SNAX/HLS Application Programming Manual

RECEIVE DATA Verb
SNAX/HLS Verbs
5–80 104707 Tandem Computers Incorporated
REVEIVE-DATA Verb The RECEIVE–DATA verb is used to transfer the top element of the receive queue to
the user.
If the receive queue is currently empty, the completion of this verb waits until some
data arrives, the session is terminated, or a SCOBOLX SEND MESSAGE operation is
interrupted.
The actual response area must be examined to determine what actually happened, as
follows:
If VERB–CODE in the reply has the value VERB–RECEIVE–DATA (value 5), then
SSCP data, operator data, or partner data is being returned. You must examine the
DATA–TYPE–RECEIVED field to classify the actual reply.
If VERB–CODE in the reply has the value VERB–SEND–DATA (value 7), then a send
acknowledgement or send error is being returned. It confirms that your partner
has received and responded to a message you sent. Note that no reply ever
conveys the verb code of VERB–SEND–AND–RECEIVE–DATA. See the discussion of
the SEND–DATA verb reply for details.
If VERB–CODE in the reply has some other value, it represents the completion of
actions initiated by a verb that was previously completed with the completion
code of RC–FORTHCOMING. This can arise either because you issued a verb with
the queued completion mode or you interrupted the request. The actual details of
the response are described with the discussion of the verb; the reply is the same as
the reply returned on the wait operation.
When partner data is indicated, the operation of this verb is dependent on the current
setting of the LMO PROFILE attribute. If LMO is NO, then complete session–partner
messages are assembled and delivered to the user with RECEIVE–DATA replies. If
LMO is YES, then individual message elements (chain elements) are delivered with
each RECEIVE–DATA reply. If no data is available, the verb is queued for later
processing (note that this causes a SCOBOLX requester to hang). Such a queued verb
completes when one of the following occurs:
Data arrives from the partner, the SSCP, or the systems operator.
The session is closed by your partner.
The session is aborted by the operator.
The verb is interrupted (a SCOBOLX feature).
Your process dies, or the file on which the verb flowed is closed.
The reply formats indicate the type of the delivered message.