Guardian Application Conversion Guide

Opening and Communicating With a High-PIN Server
Converting C Applications
5–24 096047 Tandem Computers Incorporated
Reading Status-Change System Messages. Your requester might monitor a server process
by reading these status-change system messages from $RECEIVE:
-2 CPU down: local CPU failure after process called MONITORCPUS
-8 Change in status of network node
Continue to read system message -2. Then, convert your requester to read these new
status-change messages, all of which supersede system message -8:
-100 Remote CPU down
-110 Loss of communication with node
-113 Remote CPU up
To receive system messages -100, -110, and -113, first call the MONITORNET
procedure with the enable parameter set to 1.
Processing System Messages Using the CHILD_LOST_ Procedure
Your requester might call a user-written routine to determine whether a process-
deletion or status-change message affects the server.
You might convert your requester to call the new CHILD_LOST_ procedure. The
CHILD_LOST_ procedure accepts the process handle of a process you are monitoring
and either a C-series (-2, -5, -6, or -8) or D-series (-2, -100, -101, -110, or -113) process-
deletion or status-change system message:
error = CHILD_LOST_(message,
message_length,
process_handle);
The CHILD_LOST_ error returned value indicates whether the process (or process
pair) is lost:
0 The process (or process pair) is not lost.
4 The process (or process pair) is lost.
Note System message -101 (Process deletion) contains the process handle and process descriptor of the
process that terminated. If a named process (or process pair) has terminated, this is the last opportunity
for you to save the process name of the process (or process pair).
Closing $RECEIVE
Your requester might close $RECEIVE using the CLOSE procedure:
CLOSE (receive_file_number);
You can close $RECEIVE using either the CLOSE or FILE_CLOSE_ procedure:
error = FILE_CLOSE_(receive_file_number);