Linking Natural Objects to the Natural Nucleus

The Natural nucleus is a collection of service programs such as memory administration, string handling, operating system interfaces, the compiler and the runtime environment which comprise the kernel of Natural. It is independent of the operating-system and the TP system.

The Natural nucleus consists of the environment-independent and the environment-dependent nucleus. The environment-independent nucleus can be used by several mainframe operating and TP systems. The environment-dependent nucleus contains components that depend on the operating and TP systems. For further information, see Natural Nucleus Components in the Installation for z/OS, Installation for z/VSE and Installation for BS2000 documentation.

This document describes the advantages of linking Natural objects to the Natural nucleus and provides information on how to proceed.

This section covers the following topics:


Benefits

Linking Natural objects to the Natural nucleus provides the following benefits:

  • Better Performance
    The objects are executed from the nucleus and not from the Natural buffer pool. This saves space in the buffer pool and also results in fewer database calls. (If Natural cataloged objects are not linked to the Natural nucleus, they are stored in a database file, for example Adabas, and the actual code must be loaded from this file into the buffer pool before it can be executed.)

  • Consistency
    As an object which is linked to the Natural nucleus is always executed from the nucleus, there is no effect if the cataloged object from which it was derived is deleted or changed in the Natural system file. Thus, during each TP-monitor session, the status of the object remains unchanged. A new version of an object which is linked to the nucleus can be obtained by unloading it with ULDOBJ (see below), relinking the new version to the Natural nucleus and refreshing the Natural module. (Refreshing implies that a new copy of a module is loaded into the TP monitor region.)

  • Global Error Handling
    If a cataloged object fetches another program to handle errors (for example, by using the Natural system variable *ERROR-TA), and the error-handling program cannot be loaded into the buffer pool, the original error might be missed and any subsequent error may mask the first error and lead to confusion. To prevent this situation, you can link a user-written global error-handling program to the nucleus.

ULDOBJ Utility

You can use the ULDOBJ utility to link Natural cataloged objects to the Natural nucleus. With the ULDOBJ utility, you generate an object module from a Natural cataloged object and write it to a Natural work file. The generated object module is then processed by the linkage editor and linked to the Natural nucleus.

Under z/OS and z/VSE: When an environment-independent Natural nucleus is used, the generated object module has to be linked to the environment-independent part of the nucleus.

Using ULDOBJ to Generate an Object Module

Beginn der AnweisungslisteTo invoke the ULDOBJ utility

  1. Log on to the library SYSMISC and issue the command ULDOBJ.

    15:49:39            ***** NATURAL OBJECT MAINTENANCE *****           2012-02-13
    User: XYZ                 - NATURAL ULDOBJ UTILITY -          Library: SYSMISC 
                                                                  Opsys .. z/OS    
                                                                                   
                                                                                   
                        Specify parameters below ....                              
                                                                                   
                                  Object ...... ________   (Enter '.' to exit)     
                                  Library ..... SYSMISC_                           
                                  OP System ... z/OS____
    
    
  2. Specify and confirm the following parameters:

    Object The name of the cataloged object to be processed. The object can be a program, subprogram, subroutine, helproutine or map.
    Library The name of the library containing the cataloged object.
    OP System The name of the operating system for which the object module is to be generated. (Different operating systems have different rules to which the object module must conform.) The name of the operating system must be one of the following:
    z/OS z/OS systems
    z/VSE z/VSE systems
    BS2000 BS2000 systems

    For each object processed, the ULDOBJ utility displays a report containing the following information:

    • the object type (Program, Subprogram, Subroutine, Helproutine, Map, Adapter); see Objects for Natural Application Management in the Programming Guide.

    • the name of the cataloged object processed;

    • the programming mode (S = structured mode, R = reporting mode);

    • the name of the library containing the cataloged object;

    • the name of the operating system for which the object deck was generated;

    • the size of the cataloged object and optimized code (if applicable);

    • the Natural version of the cataloged object (see Version in the Glossary);

    • statistics about the last cataloging of the object, including user and terminal IDs.

    ULDOBJ prompts for another object and library after the data from the initial input have been processed. The operating system is not requested, because it does not make sense to generate object modules for more than one operating system for the same Natural work file.

Beginn der AnweisungslisteTo terminate the ULDOBJ utility

  • After the last cataloged object has been processed, enter a "." in the first input field (Object) and press ENTER.

    The generated object module conforms to the format of the specified operating system. It is in relocatable format with non-executable code and consists of:

    • an external symbol directory (ESD),

    • a relocation dictionary (RLD),

    • text with the instructions and data corresponding to the program,

    • an END statement (end-of-module indicator for the load module).

    The generated object module is written to a Natural work file, which is used as input to a linkage editor. (Depending on the operating system, it may be better to use ULDOBJ in batch mode.)

    The generated object module must be processed by the linkage editor of the corresponding operating system before the code is executable as a load module (see the example given below). Each load module is valid once it is linked to the Natural nucleus and defined by an NTSTAT entry definition in the Natural configuration module NATCONFG (see Natural Configuration Tables).

Additional Considerations for Linking Subroutines

Once a cataloged object has been unloaded by the ULDOBJ utility and linked to the Natural nucleus, the cataloged object can be deleted from the Natural system file.

However, this is not true for an object of type "subroutine". A subroutine has two names:

  • the name specified in the statements PERFORM and DEFINE SUBROUTINE and

  • the name of the object that contains the DEFINE SUBROUTINE statement.

Natural internally associates these two names, but this is possible only if the cataloged object still exists on the Natural system file. If the cataloged object were deleted, this association would be lost and the subroutine linked to the nucleus would not be executable.

Operating System Dependency of Object Module Generation

The object module is generated in different ways, according to the operating system. These differences are listed below.

Platform Requirement
z/OS A NAME control statement is generated as the last card of the object module. It specifies the replace function. For example:
NAME TEST (R)

TEST is the name of the cataloged object.

z/VSE The object module(s) will be in LIBR format. A CATALOG control statement is generated as the first card and a "/*" as the last card of the object module. For example:
CATALOG TEST.OBJ REPLACE-YES
... ... object module ...
/+

TEST.OBJ is the name of the cataloged object.

When the LIBR utility is executed, assign SYSIPT to the work file written by the ULDOBJ utility (ASSIGN SYSIPT=work-file-1).

BS2000 The object module(s) will be in LMS format. An ADD control statement is generated as the first card and an END statement as the last card of the object module. For example:
ADDR >TEST
... ... object module ...
END

When the LMS utility is executed, assign SYSDTA to the work file written by the ULDOBJ utility (SYSFILE SYSDTA=work-file-1). The file name generated is Nvr.MOD, where vr represents the relevant product version.

If multiple cataloged objects are unloaded during execution of the utility, the object decks are appended to each other.

Example of Linking a Natural Object to the Natural Nucleus

If, for example, the objects LOGPROG and EDITPROG in the library SYSLIB are to be linked to the Natural nucleus, the following steps could be taken:

  1. Identify the cataloged objects to be linked.

    Object         Library
    -------------- --------------
    LOGPROG        SYSLIB
    EDITPROG       SYSLIB
  2. Set up the batch Natural job stream. Assuming a z/OS environment, include the following cards:

    //CMWKF01  DD DSN=ULD.NAT.PGMS,UNIT=SYSDA,DISP=(,KEEP),
    //            SPACE=(CYL,(3,1),,RLSE),VOL=SER=VVVVVV,
    //            DCB=(RECFM=FB,BLKSIZE=800,LRECL=80)
    //CMSYNIN DD *
    LOGON SYSMISC
    ULDOBJ LOGPROG,SYSLIB,OS
    EDITPROG,SYSLIB
    .
    FIN
    /*
  3. Set up the linkage editor job stream.

    //JOBCARD JOB (ACCTING),CLASS=A,MSGCLASS=X
    //*
    //* GENERATE OS LOAD MODULE FROM ULDOBJ UTILITY
    //*
    //LINK1    EXEC PGM=IEWL,PARM='LIST,LET,XREF,NCAL,RENT,REUS'
    //SYSLMOD  DD DSN=NATURAL.USER.LOAD,DISP=SHR
    //SYSUT1   DD UNIT=SYSDA,SPACE=(1024,(200,20))
    //SYSPRINT DD SYSOUT=X
    //SYSLIN   DD DSN=NAT.ULD.PGMS,DISP=OLD,UNIT=SYSDA,VOL=SER=VVVVVV  
    /*

    This step places the load modules LOGPROG and EDITPROG in the NATURAL.USER.LOAD data set.

    With an additional link-edit job, these modules can be linked together as a single load module before being linked to the nucleus in Step 5.

    //JOBCARD JOB (ACCTING),CLASS=A,MSGCLASS=X
    //*
    //* OPTIONAL JOB TO LINK CATALOGED OBJECTS TOGETHER
    //*
    //LINK2    EXEC PGM=IEWL,PARM='LIST,LET,XREF,NCAL,RENT,REUS'  
    //SYSLMOD  DD DSN=NATURAL.USER.LOAD,DISP=SHR
    //SYSUT1   DD UNIT=SYSDA,SPACE=(1024,(200,20))
    //SYSPRINT DD SYSOUT=X
    //SYSLIN   DD *
    INCLUDE SYSLMOD(LOGPROG)  LOGON NATURAL PGM
    INCLUDE SYSLMOD(EDITPROG) EDITOR NATURAL PGM
    NAME XXXXXX(R)
    /*
  4. Define the statically linked Natural programs in source module NATCONFG in the NSTATIC table for linked Natural programs:

    NTSTAT INPL,TYPE=W
    NTSTAT INPLLIB,TYPE=W
    NTSTAT AERROR,TYPE=W
    NTSTAT LOGPROG          <==== your entries  
    NTSTAT EDITPROG         <====

    TYPE=W means that a "weak" external reference to the specified program is generated rather than a normal one.

  5. Review the linkage editor job stream for the Natural nucleus and include the following:

    //*
    //* INCLUDE DDNAME AND DSN OF DATASET WHERE OBJECTS RESIDE  
    //*
    //SYSLMOD DD DSN=NATURAL.USER.LOAD,DISP=SHR
    //NATLIB DD DSN=NATURAL.USER.LOAD,DISP=SHR//*
    //SYSLIN DD*
    ...
    ...                                 INCLUDE MODULES FOR NUCLEUS
    ...
    INCLUDE NATLIB(nat-parm-module)     NATURAL PARAMETER MODULE
    INCLUDE SYSLMOD(LOGPROG)            LOGON NATURAL PGM
    INCLUDE SYSLMOD(EDITPROG)           EDITOR NATURAL PGM
    ...
    ...                                 INCLUDE ENTRY AND NAME CARDS
    ...
    /*

    nat-parm-module represents the name of the Natural parameter module.

    If the cataloged objects were linked together (as done optionally in Step 3), include this load module instead of the individual load modules in the link of the nucleus.