JPS63630A - Program calling system - Google Patents

Abstract

PURPOSE:To curtail a module control routine area by returning a module to a call origin once and calling it therefrom, without calling a call destination module from a module control routine, at the time of calling the module. CONSTITUTION:At the time of calling a module C from a module A, a module call control routine B is called once. The module control routine B which has been called checks whether the module C is loaded in a main storage or not, and in case when it is not loaded, the module C is loaded in the main storage, its load address is set to a register R15, and thereafter, a control is returned to the module A. The module A executes BALRs R14, R15, and allows them to branch into addresses shown by the register R15. In this way, even if a nest of a call becomes deep, an increase of a region caused by a module call control routine can be prevented.

Description

[Detailed Description of the Invention] [Summary] Is it modular when calling a module? Instead of calling the called module from the ff1l routine, the area of the module control routine can be reduced by returning to the calling source and calling from there.

[Industrial application field]

In the present invention, when a module A calls another module C, control is passed to a module call control routine B,
Module call control routine B loads another module C, and 1. The load address is stored in a predetermined register R.
15 and then returns control to module A. When control is returned, module A sets the above register R1.
This relates to a program calling method that branches to an address indicated by 5.

[Conventional technology]

FIG. 6 is a diagram illustrating a conventional progera calling system. In FIG. 6, A indicates a calling module, B indicates a module call control routine, and C indicates a called module. In the conventional program calling method, when module A calls module C, control is passed to the module call control routine, and module call control routine B passes control to the called module C. When control is returned from the called module C to the calling module A, the called module C returns control to the module call control routine B, and the module call control routine B returns control to the calling module.

[Problem to be solved]

In the conventional technology shown in FIG. 6, as one module calls another module and the nest gradually becomes larger, the automatic area of the module call control routine B increases, putting pressure on the user area. .

The present invention was created in view of this point, and it is an object of the present invention to provide a program calling method in which the area used by module call control routine B does not increase even if the nesting of calls becomes deep. The purpose is

Means for Solving Problem C] FIG. 1 is a diagram showing the principle of the present invention. When calling module C from module A, module calling control routine B is called once. Called module control routine F
3 checks whether module C is loaded into main memory or not, and if not loaded, loads module C into main memory and stores its load address in register R1.
5 and then returns control to module A.

Module A executes BALRR14, R15 and branches to the address indicated by register R15.

〔Example〕

Figure 2 shows the equipment configuration of the compiler. In FIG. 2, 1 indicates a source program, 2 a compiler, 3 an object module, and 4 a macro library. ? JSN9 CALL is a macro instruction newly created to implement the present invention, and an instruction sequence corresponding to this macro instruction is stored in the macro library 4.

When the compiler 2 compiles the source program 1 into an object module, does the compiler 2 compile it into an object module? JSN9CALL
Replace with the corresponding instruction sequence.

What about figure 3? It is a figure showing the outline of JSN9CALL. ? JSN9CALL Module
(A) represents a call to resident module A, and ? JSN9
CALL Module (C) is resident module C
represents a call. Also,? JSN9CALL
Module (F) Delete (0) means that non-resident module F is called and module F is not deleted after execution is completed. The entry table has modules A and B.

The offset of C9... is entered. A call to a resident module determines its offset within that module at compile time. After issuing a LOAD macro instruction during session initial processing and acquiring the start address, control can be transferred using only BALR.

DELET the resident module when the session ends
Issue an E macro. Calling the non-resident module is
A module is called when it is needed within an OAP session.

FIG. 4 is a diagram illustrating the flow of calling a non-resident module. Calling of non-resident modules is performed by the module management module of FIG. The module management module is made resident as module E. The above-mentioned module call control routine is the module management module /Iz(7). When started, the module management module performs the following processing.

■ Search for eighty tables.

■ Check whether the corresponding module exists. If YES, process (2) is performed, and if NO, process (2) is performed.

■ Issue the LOAD macro.

■ Create an entry and create an entry in the entry table.
Set address (synonymous with load address).

■ Set the entry address of the relevant module in register R15.

■ Return to the caller.

FIG. 5 is a diagram explaining the flow of deletion of a non-resident module.

■ Search the entry table.

■ Check to see if there is a modifier. YES
If the answer is ``NO'', process ``■'' is performed, and if ``NO'' is determined, process ``■'' is performed.

■ Issue a DELETE macro.

■ Delete the entry name and entry address in the entry table.

■ Return to the caller.

〔Effect of the invention〕

As is clear from the following explanation, according to the present invention, even if the nesting of calls becomes deep, it is possible to prevent the region from increasing due to the module call control routine.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the principle of the present invention, Fig. 2 is a diagram showing the equipment configuration of the compiler, and Fig. 3 is a diagram showing the equipment configuration of the compiler. A diagram showing an overview of JSN9CALL, Figure 4 is a diagram explaining the flow of calling a non-resident module, Figure 5 is a diagram showing the flow of deleting a non-resident module, and Figure 6 is a diagram explaining the conventional program calling method. be. A: Call source module, B: Module call control routine, C: Call destination module, 1...
・Source program, 2... Compiler, 3...
Object module, 4...Macro library.

Claims (1)

[Claims] When calling module C from module A, module call control routine B is called once, and after called module call control routine B calls module C, control is returned to module A, and module A to which control was returned returns. , a program calling method characterized in that control is passed to the load address of module C returned from module call control routine B.