SNAX/APC Application Programming Manual

Interprocess Communications and Units of Work
SNAX/APC Application Programming Manual—138786
2-6
The IPC Header
REQ-ERROR (3)
SNAX/APC detected an error in the IPC header or in one of the UOW headers;
or a SNAX/XF or SNAX/CDF error occurred while processing the IPC
message. None of the UOWs were processed. The IPC reply contains only the
IPC reply header. See the IPC return code for the actual error.
VERSION-CODE
In both verb requests and replies, this field contains the version of the SNAX/APC
interface used. Generally, this field must contain the text string S1, S2, S3, or S5
(S4 is reserved for future use). See specific verb descriptions for the consequences
of this choice. S1 indicates Release 2 capabilities, S2 indicates Release 3 and
parallel-session capabilities, S3 implements the conversational security feature and
S5 is generally recommended for use because it provides all earlier capabilities plus
sync point support.
HEADER-RETURN-CODE
In a verb request to SNAX/APC, this field is ignored. In a reply, this field is set by
the SNAX/APC process when REP-CODE contains REQ-ERROR (3). The possible
return codes are described at the end of this subsection.
HEADER-RETURN-CODE-DETAIL
In a reply, this field provides additional details on the return code. For example, if a
SNAX/XF or SNAX/CDF file error occurred, this field would contain the operating
system error number. This field is ignored in verb requests.
RESOURCE-ID
This field indicates the specific resources within SNAX/APC for which this IPC
message is meant. On the first IPC message, the TP must specify zeros in the
RESOURCE-ID field. On subsequent requests, the TP must use the RESOURCE-
ID value returned in the first IPC reply.
UOWS-IN
This field indicates the number of UOWs contained in this IPC message. On verb
requests, this field must be set by the TP. Think of the names UOWS-IN and
UOWS-OUT in terms of UOWs going into SNAX/APC (from the TP) and UOWs
returned out from SNAX/APC (to the TP).
UOWS-OUT
This field indicates the number of reply UOWs contained in a reply from
SNAX/APC. If the IPC REP-CODE indicates UOWS-WITH-ERROR (value 2),
UOWS-OUT indicates the number of UOWs that SNAX/APC returned in the reply
(that is, UOWS-OUT points to the UOW that caused the error). If REP-CODE
contains the value 3 (REQ-ERROR), SNAX/APC returns no UOWs, but UOWS-
OUT indicates the UOW that was in error.