Intermediate output messages

For a non-conversational 3270 transaction, the bridge exit program might be called to write an intermediate message when either the 3270 transaction has specified WAIT on the EXEC CICS SEND command or the output message buffer is full.

Under some bridge transport mechanisms, it makes sense for the bridge exit program to write an intermediate message containing the data so far. However, under BTS there is no point in trying to send an intermediate message back to the user.

If the exit program is called because of the WAIT option, it can do nothing and return.

If the exit program is called because the message buffer is full, it should :
  1. Obtain a new, larger output buffer (by issuing a GETMAIN command).
  2. Copy the contents of the original buffer into the new buffer.
  3. Release the original buffer (by issuing a FREEMAIN command).
Using this approach, all output from the 3270 transaction is sent to the client at transaction end.
The sample bridge exit program, DFH0CBAE (see Sample programs ) obtains all the storage it requires - including the storage for its output buffer - at the same time. It saves the address of the output buffer in field BRXA-OUTPUT-MESSAGE-PTR of the bridge exit area (BRXA) user area. We recommend that your exit programs do the same.
Note: When the exit program is called because the output buffer is full, field BRXA-FMT-RESPONSE of the BRXA is set to BRXA-FMT-OUTPUT-BUFFER-FULL . The current size of the storage is in field BRXA-OUTPUT-MESSAGE-LEN.