SNAX/HLS Application Programming Manual

RECEIVE-CONTROL-WAIT Verb
SNAX/HLS Verbs
104707 Tandem Computers Incorporated 5–69
RECEIVE-
CONTROL-WAIT Verb
The RECEIVE–CONTROL–WAIT verb provides a waited form of the
RECEIVE–CONTROL verb. Note that the request and reply structures given below
are exactly those for the RECEIVE–CONTROL verb.
If the receive queue for the session is not empty when the verb is issued, the verb is
replied to immediately. If the receive queue for the session is empty, the verb is
queued for later processing. Such a queued verb completes when one of the following
events occurs:
Data arrives from your partner, the SSCP, or the system operator.
The session is closed by your partner. If the session was established using the
enhanced verb set, only the oldest outstanding queued receive–type verb is replied
to as a result of this event. If the session was established using the basic verb set,
all outstanding queued receive–type verbs are replied to.
The session is aborted by the operator.
Your process dies or the file on which the verb request was issued is closed.
The verb is interrupted.
The verb–code of the reply indicates the action taken by SNAX/HLS in response to the
RECEIVE–CONTROL–WAIT verb:
If the top element is a data message, SNAX/HLS replies with the
RECEIVE–CONTROL–WAIT–REPLY format and a return code of RC–OK. Note
that all indicators on the reply format are set to valid states, except that no data is
presented. In this context, a data message is anything that would produce a
RECEIVE–DATA response to a RECEIVE–DATA verb.
In particular, the RECEIVE–DATA–QUEUED-IND field contains Y, and the user
can determine the length of the data that is awaiting delivery.
If the top element is a positive or negative response to previously sent data,
SNAX/HLS replies with a SEND–DATA–REPLY and a RETURN–CODE of
RC–NOTIFICATION or RC–REQUEST–REJECT.
If the top element records the completion of a verb issued with the queued
completion mode selected (or whose operation was interrupted), the completion
notification is passed to your program.