High performance dynamic linking through caching

Abstract

A method is disclosed for a method to dynamically link a new program image and related library programs into an executable application program image. The method provides for producing a linked list of the required programs by giving the linker an argument representing the designated program image and a naming context which contains data on the associated library programs which are to be linked together. The linker finds all of the required programs, and links them together. The parent maps the program images into the designated addresses thereby completing the linking of the executable application program. In finding the required programs, the linker first checks the image cache to see if the new program and its related library programs is already linked and cached because it was executed before. If the new program is not found in the image cache, the linker object then checks the library program cache to see if the library programs are cached in partially linked form, and will use as many of these as it can find. For any library programs that must still be located, the linker will retrieve them from a data store and will then proceed to link all library programs and the new program image together to form an executable whole. This process of caching new program images with their library programs and caching partially linked library programs individually guarantees a procedure which minimizes the time delay in program start-up when a new program is executed.