SNAX/HLS Application Programming Manual

SEND-AND-RECEIVE-DATA Verb
SNAX/HLS Verbs
104707 Tandem Computers Incorporated 5–95
SEND-AND-
RECEIVE-DATA Verb
The SEND–AND–RECEIVE–DATA verb acts like a specialized SEND–DATA followed
immediately by a RECEIVE–DATA verb. If the session is using half–duplex flip–flop
protocol, SNAX/HLS automatically sets the PREPARE–TO–RECEIVE–IND to Y.
Furthermore, in LMO mode, this request cannot be used if the
MESSAGE–COMPLETE–IND is N. If a send–check occurs (that is, something goes wrong
with the SEND–DATA portion), then SNAX/HLS formats a reply to SEND–DATA.
Note that no reply ever contains the verb code of SEND–AND–RECEIVE–DATA. If no
problems occur in the send portion, a receive request is queued as a RECEIVE–DATA
request.
Note that if the NOTIFY–IND is Y, the data returned on the receive portion reflects the
receipt of the response and does not contain application data.
The operation of this verb is the same as that documented under the SEND–DATA
and RECEIVE–DATA verbs.
There is one restriction on the use of the SEND–AND–RECEIVE–DATA verb: if at the
time the send portion of the operation is complete, a RECEIVE–CONTROL–WAIT
verb is outstanding on the session, then the verb completes as a RECEIVE–DATA verb
with a return code of RC–RCWT–ALREADY–QUEUED.