HP-UX SNAplus2 R7 LUA Programmer's Guide

Concepts

LUA Verbs

• LU session, normal ﬂow

The LU session normal ﬂow carries application data; the other ﬂows are used for control messages and start-up.

The SNAplus2 implementation of LUA does not enable applications to send data on the SSCP expedited ﬂow, and

will not return data to an application on this ﬂow.

1.3.1 Conﬁguration

Each LU used by an LUA application must be conﬁgured using the Motif administration program, the command-

line administration program, or the node operator facility (NOF) API (for more information, refer to the

HP-UX

SNAplus2 Administration Guide or the HP-UX SNAplus2 NOF Programmer’s Guide). In addition, the SNAplus2

conﬁguration may include LU pools. A pool is a group of LUs with similar characteristics, such that an application

can use any free LU from the group. This can be used to allocate LUs on a ﬁrst-come, ﬁrst-served basis when there

are more applications than LUs available, or to provide a choice of LUs on different connections.

1.4 LUA Verbs

An application accesses LUA through LUA verbs. Each verb supplies parameters to LUA, which performs the

desired function and returns parameters to the application.

1.4.1 RUI Verb Summary

The following list contains a brief summary of each of the LUA RUI verbs (for a detailed explanation of each verb,

see Chapter 4, RUI Verbs):

RUI_BID

This verb enables the application to determine when information from the host is available to be read.

RUI_INIT

This verb sets up the SSCP session for an LUA application.

UNIX

RUI_INIT_PRIMARY

This verb sets up the SSCP session for an LUA application acting as the SNA primary for communications

with a downstream LU.

RUI_PURGE

This verb cancels an outstanding RUI_READ verb.

RUI_READ

This verb receives data or status information sent from the host to the LUA application’s LU, on either the

SSCP session or the LU session.

UNIX

RUI_REINIT

This verb re-establishes the SSCP session for an LUA application after a session failure. It is intended for

use by an application that was using an LU from a pool, and needs to re-establish the session using the same

LU in order to continue its processing.