Program Creation user exit routine (PGMCREAT) enhancement

In IMS 15, you can use the new PGMCREAT type exit to dynamically create the runtime control block (PDIR) for an application program when the application program is scheduled by IMS. The program creation user exit routine (PGMCREAT) can also create the runtime control block for an associated database (DDIR). The Program Creation user exit routine (PGMCREAT) enhancement simplifies the creation of runtime program resources for application programs that run in BMP and JBP regions. With the Program Creation user exit, an IMS system programmer can schedule a BMP or JBP region without having to define the application program to IMS using the stage-1 APPLCTN macro or the IMS type-2 CREATE PGM command.

Instead of defining the program resource to IMS during IMS SYSGEN or with the CREATE PGM command, the Program Creation user exit can be used to postpone the creation of the program resource until the program is to be scheduled in a BMP or JBP region. When the program is created, the user exit can also optionally create a database resource.

Log record changes

The PGMCREAT user exit can return to IMS to create a new runtime program or database resource. When a program resource is created, an X'22' map byte X'21' log record is written. When a database resource is created, an X'22' map byte X'20' log record is written.

Requirements

Dynamic resource definition must be configured and enabled by specifying MODBLKS=DYN in the DFSDFxx or DFSCGxxx PROCLIB member.

Restrictions

If a program resource is created, the PSB associated with the program must reside in ACBLIB or the IMS Catalog. If a database resource is created, the DBD associated with the database must also reside in ACBLIB or the IMS Catalog.

Changes to system definition

To work with this exit, the system programmer needs to add the USER_EXITS section in the DFSDFxxx member of the PROCLIB data set. In the USER_EXITS section, specify the PGMCREAT exit type and the name of the user exit routine. For example,


<SECTION=USER_EXITS>
           EXITDEF=(TYPE=PGMCREAT,
             EXITS=(exitname))

Changes to administering IMS

Define the PGMCREAT user exit routines to IMS specifying EXITDEF=(TYPE=PGMCREAT,EXITS=()) in the DFSDFxxx member.

The QUERY USEREXIT command can be used to query the information of the PGMCREAT exit.

The REFRESH USEREXIT command can be used to bring in a new copy of the program create user exit.

Changes to operating and automating

IMS system programmer can schedule a BMP or JBP region without having to define the application program to IMS using the stage-1 APPLCTN macro or the IMS type-2 CREATE PGM command. When the program is created the user exit can specify to optionally create a database resource.

The REFRESH USEREXIT command can be used to bring in a new copy of the updated program create user exit without having to bring IMS down. For example,

REFRESH USEREXIT TYPE(PGMCREAT) MEMBER(PX0).

PGMCREAT is the user exit type and PX0 is the suffix for DFSDFxxx member. For more details, see IMS commands.

Changes to troubleshooting for IMS

For a list of the messages and codes that are new or changed for this enhancement, see the IMS messages and codes row in the table in Documentation changes.

For a complete list of all of the new, changed, and deleted messages, and abend codes in IMS 15, see Message and code changes in IMS 15.

Changes to commands

QUERY DB and QUERY PGM commands can now display a new definition type of PGMCREAT.

QUERY USEREXIT and REFRESH USEREXIT commands can show PGMCREAT as new Type. For example,

TYPE(exit_type) PGMCREAT - Program Creation User Exit

For a list of the commands that are new or changed for this enhancement see the IMS commands row in the table in Documentation changes.

Changes to exit routines

The Program Creation user exit routine can request that IMS dynamically create the runtime program resource for a program that is to be scheduled in a BMP or JBP dependent region. Optionally, the exit can also request that IMS create a runtime database resource. The program and optional database resource are created without requiring a restart of IMS or a type-2 CREATE command to be issued.

Documentation changes

The following publications contain new or changed information for the New function name enhancement. The links for a publication can be listed on two separate rows, with links to topics that have new content on one row and links to changed content on another. Publications that are not impacted by the enhancement are not included in the table.

Table 1. Links to topics that have new or changed content for this enhancement
Publication	Links to topics
Release planning	Command changes in IMS 15 New messages and codes for IMS 15 Changed messages and codes for IMS 15 Log record changes in IMS 15 Program Creation user exit routine (PGMCREAT) enhancement (new) (this topic)
System definition	Designing the IMS system Declaring online application programs Defining online applications Declaring online databases Macros used in IMS environments APPLCTN macro Members of the IMS PROCLIB data set > DFSDF`xxx` member of the IMS PROCLIB data set USER_EXITS section of the DFSDFxxx member
Communications and connections	ODBA and DRA connections Accessing IMS databases with CICS Configuring CICS CCTL connections to IMS DBCTL systems Accessing IMS databases through the ODBA interface
Operations and automation	Controlling IMS > Modifying and controlling system resources Modifying system resources online Creating, updating, deleting, and querying resource definitions dynamically Creating databases and database descriptors dynamically Creating application programs and application program descriptors dynamically
System administration	Introduction to IMS system administration > Introduction to the IMS system > IMS environments and configurations > IMSplex overview Dynamic resource definition in an IMSplex
IMS messages and codes	DFS messages DFS554A	abends 0421 (new) 0423 (new) 0424 (new) 0425 (new) 0426 (new)
IMS commands	IMS commands QUERY PGM command QUERY DB command QUERY USEREXIT command REFRESH USEREXIT command
Exit routines	IMS control region exit routines Guidelines for writing IMS exit routines > Introduction to IMS exit routines Exit routines eligible for callable services Refreshable exit routine types Customization exit routines IMS.SDFSSMPL data set Transaction Manager exit routines PGMCREAT user exit routine type (new)
System utilities	Generation utilities > Application Control Blocks Maintenance utility Managing DOPT PSBs