Technical data

Programming Release Notes
6.17 Mail Utility—Threads Restriction for Callable Mail
Because callable mail context information is maintained on a per-process (rather
than a per-thread) basis, multiple threads performing context-based processing
must be synchronized so that only one mail context of a given type is active at
once. Otherwise, one thread could corrupt another thread’s mail operations.
On OpenVMS Alpha systems, there is an additional restriction when kernel
threads is enabled in a multithreaded environment. In this environment, callable
mail should be used only in the initial thread.
6.18 Mathematics (MTH$) Run-Time Library—Linking Images
V6.1
This version of OpenVMS VAX provides updated versions of the Mathematics
Run-Time Library (RTL) images MTHRTL.EXE, UVMTHRTL.EXE, and
VMTHRTL.EXE that contain new entry points in support of DEC Fortran
Version 6.0. (UVMTHRTL.EXE is an alternate form of MTHRTL.EXE; references
to MTHRTL.EXE in the following paragraphs also apply to UVMTHRTL.EXE.)
Due to the large number of entry points added to MTHRTL.EXE, that image’s
transfer vector was extended and its global section match identifier incremented.
This means that images linked against the new version of MTHRTL.EXE will not
run on a system running an earlier version of OpenVMS VAX, unless that system
has also installed DEC Fortran Version 6.0. In addition, images linked against
the new MTHRTL.EXE cannot be translated to run on OpenVMS Alpha using
DECmigrate.
To link an image so that it will run on an earlier version of OpenVMS VAX,
create a directory that contains saved copies of the .EXE and .OLB files from the
SYS$LIBRARY directory of the earliest version you want to support, and define
the logical name SYS$LIBRARY to point to that directory before linking. Because
OpenVMS VAX also defines a system logical name MTHRTL to refer to either
MTHRTL.EXE or UVMTHRTL.EXE, you must also define MTHRTL as a logical
name in the process or job table to point to the copy in the directory of older
images. For example:
$ DEFINE/USER SYS$LIBRARY disk:[OLD_SYSLIB]
$ DEFINE/USER MTHRTL SYS$LIBRARY:MTHRTL.EXE
$ LINK ...
Images to be translated using DECmigrate should be linked against the
SYS$LIBRARY files of OpenVMS VAX Version 5.5-2 or earlier.
6.19 OpenVMS Registry (Alpha Only)
The release notes in this section pertain to the OpenVMS Registry.
For general release notes about the OpenVMS Registry, refer to the OpenVMS
Connectivity Developer Guide, which is installed as part of the COM for OpenVMS
installation process and available on the OpenVMS Documentation CD–ROM.
6.19.1 Registry Key Attribute Change Notifications Unsupported
V7.3
The $REGISTRY system service provides a function code, REG$FC_NOTIFY_
CHANGE_KEY_VALUE, which you can specify to receive notification when
changes are made to a key. Along with this function code, you specify the
item code REG$_NOTIFYFILTER to pass or filter certain type changes to the
key. This item code is a mask of the types of changes to pass. At this time,
6–18 Programming Release Notes