Object oriented operating system

• US 6,836,879 B1
• Filed: 02/12/1999
• Issued: 12/28/2004
• Est. Priority Date: 06/13/1997
• Status: Expired due to Term

• Current Assignee: WSOU Investments, LLC (WSOU Holdings, LLC)
• Original Assignee: Symbian Limited (Nokia Corporation)
• Inventors: Myers, Nicholas Simon
• Primary Examiner(s): Zhen, Wei Y.
• Assistant Examiner(s): Vo, Ted T.
• Application Number:
  US09/242,383
• Time in Patent Office: 2,146 Days
• Field of Search: 717/106-119, 717/162-165, 717/104
• US Class Current: 717/116
• CPC Class Codes: G06F 9/4488 Object-oriented

Abstract

An object oriented operating system handles all objects related to text strings as belonging to one of three classes, in which each class performs a different function and at least one such class is modified to do so in a way that reduces code and cycle overhead. This reduces executable code overhead to minimise the amount of memory required, and allows execution in a minimum number of cycles to minimise power consumption. The operating system is particularly well suited to ROM based mobile computing devices.

Claims

1. A computing device programmed to manipulate or access objects of the string class using an object oriented operating system, wherein the objects of the string class are derived from a single base class and the operating system handles all such objects of the string class according to one or more of the following requirements:

(a) objects of the string class for literal text are handled as belonging to a class in which a pointer points to the memory location where the text string is stored;

(b) objects of the string class for length limited text are handled as belonging to a class in which a buffer stores text of a predetermined length requiring a limited subset of available memory management functions; and

(c) objects of the string class using heap memory are handled as belonging to a class requiring the full set of available memory management functions.

2. The computing device of claim 1, further comprising a program which interfaces with the operating system and which also handles objects according to one or more of the requirements.

3. The computing device of claim 1, wherein objects satisfying one or more of the requirements are flat structures.

4. The computing device of claim 1, wherein objects of the string class for length limited text are stored in particular memory locations at run time which are not part of the heap memory.

5. The computing device of claim 1, wherein the objects are polymorphic.

6. The device of claim 5, wherein polymorphism is achieved by providing a data field for each object which identifies its class, with a different action being associated with different data field values.

7. The computing device of claim 6, wherein the data field is a part of the representation of another data item within a machine word.

8. The computing device of claim 7, wherein the same source code is used, irrespective of the character code system and character code width being used, by using aliases for class names that are character code independent.

9. The computing device of claim 8, wherein the source code using text strings is written in a manner independent of the strings'"'"' actual ASCII or Unicode implementation by using a system of aliases for class names.

10. The computing device of claim 1, wherein objects have information on the length of the data they contain and hence have no ‘

0’

terminator.

11. A method of allowing objects of the string class to be manipulated or accessed by a program using an object oriented operating system, wherein the program handles all such objects according to one or more of the following requirements:

(a) objects of the string class for literal text are handled as belonging to a class in which a pointer points to the memory location where the text string is stored;

(b) objects of the string class for length limited text are handled as belonging to a class in which a buffer stores text of a predetermined length requiring a limited subset of available memory management functions; and

(c) objects of the string class using heap memory are handled as belonging to a class requiring the full set of available memory management functions.

12. The method of claim 11, being performed by an operating system.

13. The method of claim 11, being performed by a program which interfaces with an operating system which itself also performs the method of claim 11.

14. The method of claim 11, wherein objects satisfying one or more of the requirements are flat structures.

15. The method of claim 11, wherein objects of the string class for length limited text are stored in particular memory locations at run time which are not part of the heap memory.

16. The method of claim 11, wherein the objects are polymorphic.

17. The method of claim 16, wherein polymorphism is achieved by providing a data field for each object which identifies its class, with a different action being associated with different data field values.

18. The method of claim 17, wherein the data field is a part of the representation of another data item within a machine word.

19. The method of claim 18, wherein the same source code is used, irrespective of the character code system and character code width being used, by using aliases for class names that are character code independent.

20. The method of claim 19, wherein the source code using text strings is written in a manner independent of the strings'"'"' actual ASCII or Unicode implementation by using a system of aliases for class names.

21. The method of claim 11, wherein objects have information on the length of the data they contain and hence have no ‘

0’

terminator.

22. Computer software which allows objects of the string class to be manipulated or accessed by a program using an object oriented operating system, wherein the program handles all such objects according to one or more of the following requirements:

(a) objects of the string class for literal text are handled as belonging to a class in which a pointer points to the memory location where the text string is stored;

(b) objects of the string class for length limited text are handled as belonging to a class in which a buffer stores text of a predetermined length requiring a limited subset of available memory management functions; and

(c) objects of the string class using heap memory are handled as belonging to a class requiring the fall set of available memory management functions.

23. The computer software of claim 22, being an object oriented operating system.

24. The computer software of claims 23, further comprising a program which is capable of interfacing with the object oriented operating system.

25. The computer software of claim 22, wherein in which objects satisfying one or more of the requirements are flat structures.

26. The computer software of claim 22, wherein objects of the string class for length limited text are stored in particular memory locations at run time which are not pat of the heap memory.

27. The computer software of claim 22, wherein the objects are polymorphic.

28. The computer software of claim 27, wherein polymorphism is achieved by providing a data field for each object which identifies its class, with a different action being associated with different data field values.

29. The computer software of claim 28, wherein the data field is a part of the representation of another data item within a machine word.

30. The computer software of claim 29, wherein the same source code is used, irrespective of the character code system and character code width being used, by using aliases for class names that are character code independent.

31. The computer software of claim 30, wherein the source code using text strings is written in a manner independent of the strings'"'"' actual ASCII or Unicode implementation by using a system of aliases for class names.

32. The computer software of claim 22, wherein objects have information on the length of the data they contain and hence have no ‘

0’

terminator.