H-Series Application Migration Guide (H06.03+)

Migrating TNS Applications to H-Series Systems
H-Series Application Migration Guide—429855-006
B-14
Using EPTRACE to Detect Data Misalignments
The Fail behavior can be selected in one of two ways:
•
Through SCF. This sets the default behavior for all programs on the system.
•
Through a Binder option. This method overrides the system default behavior, and
applies only to the program being bound. The Binder command to select the Fail
behavior is SET MISALIGN FAIL.
Using EPTRACE to Detect Data Misalignments
On H-series systems, you can use the EPTRACE facility for reporting misalignment
events and compatibility traps in TNS processes without halting program execution.
EPTRACE is a fully supported version of the unsupported TNS/R XLTRACE facility,
and can be safely used in a production environment.
When run against a program that contains misaligned addresses (with NoRound
enabled), EPTRACE reports the type of each trap and the code address of where each
trap occurred. Execution continues after the event. You can then use the enoft utility
(for TNS/E native programs) or Binder (for TNS programs) to map the code address
from EPTRACE to the source code location in the program.
EPTRACE runs only in the Guardian environment. See the EPTRACE Manual for more
information about using EPTRACE
These documents provide more information on detecting and correcting data
misalignments in TNS programs:
Binder Manual
C/C++ Programmer’s Guide
COBOL Manual for TNS/E Programs
TAL Programmer’s Guide Data Alignment Addendum
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 might affect programs that you are
migrating to an H-series system and that call any of these C-series procedures:
C-Series Procedure Extended DCT limits affects calls that:
FILEINFO Use the optional ldevnum parameter
GETDEVNAME (Affects all calls)
GETPPDENTRY (Affects all calls)