Method, apparatus, and program for a state machine framework

• US 20030237027A1
• Filed: 06/24/2002
• Published: 12/25/2003
• Est. Priority Date: 06/24/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Cook, John A.
• Granted Patent: US 7,010,778 B2
• Time in Patent Office: Days
• US Class Current: 714/38.1
• CPC Class Codes: G06F 8/36 Software reuse

Abstract

A programming framework is provided for designing and implementing software state machines. A state machine initializer may be created that defines the states, conditions, actions, triggers, and state transitions for the software state machines. A set of user interfaces, such as graphical user interfaces, may also be provided for creating initializers. An abstract state machine object may then be created that creates an instance of a particular state machine initializer. The state machine initializer acts as a helper to the state machine object, which uses the initializer to create an array of state transition objects. Once the state machine object creates the array of state transition objects, the state machine is ready to run. A set of programming interfaces may also be provided to define the programming framework. Events generated by one state machine may be used as triggers by another state machine. Furthermore, state values of one state machine may be used as inputs by another state machines. State machines may also share triggers and inputs.

Claims

1. A method for providing a software state machine, comprising:

providing a first state machine object, wherein the first state machine object is configured to use a first initializer object to execute a first software state machine; and

providing a second state machine object, wherein the second state machine object is configured to use a second initializer object to execute a second software state machine,

wherein the second state machine object is configured to interact with the first state machine object based on the second initializer object.

2. The method of claim 1, wherein the second state machine object is configured to embed the first state machine object.

3. The method of claim 1, wherein the second state machine object is a subclass of the first state machine object.

4. The method of claim 1, wherein the second state machine object shares a common input with the first state machine object.

5. The method of claim 1, wherein the second software state machine shares a common trigger with the first software state machine.

6. The method of claim 1, wherein the first software state machine generates at least a first event and outputs a state value.

7. The method of claim 6, wherein the second software state machine receives the first event as a trigger.

8. The method of claim 6, wherein the second software state machine receives the state value as an input.

9. The method of claim 6, wherein the state value is accessible to a software object outside of the second state machine object.

10. The method of claim 1, further comprising:

providing a third state machine object, wherein the third state machine object is configured to use a third initializer object to execute a third software state machine,

wherein the third state machine object is configured to interact with the second state machine object based on the third initializer object.

11. The method of claim 10, wherein the third state machine object is a subclass of the second state machine object.

12. The method of claim 11, wherein the second state machine object is configured to embed the first state machine object.

13. An apparatus for providing a software state machine, comprising:

a processor; and

a memory having stored therein a first state machine object, a first initializer object, a second state machine object, and a second initializer object,

wherein the first state machine object is configured to use the first initializer object to execute a first software state machine;

wherein the second state machine object is configured to use the second initializer object to execute a second software state machine; and

wherein the second state machine object is configured to interact with the first state machine object based on the second initializer object.

14. The apparatus of claim 13, wherein the second state machine object is configured to embed the first state machine object.

15. The apparatus of claim 13, wherein the second state machine object is a subclass of the first state machine object.

16. The apparatus of claim 13, wherein the second state machine object shares a common input with the first state machine object.

17. The apparatus of claim 13, wherein the second software state machine shares a common trigger with the first software state machine.

18. The apparatus of claim 13, wherein the first software state machine generates at least a first event and outputs a state value.

19. The apparatus of claim 18, wherein the second software state machine receives the first event as a trigger.

20. The apparatus of claim 18, wherein the second software state machine receives the state value as an input.

21. The apparatus of claim 18, wherein the state value is accessible to a software object outside of the second state machine object.

22. A computer program product, in a computer readable medium, for providing a software state machine, comprising:

instructions for providing a first state machine object, wherein the first state machine object is configured to use a first initializer object to execute a first software state machine; and

instructions for providing a second state machine object, wherein the second state machine object is configured to use a second initializer object to execute a second software state machine,

wherein the second state machine object is configured to interact with the first state machine object based on the second initializer object.