OEM Cache help

The application that owns the structure is responsible for documenting how to determine the following information.  For a more detailed description of each of the input fields, please refer to the IXLCONN macro.

To calculate the size of an OEM cache structure provide the following input data:

Max number of cache directory entries:

Use this input parameter to specify the maximum number of cache entries, or ENTRYCOUNT.

Max number of data elements:

Use this input parameter to specify the maximum number of data elements for the structure, or ELEMENTCOUNT.

Max number of data elements per entry:

Use this input parameter to specify a value to determine the maximum number of elements for each data entry in the coupling facility cache structure.  You can specify a value from 1 to 255 for MAXELEMNUM.

Alterable:

Use this input parameter to specify whether the cache structure is alterable or not alterable.

ALTERABLE=YES

The cache structure can be altered.

ALTERABLE=NO

The cache structure can not be altered.

Number of castout classes:

Use this input parameter to specify the number of castout classes for named data entries used with the coupling facility cache structure.  You must specify at least 1 castout class.

Number of storage classes:

Use this input parameter to specify the number of storage classes for named data entries used with the coupling facility cache structure.  You must specify at least 1 storage class.

Name class mask pattern:

Use this input parameter to specify whether the name class mask pattern definition should be applied to entry names for the purpose of assigning entries to name classes in the structure.

VALUE=YES

Indicates that a name class mask pattern definition should be applied to entry names.

VALUE=NO

Indicates that a name class mask pattern definition should not be applied to entry names.

Adjunct data:

Use this input parameter to specify whether adjunct data areas are associated with each cache entry in the coupling facility cache structure.  Each adjunct data area is 64 bytes.

ADJUNCT=YES

Indicates that each cache entry in the cache structure has an associated adjunct data area of 64 bytes.

ADJUNCT=NO

Indicates that there are no adjunct data areas specified for the cache structure.

User data field order:

Use this input parameter to indicate whether a user data field (UDF) order queue should be maintained for each castout class for the structure.

UDFORDER=YES

Indicates that user data field order queue is maintained for each castout class.

UDFORDER=NO

Indicates that user data field order queue is not maintained for each castout class.

Data element size descriptor:

Use this input parameter to specify either an element characteristic (ELEMCHAR), an element increment number (ELEMINCRNUM), or NONE for element size determination.

Data element size value:

Use this input parameter to specify a size value for the size descriptors ELEMCHAR or ELEMINCRNUM.

DESCRIPTOR=ELEMCHAR

The element size is calculated with the formula 256*(2**ELEMCHAR), where ELEMCHAR is used as the power of 2.  For example, if ELEMCHAR=0, then the size of each element is 256 bytes.

Valid size values for ELEMCHAR range from 0 to a maximum which is based on a model-dependent limit on the size of the data elements in the coupling facility.

DESCRIPTOR=ELEMINCRNUM

The element size is calculated with the formula 256*ELEMINCRNUM.  For example, if ELEMINCRNUM=1, then the size of each element is 256 bytes.

Valid size values for ELEMINCRNUM range from 1 to a maximum which is determined by a model-dependent limit on the size of data elements in the coupling facility.  ELEMINCRNUM must be a power of 2.

If the size value is non-zero, then either ELEMCHAR or ELEMINCRNUM must be specified as the descriptor.