adtools/clib2

This is a simple shared library example which consists of a set of mandatory
library functions (in "lib_base.c") and a set of user-defined functions (in
"lib_user.c"). Neither implement a really useful shared Amiga library: no
user-callable functions are included, only what you need as the absolute
minimum to make a library respond correctly to OpenLibrary() and
CloseLibrary() function calls. The code is intended to serve both as a
demonstration how to write an Amiga shared library and how such a library
could make use of clib2 library functions that are part of the 'C' standard
runtime library, but not necessarily reentrant. The term "reentrant" refers to
a property of certain library functions which allows several callers to invoke
them at the same time without any ill effects. Only few such functions exist,
such as strcpy(), strlen() or time(). Then there are others such as
localtime() or strtok() which by design are not reentrant. The thread-safe
variant of the clib2 runtime library tries to provide thread-safe (and
therefore reentrant) functions which could be used in an Amiga shared library.
But it can only go so far. The environment for which thread-safety is defined
(POSIX.1) covers application software, such as shell commands, but it does not
cover the peculiarities of Amiga shared libraries. You therefore need to
exercise caution when building a library which references code from the 'C'
runtime library. For example, you cannot safely call assert() or exit() from
within an Amiga shared library.