Description of Returned Registration Information

The system returns state information for each processed data item included in your registration block area. Mapping macro IXLYNSB maps the information. See z/OS® MVS™ Data Areas in the z/OS Internet library for a description of IXLYNSB.

IXLYNSB contains two arrays. The first array (the “NSB array”) contains state information for the corresponding named cache entry, including whether the registration was successful. The second array (the “NSBINVLCVINUM array”) contains the invalidated vector index when the corresponding named cache entry's prior registration was invalidated as a result of the REG_NAMELIST request. There is a one-to-one correlation between a registration block entry in the BUFFER area and an element in each of the arrays in the NSBAREA area. Therefore, the same index number that designates an IXLYCRRB entry in the BUFFER will also designate the corresponding NSB array entry and NSBINVLCVINUM array entry.

Table 1 describes the information returned for each data item.

Table 1. IXLCACHE Registration Block Returned Information
Field Name	Description
NSBCHANGED	Change status of cached subsystem data 0 Unchanged 1 Changed
NSBDATACACHED	Indicator of whether the associated data entry is cached or is a directory-only entry. 0 Data not cached 1 Data cached
NSBPARITY	Parity as recorded in the item's directory entry
NSBCOLOCKSTATE	State of the castout lock 00 (CAACOLS_RESET) Reset state, which is entered when the name is assigned to the directory entry or when the castout lock is reset to zeros. 01 (CAACOLS_READFORCASTOUT) Read-for-castout state, which is entered when the castout lock is obtained by a CASTOUT_DATA request. 10 (CAACOLS_WRITEWITHCASTOUT) Write with castout, which is entered when the castout lock is obtained by a WRITE_DATA request specifying GETCOLOCK=YES.
NSBINVLCVI	Indicator of whether a local cache vector index was invalidated because interest for the associated item was re-registered using a different vector index. 0 The associated NSBINVLCVINUM array entry is not valid. 1 The associated NSBINVLCVINUM array entry contains the invalidated local cache vector index number.
NSBREGPERFORMED	Indicator of whether the registration was successfully performed. 0 The registration was not successfully performed. For this data item: No directory entry for the name exists The user is not registered in the entry The user's local cache buffer for the entry was marked invalid The other NSB information for the named entry was not returned. 1 The registration was successful for the entry name and local cache vector index in the corresponding registration block. For this data item: A directory entry for the name exists The user was registered in the named entry as requested The user's local cache buffer for the entry was marked valid The other NSB information for the named entry was returned.
NSBELEMNUM	The entry size expressed as the number of elements in the entry. (This value is returned only when the cache structure is allocated in a coupling facility of CFLEVEL=4 or higher.)
NSBINVLCVINUM	The value of the local cache vector index that was invalidated when interest for the data item was re-registered using a different vector index. NSBINVLCVI indicates the validity of this value.