RDF/IMP and IMPX System Management Manual (RDF 1.3+)

Lockstep Operation
Compaq NonStop™ RDF/IMP and IMPX System Management Manual—522204-001
14-2
Starting a Lockstep Operation
Starting a Lockstep Operation
Transactions protected by a lockstep operation are begun, performed, and terminated just
as any other transaction: call BeginTransaction, do the necessary database updates,
and then call
EndTransaction.
What defines a lockstep operation is the invocation of the new DoLockstep procedure.
You issue the
DoLockstep call immediately after the associated EndTransaction
call.
The DoLockstep Procedure
How you invoke the DoLockstep procedure differs depending on whether your
applications are written in COBOL or TAL.
Including the DoLockstep in COBOL85 Applications
To invoke the DoLockstep procedure from a COBOL85 program, you must first include
the DoLockstep object module in the SPECIAL-NAMES paragraph in the
CONFIGURATION section.
CONFIGURATION SECTION.
SOURCE-COMPUTER. TANDEM T-16.
OBJECT-COMPUTER. TANDEM T-16.
SPECIAL-NAMES.
FILE "<$vol>.<subvol>.LSLIBTO" IS LOCKSTEP-LIB.
where <$vol>.<subvol> is the location where you have placed the object file.
You then invoke the DoLockstep procedure in the PROCEDURE division by using the
following statement:
ENTER TAL "DOLOCKSTEP" IN LOCKSTEP-LIB GIVING RETURN-CODE
The lockstep software provided with the NonStop
TM
RDF/IMPX product includes a
sample COBOL85 program (SLOCKCOB) that demonstrates how to use the
DoLockstep procedure in a COBOL program.
Invoking DoLockStep by way of TAL
The lockstep software provided with the NonStop
TM
RDF/IMPX product includes a
TAL header file containing the DoLockstep procedure declaration and the corresponding
object file. You must modify your program to source in the header file FDOLOCK. For
example, include the following lines of code where you add procedure declarations.
?LIST
?NOLIST, SOURCE EXTDECS
?LIST
?NOLIST, SOURCE FDOLOCK;
?LIST
After recompiling your program, you must then decide whether you want to bind the
object explicitly into your program or treat the object as a user library.