Technical data

Programming Release Notes
6.19 OpenVMS Registry (Alpha Only)
only the REG$M_CHANGENAME, REG$M_CHANGELASTSET, and REG$M_
CHANGESECURITY mask bits have any effect on which notifications are passed
or filtered. The REG$M_CHANGEATTRIBUTES mask bit is currently not
supported.
For the most part, specifying the REG$M_CHANGENAME, REG$M_
CHANGELASTSET, and REG$M_CHANGESECURITY mask bits is equivalent
to specifying the REG$M_CHANGEATTRIBUTES mask bit. Any change that
would be passed as a change to an attribute would also pass as either a name
change, update of a key, or a security descriptor change.
We expect to support notification for attribute changes in a future version of
OpenVMS.
6.19.2 Easing of Registry Data Transfer Size Restriction
V7.3
Previous versions of OpenVMS placed restrictions on the size of a data transfer
between the $REGISTRY system service and the OpenVMS Registry server. The
data transfer restrictions, in turn, placed restrictions on the maximum size of a
single block of data that can be stored or retrieved from the Registry database.
They also limited the depth of a REG$CP Search command, and placed limits
on the number of Advanced Server domain groups of which a user can be a
member. These restrictions have been eased in OpenVMS V7.3, but have not
been eliminated entirely.
Previously the restrictions were approximately 8K bytes transmit (service to
server) and approximately 4K bytes receive. The current restriction depends on
the setting of the SYSGEN parameter MAXBUF. The range for MAXBUF is 4K
to 64K, with a default of 8K.
MAXBUF is the maximum allowable size for any single buffered I/O packet. You
should be aware that by changing MAXBUF you also affect other areas of the
system that perform buffered I/O.
We expect to further ease this restriction in future versions of OpenVMS.
6.20 POSIX Threads Library
The following sections contain release notes pertaining to the Compaq POSIX
Threads Library (formerly named DECthreads).
6.20.1 Process Dumps
V7.3
If the POSIX Threads Library detects an uncorrectable serious problem at
run time (such as data structures that have been damaged by data corruption
somewhere in the application), the library may terminate the running image.
During termination, the library may trigger creation of a process dump file (which
can subsequently be used to diagnose the failure, by way of ANALYZE/PROCESS_
DUMP). The size of such a process dump file depends on the size of the process’s
address space at the time of the failure and can be quite large.
Programming Release Notes 6–19