HP-UX SNAplus2 R7 APPC Programmer's Guide

Writing Transaction Programs
APPC Entry Points: Windows Systems
long vcbptr
);
Supplied Parameters
The supplied parameters are:
eventhandle
An event handle that APPC will signal to indicate asynchronous verb completion.
vcbptr
A pointer to the VCB structure for the verb. This parameter is defined as a long integer, and so needs to be
cast from a pointer to a long integer. For more information about the VCB structure and on its usage for
individual verbs, see Chapter 3,
APPC Control Verbs and Chapter 4, APPC Conversation Verbs.
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));
Returned Values
The return value from the function is one of the following:
Handle
The function call was successful (accepted) and the return value is an asynchronous task handle. When the
verb later completes, APPC uses this handle for event notification to the application (for more information,
see Section 2.4.3, WinAsyncAPPCEx). The application also uses this handle as a parameter to the
WinAPPCCancelAsyncRequest call if it needs to cancel the outstanding verb.
0
(zero)
The function call was not successful (not accepted).
Usage
This function is intended for use with WaitForSingleObject or WaitForMultipleObjects in the Win32
API. When the asynchronous operation is complete, the application is notified through the signaling of the event.
Upon signaling of the event, examine the primary return code and secondary return code for any error conditions.
2.4.4 WinAPPCCancelAsyncRequest
The application uses this function to cancel an oustanding APPC verb (issued using the WinAsyncAPPC entry
point).
Function Call
int WINAPI WinAPPCCancelAsyncRequest (HANDLE Handle);
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