Cooperative process-wide synchronization

• US 20080250412A1
• Filed: 04/06/2007
• Published: 10/09/2008
• Est. Priority Date: 04/06/2007
• Status: Abandoned Application

• Current Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Original Assignee: Hewlett-Packard Development Company, L.P. (HP Inc.)
• Inventors: Clark, Elizabeth An-Li, Parekh, Harshadrai, Ganapathy, Hari
• Application Number:
  US11/784,325
• Publication Number:
  US 20080250412A1
• Time in Patent Office: Days
• US Class Current: 718/102
• CPC Class Codes: G06F 9/52 Program synchronisation; Mutual exclusion, e.g. by means of semaphores

Abstract

One embodiment relates to a computer-implemented method of concurrently performing a process-wide operation in a multi-threaded process being executed on a computer system so as to result in more efficient performance of the computer system. A plurality of threads of the process concurrently participate in the process-wide operation. Finishing steps of the process-wide operation are performed by a last thread participating in the process-wide operation, regardless of whether the last thread is an initiator thread or a target thread. Other embodiments, aspects, and features are also disclosed.

Claims

1. A computer-implemented method of efficiently performing a process-wide operation in a multi-threaded process being executed on a computer system, the method comprising:

initiation of the process-wide operation by an initiator thread;

assignment of an identifying number to the process-wide operation;

participation in the process-wide operation by each target thread; and

after participation, each target thread storing a copy of the identifying number so as to avoid duplicative participation.

2. The method of claim 1, wherein the identifying number comprises a process sequence number, and wherein the copy of the process sequence number is stored in a thread sequence number for that thread.

3. The method of claim 2, further comprising incrementing the process sequence number before the assignment.

4. The method of claim 1, further comprising:

acquiring a process lock which is a spin lock before the assignment of the identifying number; and

releasing the process lock after the assignment of the identifying number, but before participation in the process-wide operation by the target threads; and

subsequently acquiring and releasing the process lock during the process-wide operation so that the process lock is held in disjointed periods over a duration of the process-wide operation.

5. The method of claim 4, further comprising:

holding a process thread list lock during traversal of the target threads of the multi-threaded process, wherein the process thread list lock prevents the thread list from changing.

6. The method of claim 1, further comprising:

concurrent participation in the process-wide operation by a plurality of threads of the process.

7. The method of claim 6, wherein finishing steps of the process-wide operation are performed by a last thread participating in the process-wide operation, regardless of whether the last thread is the initiator thread or one of the target threads.

8. The method of claim 7, wherein the last thread participating in the process-wide operation is determined by comparison of a synchronized thread count with a number of live threads.

9. The method of claim 1, wherein the process-wide operation requires synchronization among multiple threads of the process.

10. The method of claim 9, wherein the process-wide operation comprises a process-wide job control stop.

11. The method of claim 9, wherein the process-wide operation comprises a process deactivation.

12. The method of claim 9, wherein the process-wide operation comprises a process suspension.

13. A computer-implemented method of cooperatively performing a process-wide operation in a multi-threaded process being executed on a computer system, the method comprising:

acquiring a process lock which is a spin lock by an initiator thread before assignment of an identifying number;

releasing the process lock after the assignment of the identifying number, but before participation in the process-wide operation by target threads; and

subsequently acquiring and releasing the process lock during the process-wide operation so that the process lock is held in disjointed periods over a duration of the process-wide operation.

14. The method of claim 13, further comprising:

concurrent participation in the process-wide operation by a plurality of threads of the process while the non-spin-lock is being held.

15. The method of claim 14, wherein finishing steps of the process-wide operation are performed by a last thread participating in the process-wide operation, regardless of whether the last thread is the initiator thread or one of the target threads.

16. A computer-implemented method of concurrently performing a process-wide operation in a multi-threaded process being executed on a computer system so as to result in more efficient performance of the computer system, the method comprising:

concurrent participation in the process-wide operation by a plurality of threads of the process; and

performance of finishing steps of the process-wide operation by a last thread participating in the process-wide operation, regardless of whether the last thread is an initiator thread or a target thread.

17. A computer system comprising:

at least one processor configured to execute computer-readable instructions;

a memory system configured to hold computer-readable instructions and data; and

an operating system comprising computer-readable instructions, wherein the instructions are configured to initiate the process-wide operation by an initiator thread, assign an identifying number to the process-wide operation, participate in the process-wide operation by each target thread, and, after participation, store a copy of the identifying number by each target thread so as to avoid duplicative participation.

18. A computer system comprising:

at least one processor configured to execute computer-readable instructions;

a memory system configured to hold computer-readable instructions and data; and

an operating system comprising computer-readable instructions, wherein the instructions are configured to acquire a process lock which is a spin lock by an initiator thread before assignment of an identifying number, release the process lock after the assignment of the identifying number, but before participation in the process-wide operation by target threads, and subsequently acquire and release the process lock during the process-wide operation so that the process lock is held in disjointed periods over a duration of the process-wide operation.

19. A computer system comprising:

at least one processor configured to execute computer-readable instructions;

a memory system configured to hold computer-readable instructions and data; and

an operating system comprising computer-readable instructions, wherein the instructions are configured to enable concurrent participation in the process-wide operation by a plurality of threads of the process, and performance of finishing steps of the process-wide operation by a last thread participating in the process-wide operation, regardless of whether the last thread is an initiator thread or a target thread.

20. A computer-implemented method of concurrently performing a process-wide operation in a multi-threaded process being executed on a computer system so as to result in more efficient performance of the computer system, the method comprising:

acquiring a process thread list lock by an initiator thread before participation in the process-wide operation by target threads, wherein the process thread list lock is a non-spin lock which prevents a thread list from changing;

holding the process thread list lock while each of the target threads is tranversed by the initiator thread; and

releasing the process thread list lock at a conclusion of the traversal whether the process wide operation is complete or not.

21. The method of claim 20, further comprising holding a process lock for each target thread to check its state and for the initiator thread to determine if the process wide operation is complete.