JPH11242604A - Agent server and storage medium wth agent server program recorded - Google Patents

Abstract

PROBLEM TO BE SOLVED: To change functions, which can be supplied to a client program, with out correcting an existing server program by allowing an agent server to inform address information of functions, which a client can use, of the client in place of a server. SOLUTION: The address of a server side program to be given to a client program 100 by an operating system is changed to instruct the client program 100 to connect with an agent server program 108 instead of a server program 116. Then, the client program 100 accesses the address described in a callable set 106 of functions informed by the agent server program 108 to request supply of functions. Thus, functions which can be supplied to the client program 100 can be extended without correcting the server program 116.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a technique for changing a function that can be provided to a client program without modifying an existing server program in a client-server system.

[0002]

2. Description of the Related Art Conventionally, there is a system that realizes a predetermined function by coordinating a server program and a client program. In this system, a server program notifies a client program of available functions. The client program requests a desired function from the functions notified from the server program. In response, the server program provides the requested function to the client program.

[0003] Such a system is generally called a client server system (CSS). Hereinafter, the client server system will be described by taking an X window system which is a client server type window system as an example.

[0004] In the X window system, a server program (X server) displays a window on a display screen of a computer on which the server program is executed, or displays the displayed window in response to a request from a client program (application program). And draw figures inside. In addition, the server program receives a user instruction or the like input to the input device, and notifies the client program of the instruction.

On the other hand, the client program requests the server program to provide various functions, such as a request to display a window on the display screen and a request to draw a figure or the like in the window. Further, the client program performs a predetermined process according to the content of the user instruction notified from the server program.

[0006] As described above, in the X Window System, a graphical user interface (GUI) for a user to interact with a computer is realized by cooperation of a server program and a client program.

[0007]

In the conventional client-server system, the functions provided by the server program are usually fixed. Also, the client program is created on the premise of the function of the target server program.

For this reason, in a client-server system in which a server program notifies a client program of an available function and the client program requests a desired function from the functions notified from the server program, There is a problem in that the functions that can be used by the client program cannot be expanded or reduced without modifying the server program, resulting in a lack of flexibility.

For example, when new hardware appears, there is a case where it is desired to extend the functions available to the client program so that the capabilities of the hardware can be utilized to the maximum. In this case, in the conventional client-server system, the server program must be modified by adding a function not originally provided by the server program to the server program.

[0010] In addition, for a certain function provided by the server program to the client program, the processing is faster when the client program executes it than when the server program executes it. In some cases, you may not want to be provided by the server program. In this case, in the conventional client-server system, the function must be deleted from the server program and the server program must be modified.

In the above-described X Window System, as a technique for alleviating the restriction that the server program and the client program are connected on a one-to-one basis,
A technique has been proposed in which a server program called a pseudo X server is interposed between a client program (application program) and a server program to be connected to the client program (real X server) (Carsten Bormann, GeroHoffmann: Xmc and Xy). -Scalab
le Window Sharing and Mobility or From X Protocol
Multiplexing to X Protocol Multicasting, pp.205-21
0, Issue 9, The XResource).

In this technique, by changing the address given to the client program, the client program is instructed to connect to the pseudo X server instead of the real X server. Further, the pseudo X server is connected to the real X server.

By doing so, the client program accesses the real X server via the pseudo X server. Therefore, in this technique, the pseudo X
By switching the real X server to be connected by the server, the client program can request a plurality of real X servers to provide a function. Specifically, the client program causes a plurality of computers on which the server program (real X server) is executed to display a window on its display screen or to display a figure or the like in the window. Becomes possible.

However, this technique does not change a protocol (X protocol) that regulates data exchange between a client program and a server program.

That is, this technique allows a client program to access a plurality of real X servers by switching the connection between the pseudo X server and the real X server, whereby the server program and the client program are paired. This relaxes the restriction that the connection is made by 1 and the function provided to the client program via the pseudo X server is no different from the function provided by the real X server.

[0016] In the technology using the pseudo X server, functions that can be used by a client program are extended,
No consideration is given to shrinking.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a technique for changing a function that can be provided to a client program without modifying an existing server program. It is in. Specifically, the functions that can be provided to client programs are expanded without modifying existing server programs,
Or to provide a technology for reducing. Further, a specific object of the present invention is to provide a technique capable of operating new hardware with conventional software. Another object of the present invention is to provide a communication technique for expanding or reducing functions provided from the server program to the client program. Further, another object of the present invention is to provide a program, a component, and an object in which each of the above technologies is implemented. It is another object of the present invention to provide an apparatus in which software that implements each of the above technologies is installed.

[0018]

In order to solve the above-mentioned problems, a proxy server of the present invention notifies a client and address information for accessing a predetermined function to the client according to a request from the client. And a server that provides a function corresponding to the address accessed by the client to the client in a client-server system, wherein the proxy server notifies the client of the address information instead of the server. In response to a request from the client, the server sends address information for accessing a function that can be provided to the client,
First means for obtaining address information from the server, second means for creating address information for accessing a function that permits use of the client by referring to the obtained address information, and And a third means for notifying the user.

Here, the server is a server program that mainly receives requests from others and provides functions (services), and the client is a client program that requests the server program to provide functions. is there. Therefore, the client and the server may operate in one information processing apparatus, or the proxy server may function as a client / server.

In the present invention, instead of the server, the proxy server notifies the client of address information of functions available to the client. Further, the proxy server refers to address information of a function that the server can provide to the client, obtained from the server, and creates address information of a function that the proxy server permits the client to use. By doing so, it is possible to change the functions that can be provided to the client program running on the client without modifying the server program running on the server.

For example, when the proxy server has a function that can be independently provided to the client, the proxy server creates address information of a function that the client is permitted to use, including the address of the function. As a result, the functions that can be provided to the client program running on the client can be extended without modifying the server program running on the server.

Also, for example, even though the address is described in the address information of the function that the server can provide to the client, the proxy server does not include the address or an address for accessing the address. Create the address information of the function that the client is permitted to use. As a result, the functions that can be provided to the client program running on the client can be reduced without modifying the server program running on the server.

When the proxy server creates the address described in the address information of the function that the server can provide to the client in the address information of the function permitted to be used by the client, the client accesses the address. Then, the server directly provides the function. The proxy server does not participate in the processing.

On the other hand, if the proxy server creates an address for accessing the address described in the address information of the function that can be provided by the server to the client in the address information of the function permitted to be used by the client, When the client accesses the address, the proxy server accesses the server again and requests the provision of the function. This makes it possible to monitor the access status of the client to the server by the proxy server, which is effective for debugging and the like.

Further, the recording medium on which the proxy server program of the present invention is recorded provides the client program with address information for accessing a predetermined function to the client program in accordance with a request from the client program, and A server program for providing a function corresponding to an address accessed by the client program to the client program, in the client-server system, a proxy for notifying the client program of the address information instead of the server program. A recording medium on which a server program is recorded, wherein the proxy server program sends the client program to the information processing apparatus in response to a request from the client program. Obtaining address information for accessing a function that can be provided to the program from the server program, and creating address information for accessing a function permitted to be used by the client program with reference to the obtained address information. And sending the created address information to the client program.

[0026]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a client server system to which an embodiment of the present invention has been applied will be described. In this embodiment, the client-server system refers to a wide range including a program mainly receiving a request from another and providing a function (service) and a program requesting the server program to provide a function. It refers to the software form. The above functions are, for example, at least one API (Application Prog
ram Interface).

The term "program" as used herein includes processes, threads, and tasks. Further, the client / server system is defined as a unit in one information processing apparatus such as inter-process communication managed by the OS. client-
It also includes software configuration that performs server-type behavior, communication via a network using sockets, and communication between objects in a distributed environment. For example, in addition to a general client-server system that performs window management, database management, hardware management, and the like in cooperation with client programs and server programs,
The relationship between an application program and a display driver that receives a request from the application program and performs drawing on a display is also included in the client-server system according to the present embodiment.

FIG. 1 is a diagram showing the positional relationship among programs constituting a client-server system to which the present embodiment is applied.

In this embodiment, by changing the address of the server-side program given to the client program 100 by the operating system (OS), the proxy server program 108 is provided to the client program 100 instead of the server program 116.
Is instructed to connect. The proxy server program 108 is connected to the server program 116. By doing so, the proxy server program 108 is interposed between the client program 100 and the server program 116 constituting the existing client-server system.

By connecting the proxy server program 108 to the plurality of server programs 116, the client program 100 and the plurality of server programs 116 are connected.
May be configured so that the proxy server program 108 is interposed therebetween. Here, the server program 116
May be a proxy server program interposed between another server program and the proxy server program 108.

In FIG. 1, callable function set 106
Is information indicating a call address of a function that the proxy server program 108 can provide to the client program 100. In this callable function set 106, the proxy server program 108
In addition to a call address for calling a function that can be provided uniquely to the client program 100, a call address for directly or indirectly calling a function that the server program 116 can provide to the client program 100 is included.

Here, the callable function set 106 is constituted, for example, as a table in which the above information is described. It may take the form of a property returned by the server that describes the server's functionality, or a set of methods provided by the server object. The callable function set 106 is created with reference to a callable function set 114 described later in accordance with the content of a request from the client program 100. Then, the client program 100 is notified. Therefore, the contents of the callable function set 106 change depending on the contents of a request from the client program 100 (what kind of function is to be provided).

The callable function set 114 is information indicating a call address of a function that the server program 116 can provide to the client program 100. This callable function set 114 is stored in the proxy server program 108.
Is created according to the content of the request from the proxy server program 108 and notified to the proxy server program 108. Therefore, the contents of the callable function set 114 change depending on the contents of a request from the proxy server program 108 (what kind of function is to be provided). Callable function set 114
Is the same as the callable function set 106, for example,
It is configured as a table describing the above information. It may take the form of a property returned by the server that describes the server's functionality, or a set of methods provided by the server object. Note that the above-mentioned request and notification correspond to an inquiry about an “interface” from a client object to a server object in the object system and a response to the inquiry.

In FIG. 1, the client program 100
Refers to the callable function set 106 notified from the proxy server program 108, and provides the desired function.
A request is made by accessing the call address of the function described in the callable function set 106. More specifically,
After referring to the callable function set 106 and acquiring the address, the client program 100 accesses the actual function call using the OS function using the address as an argument. The arrow exiting the client program 100 and passing through the callable function set 106 indicates the operation of this embodiment.

Similarly, the proxy server program 108
By referring to the callable function set 114 notified from the server program 116, a request for providing a desired function is made by accessing the call address of the function described in the callable function set 114. Proxy server program 10
The arrow exiting from FIG. 8 and passing through the callable function set 114 indicates the operation of this embodiment.

If the call address accessed by the client program 100 is an address for calling a function that the proxy server program 108 can independently provide to the client program 100, the proxy server program 108 executes the function requested by the client program 100. Is processed and provided to the client program 100. Note that the proxy server program 108 may implement the requested function by itself, or may download other programs, components, and objects that implement the requested function, or request them to perform processing. Good.

The call address accessed by the client program 100 is stored in the server program 116.
Is an address for indirectly calling a function that can be provided to the client program 100, the proxy server program 108 refers to the callable function set 114 notified from the server program 116, and requests the client program 100 A function is requested by accessing the call address of the function described in the callable function set 114. In addition, processing related to the function or the function call is performed as necessary.

In response, the server program 116
Processes the function requested by the proxy server program 108 and provides it to the proxy server program 108. The proxy server program 108 provides the function provided by the server program 116 to the client program 100 together with the result of processing performed as necessary. For example, the proxy server program 106 can simulate parallel processing with respect to a special high-speed calculation server program. That is, the proxy server program receives a plurality of calculation requests at once, and causes the server program to execute the calculations one by one. And it provides a function to return the results all together.

The call address accessed by the client program 100 is stored in the server program 116.
Is an address for directly calling a function that can be provided to the client program 100, the server program 116 processes the function requested by the client program 100 and provides the same to the client program 100.

As described above, in this embodiment, the client program 100 requests the provision of a function by accessing the address described in the callable function set 106 notified from the proxy server program 108. I have. In addition, the proxy server program 108
A callable function including a call address for calling a function that the server program 116 can provide for the client program 100 directly or indirectly, in addition to a call address for calling a function that can be provided to the client program 100 by itself. A set 106 is created.

By doing so, it is possible to extend the functions that can be provided to the client program 100 without modifying the server program 116. Further, for example, in the case where a certain function that the server program 116 can provide to the client program 100 is faster in execution by the client program 100 than by the server program 116, a proxy server that reduces the function in advance By providing the program 108, it is possible to reduce the functions that can be provided to the client program 100 without modifying the server program 116.

Hereinafter, a hardware configuration for realizing a client server system to which the present embodiment is applied will be described. As a mode of realizing the client-server system of the present embodiment, a case where the client program 100, the proxy server program 108, and the server program 116 are processed by one computer, and a case where the client program 100 is processed via a communication network such as a LAN (Local Area Network). And a plurality of computers connected in a distributed manner.

FIG. 2 shows a client program 100,
Proxy server program 108 and server program 1
FIG. 16 is a diagram showing a hardware configuration in the case of processing 16 by one computer. CPU (central processing unit) 20
0 denotes a client program 100 and a proxy server program 10 in a storage medium such as a magnetic disk or an optical disk.
The necessary programs are loaded from the secondary storage device 202 storing the server 8 and the server program 116 onto the storage device 204 such as a memory and executed. Here, reference numeral 20
Reference numeral 8 denotes a bus for performing mutual data transfer between the CPU 200, the secondary storage device 202, and the storage device 204. The operating system (OS) is 2
It is arranged in the next storage device 202 or the storage device 204.

The program loading function is provided by an operating system (O / O) installed in the computer.
It depends on the function of S). If the target program has already been loaded, it may not be newly loaded. For data exchange between programs, an inter-program communication means provided by an operating system (OS) is used. Specifically, OS
Irrespective of the message provided by, or whether or not to use a network, a network communication using a socket or a more recent interface between objects in a distributed object environment may be used.

FIG. 3 shows the client program 100,
Proxy server program 108 and server program 1
FIG. 16 is a diagram illustrating a hardware configuration in a case where a plurality of computers are processed in a distributed manner. Here, the client program 100 is processed by the computer 201a, and the proxy server program 108 is processed by the computer 201a.
b, and the server program 116 is processed by the computer 201c. 2
01d will be described later.

The computers 201a to 201d are LA
N, except that a communication controller 206 (corresponding to a LAN adapter or a terminal adapter (TA)) for performing mutual communication via a communication network 203 such as N is provided.
This is the same as the hardware configuration of the computer shown in FIG. However, the client program 100, the proxy server program 108, and the server program 116
Are computers 201a, 201b, 201
c, which is stored in the secondary storage device 202 and is loaded onto the corresponding storage device 204 and executed by the CPU 200 of the corresponding computer. The exchange of data between the programs requires a communication network 20.
3 is used.

In the example shown in FIG. 3, an example is described in which the client program 100, the proxy server program 108, and the server program 116 are configured to be processed by different computers, but the present invention is not limited to this. For example, the proxy server program 108 and the server program 116 may be processed by the same computer, and the client program 100 may be processed by another computer. Also, the processing may be performed in other combinations.

Next, the relationship between the callable function set 106 created by the proxy server program 108 and the callable function set 114 created by the server program 116 will be described. FIG. 4 shows the proxy server program 1
08, and the callable function set 11 created by the server program 116.
FIG. 4 is a diagram for explaining a relationship with No. 4; Here, a case where a proxy server program 108 is interposed between the client program 100 and the two server programs 116-A and 116-B will be described. In addition,
Each of the client program 100, the two server programs 116-A and 116-B, and the proxy server program 108 may operate on one computer as described above. It may be in one process or a different process. Also, the arrows from the client program 100 in this figure have the same meaning as the arrows in FIG.

As shown in FIG. 4, the callable function set 106 created by the proxy server program 108 has a direct call function set 300 (300-A, 300-
B), a set 302 of indirect call functions (302-A, 30)
2-B) and a set 304 of uniquely provided functions. Here, the call address described in the callable function set 114 notified from the server program 116 is set in the direct call function set 300. Specifically, the call address described in the callable function set 114-A notified from the server program 116-A is set in the direct call function set 300-A. In addition, the call address described in the callable function set 114-B notified from the server program 116-B is set in the direct call function set 300-B. More specifically,
These sets are configured on the storage device as a table in which addresses are arranged by the proxy server program,
The client program is passed a pointer to the table.

Therefore, the client program 10
0 accesses the call address described in the direct call function set 300 and requests the provision of the function, the direct server program 116 executes a process for providing the function (arrow 306 in FIG. 4). 318). In this case, the proxy server program 108 does not intervene in the processing for providing the function to the client program 100.

In the indirect call function 302, a call address of a function for accessing the call address of the callable function set 114 notified from the server program 116 is set. Specifically, a call address of a function for accessing a call address of the callable function set 114-A notified from the server program 116-A is set in the indirect call function set 302-A. Also, in the indirect call function set 302-B, a call address of a function for accessing the call address of the callable function set 114-B notified from the server program 116-B is set.

Therefore, the client program 10
0 accesses the call address described in the indirect call function set 302, the proxy server program 10
8 performs predetermined processing as necessary and describes itself as a client in the callable function set 114 of the server program 116 via the server program call interface 321 provided therein.
Access the corresponding call address and request the provision of the function. In response, the server program 116 executes a process for providing the function (arrow 30 in FIG. 4).
8, 320).

In the set of uniquely provided functions 304, call addresses of functions which cannot be provided by the server program 116 and which can be provided by the proxy server program 116 are set. The proxy server program 116
In, a module for providing a function specified by the call address described in the uniquely provided function 304 is set.

In the example shown in FIG. 4, the server program 11
6 using the functions provided by the server program 116.
A unique providing function realizing module 322 that realizes the provision of a function that cannot be provided by the server program 116 without using the function provided by the server program 116 at all. Indicate an example of setting (see arrows 310 to 314 in FIG. 4). The uniquely provided function realizing module 324 is a proxy server program 10
8 or may request another computer via a network such as the computer 201d shown in FIG. 4 to perform processing, or may download and process components from the computer 201d. May be.

The callable function set 114 created by the server program 116 is composed of three types of subsets as shown in FIG. Set 3 of functions to be directly called
26 (326-A, 326-B) corresponds to the set 300 (300-A, 300-B) of the direct call function. Specifically, a set 326-A of functions to be directly called
Is the same as the call address described in the direct call function set 300-A. Further, the call address described in the set 326-B of the directly called function is the set 300 of the directly called functions.
-Matches the call address described in B.

A set 328 (328) of functions to be indirectly called
-A, 328-B) is a set 302 of indirect call functions.
(302-A, 302-B). Specifically, the call address described in the indirect call function set 328-A is associated with the call address of the function for accessing the address described in the indirect call function set 302-A. ing. Further, the call address described in the set of indirect call target functions 328-B is the same as the call address described in the set of indirect call functions 302-B.
It is associated with a call address of a function for accessing the address.

Set 330 of functions not to be directly / indirectly called
(330-A, 330-B) describes a call address of a function that is not included in any of the direct call target function set 326 and the indirect call target function set 328, that is, a function that is not provided to the client program 100. Subset.

Here, when the server program 116 is a display driver, what functions correspond to the direct calling function, the indirect calling function, and the originally provided function in the callable function set 106 of the proxy server program 108? An example is given below. The display driver normally performs a drawing process on a display or a printer of a computer on which the display driver is mounted, according to a request of an application program. If these functions are to be used as they are, the proxy server program 108 tabulates the call addresses of these functions described in the display driver callable function set 114 as a directly callable function set.
The pointer (address) to it is passed to the client program 100.

By the way, the display driver does not usually support a function of performing drawing processing on a plurality of displays. In order to realize a function of performing drawing processing on a plurality of displays according to a request of an application program, for example, a module that realizes a function of requesting a plurality of display drivers to perform drawing processing on a display is configured. Then, the call address to the module is set in the function provided independently.

For example, when recording the number of times the application program requests the provision of a certain function provided by the display driver for debugging, the function described in the callable function set 114 of the display driver is recorded. A call address for performing access processing to a function call address is set in the indirect call function. Then, the proxy server program 108 performs a process of recording the number of accesses to the call address set in the indirect call function.

In FIG. 4, the client program 100 and the two server programs 116-A and 116 are used.
-B, the proxy server program 108 has been described.
The relationship between the callable function set 106 and the callable function set 114 in the case where there is one or three or more is basically the same. Also, the case where the server programs 116-A and 116-B are proxy server programs interposed between another server program and the proxy server program 108 will be similarly understood from the above description. .

Next, the callable function sets 106 and 114
Will be described. FIG. 5 shows a callable function set 1
It is a figure for demonstrating the structure of 06,114. As shown in FIG. 5, the callable function sets 106 and 114 are constituted by a table having a column of the callable function descriptor 402 and a table end indicator 404 indicating the end of the column. The callable function descriptor 402 is information for calling a function that can be used by the client program 100 when the callable function descriptor 402 is included in the callable function set 106, and is a proxy when the callable function descriptor 402 is included in the callable function set 114. This is information for the server program 108 to call available functions. The callable function descriptor 402 includes a callable function identifier 406 and a callable function call address 408.

The client program 100 and the proxy server program 108 use the callable function identifier 4
The search for the target function is performed using 06, and the provision of the target function is requested by accessing the corresponding callable function call address 408. If the function to be called is known in advance, the callable function call address 408 may be replaced with a pointer indicating the address indicated by the search result when compiling the program.

Next, the operation of each program constituting the client-server system to which the present embodiment is applied will be described. As described above, each program operates by being loaded from a secondary storage device such as a magnetic disk or an optical disk onto a storage device such as a memory and executed by the CPU. As a matter of course, it is the CPU that actually performs the processing.

First, the operation of the client program 100 will be described. FIG. 6 is a flowchart for explaining the operation of the client program 100. First, the client program 100 loads and starts the proxy server program 108 (Step 50).
2). More specifically, the client program 100
In response to the request, the operating system managing the system loads and starts it. For example, by changing the address referred to by the client program 100, that is, the registered address in the system for accessing the server program 116 before the client program 100 is activated, the server program 11
The proxy server program 108 can be accessed instead of 6.

Then, the client program 100
After connecting to the proxy server program 108, the first exchanged message notifies the function that the user intends to use and requests the callable function set 106 (step 504). That is, in the present embodiment,
The client program 100 is a server program 1
When the request to the client program 100 is made, the address of the proxy server program 108 is given as the address of the server program given to the client program 100.

Next, the client program 100
When the callable function set 106 becomes accessible (step 506), necessary internal processing is performed using this set (step 508), and the pre-processing ends. In an event-driven program, the event loop starts here. Thereafter, the original processing of the client program 100 is executed (step 510). For example, referring to the callable function set 106 that has become accessible,
Access the call address of the required function and receive the provision of the function. When the proxy server program 108 is installed in another computer, the client program 100 sends the proxy server program 108 to the other computer via a communication network.
To start. Thereafter, the above-described exchange is performed with the started proxy server program 108 via the communication network.

Next, the operation of the server program 116 will be described. FIG. 7 is a flowchart for explaining the operation of the server program 116. First, the server program 116 waits for a request to be sent (step 602). The received request is a proxy server program 1
If the request is for the callable function set 114 sent from the server 08 (step 604), the callable function set 114 is created according to the function contents to be used notified from the proxy server program 108 (step 606). ,
This is notified to the proxy server program 108 (step 608). The content to be notified may be only the address as the content to be notified if the table configuration is already defined. If not specified, "function name" is associated with "address".

The received request is sent to the server program 11 sent from the proxy server program 108.
If the request is the end request of step 6 (step 610), end processing is performed (step 612). Thereafter, the CPU ends the execution of the server program 116 (Step 614).
Further, when the received request is an access to the call address described in the callable function set 114 created by itself in step 606, the process of providing the function specified by the call address is performed (step 616).

Next, the operation of the proxy server program 108 will be described. FIG. 8 shows the proxy server program 1
It is a flowchart for demonstrating the operation of 08. The operation described in this flowchart is executed each time the OS is loaded and activated. Here, in order to make the description easier to understand, a case where the proxy server program 108 is interposed between the client program 100 and one server program 116 will be described. After performing various negotiations (such as transmitting functions that can be provided from the proxy server program 108 to the client program 100) first, the proxy server program 108
Wait for a request from 0 (step 70)
2).

When the request received from the client program 100 is a request for the callable function set 106 (step 704), the server program 116 to be substituted is loaded and activated (step 70).
6). A plurality of server programs 116 may be called, or the proxy server program 108 itself may process without calling. Then, the server program 116 is notified of the function that the client program 100 intends to use, which is notified from the client program 100, and the callable function set 11 is notified.
4 (step 708). If there is only one default function to be used, it is not necessary to notify the function to be used.

Next, proxy server program 108 obtains callable function set 114 (step 710).
And the client program 1 using this set
Then, a callable function set 106 for notifying 00 is created (step 712). Thereafter, the created callable function set 106 is notified to the client program 100 (step 714). This notification is obtained by, for example, copying the callable function set 106 into the storage device 204 accessible by the client program 100,
This is done by returning the address of the copy to the client program 100.

If the request received from the client program 100 is a termination request of the proxy server program 108 (step 716), the processing request is notified to the target server program 116 and termination processing is performed (step 716). 718). Thereafter, the CPU terminates the execution of the proxy server program 108 (step 72).
0).

Further, if the received request is an access to the call address described in the set of indirect call functions 302 or the set of uniquely provided functions 304 in the callable function set 106 created by itself, The process of providing the function specified by the address is performed (step 722). In the case of access to the call address described in the set 300 of direct call functions, as described above, the server program 116 to be delegated performs the direct function providing process. 108 does not intervene in the processing.

When the server program 116 is installed in another computer, the proxy server program 108 instructs the OS of the other computer to start the server program 116 via the communication network. put out. Thereafter, the above-described exchange is performed with the started server program 116 via the communication network.

Next, the creation of the callable function set 106 performed in step 712 shown in FIG. 8 will be described in detail. FIG. 9 is a flowchart for explaining the operation when the proxy server program 108 creates the callable function set 106.

First, the callable function set 106 is initialized (step 800). Next, in steps 802 to 812, the contents of the callable function descriptor 402 described in the callable function set 114 notified from the server program 116 are checked, and the callable function set 106 is created according to the result. Go. In step 802, it is determined whether or not the investigation has been completed for all the callable function descriptors 402 described in the callable function set 114. If the processing has not been completed, the process proceeds to step 804 to acquire an unchecked callable function descriptor 402 from the callable function set 114.

In step 806, it is determined whether or not the callable function descriptor 402 extracted in step 804 corresponds to the function to be directly called for the proxy server program 108. For example, the function specified by the callable function descriptor 402 is the server program 1
If the server program 116 does not need to perform any processing related to the function when the server program 116 processes the function, the function corresponds to the function to be directly called. to decide. In this case, the callable function descriptor 402 extracted in step 804 is added to the callable function set 106 as it is (step 808), and the process returns to step 802.

At step 810, it is determined whether or not the callable function descriptor 402 extracted at step 804 corresponds to the function to be indirectly called for the proxy server program 108. For example, the function specified by the callable function descriptor 402 is the server program 1
A function to be executed by the server program 116. If the proxy server program 108 needs to perform some processing related to the function when the server program 116 processes the function, the function corresponds to an indirect call target function. Judge. In this case, the callable function descriptor 402 associated with the callable function descriptor 402 retrieved in step 804, that is, the call address of the function for performing access processing to the callable function descriptor 402 retrieved in step 804 is set. A callable function descriptor 402 including the callable function descriptor 402 is created and added to the callable function set 106 (step 812), and the process returns to step 802.

Steps 806 and 81
0, the callable function descriptor 402 determined not to correspond to any of the direct call target function and the indirect call target function is the server program 1 even though the server program 116 can provide the function.
This is a descriptor for a function that has not been provided from H.16. In the present embodiment, these functions that do not need to be provided from the server program 116 are not added to the callable function set 106. As a result, the provision of functions by the server program 116 can be reduced.

The proxy server program 108 is configured to execute the callable function set 11 notified from the server program 116.
When the investigation is completed for all the callable function descriptors 402 described in Step 4, Steps 814 to 8
At 18, the function that can be provided by itself is checked with respect to the function notified from the client program 100, and a callable function set 106 is created according to the result.

At step 814, it is determined whether or not the investigation has been completed for all the functions that can be provided independently by proxy server program 108. If the processing has not been completed, the process proceeds to step 816 to check whether or not the function that can be independently provided by the proxy server program 108 is related to the function notified from the client program 100. If it is relevant, the module that the proxy server program 108 has;
Alternatively, it is checked whether or not it can be configured using the callable function set 114 notified from the server program 116 (step 816). If so, processing transfers to step 818 to actually configure the function and add the callable descriptor 402 for the function to the callable function set 106.

When the surveillance server program 108 has finished investigating all functions that can be provided independently, it adds the table end indicator 404 to the callable function descriptor 106 (step 820).

Thus, the creation of the callable function set 106 to be notified by the proxy server program 108 to the client program 100 is completed. As described above, when the creation of the callable function set 106 is completed, for example, the callable function set 106 is copied into the storage device 204 accessible by the client program 100, and the address of the copy is set to the client program 100. To return. As described above, the client program 100 accesses the call address of the descriptor of the necessary function from the callable function descriptors 402 described in the callable function set 106 notified from the proxy server program 108, and , Requesting the provision of functions. By doing so, the existing client program 10
The functions provided to the client program 100 can be extended or reduced without making any modifications to the server program 116 and the server program 116.

By applying the present invention, old software can be operated by new hardware, and software corresponding to new hardware can be operated by old hardware. That is, there is no need to create a complicated product including an old interface. If a function for verifying the operation of software is provided by a proxy server program, a debugging tool can be configured. The present invention is realized as software running on a computer, and can be distributed using a portable storage medium or distributed from a server connected to the computer via a network.

[0086]

As described above, according to the present invention,
Without modifying the existing client and server programs, the client program 10
The functions provided to the user can be extended or reduced.

[Brief description of the drawings]

FIG. 1 is a diagram showing a positional relationship among programs constituting a client-server system to which an embodiment of the present invention is applied.

FIG. 2 is a diagram illustrating a hardware configuration when a client computer 100, a proxy server program 108, and a server program 116 are processed by one computer.

FIG. 3 is a diagram showing a hardware configuration when a client program 100, a proxy server program 108, and a server program 116 are distributed and processed by a plurality of computers.

FIG. 4 is a diagram for explaining a relationship between a callable function set created by a proxy server program and a callable function set created by a server program.

FIG. 5 is a diagram for explaining a configuration of callable function sets 106 and 114.

FIG. 6 is a flowchart for explaining the operation of the client program 100.

FIG. 7 is a flowchart for explaining the operation of the server program 116;

FIG. 8 is a flowchart for explaining the operation of the proxy server program 108.

FIG. 9 is a flowchart for explaining an operation when the proxy server program 108 creates the callable function set 106.

[Explanation of symbols]

 Reference Signs List 100 client program, 106 callable function set, 108 proxy server program, 114 callable function set, 116 server program, 200 CPU, 202 secondary storage device, 203 communication network, 204 storage device , 206: communication control device, 208: bus, 300: set of direct calling functions, 302: set of indirect calling functions, 304: set of uniquely provided functions, 321: server program calling interface, 322, 324: implementation of originally provided functions Module, 326: set of functions to be directly called, 328: set of symmetric functions, 330: set of functions not to be directly / indirectly called, 402: callable function descriptor, 404: table end indicator, 406: callable Function identifier, 4 08: Callable function call address.

Claims (10)

[Claims] A client and, according to a request from the client, address information for accessing a predetermined function, is notified to the client, and a function corresponding to the address accessed by the client is transmitted to the client. A client server system comprising: a providing server; a proxy server that notifies the client of the address information instead of the server; and the server provides the client to the client according to a request from the client. First means for obtaining address information for accessing a possible function from the server, and generating address information for accessing a function permitted to use by the client by referring to the obtained address information. Second means and the created address information And a third means for notifying the client of a report. 2. The proxy server according to claim 1, wherein the first means is described in address information obtained from the server for accessing a function that the server can provide to the client. A proxy server for creating address information for accessing a function that permits use of the client, including at least one address. 3. The proxy server according to claim 1, wherein said first means is described in address information obtained from said server for accessing a function that said server can provide to said client. A server for creating address information for accessing a function that permits use of the client, including an address for accessing at least one address. 4. The proxy server according to claim 1, wherein said first means includes an address for accessing a function that said proxy server can independently provide to said client. A proxy server for creating address information for accessing a function that permits use of the proxy server. 5. The proxy server according to claim 1, wherein the first means is described in address information obtained from the server for accessing a function that the server can provide to the client. A proxy server for creating address information for accessing a function that permits use of the client without including at least one address or an address for accessing the address. 6. A function corresponding to an address accessed by the client program, based on notifying the client program of address information for accessing a predetermined function according to a request from the client program. And a server program that provides the client program with a client program, wherein instead of the server program, a recording medium in which a proxy server program for notifying the client program of the address information is recorded, The proxy server program provides the information processing device with an address for accessing a function that the server program can provide to the client program according to a request from the client program. Obtaining address information from the server program; creating address information for accessing a function that permits use of the client program by referring to the obtained address information; and transmitting the created address information to the client program. A recording medium in which a proxy server program is recorded. 7. A recording medium on which the proxy server program according to claim 6 is recorded, wherein the address information for accessing a function permitting use of the client program is obtained from the server program. A recording medium on which a proxy server program is recorded, the program including at least one address described in address information for the program to access a function that can be provided to the client program. 8. A recording medium on which the proxy server program according to claim 6 is recorded, wherein the address information for accessing a function that permits use of the client program is obtained from the server program. A recording medium on which a proxy server program is recorded, the program including an address for accessing at least one address described in address information for accessing a function that can be provided to the client program. 9. A recording medium on which the proxy server program according to claim 6 is recorded, wherein the address information for accessing a function that permits use of the client program is stored in the proxy server program. A recording medium on which a proxy server program is recorded, including an address for accessing a function that can be provided independently. 10. A recording medium on which the proxy server program according to claim 6 is recorded, wherein the address information for accessing a function permitting use of the client program is obtained from the server program. At least one address described in address information for a program to access a function that can be provided to the client program;
Alternatively, a recording medium on which a proxy server program is recorded, wherein the recording medium does not include an address for accessing the address.