Apparatus and method for swapping identities of two objects to reference the object information of the other

• US 6,023,704 A
• Filed: 01/29/1998
• Issued: 02/08/2000
• Est. Priority Date: 01/29/1998
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Munroe, Steven J., Voldal, Erik E., Halter, Steven Lester, Gerard, Scott Neal
• Primary Examiner(s): HOMERE, JEAN RAYMOND
• Application Number:
  US09/015,473
• Time in Patent Office: 740 Days
• Field of Search: 707/103, 707/4, 707/100, 395/705, 395/710, 711/170, 711/207
• US Class Current: 1/1
• CPC Class Codes: G06F 9/4488 Object-oriented
• CPC Class Codes: Y10S 707/99934 Query formulation, input preparation, or translation
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

An object identity swapper dynamically updates the configuration of an object by taking a first object, instantiating a new second object, swapping the identities of the first and second objects, and reading and converting the state data of the old object (now the second object) into the new object (now the first object). The result is that the first object identity doesn'"'"'t change, but its configuration is updated without passivating the object.

Claims

1. An apparatus comprising:

at least one processor;

a memory coupled to the at least one processor;

a first object residing in the memory, the first object having a first unique identity that references first object information;

an object identity swapper residing in the memory and executed by the at least one processor, the object identity swapper creating a second object in the memory, the second object having a second unique identity that references second object information, the object identity swapper swapping the unique identities of the first and second objects so the first unique identity references the second object information, and so the second unique identity references the first object information.

2. The apparatus of claim 1 further comprising a morph method residing in the memory, executed by the at least one processor, and called by the object identity swapper to read and convert state data from the second object to the first object.

3. The apparatus of claim 2 wherein the first and second objects each comprise a header, each header including a method table pointer and a data pointer, the object identity swapper swapping the method table pointers of the first and second objects and swapping the data pointers of the first and second objects.

4. The apparatus of claim 1 wherein the first and second objects each comprise a header, each header including a method table pointer and a data pointer, the object identity swapper swapping the method table pointers of the first and second objects and swapping the data pointers of the first and second objects, the object identity swapper further invoking a morph() method to convert the state data from the second object to the first object.

5. A computer apparatus for updating objects in an object oriented system, the apparatus comprising:

a first object residing in a memory of the computer apparatus, the first object having a first unique identity that references first object information;

means for creating a second object having a desired object configuration in the memory, the second object having a second unique identity that references second object information; and

means for swapping the unique identities of the first and second objects so the first unique identity references the second object information and so the second unique identity references the first object information.

6. A computer-implemented method for changing a first object in an object oriented system to a desired object configuration, the first object having a first unique identity that references first object information, the method comprising the steps of:

creating a second object having the desired object configuration, the second object having a second unique identity that references second object information; and

swapping the unique identities of the first and second objects so the first unique identity references the second object information and so the second unique identity references the first object information.

7. The method of claim 6 further comprising the step of reading and converting state data from the first object to the second object before swapping the identities of the first and second objects.

8. The method of claim 6 further comprising the step of reading and converting state data from the second object to the first object after swapping the identities of the first and second objects.

9. The method of claim 8 wherein the step of reading and converting state data comprises the step of invoking a morph() method on the first object.

10. The method of claim 6 further comprising the step of reading and converting state data from the first object to the second object before swapping the identities of the first and second objects.

11. The method of claim 10 wherein the step of reading and converting state data comprises the step of invoking a morph() method on the second object.

12. The method of claim 6 wherein the first and second objects each comprise a header, each header including a method table pointer and a data pointer, the step of swapping the unique identities of the first and second objects comprises the steps of:

swapping the method table pointers of the first and second objects; and

swapping the data pointers of the first and second objects.

13. A computer-implemented method for changing a first object in an object oriented system to a desired object configuration, the first object having a first unique identity, the first object including a header having a method table pointer and a data pointer, the method comprising the steps of:

instantiating a second object under a class that defines the desired object configuration, the second object having a second unique identity, the second object including a header having a method table pointer and a data pointer;

swapping the method table pointers of the first and second objects without swapping the first and second unique identities;

swapping the data pointers of the first and second objects without swapping the first and second unique identities; and

reading and converting state data of the second object into the first object.

14. The method of claim 13 wherein the step of reading and converting state data comprises the step of invoking a morph() method.

15. A computer-readable program product for updating objects in an object oriented system, the program product comprising:

an object identity swapper that takes a first object having a first unique identity that references first object information, creates a second object, the second object having a second unique identity that references second object information, the object identity swapper swapping the unique identities of the first and second objects so the first unique identity references the second object information, and so the second unique identity references the first object information; and

signal bearing media bearing the object identity swapper.

16. The program product of claim 15 wherein the signal bearing media comprises recordable media.

17. The program product of claim 15 wherein the signal bearing media comprises transmission media.

18. The program product of claim 15 further comprising a morph method residing on the signal bearing media, the morph method being called by the object identity swapper to read and convert state data from the second object to the first object.

19. The program product of claim 15 wherein the first and second objects each comprise a header, each header including a method table pointer and a data pointer, the object identity swapper swapping the method table pointers of the first and second objects and swapping the data pointers of the first and second objects.

20. The program product of claim 15 wherein the first and second objects each comprise a header, each header including a method table pointer and a data pointer, the object identity swapper swapping the method table pointers of the first and second objects and swapping the data pointers of the first and second objects, the object identity swapper further invoking a morph() method to convert the state data from the second object to the first object.