Guardian Application Conversion Guide

Converting Distributed Systems Management (DSM) Applications
Converting Other Parts of an Application
8–32 096047 Tandem Computers Incorporated
Converting DSM
Applications That Use SPI
This subsection describes how to convert a DSM application that uses the Subsystem
Programmatic Interface (SPI) to communicate with a Tandem subsystem.
You need to refer to the management programming manual for the specific subsystem.
For example, if your application communicates with FUP, refer to the File Utility
Program (FUP) Management Programming Manual for a description of the tokens and
error lists for the FUP programmatic commands and responses.
Extracting Simple Tokens From the Response Buffer
Your DSM application might try to extract a superseded C-series simple token from
the SPI response buffer.
If the information does not fit into a simple token (for example, a high PIN in an 8-bit
token), a Tandem subsystem does not return the token in the response buffer. Instead,
the subsystem returns a new simple token to hold the value but does not return an
error in ZSPI-TKN-RETCODE.
For example, a subsystem might return a process-descriptor token or process-handle
token (or both) to represent a high-PIN process. (A subsystem never returns a
synthetic process ID to represent a high-PIN process.)
If your application calls the SSGET procedure to extract a token that has been omitted
from the response buffer, it will receive SPI error number -8 (token not found). If
necessary, convert your application to handle this error.
Extracting Structured Tokens From the Response Buffer
Your DSM application might try to extract a C-series structured token that contains an
obsolete field. If the information does not fit into a field of a structured token, the
subsystem returns the token as follows:
If the field has a defined null value, the subsystem sets the field to its null value
and returns the structured token in the response buffer.
If the field does not have a defined null value, the subsystem omits the token from
the response buffer.
In either case, the subsystem returns the information in a new field of the structured
token or a new simple token; it does not return an error in ZSPI-TKN-RETCODE.
Refer to the specific management programming manual to determine the token your
application should extract.