Method and apparatus for implementing task management of computer operations

• US 8,161,453 B2
• Filed: 11/15/2005
• Issued: 04/17/2012
• Est. Priority Date: 11/16/2004
• Status: Expired due to Fees

• Current Assignee: Rabih Chrabieh
• Original Assignee: Rabih Chrabieh
• Inventors: Chrabieh, Rabih
• Primary Examiner(s): KENDALL, CHUCK O
• Application Number:
  US11/280,667
• Publication Number:
  US 20060107268A1
• Time in Patent Office: 2,345 Days
• Field of Search: None
• US Class Current: 717/106
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues

Abstract

A development and runtime framework for applications that execute in real-time operating systems. Application development is enhanced through simple instructions that allow a programmer to declare functions and sets of functions as tasks and supertasks, respectively, and manage the execution of functions, tasks and supertasks with priorities. A compiler or pre-processor provides tools for generating the code for tasks and supertasks, and the management code for managing execution. Function calls may be made directly to functions within supertasks via respective entrypoints, and the tasks are managed based on the functions being invoked. Within a supertask, a higher priority function may be runnable while a lower priority function of that supertask is suspended. A cookie is used to recognize when a register update for a supertask may be omitted, enabling more efficient context switching.

Claims

1. A method for implementing priority management of computer program operations on a system comprising a processor and a computer readable medium having instructions stored thereon comprising program code, the method comprising:

the processor obtaining a first program code comprising at least one declaration for at least one subtask, wherein said at least one subtask is further associated with a priority level;

the processor obtaining a second program code comprising at least one declaration for a supertask, said supertask comprising at least one reference to said at least one subtask; and

the processor generating a third program code comprising program code for invoking said at least one subtask and managing said supertask using said priority level, wherein higher priority subtasks may preempt lower priority subtasks within a supertask.

2. The method of claim 1, wherein obtaining said first program code further comprises obtaining at least one priority function declaration indicating said at least one function is to be called with a priority level.

3. The method of claim 1, wherein said obtaining said second program code further comprises obtaining at least one declaration for creating at least one stack.

4. The method of claim 3, wherein said obtaining said second program code further comprises obtaining at least one declaration for creating one or more schedulers.

5. The method of claim 4, wherein said one or more schedulers comprise program code for sorting said at least one reference using said priority level.

6. The method of claim 5, wherein said one or more schedulers further comprise program code for storing said at least one reference into said at least one stack.

7. The method of claim 1, wherein said generating said third computer program further comprises generating program code for activating an inactive supertask.

8. The method of claim 7, wherein said generating program code further comprises generating program code for managing a context switch between a plurality of supertasks.

9. The method of claim 8, wherein said generating program code for managing said context switch further comprises generating program code for storing a first supertask register state indicator.

10. The method of claim 9, wherein said generating program code for managing said context switch further comprises generating program code for comparing said first supertask register state indicator with a current supertask register state indicator.

11. The method of claim 10, wherein said generating program code for comparing further comprises generating program code for restoring one or more processor registers to a predetermined state when said first supertask register state indicator differs from said current supertask register state indicator.

12. A computer program product embodied in a computer readable storage medium, said computer program product comprising:

program code configured to cause a computer to invoke a subtask associated with a supertask and a priority level;

program code configured to cause a computer to invoke a scheduler for managing an invocation of said subtask, wherein higher priority subtasks may preempt lower priority subtasks within a supertask; and

program code configured to cause a computer to switch an execution context.

13. The computer program product of claim 12, further comprising program code configured to cause a computer to store a state of a currently executing supertask in a stack associated with said supertask.

14. The computer program product of claim 13, further comprising program code configured to cause a computer to invoke a scheduler associated with said supertask.

15. The computer program product of claim 14, wherein said scheduler is configured to generate a sorted set of a plurality of active supertasks using said priority level.

16. The computer program product of claim 15, wherein said scheduler is further configured to store said sorted set into said at least one stack.

17. The computer program product of claim 16, further comprising program code configured to cause a computer to manage a context switch between a plurality of supertasks.

18. The computer program product of claim 17, further comprising program code configured to cause a computer to store a supertask register state indicator.

19. The computer program product of claim 18, further comprising program code configured to cause a computer to compare said supertask register state indicator with a current register state indicator.

20. The computer program product of claim 19, further comprising program code configured to cause a computer to restore a state of one or more processor registers when said supertask register state indicator differs from said current register state indicator.

21. A computer program product comprising a computer readable medium having computer program code embedded therein, said computer program code comprising:

a supertask having a plurality of functions and a common stack, wherein each of said functions comprises a respective priority level and a respective entrypoint into said supertask, wherein higher priority functions may preempt lower priority functions within a supertask.

22. The computer program product of claim 21, wherein a first function from said plurality of functions has a different priority level than a second function from said plurality of functions.

23. The computer program product of claim 21, wherein a first function from said plurality of functions is runnable while a second function from said plurality of functions is suspended.

24. The computer program product of claim 21, wherein said supertask is configured to handle a plurality of events, wherein a first entrypoint of said superask is configured to wait on a first event and a second entrypoint of said supertask is configured to wait on a second event.

25. The computer program product of claim 21, wherein said supertask further comprises a cookie indicating a processor register state of said supertask, and wherein said computer program code is configured to compare a previously stored cookie value with said cookie when a context switch is made to said supertask, and skip a processor register update during said context switch when said scheduler cookie variable and said cookie match.

26. The computer program product of claim 25, wherein said computer program code is further configured to obtain said cookie from said supertask when a context switch is made away from said supertask.

27. The computer program product of claim 21, wherein one or more of said functions is configured to be responsive, via said respective entrypoint, to direct function calls from outside of said supertask.