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

General SPI Programming Guidelines
SPI Programming Manual—427506-006
5-29
Subsystem ID
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Remove the attributes that can be repeated from the original object type and put
them in a new object type that is a subsidiary of the original object type, making
each repetition a separate instance of the subsidiary type. The name of an
instance of the subsidiary object type is generally one of the attributes of the
subsidiary object type concatenated with the name of the instance of the original
object type.
For example, the human command interface to the Pathway subsystem has an object
type known as a server class. The attributes of a server class include attributes of
assign messages that are sent to each process of a server class as the process is
started. There can be an indefinite number of assign messages for a given server
class. The Pathway programmatic interface has an object type called a server class,
which has all the nonrepeating attributes of the human-interface server class. It also
has a server-assign object type. The attributes of the server-assign object type
describe one assign message. The name of an object of the server-assign type is
formed by taking the name of the server-class object whose assign message is being
described and concatenating it with the logical name of the assign message.
If in the human interface a server-class object name SVR1 has two assign messages
named MAT-FILE and ITM-FILE, in the programmatic interface there would be a
server-class object named SVR1 and two server-assign objects named (SVR1, MAT-
FILE) and (SVR1, ITM-FILE).
When subsidiary object types exist, the server must recognize the relationship between
them and the main object type. It must prevent adding a subsidiary object for which
there is no matching main object, and deletion of a main object must automatically
delete all subsidiary objects related to it before deleting the main object itself.
Similar instances of repeating groups of information can arise when designing
STATUS or STATS commands. The same two approaches for resolving the problem
apply to those cases, too. This can result in subsidiary object types that are only used
with the STATUS or STATS command.
Subsystem ID
All HP software for DSM uses the standard subsystem ID format defined in Subsystem
IDs (SSIDs) on page 2-44. The owner ID field in this format lets you define a
subsystem ID that is unlikely to conflict with those of NonStop Kernel subsystems
provided by HP or subsystems provided by other vendors. For this field, choose an
eight-character string to identify your company or organization.
This name must start with an alphabetic character and must contain only alphabetic,
numeric, and hyphen characters, padded on the right with blanks; no embedded blanks
are allowed except at the end. The case of alphabetic characters is significant; for
example, “COMPANY” and “Company” are recognized as different names. To avoid
confusion, HP recommends that you define your owner ID with all alphabetic
characters in uppercase, as in the HP owner ID (“TANDEMbb
”).