The options of the UCBINFO macro have the same environmental specifications, programming requirements, restrictions, register information, and performance implications described below, except where noted in the explanations of each option.
The requirements for the caller are:
Environmental factor | Requirement |
---|---|
Minimum authorization: | Problem state and any PSW key. |
Dispatchable unit mode: | Task or SRB |
Cross memory mode: | Any PASN, any HASN, any SASN |
AMODE: | 24- or 31-bit |
ASC mode: | Primary or access register (AR) |
Interrupt status: | Enabled or disabled for I/O and external interrupts |
Locks: | The caller may hold locks, but is not required to hold any |
Control parameters: | Control parameters must be in the primary address space or, for AR-mode callers, must be in an address/data space that is addressable through a public entry on the caller's dispatchable unit access list (DU-AL). |
Before issuing the UCBINFO macro, you can issue the UCBSCAN macro to obtain the device number, which you must provide as input to UCBINFO. See z/OS MVS Programming: Assembler Services Guide for information about accessing UCBs.
None.
Before issuing the UCBINFO macro, the caller does not have to place any information into any register unless using it in register notation for a particular parameter, or using it as a base register.
None.