Parameter Descriptions

The parameter descriptions are listed in alphabetical order. Default values are underlined:

,ELEMENTRATIO=elementratio

Use this input parameter to specify the data element part of the entry-to-element ratio.

A cache structure initially allocated with data elements can be altered to contain no data elements and then changed again to contain data elements.
A list structure initially allocated with data elements cannot be altered to contain no data elements.
Cache or list structures initially allocated without data elements cannot be altered to contain data elements.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the halfword field that contains the element part of the ratio.

,EMCSTG

Use this input parameter to indicate that the percentage of available storage to be set aside for event monitor controls (EMCs) is to be changed.

When EMCSTG is not specified, it is possible to have the EMC storage percent change as a result of a SIZE request unless at least one connector specified RATIO=NO at connect time.

This parameter is valid only for keyed list structures allocated in a coupling facility with CFLEVEL=4 or higher.

,EMCSTGPCT=emcstgpct

Use this input parameter to specify the percentage of available list structure storage that is to be set aside for event monitor controls (EMCs).

Specify the percentage value in hundredths of a percent. For example, to request a value of 20%, code EMCSTGPCT=2000.

The value of EMCSTGPCT must be in the range of from 0 to 10000.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the halfword field that contains a value to express the percentage of available structure storage that is to be set aside for EMCs.

,ENTRYRATIO=entryratio

Use this input parameter to specify the entry part of the entry-to-element ratio.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the halfword input field that contains the entry part of the ratio.

,MF=S

,MF=(L,mfctrl)

,MF=(L,mfctrl,mfattr)

,MF=(L,mfctrl,0D)

,MF=(E,mfctrl)

,MF=(E,mfctrl,COMPLETE)

Use MF=S to specify the standard form of the macro, which builds an inline parameter list and generates the macro invocation to transfer control to the service.

Use MF=L to specify the list form of the macro. Use the list form together with the execute form of the macro for applications that require reentrant code. The list form defines an area of storage that the execute form uses to store the parameters. Only the PLISTVER parameter can be coded with the list form of the macro.

Use MF=E to specify the execute form of the macro. Use the execute form together with the list form of the macro for applications that require reentrant code. The execute form stores the parameters into the storage area defined by the list form, and generates the macro invocation to transfer control to the service.

,mfctrl: Use this output parameter to specify a storage area to contain the parameters.
To Code: Specify the RS-type name or address (using a register from 2 to 12) of the parameter list.
,mfattr: Use this input parameter to specify the name of a 1- to 60-character string that can contain any value that is valid on an assembler DS pseudo-op. You can use this parameter to force boundary alignment of the parameter list. If you do not code mfattr, the system provides a value of 0D, which forces the parameter list to a doubleword boundary.
,COMPLETE: Use this input parameter to require that the system check for required parameters and supply defaults for omitted optional parameters.
Note: In the macro expansion you might see some defaults for optional parameters that are not documented here. The ones that are not documented do not have any effect on the macro. For example, if SMILE=var were an optional parameter and the default is SMILE=NO_SMILE then it would not be documented. However, if the default was SMILE=:-), then it would be documented because a value would be the default.

,PLISTVER=IMPLIED_VERSION

,PLISTVER=MAX

,PLISTVER=plistver

Use this input parameter to specify the version of the macro. See Understanding IXLALTER Version Support for a description of the options available with PLISTVER.

,RATIO

Use this input parameter to indicate that the entry-to-element ratio of the named structure is to be reapportioned.

When RATIO is not specified, it is possible to have the entry-to-element ratio change as a result of a SIZE request unless at least one connector specified RATIO=NO at connect time.

,REQUEST=START

,REQUEST=STOP

Use this input parameter to identify the type of structure alter request.

START: Start structure alter processing for the specified structure.
STOP: Stop alter processing for the specified structure.

,RETCODE=retcode

Use this output parameter to specify the location in which the system is to copy the return code from GPR 15.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of a fullword to contain the return code.

,RSNCODE=rsncode

Use this output parameter to specify the location in which the system is to copy the reason code from GPR 0.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of a fullword to contain the reason code.

,SIZE

Use this input parameter to indicate that the structure is to be expanded or contracted.

Note: At the time of structure allocation, the maximum structure size (MSS) value is set and remains constant as long as this instance of the structure remains allocated. The structure allocation algorithm determines the MSS based on whether the structure is allocated by counts or by size/ratios. The actual structure size may be less than or equal to the MSS value. It may be less due to one or more of the following:

INITSIZE value in the CFRM active policy
STRSIZE specified on the IXLCONN macro
Storage constraints in the coupling facility
A previous structure alter.

The actual structure size may change with the MSS value being the upper bound.

The minimum structure size (MINSS) is the minimum control space required to allocate the structure with the attributes specified. The MINSS value is established by the coupling facility based on the attributes specified when the structure was allocated. The MINSS value can change when the structure is reapportioned with an entry-to-element ratio that differs substantially from the previous ratio. MINSIZE specified in the CFRM active policy will serve as a minimum bound for the structure size on all structure allocation requests (including alter, connect, and rebuild connect) except for new structure allocation during System-managed rebuild. New structure allocation during System-managed rebuild may cause the structure to be allocated with a size smaller than MINSIZE in the CFRM active policy. The actual structure size may expand to the MSS value or contract to the MINSS value or the MINSIZE value specified in the CFRM policy. When contracting, the larger of the two values will be used.

When SIZE is not specified the structure size will not change as a result of the IXLALTER.

,STRNAME=strname

Use this input parameter to specify the name of the target structure for alter start or stop processing. The name must be defined in the CFRM (coupling facility resource management) active policy.

The structure name must be 16 characters long, padded on the right with blanks if necessary. It may contain numeric characters, uppercase alphabetic characters, national characters ($, @, #), or an underscore (_). It must begin with an uppercase alphabetic character. IBM® names begin with SYS, an IBM component prefix, or letters A-I.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the 16-character input field that contains the structure name.

,STRSIZE=strsize

Use this input parameter to specify the desired size of the structure in units of 4K (4096 bytes) blocks.

See z/OS MVS Programming: Sysplex Services Guide for information about minimum and maximum structure size.

To Code: Specify the RS-type name or address (using a register from 2 to 12) of the fullword input field that contains the number of 4K (4096 bytes) blocks to make up the structure.