TS/MP Pathsend and Server Programming Manual (G06.24+, H06.03+)

NonStop TS/MP Pathsend and Server Programming Manual–132500
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Writing Pathway Servers
This section explains how to write server programs that service requests from Pathway
requesters. Such requesters can be Pathsend requesters, SCREEN COBOL requesters, or
clients that use the Remote Server Call (RSC) product or the Pathway Open
Environment Toolkit (POET) product. Pathsend requesters are described in this manual.
SCREEN COBOL requesters are described in the Pathway/TS TCP and Terminal
Programming Guide; the SCREEN COBOL language is described in the Pathway/TS
SCREEN COBOL Reference Manual. For information about writing RSC clients, refer
to the Remote Server Call (RSC) Programming Manual. For information about writing
POET clients, refer to the Pathway Open Environment Toolkit (POET) Programming
Manual.
Pathway server programs read requests from $RECEIVE, as described in the Guardian
Programmer’s Guide and in the manuals describing Tandem programming languages.
You can write Pathway server programs in C, C++, COBOL85, Pascal, pTAL, TAL,
FORTRAN, or Extended BASIC. You should be familiar with the Guardian requester/
server model and with the $RECEIVE mechanism as implemented in the programming
language you are using.
If you are using the Transaction Management Facility (TMF) subsystem, you should
also be familiar with general programming guidelines and considerations for TMF
servers, as described in the NonStop TM/MP Application Programmer’s Guide.
Basic Pathway Server Programming
The simplest type of Pathsend server is a context-free server. This subsection provides
information related to writing context-free Pathway servers, as well as information that
applies to all Pathway servers. Writing Context-Sensitive Servers, later in this section,
provides information about the additional tasks required of a context-sensitive Pathway
server.
In X/Open and NonStop TUXEDO system terminology, a context-free server is called a
request/response server, and a context-sensitive server is called a conversational server.
Servers Shared by Different Types of Requesters
The protocol for Pathway server processes is essentially the same regardless of the type
of requester they work with. Therefore, Pathway servers can be used by more than one
type of requester; for example, by both Pathsend requesters and SCREEN COBOL
requesters, or by both Guardian requesters and clients from client/server environments.
If servers are used by several types of requester, the server program request and reply
formats must be consistent with that of all the requesters.
Note. This section describes how to write Pathway servers in the Guardian environment. You
can also write a Pathway server program in the NonStop Kernel Open System Services (OSS)
environment. The basic design considerations in this section apply also to Pathway servers in
the Open System Services environment; however, additional Open System Services
programming considerations also apply. For information about these programming
considerations, refer to the Open System Services Programmer’s Guide.