US 5,475,840 A · 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.

Claims42

Dependent claims

A method of efficiently generating a fully-linked program image of a designated program and related library programs using a dynamic linking system having an image cache, the method implemented in a computer system, the method including the steps of:

invoking said linking system with parameters representing an unlinked program image of said designated program;
searching for said fully-linked program image of said designated program and said related library programs in said image cache;
and
if said fully-linked program image is found in said image cache, then the method further includes the steps of:
retrieving said fully-linked program image with a list of program identifiers and related addresses for each said related library program from said image cache;
and
mapping said fully-linked program image of said designated program and each of said related library programs at said addresses from said list of program identifiers.

4 more elements

A method of efficiently generating a fully-linked program image of a designated program and related library programs using a dynamic linking system having a library cache and an image cache, the method being implemented in a computer system, the method including the steps of:

invoking said linking system with parameters representing an unlinked program image of said designated program;
searching for said fully-linked program image of said designated program and said related library programs in said image cache;
and
if said fully-linked program image is not found in said image cache, then the method further including the steps of:
generating an unlinked copy of said designated program;
searching for a provisionally fixed-up copy of said related library programs in said library cache;
and
if said provisionally fixed-up library programs is found in said library cache, then the method further including the steps of:
retrieving said provisionally fixed-up library programs from said library cache;
linking said provisionally fixed up library programs with each other and with said unlinked designated program to create said fully linked program image of said designated program and related library programs with a list of program identifiers and related addresses comprising an identifier and related address for said designated program and for each of said related library programs;
and
mapping said fully-linked program image of said designated program and each of said provisionally fixed-up library programs at said related addresses from said list of program identifiers.

9 more elements

invoking said linking system with parameters representing an unlinked program image of said designated program;
searching for said fully-linked program image of said designated program and said related library programs in said image cache;
and
if said fully-linked program image is not found in said image cache, then the method further including the steps of:
checking a library cache for a provisionally fixed-up copy of said related library programs and in the event that said library cache contains said provisionally fixed-up related library programs retrieving said provisionally fixed up library programs;
and
if said provisionally fixed up library programs is not found in said library cache, then the method further including the steps of:
creating a list of library program identifiers and related addresses from said library cache;
linking each of said library programs to each other and to said program image to create said fully-linked program image;
and
mapping said fully-linked program image identified by said program identifiers at said related address from said list of program identifiers.

8 more elements

An image caching system for providing a fully-linked program image of a designated program and related library programs to a dynamic linking system, the caching system being implemented in a computer system, the image caching system comprising:

an image cache for caching said fully-linked program image with a list of program identifiers and related addresses for each said related library program, said list for mapping said fully-linked program image;
a first searching facility, coupled to said image cache, for searching said image cache to determine whether said image cache contains said fully-linked program image, said search being made in response to a request to link said designated program;
and
a first communications facility, coupled to said first searching facility, for responding to said request to link said designated program, said response containing said list of program identifiers and addresses related to said program identifiers obtained from said image cache in the event that said fully linked-program image is found in said image cache.

1 more element

An image caching system for providing provisionally fixed-up library programs to a dynamic linking system for linking with an unlinked program image of a designated program to create a fully-linked program image, of said designated program, the caching system being implemented in a computer system, the image caching system comprising:

a library cache for caching provisionally fixed-up library programs;
a first searching facility, coupled to said library cache, for searching said library cache to determine whether at least one of said provisionally fixed-up library programs matches at least one of said related library programs, said search being made in response to a request to link said designated program when said fully-linked program image of said designated program is not found by the dynamic linking system;
and
a first linking facility, coupled to said first said searching facility, for linking a found library program to said designated program, in the event that said found library program is found in said library cache.

1 more element

Dependencies are inferred from the claim text.

High performance dynamic linking through caching

Life of this patent

High performance dynamic linking through caching

Life of this patent

Abstract

Claims42