the client-side process repeatedly execute data processing, data transmission processing, and data reception processing.
A server / client communication system as described. 8. The data processing is characterized by processing data, then processing data transmission to a partner process, and executing data reception processing from the partner process. The server / client communication system according to claim 7. 9. In the data transmission process, an exclusive control flag is set for a file, then the data transmission process is executed, and further, a process of setting the release of the exclusive control flag for the file is executed. The server / client communication system according to claim 7, wherein 10. In the data receiving process, a process of confirming data reception, a process of confirming existence of received data, a process of referring to setting of an exclusive control flag in a file, and a process of 8. The server / client communication system according to claim 7, wherein the following processing is performed. 11. The server-side process is one,
A plurality of client-side processes are provided, and an address for each of the client-side processes is assigned to a file in an internal storage unit in the server or the client, and setting or release of an exclusive control flag is further performed for each of the addresses. 2. The server / client communication system according to claim 1, further comprising executing exclusive control in inter-process communication. 12. A server machine which processes and distributes data from a host device, and another server machine which is connected to the server machine via a local area network and executes inter-process communication and network file system processing. Wherein the server machine executes exclusive control in inter-process communication as a single system, and the server machine executes exclusive control in inter-process communication as a server / process system between the server machine and another server machine. A server / client communication system, comprising: 13. The server machine, further comprising: a control program execution unit serving as a server-side process and a display program execution unit for displaying data from a host device serving as a client-side process, wherein the other server machine 13. The server / client according to claim 12, further comprising a display program execution unit serving as a client-side process for executing inter-process communication and network file system processing with the control program execution unit through a local area network. Communications system. 14. A printer for outputting a hard copy on which data from a host device is printed is connected to the control program execution unit, and the display program execution unit executes processing for displaying data from the host device on a screen. 14. The server / client communication system according to claim 13, wherein the display program execution unit includes a screen display unit.