System and method for run time configuration of objects in an object oriented computing environment

• US 5,437,025 A
• Filed: 01/26/1993
• Issued: 07/25/1995
• Est. Priority Date: 01/26/1993
• Status: Expired due to Fees

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Bale, Richard C., Rich, William L., Shackelford, Floyd W.
• Primary Examiner(s): Black, Thomas G.
• Assistant Examiner(s): WANG, PETER
• Application Number:
  US08/009,297
• Time in Patent Office: 910 Days
• Field of Search: 395/600, 395/650
• US Class Current: 1/1
• CPC Class Codes: G06F 9/449 Object-oriented method invocation or resolution
• CPC Class Codes: Y10S 707/99944 Object-oriented database structure

Abstract

A system and method for run time configuration of objects within an object oriented computing environment permits class substitution, instance redirection and class redirection at run time. Class redirection permits class message calls to be redirected from a first class to a second class at run time. In class redirection, the second class uses all new instances of the first class. Instance redirection enables both class messages and instance messages to be redirected from the first class to the second class of run time. In instance redirection, the second class uses all new and existing instances of the first class. Class substitution enables both class messages and instance messages to be redirected and also enables insertion of a new class into the class hierarchy at run time. In class substitution, the second class uses all new instances and existing instances of the first class and all new instances and existing instances of the descendants of the first class. Class substitution, instance redirection, and class redirection can be used individually or in combination. In addition, multiple classes can be linked together into a single run time module to enhance performance.

Claims

1. A system for configuring objects during execution of an object oriented computing environment on a computing platform comprising:

a computing platform;

a plurality of objects residing on said computing platform each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of pointers stored on said computing platform, including pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class, and including pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

class redirecting means, executing on said computing platform and responsive to a class message which is sent by said object manager executing on said computing platform to one of said first object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said class message which is sent to said one of said first object classes, to the corresponding one of said second object classes; and

instance redirecting means, executing on said computing platform and responsive to an instance message which is sent by said object manager executing on said computing platform to one of said third object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said instance message which is sent to said one of said third object classes to the corresponding one of said fourth object classes.

2. A method for configuring objects during execution of an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platforms, each associated with an object and each containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

storing pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class;

storing pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

redirecting a class message which is sent to one of said first object classes, to the corresponding one of said second object classes, in response to receipt of a class message which is sent by said object manager executing on said computing platform to said one of said first object classes during execution of said object oriented computing environment on said computing platform; and

redirecting an instance message which is sent to one of said third object classes to the corresponding one of said fourth object classes in response to receipt of an instance message which is sent by said object manager executing on said computing platform to said one of said third object classes during execution of said object oriented computing environment on said computing platform.

3. A method for configuring objects in an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform, each having an object identifier and each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platform, each associated with an object and each having an instance frame containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending class messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object oriented computing environment further including a plurality of system data blocks residing on said computing platform, each associated with an object class and each including an instance redirecting pointer for identifying a system data block associated with a child class of the object class, and a plurality of object references residing on said computing platform, each associated with an object, and each including an instance identifying pointer for identifying an instance of the corresponding object, and a system data block pointer for identifying the system data block of the class of said instance for the corresponding object, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

setting the instance redirecting pointer in the system data block of a first parent class to identify the system data block associated with a first child class, in response to an instance redirect request to redirect said first parent class to said first child class;

obtaining the associated instance redirecting pointer from the system data block for said first parent class;

obtaining the associated object identifier for said first parent class;

storing the obtained instance redirecting pointer in the instance identifying pointer of the object reference of said first child class;

storing the obtained object identifier in the system data block pointer of the object reference of said first child class;

obtaining the instance redirecting pointer and the object identifier from the object reference of said first child class, in response to an instance message which is directed to said first parent class;

responding to said instance message using the obtained instance redirecting pointer and object identifier;

obtaining the instance redirecting pointer and the object identifier from an object reference to the parent class other than said first parent class; and

responding to said instance message using the obtained instance redirecting pointer and the object identifier to the parent class other than said first parent class.

4. A method for configuring objects during execution of an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

storing pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class;

storing pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

verifying that said second object class is a child of said first object class;

redirecting a class message which is sent to one of said first object classes, to the corresponding one of said second object classes, in response to receipt of a class message which is sent by said object manager executing on said computing platform to said one of said first object classes during execution of said object oriented computing environment on said computing platform, only if said corresponding one of said second object classes is a child of said corresponding one of said first object classes; and

redirecting an instance message which is sent to one of said third object classes to the corresponding one of said fourth object classes in response to receipt of an instance message which is sent by said object manager executing on said computing platform to said one of said third object classes during execution of said object oriented computing environment on said computing platform.

5. A system for configuring objects in an object oriented computing environment comprising:

a computing platform;

a plurality of objects residing on said computing platform, each having an object identifier and each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each having an instance frame containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending class messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of system data blocks residing on said computing platform, each associated with an object class and each including an instance redirecting pointer for identifying a system data block associated with a child class of the object class;

a plurality of object references residing on said computing platform, each associated with an object, and each including an instance identifying pointer for identifying an instance of the corresponding object, and a system data block pointer for identifying the system data block of the class of said instance for the corresponding object;

run time initialization means, executing on said computing platform and responsive to an instance redirect request to redirect a first parent class to a first child class, for setting the instance redirecting pointer in the system data block of said first parent class to identify the system data block associated with said first child class;

set object identification means, executing on said computing platform and responsive to said run time initialization means executing on said computing platform, for obtaining the associated instance redirecting pointer from the system data block for said first parent class, and for obtaining the associated object identifier for said first parent class, and for storing the obtained instance redirecting pointer in the instance identifying pointer of the object reference of said first child class and for storing the obtained object identifier in the system data block pointer of the object reference of said first child class;

means, executing on said computing platform and responsive to an instance message which is directed to said first parent class, for obtaining the instance redirecting pointer and the object identifier from the object reference of said first child class, and for responding to said instance message using the obtained instance redirecting pointer and object identifier of said first child class; and

means, executing on said computing platform and responsive to an instance message which is directed to a parent class other than said first parent class, for obtaining the instance redirecting pointer and the object identifier from an object reference to the parent class other than said first parent class, and for responding to said instance message using the obtained instance redirecting pointer and object identifier to the parent class other than said first parent class.

6. A system for configuring objects during execution of an object oriented computing environment on a computing platform, comprising:

a computing platform;

a plurality of objects residing on said computing platform, each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of pointers stored on said computing platform, including pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class, and including pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

class redirecting means, executing on said computing platform and responsive to a class message which is sent by said object manager executing on said computing platform to one of said first object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said class message which is sent to said one of said first object classes, to the corresponding one of said second object classes;

instance redirecting means, executing on said computing platform and responsive to an instance message which is sent by said object manager executing on said computing platform to one of said third object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said instance message which is sent to said one of said third object classes to the corresponding one of said fourth object classes; and

means, executing on said computing platform, for verifying that said second object class is a child of said first object class;

wherein said class redirecting means is further responsive to said verifying means for redirecting said class message which is sent to said one of said first object classes, to the corresponding one of said second object classes only if said corresponding one of said second object classes is a child of said corresponding one of said first object classes.

7. A system for configuring objects during execution of an object oriented computing environment on a computing platform comprising:

a computing platform;

a plurality of objects residing on said computing platform, each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of pointers stored on said computing platform, including pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class, including pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class, and including pointers to fifth object classes and corresponding pointers to sixth object classes which substitute for the corresponding fifth object class;

class redirecting means, executing on said computing platform and responsive to a class message which is sent by said object manager executing on said computing platform to one of said first object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said class message which is sent to said one of said first object classes, to the corresponding one of said second object classes; and

instance redirecting means, executing on said computing platform and responsive to an instance message which is sent by said object manager executing on said computing platform to one of said third object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said instance message which is sent to said one of said third object classes to the corresponding one of said fourth object classes; and

class substituting means, executing on said computing platform and responsive to said plurality of stored pointers, for substituting one of said sixth object classes for the corresponding one of said fifth object classes in said hierarchy of object classes.

8. The system of claim 7 further including an eighth object class, said eighth object class being arranged in said hierarchy of classes as a child of said fifth object class, said class substituting means executing on said computing platform further comprising means for rearranging said hierarchy of classes such that said eighth object class is a child of said sixth object class and said eighth class is no longer a child of said fifth object class.

9. A system for configuring objects during execution of an object oriented computing environment on a computing platform comprising:

a computing platform;

a plurality of objects residing on said computing platform, each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of pointers stored on said computing platform, including pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class, and including pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

class redirecting means, executing on said computing platform and responsive to a class message which is sent by said object manager executing on said computing platform to one of said first object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said class message which is sent to said one of said first object classes, to the corresponding one of said second object classes; and

instance redirecting means, executing on said computing platform and responsive to an instance message which is sent by said object manager executing on said computing platform to one of said third object classes during execution of said object oriented computing environment on said computing platform, and responsive to said plurality of stored pointers, for redirecting said instance message which is sent to said one of said third object classes to the corresponding one of said fourth object classes; and

means, executing on said computing platform, for verifying that said fourth object class is a child of said third object class;

wherein said instance redirecting means is further responsive to said verifying means for redirecting said instance message which is sent to said one of said third object classes, to the corresponding one of said second object classes only if said corresponding one of said fourth object classes is a child of said corresponding one of said third object classes.

10. The system of claim 9 further including a seventh object class, said seventh object class being arranged in said hierarchy of classes as a child of said third object class, said instance directing means executing on said computing platform further comprising means for preventing redirection from said seventh object class, of instance messages which are sent by said object manager to said seventh object class.

11. A method for configuring objects during execution of an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform, each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

storing pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class;

storing pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

redirecting a class message which is sent to one of said first object classes, to the corresponding one of said second object classes, in response to receipt of a class message which is sent by said object manager executing on said computing platform to said one of said first object classes during execution of said object oriented computing environment on said computing platform; and

redirecting an instance message which is sent to one of said third object classes to the corresponding one of said fourth object classes in response to receipt of an instance message which is sent by said object manager executing on said computing platform to said one of said third object classes during execution of said object oriented computing environment on said computing platform;

storing pointers to fifth object classes and corresponding pointers to sixth object classes which substitute for the corresponding fifth object class; and

substituting one of said sixth object classes for the corresponding one of said fifth object classes in said hierarchy of object classes.

12. The method of claim 11 wherein said object oriented computing environment further includes an eighth object class, said eighth object class being arranged in said hierarchy of classes as a child of said fifth object class, and wherein said substituting step is followed by the step of rearranging said hierarchy of classes such that said eighth object class is a child of said sixth object class and said eighth class is no longer a child of said fifth object class.

13. A method for configuring objects during execution of an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platform, each associated with an object and each containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending object messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

storing pointers to first object classes from which class messages are redirected and corresponding pointers to second object classes to receive and process a redirected class message from the corresponding first object class;

storing pointers to third object classes from which instance messages are redirected and corresponding pointers to fourth object classes to receive and process a redirected instance message from the corresponding third object class;

redirecting a class message which is sent to one of said first object classes, to the corresponding one of said second object classes, in response to receipt of a class message which is sent by said object manager executing on said computing platform to said one of said first object classes during execution of said object oriented computing environment on said computing platform;

verifying that said fourth object class is a child of said third object class; and

redirecting an instance message which is sent to one of said third object classes to the corresponding one of said fourth object classes in response to receipt of an instance message which is sent by said object manager executing on said computing platform to said one of said third object classes during execution of said object oriented computing environment on said computing platform;

wherein said instance redirecting step further comprises the step of redirecting said instance message which is sent to said one of said third object classes, to the corresponding one of said second object classes, only if said corresponding one of said fourth object classes is a child of said corresponding one of said third object classes.

14. The method of claim 13 wherein said object oriented computing environment further includes a seventh object class, said seventh object class being arranged in said hierarchy of classes as a child of said third object class, and wherein said instance directing step is followed by the step of preventing redirection from said seventh object class, of instance messages which are sent by said object manager to said seventh object class.

15. A system for configuring objects in an object oriented computing environment comprising:

a computing platform;

a plurality of objects residing on said computing platform, each having an object identifier and each including an object frame containing data attributes and at least one object method for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes;

a plurality of instances residing on said computing platform, each associated with an object and each having an instance frame containing data related to a corresponding attribute of the associated object;

an object manager executing on said computing platform for sending class messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods;

a plurality of system data blocks residing on said computing platform, each associated with an object class and each including an instance redirecting pointer for identifying a system data block associated with a child class of the object class and a class redirecting pointer for identifying a system data block associated with a child class of the object class;

a plurality of object references residing on said computing platform, each associated with an object, and each including an instance identifying pointer for identifying an instance of the corresponding object, a system data block pointer for identifying the system data block of the class of said instance for the corresponding object, a class identifying pointer for identifying a class of the corresponding object, and a system data block pointer for identifying the system data block of the class of the corresponding object;

run time initialization means, executing on said computing platform and responsive to an instance redirect request to redirect a first parent class to a first child class, for setting the instance redirecting pointer in the system data block of said first parent class to identify the system data block associated with said first child class and further responsive to a class redirect request to redirect a second parent class to a second child class, for setting the class redirecting pointer in the system data block of said second parent class to identify the system data block associated with said second child class;

set object identification means, executing on said computing platform and responsive to said run time initialization means executing on said computing platform, for obtaining the associated instance redirecting pointer from the system data block for said first parent class, for obtaining the associated object identifier for said first parent class, and for storing the obtained instance redirecting pointer for said first parent class in the instance identifying pointer of the object reference of said first child class and for storing the obtained object identifier for said first parent class in the system data block pointer of the object reference of said first child class, and for obtaining the associated class redirecting pointer from the system data block for said second parent class, for obtaining the associated object identifier for said second parent class, for storing the obtained class redirecting pointer for said second parent class in the class identifying pointer of the object reference of said second child class, and for storing the obtained object identifier for said second parent class in the system data block pointer of the object reference of said second child class;

means, executing on said computing platform and responsive to an instance message which is directed to said first parent class, for obtaining the instance redirecting pointer and the object identifier from the object reference of said first child class, and for responding to said instance message using the obtained instance redirecting pointer and object identifier; and

means, executing on said computer platform and responsive to a class message which is directed to said second parent class, for obtaining the class redirecting pointer and the object identifier from the object reference of said second child class, and for responding to said class message using the obtained class redirecting pointer and object identifier.

16. The system of claim 15:

wherein said first child class and said second child class are an identical child class; and

wherein said first parent class and said second parent class are an identical parent class.

17. The system of claim 15:

wherein each system data block residing on said computing platform further includes a class substituting pointer for identifying a system data block associated with a child class of the object class; and

wherein said run time initialization means executing on said computing platform is further responsive to a class substitute request to substitute a third child class for a third parent class, for setting the class substituting pointer in the system data block of said third parent class to identify the system data block associated with said third child class;

said system further comprising means, executing on said computing platform and responsive to a class message and an instance message which is directed to said third parent class for obtaining the class substituting pointer in the system data block of said third parent class, and responsive to the obtained class substituting pointer for replacing the system data block of said third child class with the system data block of said third parent class, such that said third child class substitutes for said third parent class.

18. The system of claim 17 wherein said run time initialization means executing on said computing platform further comprises means executing on said computing platform for confirming that the third parent class is a parent of the third child class.

19. The system of claim 17:

wherein said first child class, said second child class and said third child class are an identical child class; and

wherein said first parent class, said second parent class and said third parent class are an identical parent class.

20. A method for configuring objects in an object oriented computing environment on a computing platform, said object oriented computing environment including a plurality of objects residing on said computing platform, each having an object identifier and each including an object frame containing data attributes and at least one object method executing on said computing platform for performing actions on the associated object, said objects being arranged in a hierarchy of object classes to define parent and child classes such that child classes inherit the data attributes and methods of parent classes, said object oriented computing environment further including a plurality of instances residing on said computing platform, each associated with an object and each having an instance frame containing data related to a corresponding attribute of the associated object, said object oriented computing environment further including an object manager executing on said computing platform for sending class messages to said objects to perform actions on the associated object frame using the associated object methods, and for sending instance messages to said instances to perform actions on the associated instance frame using the associated object methods, said object oriented computing environment further including a plurality of system data blocks residing on said computing platform, each associated with an object class and each including an instance redirecting pointer for identifying a system data block associated with a child class of the object class, a class redirecting pointer for identifying a system data block associated with a child class of the object class, and a plurality of object references residing on said computing platform, each associated with an object, and each including an instance identifying pointer for identifying an instance of the corresponding object, a class identifying pointer for identifying a class of the corresponding object, and a system data block pointer for identifying the system data block of the class of the corresponding object and a system data block pointer for identifying the system data block of the class of said instance for the corresponding object, said object configuring method comprising the following steps which are performed by said computing platform during execution of said object oriented programming environment on said computing platform:

setting the instance redirecting pointer in the system data block of a first parent class to identify the system data block associated with a first child class, in response to an instance redirect request to redirect said first parent class to said first child class;

obtaining the associated instance redirecting pointer from the system data block for said first parent class;

obtaining the associated object identifier for said first parent class;

storing the obtained instance redirecting pointer in the instance identifying pointer of the object reference of said first child class;

storing the obtained object identifier in the system data block pointer of the object reference of said first child class;

obtaining the instance redirecting pointer and the object identifier from the object reference of said first child class, in response to an instance message which is directed to said first parent class;

responding to said instance message using the obtained instance redirecting pointer and object identifier, to thereby redirect instance messages from said first parent class to said first child class;

setting the class redirecting pointer in the system data block of a second parent class to identify the system data block associated with a second child class, in response to a class redirect request to redirect said second parent class to said second child class;

obtaining the associated class redirecting pointer from the system data block for said second parent class;

obtaining the associated object identifier for said second parent class;

storing the obtained class redirecting pointer in the class identifying pointer of the object reference of said second child class;

storing the obtained object identifier in the system data block pointer of the object reference of said second child class;

obtaining the class redirecting pointer and the object identifier from the object reference of said second child class, in response to a class message which is directed to said second parent class; and

responding to said class message using the obtained class redirecting pointer and object identifier, to thereby also redirect class messages from said second parent class to said second child class.

21. The method of claim 20:

wherein said first child class and said second child class are an identical child class; and

wherein said first parent class and said second parent class are an identical parent class.

22. The method of claim 20:

wherein each system data block further includes a class substituting pointer for identifying a system data block associated with a child class of the object class, said method further comprising the steps of;

setting the class substituting pointer in the system data block of a third parent class to identify the system data block associated with said a child class, in response to a class substitute request to substitute said third child class for said third parent class;

obtaining the class substituting pointer in the system data block of said third parent class, in response to a class message and an instance message which is directed to said third parent class; and

replacing the system data block of said third child class with the system data block of said third parent class, such that said third child class substitutes for said third parent class.

23. The method of claim 22 further comprising the step of confirming that the third parent class is a parent of the third child class, prior to performing said replacing step.

24. The method of claim 22:

wherein said first child class, said second child class and said third child class are an identical child class; and

wherein said first parent class, said second parent class and said third parent class are an identical parent class.