Tracker class for object-oriented programming environments

• US 5,940,616 A
• Filed: 05/31/1996
• Issued: 08/17/1999
• Est. Priority Date: 05/31/1996
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Wang, I-Shin Andy
• Primary Examiner(s): Trammell, James P.
• Assistant Examiner(s): SMITH-STEWART, DEMETRA R
• Application Number:
  US08/656,445
• Time in Patent Office: 1,173 Days
• Field of Search: 395/500, 395/700, 395/701, 395/705, 395/683, 395/704, 395/710, 395/183.14, 395/183.18, 395/702, 364/280, 364/280.4, 364/281.3, 364/282.1, 364/284, 364/284.3, 707/101
• US Class Current: 717/127
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 8/24 Object-oriented

Abstract

The present invention discloses a method, apparatus, and article of manufacture for providing object tracking capabilities in object-oriented programming environments using a tracker class and associated functions, and a memory for storing tracker objects. The tracker class, once defined as a base class of any target class that needs the tracking capability, automatically tracks all the objects instantiated from the target class in a linked list. Objects instantiated from classes derived from the tracker class are automatically tracked when the target objects are initialized, be it on a heap or on a stack, because the constructor of the tracker class is invoked by the constructor of the target class. The tracker class is defined as a template, so that it can be applied to any type of target object.

Claims

1. A method of tracking objects in an object-oriented programming environment executed by a computer, comprising the steps of:

(a) creating a target object and associated tracker object in a memory of the computer, wherein the tracker object is associated with the target object through inheritance of a tracker class that generates the tracker object by a target class that generates the target object;

(b) storing a pointer to the target object in the associated tracker object;

(c) inserting the associated tracker object into a data structure in the memory of the computer, so that the target object can be managed in a well-defined manner; and

(d) performing a management function on the target object using a member function of the tracker object.

2. The method of claim 1, wherein the creating step comprises the step of performing a constructor function for the target class in the memory of the computer to create the target object, wherein the constructor function for the target class invokes a constructor function for the tracker class that is performed by the computer to create the tracker object.

3. The method of claim 1, wherein the tracker class comprises a template that is customized according to a data type for the target class.

4. The method of claim 1, wherein the storing step further comprises the step of casting the pointer to the target object stored in the associated tracker object to adjust an address for a first memory location of the target object.

5. The method of claim 1, wherein the data structure comprises a linked list.

6. The method of claim 1, further comprising the step of allocating a static root pointer for the data structure in the memory of the computer.

7. The method of claim 1, further comprising the step of preventing member-by-member copying of the target objects when creating the tracker objects.

8. The method of claim 1, further comprising the step of deleting the target object from the memory of the computer.

9. The method of claim 8, wherein the deleting step comprises the step of performing a destructor function for the target class in the memory of the computer to delete the target object, wherein the destructor function for the target class invokes a destructor function for the tracker class that is performed by the computer to delete the tracker object.

10. The method of claim 9, wherein the performing step comprises the steps of removing the associated tracker object from the data structure in the memory of the computer, deleting the target object from the memory of the computer, and deleting the associated tracker object from the memory of the computer.

11. An apparatus for tracking objects in an object-oriented programming environment executed by a computer, comprising:

(a) a computer having a memory;

(b) means, performed by the computer, for creating a target object and associated tracker object in a memory of the computer, wherein the tracker object is associated with the target object through inheritance of a tracker class that generates the tracker object by a target class that generates the target object;

(c) means, performed by the computer, for storing a pointer to the target object in the associated tracker object;

(d) means, performed by the computer, for inserting the associated tracker object into a data structure in the memory of the computer, so that the target object can be managed in a well-defined manner; and

(e) means, performed by the computer, for performing a management function on the target object using a member function of the tracker object.

14. The apparatus of claim 11, wherein the means for creating comprises the means for performing a constructor function for the target class in the memory of the computer to create the target object, wherein the constructor function for the target class invokes a constructor function for the tracker class that is performed by the computer to create the tracker object.

15. The apparatus of claim 11, wherein the tracker class comprises a template that is customized according to a data type for the target class.

16. The apparatus of claim 11, wherein the means for storing further comprises the means for casting the pointer to the target object stored in the associated tracker object to adjust an address for a first memory location of the target object.

17. The apparatus of claim 11, wherein the data structure comprises a linked list.

18. The apparatus of claim 11, further comprising the means for allocating a static root pointer for the data structure in the memory of the computer.

19. The apparatus of claim 11, further comprising the means for preventing member-by-member copying of the target objects when creating the tracker objects.

20. The apparatus of claim 11, further comprising the means for deleting the target object from the memory of the computer.

21. The apparatus of claim 20, wherein the means for deleting comprises the means for performing a destructor function for the target class in the memory of the computer to delete the target object, wherein the destructor function for the target class invokes a destructor function for the tracker class that is performed by the computer to delete the tracker object.

22. The apparatus of claim 21, wherein the means for performing comprises:

means for removing the associated tracker object from the data structure in the memory of the computer;

means for deleting the target object from the memory of the computer; and

means for deleting the associated tracker object from the memory of the computer.

12. A program storage device, readable by a computer having a memory and coupled to a data storage device, tangibly embodying one or more programs of instructions executable by the computer to perform method steps for tracking objects in an object-oriented programming environment executed by the computer, the method comprising the steps of:

(a) creating a target object and associated tracker object in a memory of the computer, wherein the tracker object is associated with the target object through inheritance of a tracker class that generates the tracker object by a target class that generates the target object;

(b) storing a pointer to the target object in the associated tracker object;

(c) inserting the associated tracker object into a data structure in the memory of the computer, so that the target object can be managed in a well-defined manner; and

(d) performing a management function on the target object using a member function of the tracker object.

23. The program storage device of claim 12, wherein the creating step comprises the step of performing a constructor function for the target class in the memory of the computer to create the target object, wherein the constructor function for the target class invokes a constructor function for the tracker class that is performed by the computer to create the tracker object.

24. The program storage device of claim 12, wherein the tracker class comprises a template that is customized according to a data type for the target class.

25. The program storage device of claim 12, wherein the storing step further comprises the step of casting the pointer to the target object stored in the associated tracker object to adjust an address for a first memory location of the target object.

26. The program storage device of claim 12, wherein the data structure comprises a linked list.

27. The program storage device of claim 12, further comprising the step of allocating a static root pointer for the data structure in the memory of the computer.

28. The program storage device of claim 12, further comprising the step of preventing member-by-member copying of the target objects when creating the tracker objects.

29. The program storage device of claim 12, further comprising the step of deleting the target object from the memory of the computer.

30. The program storage device of claim 29, wherein the deleting step comprises the step of performing a destructor function for the target class in the memory of the computer to delete the target object, wherein the destructor function for the target class invokes a destructor function for the tracker class that is performed by the computer to delete the tracker object.

31. The program storage device of claim 30, wherein the performing step comprises the steps of removing the associated tracker object from the data structure in the memory of the computer, deleting the target object from the memory of the computer, and deleting the associated tracker object from the memory of the computer.

13. A memory for storing data for tracking objects in an object-oriented programming environment executed by a computer, comprising:

a data structure stored in a memory of the computer, the data structure including;

one or more tracker objects, each associated with a target object residing in the memory of the computer,

wherein the tracker object is associated with the target object through inheritance of a tracker class that generates the tracker object by a target class that generates the target object,

wherein the tracker object stores a pointer to the associated target object, so that the target object can be tracked, so that the target object can be managed in a well-defined manner, and

wherein the tracker object includes a method function for performing a management function on the target object.