HP-UX SNAplus2 R7 APPC Programmer's Guide

Writing Transaction Programs
APPC Entry Points: HP-UX Systems
AP_CORR corr
);
typedef void (*AP_CALLBACK) (
void * vcb,
unsigned char tp_id[8],
AP_UINT32 conv_id,
AP_CORR corr
);
typedef union ap_corr {
void * corr_p;
AP_UINT32 corr_l;
AP_INT32 corr_i;
} AP_CORR;
Parameter types such as AP_UINT32, used in these entry points and in the APPC VCBs, are defined in the common
header file /usr/include/sna/values_c.h, which is included by the APPC header file /usr/include/
sna/appc_c.h.
Supplied Parameters
When the application uses the APPC_Async entry point to issue a verb, it supplies the following parameters:
vcb
Pointer to a Verb Control Block (VCB) that contains the parameters for the verb being issued. The VCB
structure for each verb is described in Chapter 3, APPC Control Verbs and Chapter 4, APPC Conversation
Verbs. These structures are defined in the APPC header file appc_c.h.
Note
The APPC VCBs contain many parameters marked as “reserved”; some of these are
used internally by the SNAplus2 software, and others are not used in this version
but may be used in future versions. Your application must not attempt to access any
of these reserved parameters; instead, it must set the entire contents of the VCB to
zero to ensure that all of these parameters are zero, before it sets other parameters
that are used by the verb. This ensures that SNAplus2 will not misinterpret any of
its internally-used parameters, and also that your application will continue to work
with future SNAplus2 versions in which these parameters may be used to provide
new functions.
To set the VCB contents to zero, use memset:
memset(vcb, 0, sizeof(vcb));
comp_proc
The callback routine that SNAplus2 will call when the verb completes. For more information about the
requirements for a callback routine, see Section 2.3.3, Callback Routine for Asynchronous Verb Completion.
corr
An optional correlator for use by the application. This parameter is defined as a C union so that the application
can specify any of three different parameter types (pointer, unsigned long, or integer).
SNAplus2 does not use this value, but passes it as a parameter to the callback routine when the verb completes.
This value enables the application to correlate the returned information with its other processing.
51