Types of Linkages

Linkage between a client library and a server library is established at run time by the operating system, based on the values of the library attributes of the client library. There are three ways a client library can link to a server library: implicitly, explicitly, or directly.

Linkage Errors

Linkage errors have different effects, depending on the type of linkage that is used. If an implicit linkage results in an error, that error is fatal for the client program. On the other hand, if an explicit or direct linkage results in an error, the error is nonfatal and is communicated to the client program as a LINKLIBRARY function result.

Implicit Initiations

If a process attempts to link to a server library, and no frozen instance of that library is currently available, the system performs an implicit initiation of the library. This implicit initiation can occur regardless of whether the linkage attempt was an implicit linkage, an explicit linkage, or a direct linkage. Refer to Implicitly Initiating a Server Library later in this section.