HP-UX SNAplus2 R7 APPC Programmer's Guide

Writing Transaction Programs

APPC Verb Summary

2.2.3 Receiving Data

The following verbs enable a TP to receive data from its partner TP:

MC_RECEIVE_AND_WAIT or RECEIVE_AND_WAIT

Issuing this verb while the conversation is in Receive state causes the local TP to receive any data that is

currently available from the partner TP. If no data is available, the local TP waits for data to arrive.

Issuing this verb while the conversation is in Send state ﬂushes the LU’s send buffer and changes the

conversation state to Receive. The local TP then begins to receive data.

MC_RECEIVE_AND_POST or RECEIVE_AND_POST

Issuing this verb while the conversation is in Receive state changes the conversation state to Pending_Post

and causes the local TP to receive data asynchronously. This enables the local TP to proceed with processing

while data is still arriving at the local LU.

Issuing this verb while the conversation is in Send state ﬂushes the LU’s send buffer and changes the

conversation state to Pending_Post. The local TP then begins to receive data asynchronously.

MC_RECEIVE_IMMEDIATE or RECEIVE_IMMEDIATE

This verb receives any data that is currently available from the partner TP. If no data is available, the local

TP does not wait. Unlike the other RECEIVE verbs, this verb can be issued only in Receive state and not in

Send state.

MC_RECEIVE_EXPEDITED_DATA or RECEIVE_EXPEDITED_DATA

This verb receives any expedited data that is currently available from the partner TP. If no data is available,

the verb can either return immediately or wait until data arrives.

2.2.4 Conﬁrming Receipt of Data or Reporting Errors

The following verbs conﬁrm receipt of data or report an error:

MC_CONFIRMED or CONFIRMED

This verb replies to a conﬁrmation request from the partner TP. It informs the partner TP that the local TP

has received and processed the data without error.

MC_SEND_ERROR or SEND_ERROR

This verb notiﬁes the partner TP that the local TP has encountered an application-level error.

2.2.5 Getting Information

The following verbs provide information to TPs:

MC_GET_ATTRIBUTES or GET_ATTRIBUTES

This verb is used by a TP to obtain the attributes of the conversation.

GET_TYPE

This verb is used by a TP to determine the conversation type (basic or mapped) of a particular conversation,

and whether the conversation operates in full-duplex or half-duplex mode. With this information, the TP can

determine the correct verbs to issue on this conversation.

UNIX

GET_LU_STATUS

This verb is used by a TP to obtain information about the number of sessions between its local LU and a

speciﬁed partner LU, and whether the number of sessions has dropped to 0 (zero) at any time since the verb