Guardian Application Conversion Guide

Converting Basic Elements of a TAL Program
Converting TAL Applications
3–4 096047 Tandem Computers Incorporated
Declaring and Using
Programming Variables
When converting your program to use the D-series enhanced interface, there are
several variables that you might need to add or modify. These variables include:
Variables that contain a PIN
File-system error numbers
Guardian file names, including disk file names, device names, and process file
names
Process identifiers, including process IDs, process handles, and process descriptors
The following paragraphs describe how to declare these entities to the D-series
enhanced interface.
Declaring CPU and PIN Variables
Your existing program might declare either a 16-bit integer variable for both the CPU
and PIN values or an 8-bit variable for a PIN value:
STRING primary^cpu, ! CPU of primary process.
primary^pin; ! PIN of primary process.
INT cpu^and^pin; ! CPU and PIN values.
Declare all PIN values, including backup-process PINs, as 16-bit integer variables. For
CPU and PIN values, declare each item as a separate 16-bit integer variable:
INT primary^cpu, ! CPU of primary process.
primary^pin; ! PIN of primary process.
Declaring and Checking File-System Error Numbers
You might need to convert the parts of your program that declare and check file-
system error variables. For example, your program might declare a STRING variable
for a file-system error number:
STRING fs^error^number;
Declare a file-system error number as a 16-bit integer variable:
INT fs^error^number;
Your program might also include procedures that assume a maximum value for a
file-system error number (for example, 255). A D-series file-system error number can
be a maximum of 16 bits. Therefore, to make sure that your procedures do not exclude
any new error numbers, you should allow for up to 5 decimal digits for error numbers.
Also, because Tandem might define additional error numbers in future releases, do
not consider currently undefined numbers as invalid.
For a list and description of all file-system error numbers, refer to the Guardian
Procedure Errors and Messages Manual.