TNS/E Native Application Conversion Guide
Developing a Conversion Strategy
TNS/E Native Application Conversion Guide—529659-003
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Adjusting for Increased DCT Limits
In some cases, two logically equivalent but syntactically different fragments of code
might be required: one for TNS compilers and one for native compilers. Such code can
be isolated within a source file for conditional compilation:
For source code compiled with both the pTAL and TAL compilers, you must first check
the syntax of the program with the pTAL compiler’s syntax checking option and then
compile the program with the TAL compiler. The D31 TAL compiler supports but does
not check most pTAL language features.
Adjusting for Increased DCT Limits
The Destination Control Table (DCT) contains entries for logical device numbers and
named processes. The DCT limit refers to the maximum number of logical device
numbers and named processes that the operating system can accommodate. As of the
G06.23 RVU, the size of the DCT can optionally be increased from its previous limit of
32,767 (a logical device number can have at most 15 bits) to 65,376 (a logical device
number can have up to 16 bits). This change can affect programs that you are
migrating to an H-series system and that call any of these C-series procedures:
In G06.23 and later G-series RVUs, the default setting for extended DCT limits is OFF
(extended limits are not in effect). In H-series RVUs, the default setting for extended
DCT limits is ON (extended limits are in effect). Therefore, if you have not yet changed
any affected applications to allow for increased limits, you must do one of the following:
•
Ensure that the system default for or DCT limits extension is reset to OFF (enter an
SCF command).
•
Change your program to allow for the increased DCT limits.
Language For conditional compilation, use: For more information, see:
C
C++
#ifdef macros
C/C++ Programmer’s Guide
COBOL IF, IFNOT, ENDIF, SETTOG, and
RESETTOG directives
COBOL Manual for TNS/E
Programs
pTAL IF directives
pTAL Reference Manual
C-Series Procedure Extended DCT limits affect calls that:
FILEINFO Use the optional
ldevnum
parameter
GETDEVNAME (Affects all calls)
GETPPDENTRY (Affects all calls)
GETSYSTEMNAME Use the return value as an ldev or check for specific error
codes
LOCATESYSTEM Use the return value as an ldev or check for specific error
codes
LOOKUPPROCESSNAME Pass a DCT index in the
ppd
parameter