Techniques for switching threads within routines

• US 8,589,925 B2
• Filed: 10/25/2007
• Issued: 11/19/2013
• Est. Priority Date: 10/25/2007
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Cwalina, Krzysztof
• Primary Examiner(s): Puente, Emerson
• Assistant Examiner(s): SWIFT, CHARLES M
• Application Number:
  US11/977,593
• Publication Number:
  US 20090113436A1
• Time in Patent Office: 2,217 Days
• Field of Search: 718/100, 718/108
• US Class Current: 718/100
• CPC Class Codes: G06F 9/4484 Executing subprograms
• CPC Class Codes: G06F 9/46 Multiprogramming arrangements
• CPC Class Codes: G06F 9/461 Saving or restoring of program or task context
• CPC Class Codes: G06F 9/48 Program initiating; Program switching, e.g. by interrupt
• CPC Class Codes: G06F 9/4806 Task transfer initiation or dispatching
• CPC Class Codes: G06F 9/4843 by program, e.g. task dispatcher, supervisor, operating system
• CPC Class Codes: G06F 9/485 Task life-cycle, e.g. stopping, restarting, resuming execution G06F9/4881 takes precedence
• CPC Class Codes: G06F 9/4856 resumption being on a different machine, e.g. task migration, virtual machine migration G06F9/5088 takes precedence
• CPC Class Codes: G06F 9/4881 Scheduling strategies for dispatcher, e.g. round robin, multi-level priority queues
• CPC Class Codes: G06F 9/50 Allocation of resources, e.g. of the central processing unit [CPU]
• CPC Class Codes: G06F 9/5005 to service a request
• CPC Class Codes: G06F 9/5011 the resources being hardware resources other than CPUs, Servers and Terminals
• CPC Class Codes: G06F 9/5022 Mechanisms to release resources
• CPC Class Codes: G06F 9/5027 the resource being a machine, e.g. CPUs, Servers, Terminals
• CPC Class Codes: G06F 9/5038 considering the execution order of a plurality of tasks, e.g. taking priority or time dependency constraints into consideration scheduling strategies G06F9/4881 and subgroups

Abstract

Various technologies and techniques are disclosed for switching threads within routines. A controller routine receives a request from an originating routine to execute a coroutine, and executes the coroutine on an initial thread. The controller routine receives a response back from the coroutine when the coroutine exits based upon a return statement. Upon return, the coroutine indicates a subsequent thread that the coroutine should be executed on when the coroutine is executed a subsequent time. The controller routine executes the coroutine the subsequent time on the subsequent thread. The coroutine picks up execution at a line of code following the return statement. Multiple return statements can be included in the coroutine, and the threads can be switched multiple times using this same approach. Graphical user interface logic and worker thread logic can be co-mingled into a single routine.

Claims

1. A computer-readable memory storing computer-executable instructions for causing a computer to perform operations comprising:

receiving a request from an originating routine to execute a coroutine;

executing an initial portion of the coroutine on an initial thread;

receiving a response back from the coroutine when the coroutine returns based upon a return statement, wherein the return statement identifies a subsequent thread different than the initial thread; and

executing a subsequent portion of the coroutine a subsequent time on the subsequent thread that was indicated by the coroutine in the return statement upon return.

2. The computer-readable memory of claim 1, further storing computer-executable instructions for causing a computer to perform operations comprising:

executing the coroutine a plurality of times until an end of the coroutine is reached, each time executing the coroutine on a most recent subsequent thread indicated by the coroutine upon a most recent return.

3. The computer-readable memory of claim 1, the operations further comprising specifying the subsequent thread as a parameter to the return statement.

4. The computer-readable memory of claim 1, further comprising using the subsequent thread for processing worker thread logic.

5. A method for switching threads partially through a routine comprising the steps of:

starting an execution of an initial portion of a routine on a first thread;

exiting the routine at an end point of the initial portion of the routine due to a first return statement, with the first return statement having a subsequent thread identifier which identifies a subsequent thread different than the first thread;

resuming code execution of a subsequent portion of the routine on the subsequent thread specified in the subsequent thread identifier; and

picking up code execution in the routine at a line of code following the first return statement.

6. The method of claim 5, further comprising using at least one of the first thread or the subsequent thread for processing graphical user interface logic.

7. The method of claim 5, further comprising using at least one of the first thread or the subsequent thread for processing worker logic.

8. The method of claim 5, further comprising implementing the routine as a coroutine.

9. The method of claim 8, further comprising using the first thread to handle a different type of operation than the subsequent thread.

10. The method of claim 5, further comprising identifying the subsequent thread as a parameter in the return statement.

11. The method of claim 5, further comprising:

repeating the exiting, resuming, and picking up steps a plurality of times until an end of the routine is reached.

12. The method of claim 5, further comprising implementing a first line of code contained in the routine as the first return statement.

13. The method of claim 5, further comprising specifying a first desired thread for execution in the subsequent thread identifier.

14. A method for co-mingling graphical user interface logic and worker thread logic in a single routine comprising the steps of:

starting code execution of an initial portion of logic included in a coroutine, the initial portion of logic being executed on a first thread to receive user input;

receiving the user input;

exiting the coroutine partially through to switch to a second thread, the second thread identified by a return statement and being a different thread than the first thread; and

resuming code execution of a subsequent portion of logic included in the coroutine on the second thread in response to the user input.

15. The method of claim 14, further comprising performing the exiting step upon reaching the return statement.

16. The method of claim 15, further comprising including in the return statement a thread identifier as a parameter to specify a next thread that execution should be resumed on.

17. The method of claim 16, further comprising including a plurality of return statements in the routine to indicate when thread switching should occur.

18. The method of claim 14, further comprising calling the coroutine a plurality of times by a controller routine that is responsible for calling the coroutine on a proper thread.

19. The method of claim 18, further comprising calling the controller routine by an originating routine.

20. The method of claim 19, further comprising including in the originating routine a request to call the coroutine.