Thread execution analyzer

• US 8,418,148 B2
• Filed: 02/27/2009
• Issued: 04/09/2013
• Est. Priority Date: 02/27/2009
• Status: Active Grant

• Current Assignee: Microsoft Technology Licensing LLC (Microsoft Corporation)
• Original Assignee: Microsoft Corporation
• Inventors: Shafi, Hazim, Adelberg, Brian, Sedky, Khaled S.
• Primary Examiner(s): KENDALL, CHUCK O
• Application Number:
  US12/394,445
• Publication Number:
  US 20100223600A1
• Time in Patent Office: 1,502 Days
• Field of Search: None
• US Class Current: 717/131
• CPC Class Codes: G06F 11/3636 by tracing the execution of the program

Abstract

A thread execution analyzer analyzes blocking events of threads in a program using execution data and callstacks collected at the blocking events. The thread execution analyzer attempts to identify an application programming interface (API) responsible for each blocking event and provides blocking analysis information to a user. The blocking analysis information may be used by a developer of the program to understand the causes of blocking events that occur for threads of the program.

Claims

1. A method performed by a computer system, the method comprising:

analyzing a first context switch data of a first thread of a program, the first context switch data stored in response to a first blocking event corresponding to the first thread;

correlating the first blocking event with a first one of a plurality of blocking classes using the first context switch data; and

providing a first indication of the first thread, the first blocking event, and the first one of the plurality of blocking classes as part of a blocking analysis output.

2. The method of claim 1 further comprising:

matching a stack frame in a callstack in the first context switch data to a known blocking application programming interface (API) signature; and

associating the known blocking API signature with the first one of the plurality of blocking classes.

3. The method of claim 2 further comprising:

performing symbol resolution on the stack frame prior to matching the stack frame to the known blocking API signature.

4. The method of claim 2 further comprising:

providing a second indication of the known blocking API signature as part of the blocking analysis output.

5. The method of claim 1 wherein the first indication includes a graphical timeline with an execution period and a first blocked period corresponding to the first blocking event.

6. The method of claim 5 wherein a first color of the blocked period corresponds to the first one of the plurality of blocking classes.

7. The method of claim 6 further comprising:

analyzing a second context switch data of the first thread, the second context switch data stored in response to a second blocking event corresponding to the first thread;

correlating the second blocking event with a second one of a plurality of blocking classes using the second context switch data; and

providing a second indication of the first thread, the second blocking event, and the second one of the plurality of blocking classes as part of the blocking analysis output.

8. The method of claim 7 wherein the graphical timeline includes a second blocked period corresponding to the second blocking event, and wherein a second color of the blocked period corresponds to the second one of the plurality of blocking classes.

9. The method of claim 1 further comprising:

analyzing a second context switch data of a second thread of the program, the second context switch data stored in response to a second blocking event corresponding to the second thread;

correlating the second blocking event with a second one of a plurality of blocking classes using the second context switch data; and

providing a second indication of the second thread, the second blocking event, and the second one of the plurality of blocking classes as part of the blocking analysis output.

10. A method performed by a computer system, the method comprising:

employing at least one processor configured to execute computer-executable instructions stored in memory to perform the following acts;

generating first and second thread execution analyses that correspond to first and second threads, respectively; and

displaying first and second representations of the first and the second thread execution analyses, each of the representations including one or more respective execution periods, one or more respective blocking periods, and respective indications of one of a plurality of blocking classes for each blocking period.

11. The method of claim 10 further comprising:

detecting a known blocking application programming interface (API) corresponding to one of the blocking periods of the first thread; and

displaying the known blocking API as part of the first representation.

12. The method of claim 11 further comprising:

displaying the known blocking API as part of a tool tip in response to an input from a user.

13. The method of claim 11 further comprising:

displaying a graph indicating delay times for each of the plurality of blocking classes for the first thread.

14. The method of claim 11 further comprising:

displaying a listing of application programming interfaces (API) that correspond to the blocking periods of the first and the second threads.

15. A computer-readable storage medium storing computer-executable instructions that, when executed by a computer system, perform a method comprising:

executing a program including at least one thread;

storing execution data including a callstack corresponding to the thread in response to detecting a context switch of the thread;

matching a stack frame of the callstack in the execution data to a known blocking application programming interface (API) signature;

correlating the context switch with one of a plurality of blocking classes, indicative of categories of blocking causes, associated with the known blocking API signature; and

providing a first indication of the thread, the context switch, and the one of the plurality of blocking classes as part of a blocking analysis output.

16. The computer-readable storage medium of claim 15, the method further comprising:

performing symbol resolution on the stack frame prior to matching the stack frame to the known blocking API signature.

17. The computer-readable storage medium of claim 15, the method further comprising:

providing a second indication of the known blocking API signature as part of the blocking analysis output.

18. The computer-readable storage medium of claim 17, the method further comprising:

providing a third indication of a line number corresponding to the known blocking API signature in the program.

19. The computer-readable storage medium of claim 15, the method further comprising:

adjusting a display of the first indication in response to a user inputs that indicates one of a period of execution or the thread.

20. The computer-readable storage medium of claim 15, the method further comprising:

displaying the one of the plurality of blocking classes as part of a tool tip in response to an input from a user.