SPI Common Extensions Manual

Glossary
SPI Common Extensions Manual—427508-001
Glossary-6
list
list. In an SPI message, a group of tokens that defines a context for scanning the buffer
and extracting tokens with the SSGET procedure. A list imposes a hierarchy on the
buffer. To retrieve tokens from a list, a program must enter the list by retrieving the
initial list token, retrieve tokens from the list, then exit the list to the next higher level of
tokens by retrieving the end-list token. SPI defines four kinds of lists: data lists, error
lists, segment lists, and generic lists.
list token. A token that marks the beginning of a list in an SPI message. The four list tokens
each mark one of the four types of SPI lists: ZSPI-TKN-DATALIST for data lists,
ZSPI-TKN-ERRLIST for error lists, ZSPI-TKN-SEGLIST for segment lists, and
ZSPI-TKN-LIST for generic lists. Compare with end-list token; see also syntax token.
management application. A program that manages a subsystem and its objects by issuing
commands, retrieving event messages, or both. A management application is a
requester with respect to the subsystem server to which it sends commands.
management interface. An interactive or programmatic interface through which one can
manage a subsystem and its objects. In some subsystems, a specific process is
dedicated to the management interface. In other subsystems, the process that
provides the management interface also performs other functions.
manager process. A subsystem process that supports the SPI command interface for that
subsystem. Management applications send commands to and receive responses from
subsystem manager processes. The Expand manager process, $ZNET, and the
X25AM line handlers are examples of manager processes.
maximum field version. In an SPI message, the latest version associated with any non-null
field of any extensible structured token in the message. The maximum field version of
the SPI message is contained in a header token. It corresponds to the version of the
oldest server or requester that can successfully process the message.
message. A block of information, usually in the form of a structure, that is sent from one
process to another. See also SPI message.
message buffer. A block of memory used for temporary storage of an interprocess
message. See also SPI buffer.
message code. The contents of the first word of an interprocess message. A message
code of -28 identifies the message as an SPI message.
nested error list. An error list contained in another error list. When an error in one
subsystem or in a library procedure prevents another subsystem from performing a
command, the calling subsystem reports this pass-through error by nesting it within its
own error list. For instance, a response from FUP might include an error list explaining
the FUP error, which in turn contains an error list explaining the SORT error that
caused the FUP error. See also pass-through error.
next-token position. The location where the next SSGET operation will take place.
Compare with current-token position and initial position.