Wherever possible, the LayGO API is provided in the form of sharable object files: dynamically linked libraries (DLLs) for Win32 and shared objects for Solaris and Linux. Client programs generally access the exported functions from these files by statically linking to the appropriate export library when the program is built.
The advantages of static or build-time linking are:
Most operating systems which support shared objects also support an alternative
to implicit loading with build-time symbol resolution. Sometimes called explicit loading, this alternative allows loading of shared objects under program control, with the
program performing its own explicit symbol resolution at runtime. This is usually
known (somewhat confusingly)
as dynamic loading since the decision about which shared objects to load
is made "dynamically" at runtime instead of "statically" at link-time.
Dynamic loading is accomplished through the
API in Win32 and the
dlopen() API in Unix.
The option of dynamically loading LayGO shared objects has always been available to LayGO client programs on a do-it-yourself basis. Now the LayGO Toolkit supports a portable, type-safe dynamic loading option through a new set of API functions. This manual explains how to write and build programs using the LayGO Dynamic Loading API.