Software Reference Manual - NetEx

4. The record module may return an informational message, an abnormal end message, or an end of information
message. If the message indicates an end of transfer, the record module will have already closed
the file. Forward the message to the control module and free any storage if an end message was passed
up.
5. The control module may call with an abnormal end indication based on a loss of communications or an
abort issued by the receiving BFX module. In that case, call the record module with an abnormal end indication.
On return, the file should have been closed. Free any allocated storage areas and return to the
control module for the last time.
Receiving Record Module (RRM)
The receiving record module is actually responsible for the QSAM I/O that will put the logical records in the
file designated by the user. It opens the file, determines record format and logical record formatting requirements,
and issues PUT macros to write the data when it is delivered by the block module. If I/O errors occur,
it is responsible for analyzing the errors, determining if the error is fatal or not, and returning a comprehensible
error message to the block module in the event of an I/O error.
The BFX default receiving record module operates as follows:
1. When the receiving record module receives control for the first time, it opens the file whose DDNAME is
passed to it from the block module. Using the LRECL parameter produced as a result of the OPEN, it returns
the maximum logical record length to the block module. If the specified BLOCK= parameter is not
large enough to accommodate the largest logical record, then the RCV module will adjust the value of
BLOCK upwards. If the open for the file does not succeed, then the record module will return an open
failure message to the block module for logging.
2. Subsequent calls to the record module will provide the address and length of the logical record. The record
module will PUT (WRITE for VBS format) this record to the file, adding V-format header information
if needed. If record type conversion is called for, then it will truncate or pad the record before it is
written.
3. If the record module is called with an error or EOF indication, then the record module will close the file
and return to the block module.
Sending Record Module (SRM)
The sending record module is responsible for reading logical records from the file to be sent over the network.
On the first call, it will open the file for input. Subsequently, it will provide a logical record every time it is
called. When end of file is reached or a permanent error is detected in reading the file, then it will close the
file, generate a termination message, and return.
SRM flow of control proceeds as follows:
1. When the sending record module receives control for the first time, it opens the file whose DDNAME is
passed to it from the block module. Using the LRECL parameter produced as a result of the OPEN, it returns
the maximum logical record length to the block module. If the specified BLOCK= parameter is not large
enough to accommodate the largest logical record, then the SND module will adjust the value of BLOCK upwards.
If the open for the file does not succeed, then the record module will return an open failure message to
the block module for logging.
2. Subsequent calls to the record module will provide the address and length in which the logical record is to
be placed. The record module will GET the record into this block module provided area.
3. If the record module is called with an error or EOF indication, then the record module will close the file
and return to the block module.
Page 88 Appendix B: BFX Internal Summary MAN-REF-H211-05