HP-UX SNAplus2 R7 APPC Programmer's Guide

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APPC Conversation Verbs

MC_DEALLOCATE and DEALLOCATE

dealloc_type

Allowed state

AP_FLUSH

Send_Receive (full-duplex conversation only), Send or

Send_Pending

AP_SYNC_LEVEL

Send_Receive (full-duplex conversation only), Send or

Send_Pending

AP_ABEND

AP_ABEND_PROG

AP_ABEND_SVC

AP_ABEND_TIMER

Any except Reset

4.5.8 State Change

State changes, summarized in the following table, are based on the value of the primary_rc parameter.

primary_rc

New state

AP_OK

Receive_Only (full-duplex conversation with

dealloc_type set to AP_FLUSH or AP_SYNC_LEVEL),

or Reset (all other cases)

AP_PARAMETER_CHECK

AP_STATE_CHECK

AP_CONVERSATION_TYPE_MIXED

AP_INVALID_VERB

AP_INVALID_VERB_SEGMENT

AP_STACK_TOO_SMALL

AP_TP_BUSY

AP_UNEXPECTED_DOS_ERROR

No change

AP_ALLOCATION_ERROR

AP_CONV_FAILURE_RETRY

AP_CONV_FAILURE_NO_RETRY

Reset

AP_DEALLOC_ABEND

AP_DEALLOC_ABEND_PROG

AP_DEALLOC_ABEND_SVC

AP_DEALLOC_ABEND_TIMER

Reset

AP_PROG_ERROR_PURGING

AP_SVC_ERROR_PURGING

Receive

4.5.9 Implied Forget Notiﬁcation

UNIX

The Syncpoint protocols include a feature known as “implied forget”, which means that the FORGET PS Header

(the last message in a Syncpoint exchange) is not always required. When the protocol requires a FORGET as the

next message to be received on a session, the next data ﬂow received on that session implies that the FORGET has

been received.

However, if the message that precedes the FORGET indicates that the conversation is being deallocated, the

application no longer has access to the session, and so cannot tell when the next data ﬂow occurs. To provide

this information, SNAplus2 enables the application to specify a callback routine on the [MC_]DEALLOCATE verb;

SNAplus2 then calls this routine when the next data ﬂow occurs on the session, or when the session ends (either

normally or abnormally).

If an application uses this feature, it should wait for the callback routine to be called before issuing the TP_ENDED

verb for this TP. SNAplus2 will not call the callback routine after TP_ENDED has been issued.

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