JPH04282724A - Address resolving system between programs - Google Patents

Abstract

PURPOSE:To offer an inter-program address resolving system capable of executing highly efficient system operation even in the case of using a system having severe performance conditions or a system having low processing capacity by removing overhead due to a dynamic link at the time of shifting control between programs. CONSTITUTION:In a state (1) that the address resolution of a load module has been executed and the load module has been loaded to a memory, each load module has a retrieving information table and an object module for executing processing on its leading part, the retrieving information table of a load module to be shifted is retrieved based upon a parameter by a control shifting means for shifting control from a control shifting load module to a load module to which control is to be shifted by using (2) a setting means for setting up the parameter for retrieving the retrieving information table and control is shifted (4) to an object module in the load module to be shifted.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an address resolution method between programs, and more particularly to an address resolution method between different programs (load modules) during control transfer between programs.

0002

[Prior Art] Normally, when executing a program, a plurality of object modules, which are the output results of a compiler, are collected and
This is input into a linkage editing program (hereinafter referred to as a linkage editor) to obtain a load module in which addresses between object modules have been resolved and execute it. Address resolution here means that when a program refers to information in another program or transfers control to another program, the address of the reference destination or transfer destination is set in the reference source or transfer source program. It means to put.

[0003] Recently, due to the expansion of program scale, in order to simplify the program installation work, programs are registered in computers without going through a linkage editor, and a destination address is assigned each time there is a request for startup (control transfer). , program execution using a dynamic link method to resolve addresses is commonly used.

FIG. 6 shows a conventional address resolution method. In the object module output by the compiler, the address of a reference destination or migration destination of another program is generally left unresolved. For example, in the same figure, if programs A and B are respectively associated with object modules, program A's “CALLLab
address (3) of request destination (CALL destination) “abc” of “c”
600) is not set to program A. In such cases, the linkage editor resolves unresolved addresses. In the example shown in the figure, the linkage editor sets in program A the address (3600) of the request destination (CALL destination) of program A's "CALL abc".

On the other hand, dynamic linking differs from linkage editors in that they resolve addresses in advance before program execution.
is input, the corresponding address is specified, and the address is set in the reference source or control transfer source object module.

FIG. 7 shows an example of control transfer in a general dynamic link system. In this example, load module A70 is the load module that is the source of the control transfer request, and load module B72 is the load module that is the control transfer destination. This control transfer will be explained in the case where the load module A 70 calls the load module B 72 by the dynamic link program 71.

First, the object module A73 in the load module A70 transfers control to the load module B72.
A control transition request is made to the dynamic link program 71 to transition to. Next, the dynamic link program 71 identifies the load module name from the entry name specified in the object module A73 in the load module A71. In this example, load module B
72 is specified. The dynamic link program 71 performs open processing for the load module B72,
The logical space is determined, the object module B74 in the load module B72 is loaded, the control transfer process is executed, and finally the unload process is performed.

[0008] Such a dynamic link function is a function that is executed in a state that includes external reference symbols whose addresses have not yet been determined, and dynamically connects external reference symbols whose addresses have not yet been determined during execution.

[0009]

[Problem to be solved by the invention] However, each object module in a load module is linked by a linkage editor, and becomes a load module that resolves the address of the control transfer destination and data reference destination before execution, and the address is resolved. Control transfer and data reference within a unit load module is possible, but control transfer and data reference across load modules is not possible.

[0010] Furthermore, in systems with strict performance requirements or systems with low processing power, the operating system may not have a dynamic link function, or even if the operating system can use a dynamic link program, the overhead time of the above processing may be high. Operating systems with large numbers have a problem of poor system efficiency.

The present invention has been made in view of the above points, and an object of the present invention is to provide an address resolution method between programs that eliminates the overhead caused by dynamic linking and allows more efficient system operation.

0012

Means for Solving the Problems FIG. 1 shows a diagram for explaining the principle of the present invention. At the beginning of the program, there is a load module that has a search information table in which a unique absolute address within the system and when control is transferred within the self-load module is set, and an object module that performs actual processing.
Use the link editing program between programs to set the address of the load module to which control is to be transferred to the load module to which control is to be transferred, load the load module into memory (1), and set the object module information of the load module to which control is to be transferred. Set parameters for searching the search information table (2), use the parameters as keys to search the search information table of the load module to which control is to be transferred (3), and search the search results from the load module to which control is to be transferred. The control is transferred to the load module to which the control is transferred (4).

[0013]

[Operation] The present invention realizes functions other than the address resolution function such as load module open processing, logical space allocation, and memory loading in advance when starting the system using a general operating system, and when controlling transfer and data reference. Address resolution processing is performed using the load module that has already been loaded onto the memory. An entry table is provided at the beginning of the load module to list the names of the load module's control transfer destinations and data references to unique addresses within the system.
Furthermore, a control transfer processing means is provided which searches for the address of the load module to which the control is to be transferred by searching by parameters using the entry table, and obtains the address to which the control is to be transferred.

[0014] Furthermore, it is defined which load module the object module corresponds to, and a search is made using the entry name in the entry table to obtain the control transfer destination address. This makes it possible to migrate references across programs, and resolve unresolved reference addresses or migration addresses for other programs.

[0015]

[Embodiment] First, the configuration of the present invention will be explained. Figure 2
shows the configuration of the present invention. In the figure, the load module 20 is the load module that requests control transfer (C
ALL), the load module 30 is the migration destination load module. These load modules 20,
30 includes an entry table and an object module. The control transfer processing unit 40 is the load module 20
, 30 entry tables are searched to perform address resolution processing.

[0016] Here, a series of dynamic link processes performed in the conventional method include specifying the load module name by entry name, load module open processing, logical space determination, address resolution between modules, and load processing (control transfer). processing) and unloading processing, etc. should be performed before starting the system. As a result, these processes become overhead that can be reduced during program execution. However, although it is possible to transfer control and refer to data within the load module that is the unit for which the address has been resolved, transfer of control and referencing data across load modules is not possible in this state.

Next, a method for resolving addresses between modules according to the present invention will be explained. FIG. 3 shows an example of the configuration of the load module of the present invention. An entry table 21 is provided at the beginning of the load module 20 that has a list of names of control transfer destinations and data reference destinations within the load module itself, together with addresses within the system, and the entry table 21 is composed of a name section 22 and an address section 23. be done. The name section 22 sets the name of the reference destination and the migration destination, and the address section 2
3, an absolute address for the unique name part 22 within the system is set by the linkage editor. All object modules to be referenced and migrated from other load modules are registered in this address field 23.

With this method, if each load module has an equivalent structure, the address of the object module in the other load module can be obtained by referring to the entry table of the other load module, and the address of the object module in the other load module can be obtained, referenced, and
Control transfer becomes possible.

Next, a method of control transfer using the above entry table 21 will be explained. In this embodiment, for the sake of explanation, it is assumed that one object module has one control transfer destination (entry).

FIG. 4 is a diagram for explaining one embodiment of the present invention. In this embodiment, control transfer request source load module 2
0, the control transfer processing unit 40 and the control transfer destination load module 30 are configured. The load module 20 and the load module 30 each have an entry table 2
1 and 31 are set. First, entry name “1a”
Control is transferred to object module a (entry name 1a) of load module 20 according to the specified address,
Furthermore, control is transferred from object module a to object module β (entry name 2β) in load module 41. At this time, the control transfer processing unit 40
performs control transfer by calling the control transfer process from object module a.

The control transfer processing unit 40 is the load module 2
The entry name of object module β (
2β). At this time, the first method will be described as a method for knowing in which load module within the same system the object module β exists.

The control transfer processing section 40 searches for the load module 30 based on the parameters given from within the load module 20. The parameters here include the load module name "LM2" and the entry name "2β". When searching for entry name 2β of object module β, a method for knowing in which load module in the same system object module β exists is to first specify the load module name as object module a and give it as a parameter. There is.

In this method, the link editor gives the load module name and entry name from object module a in the load module 20 as parameters. For example, change the parameter load module name to “LM2”.
”, and the entry name is “2β”.

As a result, the control transfer processing unit 40 sets the control transfer destination in the load module 30 with the entry name "
2β" (1). Next, the address of the object module β, which is a unique address within the system, is obtained from the address field 33 corresponding to "2β" in the name field 32 of the load module 30 ( 2).The control transfer processing unit 40 that has obtained the address surrenders the running right of the CPU (central processing unit) to the object module β to which control is transferred (3).Thereby, control is transferred to the object module β (4).Object When the execution of the module β is completed, control is returned to the object module a in the load module 20 (5).

A second method is to have a correspondence table in the control transfer processing section 40 and define in advance which load module the object module β exists in. FIG. 5 is a diagram showing another embodiment of the present invention. In the figure, the same components as those in FIG. 4 are given the same reference numerals, and the explanation thereof will be omitted. The control transfer processing unit 40 includes a correspondence table 50 that defines in advance which load module an object module exists in. In the target table 50, entry names and corresponding load module names are defined.

In this method, since the load module name has already been defined, the control transfer processing unit 40 uses the entry name given by the object module a in the load module 20 as a key.
Search for 0.

For example, object module a in the load module 20 provides only the entry name "2β" as a parameter. Next, using that parameter, the load module name corresponding to the parameter "2β" is searched from the entry names in the correspondence table 50. The load module name in this case is "LM2" (1). Therefore, the control transfer processing unit 40 searches the entry table 42 of the load module 41 (2). Searches for the address corresponding to the entry name in the entry table 42, finds a predefined unique address within the system (3), and having acquired the address, the control transfer processing unit 40 transfers the CPU running right to the object module β. Do (4). When the execution of the object module β is completed, control returns to the return destination address (control transfer processing unit 40) (5). Therefore,
The control transfer processing unit 40 returns control to the object module a of the load module 20 that is the source of the control transfer request (
6).

In this way, locations (entries) that are referenced from other programs or to which control is transferred within the own program are defined as an entry table at the beginning of the program (load module), and the entries can be referenced by looking into the entry table. By specifying the control transfer destination, reference across programs and control transfer can be realized.

[0029]

[Effects of the Invention] As described above, according to the present invention, it is possible to avoid the overhead of opening (initializing) a load module, allocating logical space, and loading memory at the time of control transfer by dynamic linking in control transfer processing. can. Further, even in an operating system that does not have a dynamic link function, high-speed performance can be obtained by using a function equivalent to a dynamic link function.

[Brief explanation of the drawing]

FIG. 1 is a diagram for explaining the principle of the present invention.

FIG. 2 is a diagram showing the configuration of the present invention.

FIG. 3 is a diagram showing an example of the configuration of a load module of the present invention.

FIG. 4 is a diagram for explaining one embodiment of the present invention.

FIG. 5 is a diagram for explaining another embodiment of the present invention.

FIG. 6 is a diagram showing a conventional address resolution method.

FIG. 7 is a diagram showing an example of control transition in a general dynamic link method.

[Explanation of symbols]

20 Control transfer source load module 21, 31 Entry table 22, 32 Name part 23, 33 Address part 30 Control transfer destination load module 40 Control transition processing section 50 Target table

Claims (1)

[Claims] Claim 1: A load module that has a search information table in which an absolute address unique within the system and at the time of control transfer within the self-load module is set at the beginning of the program, and an object module that performs actual processing, is connected and edited between programs. The program sets the address of the load module to which control is to be transferred to the load module from which control is to be transferred, loads the load module into memory, and uses the information of the object module of the load module from which control is to transfer to the search information table. Set a parameter to search for, use the parameter as a key to search the search information table of the load module to which control is to be transferred, and transfer control from the source load module to the load module to which control is to be transferred that corresponds to the search result. An address resolution method between programs characterized by transfer of control.