IP Library Granted Patent US 9,501,382
Granted Patent B2
US 9,501,382 · App. 14/313,890 · Granted Nov 22, 2016

Systems and methods of detecting power bugs

Inventors: Yu Charlie Hu (West Lafayette, IN); Abhilash Jindal (West Lafayette, IN); Samuel Midkiff (West Lafayette, IN); Abhinav Pathak (San Jose, CA)
Assignee: PURDUE RESEARCH FOUNDATION
G06F11/3604G06F8/20G06F8/433G06F11/3466
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Quick Facts
Patent No.
US 9,501,382
App. No.
14/313,890
Granted
Nov 22, 2016
Kind
B2
Abstract

Embodiments of the present invention provide a system and methods for detecting power bugs. In one embodiment, a computer-implemented method for analyzing a computer code includes generating a control flow graph for at least a portion of the computer code at a processor. The method further includes identifying power bugs by traversing the control flow graph if the control flow graph exits without performing a function call to deactivate power to any component of a device configured to execute computer executable instructions based on the computer code after performing a function call to activate power.

Claims (58)

1. A computer-implemented method for analyzing a computer code, the method comprising:

at a processor, generating a control flow graph for at least a portion of the computer code; and

identifying power bugs by traversing the control flow graph to identify if the control flow graph exits without performing a function call to deactivate power to any component of a device configured to execute computer executable instructions based on the computer code after performing a function call to activate power,

wherein the step of identifying power bugs comprises applying a forward dataflow analysis,

wherein applying the forward dataflow analysis comprises

applying a reaching definitions analysis to identify any mismatch in definitions relating to function calls for activating or deactivating power, and

wherein applying the reaching definitions analysis comprises

identifying steps in the control flow graph relating to function calls for activating or deactivating power,

defining a power variable for each step with a function call for activation and for each step with a function call for deactivation that are identified,

assigning a first binary value to the power variable for each function call for activation and assigning an opposite second binary value to the power variable for each function call for deactivation,

generating a set of definitions of the power variable reaching an EXIT block of the control flow graph, and

identifying a power bug if any definition of the first binary value is identified in the set of definitions of the power variable at the EXIT block.

2. The method of claim 1 , further comprising generating an error message if the control flow graph exits without performing a function call to deactivate power to any component.

3. The method of claim 2 , further comprising storing the error message in a non-transitory memory medium.

4. The method of claim 1 , wherein the computer executable instructions are configured to run on a power constrained device.

5. The method of claim 4 , wherein the function call to activate power comprises a function call to prevent the power constrained device from going to sleep, and wherein the function call to deactivate power comprises a function call to re-allow the power constrained device to go to sleep.

6. The method of claim 4 , further comprising:

receiving the computer code; and

removing the identified power bugs.

7. The method of claim 6 , further comprising:

after removing the identified power bugs, generating the computer executable instructions by compiling the computer code if the computer code exits after performing a function call to deactivate power to any component previously activated; and storing the computer executable instructions in a non-transitory memory medium.

8. The method of claim 7 , further comprising:

providing an application comprising the computer executable instructions to a user device at an online market place.

9. The method of claim 1 , wherein applying the forward dataflow analysis comprises applying a live variable analysis, or an available expressions analysis.

10. The method of claim 1 , wherein the computer code is configured to execute as a single thread process.

11. The method of claim 1 , wherein generating the control flow graph comprises:

generating individual control flow graph for each event handler in the computer code comprising a plurality of event handlers; and

stitching together the individual control flow graphs.

12. The method of claim 1 , wherein computer code is configured to execute as a multi-threaded application.

13. The method of claim 12 , wherein generating the control flow graph comprises generating a control flow graph for a multi-threaded application.

14. The method of claim 13 , wherein generating the control flow graph comprises:

generating individual control flow graph for each thread;

connecting a fork spawning each thread with an ENTRY block of the individual control flow graph for that thread; and

connecting an EXIT block of the individual control flow graph for that thread with a join node or with another ENTRY block of another individual control flow graph of another thread.

15. A computing device comprising:

a processor configured to execute a debugging tool, the debugging tool configured to:

generate a control flow graph for at least a portion of a computer code, and

identify power bugs by detecting if the control flow graph exits without performing a function call for deactivating power to any component of a device configured to execute computer executable instructions based on the computer code by traversing the control flow graph after performing a function call to activate power,

wherein the step of identify power bugs comprises apply a forward dataflow analysis,

wherein apply the forward dataflow analysis comprises

apply a reaching definitions analysis to identify any mismatch in definitions relating to function calls for activating or deactivating power, and wherein apply the reaching definitions analysis comprises

identify steps in the control flow graph relating to function calls for activating or deactivating power,

define a power variable for each step with a function call for activation and for each step with a function call for deactivation that are identified,

assign a first binary value to the power variable for each function call for activation and assigning an opposite second binary value to the power variable for each function call for deactivation,

generate a set of definitions of the power variable reaching an EXIT block of the control flow graph, and

identify a power bug if any definition of the first binary value is identified in the set of definitions of the power variable at the EXIT block.

16. A non-transitory storage medium comprising a debugging tool, the debugging tool configured to analyze a computer code by:

generating a control flow graph for at least a portion of the computer code; and

identifying power bugs by detecting if the control flow graph exits without performing a function call for deactivating power to any component of a device configured to execute computer executable instructions based on the computer code by traversing the control flow graph after performing a function call to activate power,

wherein the step of identifying power bugs comprises applying a forward dataflow analysis,

wherein applying the forward dataflow analysis comprises

applying a reaching definitions analysis to identify any mismatch in definitions relating to function calls for activating or deactivating power, and

wherein applying the reaching definitions analysis comprises

identifying steps in the control flow graph relating to function calls for activating or deactivating power,

defining a power variable for each step with a function call for activation and for each step with a function call for deactivation that are identified,

assigning a first binary value to the power variable for each function call for activation and assigning an opposite second binary value to the power variable for each function call for deactivation,

generating a set of definitions of the power variable reaching an EXIT block of the control flow graph, and

identifying a power bug if any definition of the first binary value is identified in the set of definitions of the power variable at the EXIT block.

Assignments (2)
CONFIRMATORY LICENSE Recorded Dec 31, 2014
From: PURDUE UNIVERSITY
To: NATIONAL SCIENCE FOUNDATION
Reel/Frame 034716/0901 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Sep 15, 2014
From: HU, YU CHARLIE; MIDKIFF, SAMUEL; JINDAL, ABHILASH; PATHAK, ABHINAV
To: PURDUE RESEARCH FOUNDATION
Reel/Frame 033736/0449 →
Continuity (2)
Provisional Application 61839334 · Jun 25, 2013
Related Publication 20140380283A1 · Dec 25, 2014