System and method for providing shared global offset table for common shared library in a computer system

• US 6,260,075 B1
• Filed: 06/19/1995
• Issued: 07/10/2001
• Est. Priority Date: 06/19/1995
• Status: Expired due to Term

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cabrero, Jose E., Holland, Ian M.
• Primary Examiner(s): Banankhah, Majid A.
• Assistant Examiner(s): CALDWELL, PATRICIA G
• Application Number:
  US08/491,660
• Time in Patent Office: 2,213 Days
• Field of Search: 395/700, 395/828, 395/561, 395/710, 395/376, 709/310-332, 711/213, 711/221
• US Class Current: 719/310
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading

Abstract

A computer system employing a microkernel executes two different tasks, e.g., operating systems, yet uses common shared libraries. Rather than each task setting up its own libraries, during compile a global offset table is set up for each task so that the tasks can use common shared libraries. An abstractions layer is established to allow the tasks to share the global offset table, and thus to use common shared libraries. Threading package related services are resolved via the abstractions mechanism. This abstractions mechanism includes services implemented as operating system abstractions, and include thread creation, exit from a thread, etc. Abstracted functions utilize pointers to runtime environment-specific functions, and are utilized by the task'"'"'s runtime environment.

Claims

1. A method of operating a computer system, comprising the steps of:

providing a microkernel running in the most privileged state of said computer for supporting a plurality of different personality servers, at least one of said personality servers behaving like a commonly-used operating system;

generating a first applications task by one of said personality servers and a global offset table used by said first applications task; and

generating a second applications task by another of said personality servers, and using said global offset table by said second applications task;

providing at least one common shared library which is shared by at least said first and second applications tasks generated by said personality servers;

providing an abstractions layer in each one of said common shared libraries and interfacing said common shared libraries with said first and second applications tasks and personality servers via a root layer of said personality servers and said abstractions layer.

2. A method of operating a computer system according to claim 1 including the steps of implementing in said abstractions layer as abstracted functions at least the services of thread creation and thread exit.

3. A method of operating a computer system according to claim 2 wherein said abstracted functions utilize pointers to runtime specific functions.

4. A method of operating a computer system according to claim 1 wherein there are two of said personality servers, one of which is for an OS2 personality and the other of which is for a personality-neutral function.

5. A method of operating a computer system according to claim 4 wherein there are at least two of said common shared libraries.

6. A computer system, comprising:

means for providing a microkernel running in the most privileged state of said computer for supporting a plurality of different personally servers, at least one of said personality servers behaving like a commonly-used operating system;

means for generating a first applications tasks by one of said personality servers and for generating a global offset table used by said first application task; and

means for generating a second application task by another of said personality servers and using said global offset table by said second application task;

means for providing at least one common shared library which is shared by at least said first and second applications tasks generated by said personality servers;

means for providing an abstractions layer in each one of said common shared libraries for interfacing said common shared libraries with said personality servers and said first and second application tasks via a root layer of said personality servers and via said abstractions layer.

7. A system according to claim 6 including the steps of implementing in said abstractions layer as abstracted functions at least the services of thread creation and thread exit.

8. A system according to claim 7 wherein said abstracted functions utilize pointers to runtime specific functions.

9. A system according to claim 6 wherein there are two of said personality servers, one of which is for an OS2 personality and the other of which is for a personality-neutral function.

10. A system according to claim 9 wherein there are at least two of said common shared libraries.

11. A program product residing in computer memory in a computer system for providing operating system and common shared library services, said program product comprising:

means for providing a microkernel running in the most privileged state of said computer system for supporting a plurality of different personality servers, at least one of said personality servers behaving like a commonly-used operating system;

means for generating a first applications task by one of said personality servers and for generating a global offset table used by said first applications task; and

means for generating a second applications task by another of said personality servers and using said global offset table by said second applications task;

means for providing at least one common shared library which is shared by at least said first and second applications tasks generated by said personality servers;

means for providing an abstractions layer in each one of said common shared libraries for interfacing said common shared libraries with said personality servers and said first and second applications tasks via a root layer of said personality servers and via said abstractions layer; and

signal-bearing media bearing said means for providing and means for generating.