DLL Programmer's Guide for TNS/R Systems

Sample Sessions and Usage Notes
DLL Programmer’s Guide for TNS/R Systems—522203-002
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Usage Notes
Usage Notes
No Support for DLL Tools on UNIX Systems
This is a reminder. Developers, such as private SRL providers who build their SRLs on
UNIX (for example, SUN) workstations should already be aware that the DLL-enabled
compilers and linkers run only under Guardian, OSS and Windows (under ETK)
environments. These developers will have to migrate at least some part of their
development environment to NSK, PC or OSS.
The Impact of DLLs on Existing TNS/R Product Software
This note describes the changes needed to existing NonStop Server application
software products when DLLs are introduced on a TNS/R system. This applies to
software from NSSO, partners, and third parties, as well as to existing customer
applications.
General
If you elect not to use DLLs, then because existing mechanisms continue to work as
before, no changes need be made to your software products. However, if you adopt
DLLs for an application, any linkfile products to be linked into your PIC application must
be recompiled as PIC. Also, loadfile products that are either programs or SRLs (except
for public SRLs) must converted to PIC programs or DLLs respectively. Products are
unaffected if they do not ship library code, or if all their library code is in a public SRL.
Linkable Library Products
A linkable native library is one that the customer links into his own code to create a
loadfile. In the past, application software was often provided to NonStop Server
customers in linkable native library form, because the NonStop Kernel only supported
a program and an optional User Library in a process. Software formerly provided as a
linkable native library can continue to be linkable and should be provided in both PIC
and non-PIC form, with different names. However, with availability of DLLs, the
NonStop Kernel can support an arbitrary number of DLLs per process, so it might be
preferable to provide what was formerly a linkable native library as one or more
ordinary DLLs.
Loadable Library Products
To make it usable in PIC applications, software formerly provided only as a private SRL
must also be provided as one or more DLLs. The DLLs need different names from the
SRL. The most common form of private SRL is the native User Library. However, a few
products also provide a “named” private SRL, which is a feature that was never
externalized. This note applies to both.