Systems and methods of reporting multiple threads involved in a potential data race

• US 20060200823A1
• Filed: 03/02/2005
• Published: 09/07/2006
• Est. Priority Date: 03/02/2005
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Rodeheffer, Thomas L., Yu, Yuan
• Granted Patent: US 7,620,852 B2
• Time in Patent Office: Days
• US Class Current: 718/100
• CPC Class Codes: G06F 11/0715 in a system implementing multitasking multitasking per se G06F9/46
• CPC Class Codes: G06F 11/073 in a memory management context, e.g. virtual memory or cache management memory management G06F12/00; testing of static memory units G11C29/00
• CPC Class Codes: G06F 11/0751 Error or fault detection not based on redundancy power supply failures G06F1/30; network fault management H04L41/06
• CPC Class Codes: G06F 11/0778 Dumping, i.e. gathering error/state information after a fault for later diagnosis
• CPC Class Codes: G06F 11/3632 of specific synchronisation aspects
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program
• CPC Class Codes: G06F 2209/523 Mode
• CPC Class Codes: G06F 9/524 Deadlock detection or avoidance

Abstract

Criteria are defined for determining when additional stack dumps would be saved and presented (e.g., to the developer). This provides more information for the developer to use for debugging, and yet does not overburden the developer with irrelevent information. Suspicious activity worthy of an additional stack dumps may be defined as a thread accessing an already suspicious location that is different than the original thread, a write access being made and no write access having yet been made to the target location, or if the lockset being held by the thread accessing the location is omitted from the intersection of all locksets involved in stack dumps for the location.

Claims

1. A method of reporting a warning involving a prospective data race, comprising:

determining if a violation of a locking discipline has occurred;

reporting a warning if the violation has occurred;

detecting a subsequent violation;

determining if at least one predetermined criterion regarding the subsequent violation is met; and

reporting a warning directed to the subsequent violation if the at least one predetermined criterion is met.

2. The method of claim 1, wherein the violation of the locking discipline is related to the prospective data race.

3. The method of claim 1, wherein the subsequent violation comprises a thread making an access for a location, and wherein the at least one predetermined criterion comprises whether the thread making the access has not yet been involved in a stack dump for the location.

4. The method of claim 1, wherein the subsequent violation comprises a write access for a location, and wherein the at least one predetermined criterion comprises no write access has been involved in a stack dump for the location.

5. The method of claim 1, wherein the at least one predetermined criterion comprises a lock set omitting a lock from the intersection of all lock sets involved in stack dumps for a location.

6. The method of claim 1, further comprising dumping a stack if the violation has occurred.

7. The method of claim 1, further comprising dumping a stack if the at least one predetermined criterion is met.

8. The method of claim 1, wherein the warning is related to a stack dump containing information about the subsequent violation.

9. The method of claim 1, wherein the violation of the locking discipline comprises a suspicious access pattern.

10. A method of reporting a warning involving a prospective data race, comprising:

detecting a suspicious access pattern at a location pursuant to a thread;

dumping a stack;

detecting a subsequent suspicious access pattern at the location; and

dumping another stack if the subsequent suspicious access pattern is caused by a different thread.

11. The method of claim 10, further comprising setting the state of the location to a warning state after detecting the suspicious access pattern.

12. The method of claim 11, further comprising storing an identity of the thread.

13. The method of claim 11, further comprising setting the state of the location to a second warning state if the subsequent suspicious access pattern is caused by the different thread.

14. The method of claim 13, further comprising storing an identity of the different thread.

15. The method of claim 13, further comprising reporting a warning pursuant to the second warning state.

16. The method of claim 15, wherein the warning comprises information about the subsequent suspicious access pattern.

17. A computer-readable medium with computer-executable instructions stored thereon for:

determining if a violation of a locking discipline has occurred;

reporting a warning if the violation has occurred;

detecting a subsequent violation;

determining if at least one predetermined criterion regarding the subsequent violation is met; and

reporting a warning directed to the subsequent violation if the at least one predetermined criterion is met.

18. The computer-readable medium of claim 17, wherein the violation of the locking discipline is related to a prospective data race.

19. The computer-readable medium of claim 17, further comprising computer-executable instructions for:

dumping a stack if the violation has occurred, and dumping another stack if the at least one predetermined criterion is met.

20. The computer-readable medium of claim 17, wherein the violation of the locking discipline comprises a suspicious access pattern.