JPH01191232A - External module acquiring system - Google Patents

Abstract

PURPOSE:To set necessary file resources to only an object module store file by linking dynamically an object module existing in the object module store file to a load module in a main storage. CONSTITUTION:A dynamic link means 4 executes a solution of a reference of an undefined external symbol by using an external symbol management table 6 for recording an external symbol existing in a main storage 1, a hash table for managing the external symbol management table 6 and an undefined reference chain which corresponds to undefined external symbols, respectively and links a reference part to these external symbols, to a list format, based on information for a static linker which a file 30 for storing an object module being an external module has. Also, the object module 3 is placed again in the main storage 1, and an inlet name registering means 7 outputs an interface routine 8 for making the object module 3 which has been placed again by the dynamic link means 4 executable as one module for forming an object module. In such a way, file resources can be curtailed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an external module acquisition method, and more particularly, the present invention relates to an external module acquisition method, and in particular, a load module that is being executed dynamically links an object module existing in an object module storage file to a self-load module. This invention relates to a method for acquiring an external module that can be executed as one module.

[Conventional technology]

Conventionally, as this type of external module acquisition method, there is a method in which a load module being executed links and operates another load module as one module of its own load module.

In addition, the load module being executed starts the static linker using the file containing the self-load module and the file containing the object module to be linked as input files, and the load module output to the file as a result and the self-load module There is a method of making an object module executable as one module of the self-loading module by using a method of reflecting the difference between the module and the self-loading module.

[Problem to be solved by the invention]

In the conventional external module acquisition method described above, in the case of the method of linking load modules, each module linked to the fal main load module must constitute a load module. Before executing a module, all the load modules to be linked must be created in advance (bl If multiple of these load modules are doing dynamic memory management, each load module must be Even if the module operates without any contradiction, there are drawbacks such as the strong possibility that conflicts will occur between dynamic memory management due to linking these load modules.

On the other hand, in the case of the method of starting the static linker at runtime, the file that stores the fc) self-loading module is input to the static linker, so this file has a format that allows re-input of the static linker. Generally, such a load module storage file requires larger file resources than a normal load module storage file.In comparing the load module output by the fdl static linker and its own load module, The entrance of the newly added object module is unknown from the increment alone, and some kind of analysis is required for the object module storage file, so a lot of input/output processing is performed in conjunction with static linker processing. However, there are drawbacks such as a long processing time required to acquire external modules.

In view of the above points, an object of the present invention is to dynamically link an object module existing in an object module storage file to a load module in main memory, and execute the object module as one module forming a load module. The purpose of the present invention is to provide an external module acquisition method that enables the acquisition of external modules.

[Means to solve the problem]

In the external module acquisition method of the present invention, a load module loaded onto the main memory and being executed loads an external module existing in an external storage device onto the main memory, and forms this external module as a self-load module. In an external module acquisition method capable of being executed as one module, an external symbol records an external symbol existing in the main memory based on information for a static linker included in a file storing an object module as the external module. References to undefined external symbols are made using a management table, a hash table that manages this external symbol management table, and an undefined reference chain that connects references to these external symbols in a list format corresponding to each undefined external symbol. dynamic linking means for solving the problem and relocating the object module in the main memory, and making the object module relocated by the dynamic linking means executable as one module forming the load module. and an entrance name registration means for outputting an interface routine.

[Effect]

In the external module acquisition method of the present invention, the dynamic linking means performs external symbol management that records external symbols existing in the main memory based on information for a static linker that a file that stores an object module as an external module has. Resolving references to undefined external symbols using an undefined reference chain that connects references to these external symbols in a list format corresponding to tables, hash tables that manage external symbol management tables, and undefined external symbols. and relocate the object module in main memory,
The entrance name registration means outputs an interface routine for making the object module relocated by the dynamic linking means executable as one module forming a load module.

〔Example〕

Next, the present invention will be explained in detail with reference to the drawings.

FIG. 1 is a block diagram showing the configuration of an external module acquisition method according to an embodiment of the present invention.6 The external module acquisition method according to this embodiment includes a main memory 1 and a load loaded on the main memory 1. External symbols are created based on information for the module 2, the object module 3 stored in the object module storage file 30 on the external storage device, and the static linker (not shown) that the object module storage file 30 has. Management table 6. Hash table 5 and undefined reference chain 9 (see Figures 3 and 8)
a dynamic linking means 4 that resolves references to undefined external symbols and relocates the object module 3 in the main memory 1 using External symbol management table 6 that records external symbols existing in the interface routine 8
an interface routine 8 for making the object module 3 relocated by the dynamic linking means 4 executable as one module forming the self-loading module 2, and an undefined external symbol. The main part thereof consists of an undefined reference chain 9 that corresponds to each of the external symbols and connects references to these external symbols in a list format.

Referring to FIG. 2, the external symbol management table 6 includes a symbol name address 61, a module entrance address, a symbol start address, or an undefined reference chain 9.
a reference resolution entry 62 that stores the start address of
Type indicator ra indicating the type of content of the reference resolution entry 62
63, and a hash chain entry 64 that connects external symbol management tables 6 for external symbols having the same hash value.

Referring to FIG. 3, the undefined reference chain 9 is composed of entries consisting of a next entry address 91 and a reference location address 92 connected in a list format. In addition,
The terminal entry of the undefined reference chain 9 is determined by the next entry address 91 being 0.

Referring to FIG. 4, the processing in the dynamic linking means 4 includes an initialization determination step 41 and an initialization processing step 4.
2, a reference resolution step 43, and a relocation step 44.

Referring to FIG. 5, the processing in the entrance name registration means 7 consists of an external symbol name input step 71, an interface routine output step 72, and an interface routine recording step 73.

Referring to FIG. 6, the processing in the interface routine 8 consists of a call parameter creation step 81, an object module call step 82, and a return value creation step 83. Note that it is easy to add to the interface routine 8 processes for setting and canceling register saving and restoring 2 exception handlers, etc., as necessary.

Next, the operation of the external module acquisition method of this embodiment configured as described above will be explained with reference to FIGS. 7 to 9.

It is now assumed that the load module 2 is loaded into the main memory 1 and is operating, and the load module 2 does not have any information regarding the object module 3.

When there is an instruction to acquire the object module 3 along with the operation of the load module 2, the dynamic linking means 4 is activated.

The dynamic linking means 4 first checks whether or not the initialization process has been completed (step 41). Various methods can be used for checking, but in this embodiment, the initialization completion flag (not shown) is used. ) and check its value.

If the initialization process has not been completed, dynamic linking means 4
As shown in FIG. 7, the initialization process includes the creation of a hash table 5 and the creation of a module that has an entrance in the load module 2 and is to be shared with an external module (for example, the memory management module 21゜l10 (input Output) module 2
2, etc.), and sets the initialization completion flag to a value indicating that the initialization has been completed (step 42).

If the initialization process has been completed in step 41, the dynamic linking means 4 skips step 42.

Next, the dynamic linking means 4 secures an area for loading the object module 3 on the main memory 1, and extracts the area for the static linker from the object module storage file 30 storing the object module 3 to be acquired. Parts other than information, that is, object module 3
body (hereinafter simply referred to as object module)
Load.

Subsequently, the dynamic linking means 4 performs linking for the external symbols possessed by the object module 3 and the external symbols referenced from the object module 3 based on the information for the static linker recorded in the object module storage file 30. The external symbol management table 6 is created and updated (step 43).

To explain in detail the process of creating and updating the external symbol management table 6, there are the following cases (1) to (2) in resolving references to external symbols.

■ When the object module 3 already loaded on the main memory l has no information regarding the symbol, and the symbol is defined in the newly loaded object module 3.

In this case, the dynamic linking means 4 allocates the external symbol management table 6 for this symbol on the main memory 1 and writes the symbol name address 61 therein.

Next, the start address of the symbol is calculated from the storage address of the object module 3, and the reference resolution entry 6
Fill in 2. Then, write in the type indicator 63 that it has been defined.

■ When the object module 3 already loaded on the main memory 1 does not have information regarding the symbol, and the symbol is referenced in the newly loaded object module 3.

In this case, the dynamic linking means 4 allocates the external symbol management table 6 for this symbol on the main memory 1, writes the symbol name address 61, and writes the reference resolution entry 62 into the O Enter the type mark 1li63
Enter the fact that it is undefined.

■ When there is a definition for a symbol in the object module 3 that has already been loaded into the main memory 1, and the symbol is also defined in the newly loaded object module 3.

Since this case does not normally occur, the dynamic linking means 4 interrupts the process as an error in the user's specification.

■ When there is a definition for a symbol in the object module 3 that has already been loaded into the main memory 1, and the symbol is referenced in the newly loaded object module 3.

In this case, the dynamic linking means 4 writes the address of the actual symbol to the reference location in the subsequent relocation process (see (2) below), and therefore does not perform the process in step 23.

■ When there is a reference to the symbol in the object module 3 that has already been loaded into the main memory l, and the symbol is defined in the newly loaded object module 3.

In this case, in the relocation process of the object module 3 that has already been loaded, the reference location to the symbol is recorded by the undefined reference chain 9 (see (3) below).

For example, as shown in FIG.
Assume that a reference to the symbol MI exists in an undefined state. For this state, as shown in FIG. 9, the object module 3 having the definition of the symbol SYMI
When loaded into the main memory 1, the dynamic linking means 4 loads the reference point address 92 of each entry of the undefined reference chain 9.
Write the start address of symbol SYMI at the address indicated by . Next, the symbol S is also added to the reference resolution entry 62 of the external symbol management table 6 for the symbol SYMI.
Enter the starting address of YMI. Next, type indicator 6
3 is updated to the defined tongue.

■ When there is a reference to the symbol in the object module 3 that has already been loaded into the main memory 1, and the symbol is also referenced in the newly loaded object module 3.

In this case, the dynamic linking means 4 extends the undefined reference chain 9 for the symbol in the subsequent relocation process (see (3) below), so no processing is performed in step 43.

Subsequently, the dynamic linking means 4 links the object modules in the main memory 1 based on the information for relocation, which is the manual information of the static linker, recorded in the object module storage file 30. A relocation process is performed on the data (step 44).

Relocation is required in the following reference locations: fil~
Regarding (3).

+11 For references within the newly loaded object module 3 itself.

In this case, the dynamic linking means 4 re-enters the start address of the object module 3 into the reference location in addition to the value entered in the reference location, that is, the offset value from the object module 3.

(2) As a result of the reference resolution process, the reference from the newly loaded object module 3 is resolved using an external symbol existing in the main memory 1 (see (2) above).

In this case, the dynamic linking means 4 determines which external symbol the reference location refers to from the information for relocation recorded in the object module storage file 30, and manages the corresponding external symbol. When the type mark 1l163 in Table 6 is examined, the external symbol is already defined, so the contents of the reference resolution entry 62 are transferred to the reference location.

(3) As a result of the reference resolution processing, the reference from the newly loaded object module 3 remains unresolved even if an external symbol existing in the main memory 1 is used, and it is necessary to extend the undefined reference chain 9. If there is (see ■ above).

In this case, the dynamic linking means 4 determines which external symbol the reference location refers to from the information for relocation recorded in the object module storage file 30, and manages the corresponding external symbol. Examining the type index @63 in Table 6, the external symbol is undefined, so one entry of undefined reference chain 9 is allocated on main memory 1, and the reference resolution entry of external symbol management table 6 is set to the next entry address 91. 62, enter the address of the reference location of the external symbol in the reference location address 92, and enter the address of the entry of the undefined reference chain 9 in the reference resolution entry 62 of the external symbol management table 6.

With the above steps, the operation of the dynamic linking means 4 is completed.

The object module 3 loaded onto the main memory 1 by the dynamic linking means 4 has completed reference resolution and relocation, but the load module 2 has an established method for passing parameters to the object module 3. Therefore, in the state immediately after the operation of the dynamic linking means 4 is completed, the load module 2 transfers the object module 3 to one of its own load modules 2.
It is not possible to run it as a module.

Therefore, following the completion of the operation of the dynamic linking means 4, the entrance name registration means 7 is activated.

The entrance name registration means 7 first inputs the external symbol name, description language, return data type, and parameter data type of the object module 3 from the user (step 71). Note that the method of passing parameters differs depending on the description language of object module 3 (
For example, in C language, parameter passing is done by value,
In the FORTRAN language, the interface routine 8 needs to make a call corresponding to the description language of the object module 3, and for this purpose, it is essential to obtain the description language as information.

Next, as shown in FIG. 1, the entrance name registration means 7 outputs the interface routine 8 onto the main memory 1 (step 72), and by pointing the start address from the load module 2, the interface routine is output to the load module 2. 8 is recorded (step 73).

Next, load object module 3 into module 2
The operation when executed as one module that forms the following will be explained.

When the load module 2 that is being executed starts the object module 3, control is passed to the interface routine 8. The interface routine 8 creates call parameters based on the parameters passed from the load module 2 (step 81), calls the object module 3 as a subroutine (step 82), and when the operation of the object module 3 is completed, the interface routine 8 When control returns to step 83, the interface routine 8 creates a return value to the load module 2 based on the data returned from the object module 3 (step 83), and returns control to the load module 2.

〔Effect of the invention〕

As explained above, the present invention dynamically links the object module existing in the object module storage file to the load module in the main memory, so that the user can simply make the external module to be called an object module. Often, there is no need to run a static linker, and as a result, the only file resource required is the object module storage file.

Also, references between each module are resolved dynamically, so
External symbols defined by the main load module can be referenced by the called external module, and as a result, multiple modules can dynamically operate in the same process space by, for example, sharing a memory management module. This has the effect of making it possible to perform memory management.

Furthermore, by calling the external module loaded via the interface routine, the user does not have to consider the calling procedure at all when calling the external module.

[Brief explanation of the drawing]

FIG. 1 is a block diagram showing the configuration of an external module acquisition method according to an embodiment of the present invention. FIG. 2 is a diagram showing the configuration of the external symbol management table in FIG. 1. FIG. FIG. 4 is a flowchart showing the processing of the dynamic linking means in FIG. 1; FIG. 5 is a flowchart showing the processing of the entrance name registration means in FIG. 1; FIG. 6 is a flowchart showing the processing of the entrance name registration means in FIG. A flowchart showing the processing of the interface routine in Fig. 1, Fig. 7 is a diagram for explaining the initialization processing by the dynamic link means in Fig. 1, and Fig. 8 is a flowchart showing the processing of the interface routine in Fig. 1. FIG. 9 is a diagram showing an example of an undefined reference chain in storage, and is a diagram showing a state in which the undefined external symbols shown in FIG. 8 have been eliminated by relocation processing. In the figure, 1... Main memory, 2... Load module, 3... Object module, 4... Dynamic link means, 5... Huffsh table, 6... External symbol management table, 7 ... Entrance name registration means, 8... Interface routine, 9... Undefined reference chain, 21... Memory management module, 22... I10 module, 30... Object module storage file, 61
...Symbol name address, 62...Entry for reference resolution, 63...Type indicator, 64...Hatsch chain entry, 91...Next entry address, 92...Reference location address.

Claims (1)

[Claims] A load module loaded onto the main memory and being executed loads an external module existing in an external storage device onto the main memory, and uses this external module as one module forming its own load module. an external symbol management table that records external symbols existing in the main memory based on information for a static linker included in a file storing an object module as the external module; References to undefined external symbols are resolved using a hash table that manages this external symbol management table and an undefined reference chain that connects references to these external symbols in a list format corresponding to each undefined external symbol. dynamic linking means for relocating the object module in the main memory; and an interface routine for making the object module relocated by the dynamic linking means executable as one module forming the load module. An external module acquisition method comprising: an entrance name registration means for outputting; and an external module acquisition method.