System for dynamic run-time binding of software modules in a computer system

• US 5,339,430 A
• Filed: 07/01/1992
• Issued: 08/16/1994
• Est. Priority Date: 07/01/1992
• Status: Expired due to Term

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: Lundin, Kenneth, Markstrom, Ulf
• Primary Examiner(s): Kriess, Kevin A.
• Application Number:
  US07/907,307
• Time in Patent Office: 776 Days
• Field of Search: 395/700, 395/600, 395/650, 320/110.1
• US Class Current: 719/332
• CPC Class Codes: G06F 8/656 while running
• CPC Class Codes: G06F 9/44521 Dynamic linking or loading; Link editing at or after load time, e.g. Java class loading
• CPC Class Codes: G06F 9/44536 Selecting among different versions

Abstract

In telecommunications switching systems, software is frequently modified, enhanced or replaced altogether by new versions. The implementation or integration of the new or revised software into the operational system must be accomplished in accordance with strict requirements for not disturbing the ongoing activities of the system. Therefore, it is desirable that the system not be halted while the change to the new software is made. Rather, the preferred approach is to be able to replace software modules with new versions on the fly, during system operation. The smooth modification made possible in the disclosed system allows such changes with minimal disturbance to ongoing activities by dynamically linking and binding software modules during execution. The disclosed system accomplishes this by applying expanded object-oriented programming techniques and utilizing language-independent interface specifications that remain unchanged and that obviate the need for storing symbolic information that would be subject to change following modification.

Claims

1. A method of dynamically binding, within a computing system having a kernel, first and second software modules respectively contained within first and second software applications, said method comprising the steps of:

providing a linked procedure call mechanism having a trader portion;

providing a client interface, said client interface capable of accessing said trader portion;

providing a server interface, said server interface capable of accessing said trader portion;

inserting said client interface into said first software module;

inserting said server interface into said second software module;

identifying said client interface by executing said first software module;

identifying said server interface by accessing said trader portion with said identified client interface; and

substituting said server interface in place of said identified client interface, during execution of said first software module, thereby dynamically binding said first and second software modules.

2. The method of claim 1 further comprising the step of:

generating said client interface and said server interface from a common interface specification.

3. The method of claim 2 wherein the step of generating said client interface and said server interface from a common interface specification includes the step of:

generating, with an off-line stub generation tool, both client objects and server objects from said common interface specification, said off-line stub generation tool providing coordination between said client objects and said server objects.

4. The method of claim 3 wherein the step of generating, with an off-line stub generation tool, both client objects and server objects from said common interface specification includes the steps of:

generating a file containing at least one client object; and

generating a file containing at least one server object.

5. The method of claim 4 wherein the step of generating a file containing at least one client object includes the step of:

generating a file containing one client object which is compatible with an associated server object in said generated file containing said server objects.

6. The method of claim 2 further comprising the step of:

creating said common interface specification using an object-oriented interface description language.

7. The method of claim 6 wherein said step of creating said common interface specification further includes the steps of

naming the common interface specification;

identifying other interfaces used as a base for said named common interface specification;

creating at least one constructor, said constructor demonstrating how to create instances of objects specifying said named common interface specification; and

creating at least one method-specification for performing functions of said named common interface specification, said method-specification including a method name, arguments, return type and exceptions.

8. The method of claim 6 wherein the step of creating a common interface specification using an object-oriented interface description language includes the step of:

creating said common interface specification from a base interface, said common interface specification inheriting specified methods of said base interface.

9. The method of claim 2 further comprising the step of:

creating said common interface specification in a computer program language-independent fashion using an object oriented paradigm.

10. The method of claim 9 wherein the step of providing a client interface includes the step of:

providing a client object, said client object capable of accessing said trader portion.

11. The method of claim 9 further comprising the step of:

inserting said server interface'"'"'s location into said trader portion.

12. The method of claim 9 wherein the step of providing a server interface includes the step of:

providing a server object, said server object capable of accessing said trader portion.

13. The method of claim 12 further comprising the steps of:

loading, into said computing system, a third software application containing a third software module, said third software module including server objects which are compatible with said server objects inserted into said second software module; and

inserting the location of said server objects contained within said third software module into said trader portion.

14. The method of claim 13 further comprising the step of:

directing a process, created prior to loading said third software module, to said second software module by accessing said trader portion with said kernel.

15. The method of claim 13 further comprising the step of:

directing a process, created subsequent to loading said third software module, to said third software module by accessing said trader portion with said kernel.

16. A method of dynamically binding, within a computing system having a shared memory and a kernel, first and second software modules respectively contained within first and second software applications, said method comprising the steps of:

providing a linked procedure call mechanism having a trader portion;

loading said first software module into said shared memory of said computing system, said first software module including a client interface;

loading said second software module into said shared memory of said computing system, said second software module including a server interface;

inserting into said trader portion a memory address of said server interface;

identifying said client interface by executing said first software module;

identifying said server interface by accessing said trader portion with said identified client interface; and

substituting said server interface by accessing said trader client interface, during execution of said first software module, thereby dynamically binding said first and second software modules.

17. The method of claim 16 further comprising the steps of:

loading a plurality of software modules into said shared memory of said computing system, each of said plurality of software modules including an associated client interface; and

substituting said server interface in place of each of said associated client interfaces being executed.

18. The method of claim 17 further comprising the steps of:

inserting a plurality of server interfaces into said first software module;

inserting a plurality of client interfaces compatible with said plurality of server interfaces into said second software module; and

inserting the address of each of said plurality of server interfaces into said trader portion.

19. The method of claim 18 further comprising the step of:

generating a unique number which identifies both said client interface and said server interface.

20. The method of claim 19 further comprising the steps of:

inserting said generated unique number into said trader portion; and

inserting said server interface'"'"'s memory address into said trader portion.

21. An Apparatus for dynamically binding, within a computing system having a kernel, first and second software modules respectively contained within first and second software applications, said Apparatus comprising:

means for providing a linked procedure call mechanism having a trader portion;

means for providing a client interface, said client interface capable of accessing said trader portion;

means for providing a server interface, said server interface capable of accessing said trader portion;

means for inserting said client interface into said first software module;

means for inserting said server interface into said second software module;

means for identifying said client interface by executing said first software module;

means for identifying said server interface by accessing said trader portion with said identified client interface; and

means for substituting said server interface in place of said identified client interface, during execution of said first software module, thereby dynamically binding said first and second software modules.

22. The Apparatus of claim 21 further comprising:

means for generating said client interface and said server interface from a common interface specification.

23. The Apparatus of claim 22 wherein the means for generating said client interface and said server interface from a common interface specification includes:

means for generating, with an off=line stub generation tool, both client objects and server objects from said common interface specification, said off-line stub generation tool providing coordination between said client objects and said server objects.

24. The Apparatus of claim 23 wherein the means for generating, with an off-line stub generation tool, both client objects and server objects from said common interface specification includes:

means for generating a file containing at least one client object; and

means for generating a file containing at least one server object.

25. The Apparatus of claim 24 wherein the means for generating a file containing at least one client object includes:

means for generating a file containing one client object which is compatible with an associated server object in said generated file for said server objects.

26. The Apparatus of claim 22 further comprising:

means for creating said common interface specification using an object-oriented interface description language.

27. The Apparatus of claim 26 wherein said means for creating said common interface specification further includes:

a name for the common interface specification;

means for identifying other interfaces used as a base for said named common interface specification;

means for creating at least one constructor, said constructor demonstrating how to create instances of objects specifying said named common interface specification; and

means for creating at least one method-specification for performing functions of said named common interface specification, said method-specification including a method name, arguments, return type and exceptions.

28. The Apparatus of claim 26 wherein the means for creating a common interface specification using an object-oriented interface description language includes:

means for creating said common interface specification from a base interface, said common interface specification inheriting specified methods of said base interface.

29. The Apparatus of claim 22 further comprising:

means for creating said common interface specification in a computer program language-independent fashion using an object oriented paradigm.

30. The Apparatus of claim 21 wherein the means for providing a client interface includes:

means for providing a client object, said client object capable of accessing said trader portion.

31. The Apparatus of claim 21 further comprising:

means for inserting said server interface'"'"'s location into said trader portion.

32. The Apparatus of claim 21 wherein the means for providing a server interface includes:

means for providing a server object, said server object capable of accessing said trader portion.

33. The Apparatus of claim 32 further comprising:

means for loading, into said computing system, a third software application containing a third software module, said third software module including server objects which are compatible with said server objects inserted into said second software module; and

means for inserting the location of said server objects contained within said third software module into said trader portion.

34. The Apparatus of claim 33 further comprising:

means for directing a process, created prior to loading said third software module, to said second software module by accessing said trader portion with said kernel.

35. The Apparatus of claim 33 further comprising:

means for directing a process, created subsequent to loading said third software module, to said third software module by accessing said trader portion with said kernel.