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

SPI Concepts and Protocol
SPI Programming Manual—427506-006
2-50
Continuing Despite Errors
corresponding TACL built-in function descriptions in Section 8, SPI Programming in
TACL.
Continuing Despite Errors
Some subsystems support another standard SPI token to let the requester specify
under what conditions the server should continue processing a set of objects. This is
the allow-type token (ZSPI-TKN-ALLOW-TYPE). This token is useful when the
application is performing a command on a large number of objects (for instance,
terminals) and wants to operate immediately on as many of those objects as it can,
even if errors or warnings occur for some objects. In such cases, the application can
address the cases with errors or warnings later.
ZSPI-TKN-ALLOW-TYPE has three possible values:
•
ZSPI-VAL-NORM-ONLY directs the server to continue processing on the next
object in the set only if the command was completely successful, with no warnings,
on the previous object—that is, if the response record on that object contained no
error list. This action is the default if the allow-type token is not included in the
command.
•
ZSPI-VAL-WARN-AND-NORM directs the server to continue processing on the
next object if the command completed its operation on the previous object,
regardless of warnings—that is, if the value of the return token was zero (error lists
representing warnings can be present).
•
ZSPI-VAL-ERR-WARN-AND-NORM directs the server to continue processing on
the next object regardless of any problems encountered on the previous object.
If a condition occurs that, based on the allow-type value, directs the subsystem not to
process the next object, the server completes the response record for the object on
which the unusual condition occurred (if it has not already been completed), adds a
context token to the response if appropriate, and sends the response to the requester.
The requester can take appropriate corrective action for the error or warning, and then
reissue the command to have the subsystem continue processing with the next object
in the set.
The allow-type feature controls only whether the server proceeds to the next object in a
set when the action of a command on one object yields an error or warning. This
feature does not influence the action on an object after the server has begun work on
that object. For example, selecting ZSPI-VAL-NORM-ONLY does not mean that the
server should stop the operation on an object immediately when a warning condition is
detected. The operation on that object still continues to completion. After completing
with that object, the server notices that a warning occurred on the object, and it issues
a response at that point.
NonStop Kernel subsystems that support the allow-type feature do so for all
commands that can cause some action or modification of an object and can accept the
specification of more than one object in a single command. NonStop Kernel