DLL Programmer's Guide for TNS/R Systems

DLL Programmer’s Guide for TNS/R Systems—522203-002
Glossary-1
Glossary
code file: A file comprising instructions that can be executed or emulated by a
computer. Native code files can be either linkable (linkfiles) or loadable (loadfiles).
Object files and binaries are other names for code files.
client (of a loadable library): A loadfile that uses functions or data from a library.
default: The choice made when the user does not direct otherwise.
direct reference (of a loadfile): A library listed in a loadfile’s libList.
DLL: A PIC library that offers functions or data for use by other PIC loadfiles. In UNIX,
this type of file is known as a shared object file or dynamic shared object (DSO).
dynamic loading: Loading and opening DLLs under programmatic control after the
program is loaded and execution has begun.
explicit library: Any library that is named in the libList of any client loadifle or is a user
library of a client program.
export: To provide a symbol definition for use by other loadfiles. A loadfile offers for
export a symbol definition for use by other loadfiles that need a data item or
function having that symbolic name.
gblzd: globalized [symbol]
globalized import: The import-control characteristic of a loadfile that allows it to import
symbols from any loadfile in the loadList of the program with which it is loaded.
When those loadfiles offer multiple definitions of the same symbol, those loadfiles
are searched in loadList sequence and the first definition found takes precedence.
See also searchList.
globalized symbol: an exported symbol generated by the C++ compiler that may have
multiple definitions, of which the linker and loader must assure only one is used
throughout the process.
hybrid SRL: An SRL that has been augmented by the addition of a dynamic section
that exports the SRL's symbols in a form that can be used by PIC clients. A hybrid
SRL looks like a DLL to PIC clients (except it cannot be loaded at other addresses,
and cannot itself link to DLLs). The code and data are no different in a hybrid SRL,
and the hybrid-SRL semantics for non-PIC clients are the same as SRL semantics.
import: To refer to a symbol definition in another loadfile. A loadfile imports a symbol
definition when it needs a data item or function having that symbolic name.
import control: The characteristic of a loadfile that determines from which other
loadfiles it can import symbol definitions. The programmer sets a loadfile's import
control at link time. That import control can be localized, globalized, or
semi-globalized. A loadfile's import control governs the way the loader constructs
that loadfile's searchList and affects the search only for symbols required by that
loadfile.