>>-$JCTXADD--JCT--=--rx-addr--,--TYPE--=--+-'xxxx'--+----------->
                                          '-rx-addr-'   

>--,--MOD--=--value--,--LENGTH--=--value------------------------>

>--+-,--OKRET--=--rx-addr--+----------------------+-+----------->
   |                       '-,--ERRET--=--rx-addr-' |   
   '-,--ERRET--=--rx-addr--+----------------------+-'   
                           '-,--OKRET--=--rx-addr-'     

>--+----------------------+--+------------------------+--------->
   '-,--FOUND--=--rx-addr-'  '-,--NOSPACE--=--rx-addr-'   

>--+----------------------+------------------------------------><
   |            .-SPOOL-. |   
   '-,--LOC--=--+-LOCAL-+-'   

JCT=

Specifies the address of the $JCT control block to which JES2 should add this extension.

This parameter is required.

ERRET=

Specifies the label to receive control if the extension cannot be added for a reason other than those specified through the FOUND= or NOSPACE= parameter (for example, the JCT= parameter does not point to a valid $JCT control block).

If you do not specify a value for the FOUND= parameter, ERRET= specifies the label to receive control if the extension cannot be added because an extension with a matching type and modifier already exist. If you do not specify a value for the NOSPACE= parameter, ERRET= specifies the label to receive control if the extension cannot be added because the $JCT is too small.

You must specify the ERRET= parameter, the OKRET= parameter, or both.

TYPE=

Specifies either a 1 to 4-character string enclosed in quotation marks (‘xxxx’), or the address of a 4-byte field containing such a string, to serve as an identifier for the extension. The strings ‘IBM’ and ‘JES2’ are reserved for IBM® use.

Note: JES2 pads character strings of less than 4 characters with trailing blanks.

MOD=

Specifies a value (0-32767) that allows an application to specify a series of extensions to the $JCT from a single source (through the TYPE= parameter) and to differentiate extensions through this parameter.

MOD= can be specified as:

• A numeric value
• A symbol equated to a value
• A register containing a value
• The address of a 2-byte field containing the value

This parameter is required.

LENGTH=

Specifies the length of the extension (0-4095) to be added to the $JCT control block. This specification must include the length of the $JCTX prefix area (defined by the value of JCXORG-JCTX field).

The LENGTH= parameter can be specified as:

• A numeric value
• A symbol equated to a value
  Note: Use an equate to define a field - field value:

  JCTXULEN EQU   JCTXUEND-JCTX

  Then specify the value for length in the macro:

  LENGTH=JCTXULEN

  If you specify the field - field expression in the macro rather than using an equate to define the expression, JES2 uses the relocatable address from the expression rather than the value.

• A register containing a value
• The address of a 2-byte field containing the length.

The maximum size depends on the:

• $JCT size (IBM provides a 512-byte spool buffer; any additional space might not be preserved from release to release. To determine the amount of spool used by $JCT extensions, see Using the $JCTX macro extension service.)
• Buffer size (BUFSIZE= parameter on the SPOOLDEF initialization statement)
• Number of extensions already defined in the $JCT control block.

This parameter is required.

OKRET=

Specifies the label to receive control if JES2 adds the extension successfully; R1 points to the new section on return.

You must specify the OKRET= parameter, the ERRET= parameter, or both.

FOUND=

Specifies the label to receive control if an extension with a matching type and modifier already exists in the $JCT control block; R1 points to the existing section on return.

If you do not specify this parameter, FOUND= defaults to the value of the ERRET= parameter.

NOSPACE=

Specifies the label to receive control if there is insufficient space in the $JCT control block to add this extension.

If you do not specify this parameter, NOSPACE= defaults to the value of the ERRET= parameter.

LOC=

Specifies whether or not the extension should be SPOOLed.

LOC can be specified as:

• SPOOL
• LOCAL

LOC=SPOOL places the extension in the SPOOLed portion of the JCT. LOC=LOCAL places the extension in working storage that is not SPOOLed.

Local extensions are only supported in certain environments. Every extension must have a unique TYPE/MOD irrespective of the extension's location. Default is LOC=SPOOL.

Authorization:

Supervisor state, key 0 or 1.

Dispatchable unit mode:

Task

JES environment:

Any JES2 environment

Cross Memory Mode:

PASN = HASN

AMODE:

24- or 31- bit

ASC mode:

Primary

Interrupt status

Enabled for I/O and external interrupts

Serialization:

The $JCT control block must be serialized; this could mean that the caller has to obtain the job lock or the SJB lock.

Locks:

No locks are obtained or freed by the $JCTXADD macro.

Control parameters:

None

You must specify $HCCT, $JCTX, and $TRE on the $MODULE invocation to use this macro.

None.

R0 - R10:

N/A

R11:

HCT, HCCT, or HFCT, depending on JES2 environment.

R12:

N/A

R13

Address of PCE or address of an available 72-byte save area

R14-15:

N/A

R0:

Used as a work register by the system.

R1:

Pointer to the $JCT control block extension, or 0.

R2 - R13:

Unchanged

R14

Used as a work register by the system.

R15:

Return code

        $JCTXADD TYPE='USER',
               MOD=1,
               JCT=JCT,
               LENGTH=JCXLEN1,
               FOUND=ADDOK,
               ERRET=EXTERR

ADDOK    DS    OH

JCTX     DSECT
         ORG   JCTXORG

JCTXLEN1 EQU   *-JCTX     Installation fields for extension 1
         ORG   JCXORG

JCTXLEN2 EQU   *-JCTX     Installation fields for extension 2
         ORG   JCXORG

If the extension is successfully added (or already exists in the $JCT), processing continues at the next sequential instruction. Otherwise, processing continues at label EXTERR.