gtpa2m12Application Programming

Run-Time Libraries

Note:
The following describes run-time (nondynamic) libraries only. See "Dynamic Link Library (DLL) Support" for more information about DLLs.

Support for multiple libraries of functions is supported. These libraries must reside in main storage. The IBM-shipped libraries are the most widely used libraries in the complex. They are allocated as PRELOAD and loaded during restart. Figure 11 shows an example of a library load module. If a library is not loaded during restart, the online system cannot use it.

Figure 11. Components of an ISO-C Library Load Module


The TPF library startup code contains data about the library load module and code that processes the secondary library linkage. IDSLST DSECT is used to map the data portion of the startup code.

All libraries should be allocated as core resident, PRELOAD, shared, and with a 31-bit addressing mode. These attributes are assumed by the loader regardless of how the libraries are allocated. Moreover, ISO-C programs cannot be allocated as private or as I-stream unique.

If a new library is being created and loaded with the E-type loader, a new program name is needed. It is not possible to load a new version of an existing program that contains the new library unless the existing version is a library.