SPI Programming Manual (G06.24+, H06.03+, J06.03+)

SPI Concepts and Protocol
SPI Programming Manual—427506-006
2-49
Pass-Through Errors
Each error list contains an error token (ZSPI-TKN-ERROR) that identifies the error
described by other tokens in the list. ZSPI-TKN-ERROR is a fixed structure consisting
of the subsystem ID of the subsystem that reported the error and the error number of
an error defined by that subsystem. (The version portion of the subsystem ID in an
error token can be either zero or the version of the subsystem reporting the error.)
Every error list must contain one error token, and it can also contain additional tokens
and embedded error lists giving more information about the error.
Pass-Through Errors
A subsystem can pass on an error list from another subsystem; in general, the error list
describing the pass-through error is qualified by a subsystem ID other than that of the
subsystem composing the response message. If an error list is qualified by the
subsystem ID of another subsystem, all tokens within those lists are implicitly qualified
by that subsystem ID.
Some software facilities for the NonStop server, including some operating system
procedures and the file system, do not have a programmatic command interface based
on SPI, but do define standard error lists. If a NonStop Kernel subsystem that does
have an SPI-based command interface calls one of these facilities and receives an
error, the subsystem usually tries to recover from the error. If that is impossible, the
subsystem reports the error in an SPI error token (ZSPI-TKN-ERROR), embeds it in an
error list of the prescribed form, and encloses this error list in its response. This
practice ensures that errors from NonStop Kernel subsystems and software
components are reported in a consistent way.
The SPI procedures detect certain errors, which are reported in the status parameter of
the procedure call. When a NonStop Kernel subsystem calls one of the SPI procedures
and receives a nonzero status from which it (the subsystem) cannot recover, the
subsystem returns to the application an error list containing information about the error.
For descriptions of the SPI errors, see Appendix A, Errors
. For descriptions of the error
lists returned by NonStop Kernel subsystems when they encounter an SPI procedure
error from which they cannot recover, see the
Guardian Procedure Errors and
Messages Manual . To identify which errors can occur on calls to each procedure, see
the SPI procedure descriptions in Section 3, The SPI Procedures
, and the
Figure 2-16. Error List Contents
(error list token) (error-list token)(error-list) (error-list)(token) (token)(error) (token)
ZSPI-TKN-ERRLIST
ZSPI-TKN-ERROR
ZSPI-TKN-ENDLIST
(In any order)
VST020.vsd