HP-UX SNAplus2 R7 APPC Programmer's Guide

Writing Transaction Programs
APPC Entry Points: HP-UX Systems
REJECT_ATTACH
This verb is used to notify SNAplus2 that the application does not intend to start the TP that corresponds to
this Attach.
ABORT_ATTACH
This verb is used to end the processing of the Attach by this TP server after the Attach has been accepted using
an ACCEPT_ATTACH verb because the TP server or TP has encountered an error during further processing.
UNREGISTER_TP
This verb is used to notify SNAplus2 that the application no longer wishes to process Attaches for this
previously registered TP.
UNREGISTER_TP_SERVER
This verb is used to notify SNAplus2 that the application does not want to receive Attach notifications for
the specified TP.
2.3 APPC Entry Points: HP-UX Systems
UNIX
An application accesses APPC using the following entry points:
APPC
Issues an APPC verb synchronously. SNAplus2 does not return control to the application until verb processing
has finished.
APPC_Async
Issues an APPC verb asynchronously. SNAplus2 returns control to the application immediately, with a returned
value indicating whether verb processing is still in progress or has completed. In most cases, verb processing is
still in progress when control returns to the application; SNAplus2 then uses an application-supplied callback
routine to return the results of the verb processing. In some cases, verb processing is complete when SNAplus2
returns control to the application; SNAplus2 does not use the application’s callback routine.
Note
TP server verbs, as described in Chapter 5, TP Server Verbs, must be issued using the
asynchronous entry point APPC_Async, and not the synchronous entry point APPC.
The entry points APPC and APPC_Async are defined in the APPC header file /usr/include/sna/appc_c.h.
An application that performs a single task, and can suspend while waiting for information either from SNAplus2
or from the remote system, need only use the APPC (synchronous) entry point.
If the application performs multiple tasks (such as communicating with more than one remote program at a time,
or performing other processing in addition to APPC verbs), you may need to ensure that it does not suspend while
waiting for information. In this case, the application should use the APPC_Async (asynchronous) entry point,
supplying a callback routine that SNAplus2 can use to return information when it is available.
The following sections describe these entry points, and also describe some additional application-defined functions
which the application must supply to them.
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