COBOL Manual for TNS and TNS/R Programs

Migrating TNS Programs to Native Programs
HP COBOL Manual for TNS and TNS/R Programs—522555-006
33-8
Misalignment Handling
Because a process can run for a long time, the tracing facility samples the process
(that is, checks its exception data) periodically (approximately once an hour). If the
process recorded an exception since the previous sample, the tracing facility records
an entry in the EMS log. If the process ends and an exception has occurred since the
last sample, the operating system produces a final Event Management Service (EMS)
event.
The EMS event includes:
•
The process’s exception count
•
Details about one misaligned-address exception, including the program address,
data address, and relevant code-file names
Sampling is short and infrequent enough to avoid flooding the EMS log, even for a
continuous process with many misaligned-address exceptions. One sample logs a
maximum of 100 events, and at most one event is logged for any process.
If misaligned-address exceptions occur in different periods of a process, the operating
system produces multiple EMS events for the same process, and these EMS events
might have different program addresses.
For more information about EMS events or the EMS log, see the EMS Manual.
Misalignment Handling
Misalignment handling is determined by these SCF attributes, which are set system-
wide (that is, for all processors in the node) by those who configure the system:
•
MISALIGNLOG
•
TNSMISALIGN
•
NATIVEATOMICMISALIGN (does not apply to TNS HP COBOL programs)
MISALIGNLOG enables or disables the tracing facility (see Misalignment Tracing
Facility).
TNSMISALIGN applies to all programs running in TNS mode or accelerated mode.
NATIVEATOMICMISALIGN applies to calls to pTAL atomic functions in programs
running in TNS/R and TNS/E native mode. Nonatomic accesses in TNS/R and TNS/E
native mode are always NOROUND (for the definition of NOROUND, see Table 33-1).
Table 33-1 lists and describes the possible settings for TNSMISALIGN. Each setting
represents a different misalignment handling method. For more information about
TNSMISALIGN, see the SCF Reference Manual for the Kernel Subsystem.