Yes, and if you link against something compiled with cc3290.dll (or whatever Borland's C runtime was called) you too will have bad time unless you structure you

Yes, and if you link against something compiled with cc3290.dll (or whatever Borland's C runtime was called) you too will have bad time unless you structure your library with explicit understanding that there may be any number of C runtimes inside one process, including zero. Expose CreateX()/FreeX() from your library or arrange that the process would on start up pass to your library a table of allocation/deallocation functions to use and use those.