Guardian Application Conversion Guide

Being Opened by and Communicating With a High-PIN Requester
Converting TAL Applications
096047 Tandem Computers Incorporated 3–53
Using the OPENER_LOST_ Procedure to Maintain an Opener Table
After receiving a status-change message, your server might call one or more routines
to maintain its opener table.
You might want to use the OPENER_LOST_ procedure to maintain your opener table.
OPENER_LOST_ determines whether a status-change message affects your opener
table and updates the appropriate table entry if an opener was lost.
OPENER_LOST_ accepts a C-series (-2 or -8) or D-series (-2, -100, -110, or -113) status-
change message and searches your opener table for any processes affected by the
message. If OPENER_LOST_ determines that an opener has been lost, it updates the
opener-table entry and returns the index of the entry and an error value. The error
value indicates the reason for the opener-table change:
error
Value Reason
4 A backup process opener is lost
5 A primary process opener is lost; the backup process is now the primary process
6 The primary process and backup process (if it exists) openers for a table entry are lost; the
table entry is now free
When OPENER_LOST_ returns an error value of zero, processing is complete for the
message.
To process all entries in your opener table for a status-change message, set up a loop
similar to the one shown below. The opener table must be defined as described under
“Defining an Opener Table,” earlier in this subsection.
done := 0; ! Set control for start of loop.
index := -1; ! Set index for start of loop.
DO BEGIN
error := OPENER_LOST_(message:message^length,
opener^table.openers,
index,
opener^table.current^count,
$LEN(opener^table.openers));
CASE error OF
BEGIN
4 -> ! Processing for lost backup opener
5 -> ! Processing for lost primary opener
6 -> ! Processing for lost opener
! (primary and backup for a process pair)
OTHERWISE -> done = -1 ! Processing is finished or
! error occurred
END;
END
UNTIL done;