SNAX/HLS Configuration and Control Manual

Step 5. Planning for Programming Standards

Planning the SNAX/HLS Environment

2–32 104705 Tandem Computers Incorporated

These indicators provide the HLS application with information about which state to

assume so that mismatches and RA-DEFER responses can be avoided.

If ENTER-SEND-STATE-IND is set on a RECEIVE-DATA reply, it signals that the

application should now send data. In effect, the indicator, when it contains “Y,”

should be interpreted as “The session partner has relinquished the right to send

data, and is waiting for me to send something. Therefore, I should send

something.”

If ENTER-RECEIVE-STATE-IND is set in a SEND-DATA reply, it indicates that

the other partner wants to send data. The indicator should be interpreted as

“Partner wants to send, so I should allow it when it is convenient for me, by

setting PREPARE-TO-RECEIVE-IND is set to Y on a subsequent SEND-DATA

message.”

SCOBOLX Naming

Conventions

To help achieve flexible and tunable Pathway environments, this subsection suggests

standard conventions for naming SNAX/HLS server classes and for passing LU names

to SCOBOLX applications at initialization.

Recall that in a Pathway environment a given TCP can control a set of requesters that

are issuing verbs to SNAX/HLS processes in several server classes. Of course, each

SNAX/HLS process is a server class. The major design point is to construct a standard

such that a simple configuration change can at the same time alter the LU used by a

given requester and alter the server class used by the requester to access the

appropriate SNAX/HLS process that controls the LU.

This design goal can be achieved by making the Pathway server class name for a

SNAX/HLS process the same as the name for the SNAX/HLS process (omitting the

system name and dollar sign). By following such a convention, a simple redefinition

of the SCOBOLX special register TERMINAL-FILENAME can serve the purpose. The

line name X(8), and subdevice name X(8). A variable isolating the low-order 6 bytes of

the process name (thus removing the system number) is used as the server-class-name

variable in any SEND statement that delivers a verb to the SNAX/HLS server. This

technique works only when the host Tandem system is part of an Expand network or

is a named system. If the system is not named, a variable isolating the low-order 7

bytes should be used.

The sample code below demonstrates the convention for both cases. Assume 20 36xx

terminals spread between 2 TCPs and 2 SNAX/HLS processes:

TCP1 handles terminals 1-10.

TCP2 handles terminals 11-20.

$HLS1 handles terminals 1-11.

$HLS2 handles terminals 12-20.