The generic thunking mechanism provides functions that allow a 16-bit application to load a Win32®-based DLL, get the addresses of its exported functions, call the functions (passing each one up to thirty-two 32-bit arguments), convert 16:16 (WOW) addresses to 0:32 addresses (useful if you need to build up a 32-bit structure that contains pointers and pass a pointer to it), and free the Win32-based DLL. This process is similar to the run-time dynamic linking used between a Win32-based application and a Win32-based DLL.
You may find that other IPC mechanisms are more powerful and portable. Keep this in mind when deciding whether or not to use thunks.
Note Microsoft® Windows® 95 and Windows® 98 provide another thunking mechanism called flat thunks. For more information, see Thunk Compiler.