Programming Release Notes
5.4 AST Delivery Clarification in Programs using POSIX Threads
Also, note that much of the material in Section B.12.5 of the Guide describes a
possible future version of OpenVMS. The description of generalized "per-thread"
or thread-targeted ASTs represents possible future enhancements to the operating
system. In all OpenVMS releases to date, however, user-mode ASTs are treated
as if they are directed to the process as a whole.
5.5 RMS $PARSE Validation of Directory Files
V8.3-1H1
Starting with OpenVMS Version 8.3, the $PARSE service further validates
all directories named in a directory specification to ensure that the directory
characteristic is set. In previous OpenVMS versions, attempting to use a file
with a .DIR extension that was not a directory resulted in a SS$_BADIRECTORY
error from the $OPEN service, but not necessarily from the $PARSE service. As
of Version 8.3, the error is consistently returned by the $PARSE service as long
as it is not a syntax-only $PARSE.
5.6 No-IOLOCK8 Fibre Channel Port Drivers
V8.3-1H1
Many I/O subsystem components synchronize their operations across CPUs
by using the IOLOCK8 spinlock, which has made acquiring the spinlock a
performance bottleneck. As of Version 8.3-1H1, each Fibre Channel port driver
(SYS$PGQDRIVER, SYS$PGADRIVER and SYS$FGEDRIVER) device uses
its own port-specific spinlock instead of IOLOCK8 to synchronize its internal
operations. In most configurations, this results in a significant decrease in the
amount of time each CPU spends waiting for the IOLOCK8 spinlock as well as
some increase in the Fibre Channel I/O rate.
Some minor changes are required to any class driver that connects to one of these
new port drivers, so customers must determine whether they are running any
non-HP class drivers that will not work with them. The simplest way to do this is
to examine the output of the SDA command
CLUE SCSI/SUMMARY
and see whether
the name of any third-party class driver device appears in the device hierarchy
for an FGx0 or PGx0 port device in the "Device" column.
For more information, refer to the notes following this sample SDA session.
$ ANALYZE/SYSTEM
OpenVMS system analyzer
SDA> CLUE SCSI /SUMMARY
5–4 Programming Release Notes
