NESL. CAreDroid: Adaptation Framework for Android Context-Aware Applications. Salma Elmalaki Lucas Wanner Mani Srivastava

Transcription

1 CAreDroid: Adaptation Framework for Android Context-Aware Applications Salma Elmalaki Lucas Wanner Mani Srivastava 1

2 Isolated Disconnected Unaware Photo Courtesy: Student Portal 2

3 Computing From Isolation to Awareness Photo Courtesy: Mobile innovation lab 3

4 Sense 4

5 Sense Understand 5

6 Sense Adapt Emergency Understand 6

7 Sense CAreDroid Eme Adapt Understand 7

8 CAreDroid Challenges 1. Automatically adapt to the environmental change at runtime. 2. Adaptation should be burden-free for the user. 3. Overhead of reading the environmental context should be small. Sense Understand Adapt 8

9 What is Context-awareness? ContextOS: A Context Aware Operating ErdOS: System Achieving for Energy Mobile Devices ([GreenCom 13]) Fusing mobile, Savings sensor, in and social data to fully enable context-aware Mobile computing A System ([HotMobile ([MobiArch 11]) Context-Aware '10]) Approach for Battery Lifetime Prediction in Smart Phones ([SAC 11]) adapt sense The Latency Accuracy and Battery LAB Abstraction: Programmer Productivity and Energy Efficiency for Continuous Mobile Context Sensing ([OOPSLA 13]) understand ACE: Exploiting Correlation for Energy- Efficient and Continuous Balancing Context Energy, Latency and Sensing (MobiSys 12) Accuracy for Mobile Sensor Data SymPhoney: Classification A Coordinated (SenSys 11) Sensing Flow Execution Engine for Concurrent Mobile Sensing Applications (SenSys 12) 9

10 Adaptation Realization f() Program f1() f2() f3() Location Temperature Context-Aware System Activity fn() Connectivity Battery Status Function Adaptation 10

11 Adaptation Realization f() Program f1() f2() f3() Location Temperature Context-Aware System Activity fn() Connectivity Battery Status Function Adaptation 11

12 Adaptation Realization f() Program f1() f2() f3() Location Temperature Context-Aware System Activity fn() Connectivity Battery Status Function Adaptation 12

13 CAreDroid Architecture Usability Performance 13

14 CAreDroid Architecture Application Layer app f f 1 f 2 f 3 g g 1 g 2 g 3 Application Layer System Layer Sensitive function registration & config parsing Adaptation Engine Context Monitoring Context Sensors 14

15 CAreDroid Architecture Application Layer app f f 1 f 2 f 3 Application Layer g g 1 g 2 g 3 System Layer Sensitive function registration & config parsing Adaptation Engine Context Monitoring System Layer Context Sensors Temperature Energy Connectivity 15

16 CAreDroid Architecture Application Layer app f f 1 f 2 f 3 Application Layer g g 1 g 2 g 3 System Layer Sensitive function registration & config parsing Adaptation Engine Context Monitoring System Layer Context Sensors Temperature Energy Connectivity Context Sensors 16

17 uration app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 Sensitive function registration & config parsing Adaptation Engine System Layer Context Monitoring Context Sensors Temperature Energy Connectivity 17

18 Function Registration The sensitive function registration part is responsible for: understanding the ranges of operations of each method integrate it in the Android run-time system app Sensitive function registration & config parsing f f 1 f 2 f 3 g Adaptation Engine Application Layer g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity 18

19 app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 Function Registration &. Parsing Sensitive function registration & config parsing Adaptation Engine System Layer Context Monitoring Context Sensors Temperature Energy Connectivity Normal Android Normal Android Flow Development time.java Compilation and packaging time.class.dex Installation time intercept.odex CAreDriod Flow CAreDroid Sensitive Method Discovery Replacement Map Table of of of Range Identifiers Identifiers.apk extended.odex 19

20 app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 Function Registration &. Parsing Sensitive function registration & config parsing Adaptation Engine System Layer Context Monitoring Context Sensors Temperature Energy Connectivity Normal Android Normal Android Flow Development time.java Compilation and packaging time.class.dex Installation time intercept.odex CAreDriod Flow CAreDroid Sensitive Method Discovery Replacement Map Table of of of Range Identifiers Identifiers.apk extended.odex 20

21 app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 Function Registration &. Parsing Sensitive function registration & config parsing Adaptation Engine System Layer Context Monitoring Context Sensors Temperature Energy Connectivity Normal Android Normal Android Flow Development time.java Compilation and packaging time.class.dex Installation time intercept.odex CAreDriod Flow CAreDroid Sensitive Method Discovery Replacement Map Table of of of Range Identifiers Identifiers.apk extended.odex 21

22 app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 Function Registration &. Parsing Sensitive function registration & config parsing Adaptation Engine System Layer Context Monitoring Context Sensors Temperature Energy Connectivity Normal Android Normal Android Flow Development time.java Compilation and packaging time.class.dex Installation time intercept.odex CAreDriod Flow CAreDroid Sensitive Method Discovery Replacement Map Table of of of Range Identifiers Identifiers.apk extended.odex 22

23 Context Monitoring 1. Battery state: capacity, temperature, voltage 2. Connectivity state: WiFi connection status, WiFi link quality, RSSI received signal strength indication 3. Location: GPS location 4. Mobility: run, walk, still Bypassing the HAL layer and the associated sensor managers. Snooping on the interface between the HAL and the low-level device drivers through the sysfs virtual file system. app Sensitive function registration & config parsing f f 1 f 2 f 3 Adaptation Engine Application Layer g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g 23

24 Adaptation Engine It is where the method replacement happens at runtime. app Application Layer f f 1 f 2 f 3 g g 1 g 2 g 3 System Layer Sensitive function registration & config parsing Adaptation Engine Context Monitoring Context Sensors Temperature Energy Connectivity 24

25 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 25

26 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 26

27 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 27

28 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 28

29 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 29

30 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 30

31 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g B CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal T Android V S CAreDroid W Q M L Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced 4 Method 5 ID cache hit Resolution cache miss Cache Operation Range Identifiers M1 M2 M3 M4 M Replacement Map Current Context update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Best Fit policy Must Fit policy 31

32 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 32

33 app Application Layer f f 1 f 2 f 3 Adaptation Engine Sensitive function registration & config parsing Adaptation Engine g 1 g 2 g 3 System Layer Context Monitoring Context Sensors Temperature Energy Connectivity g CAreDriod Flow Normal Android Flow invoke-virtual-quick Normal Android CAreDroid Dalvik Interpreter CAreDroid Dalvik Interpreter Extension Class ID Table of of of Range Identifiers Identifiers intercept Class Virtual Table Replaced cache miss Operation Range Identifiers Resolution Cache Replacement Map cache hit update cache CAreDroid Decision Graph Execute method Pointer to method byte code Replaced Current Context 33

34 Evaluation 1. Push context monitoring and adaptation to runtime system 2. At least 2x fewer lines of code 3. At least 10 more efficient in execution time 34

35 Context-aware Camera Still Still position position Walking! (non context aware) Walking! (with CAreDroid) 35

36 Context-aware Camera Still Still position position Walking! (non-context aware) Walking! (with CAreDroid) 36

37 Context-aware Camera Still Still position position Walking! (non-context aware) Walking! (with (With CAreDroid) 37

38 Analysis - Significant Line of Code (SLOC) Platform SLOC %Increase 38

39 Analysis of CAreDroid 1. Analyze the effect of cache in the adaptation engine 2. Examine the overhead of context-monitoring module 3. The difference in energy and execution time between pure Java implementation using Android APIs and CAreDroid 39

40 Testbed and testing environment Nexus 4 Android API 17 Overhead of system image is 4.6% 40

41 Analysis Execution time Platform CPU time (ms) Overhead Without cache With cache f1 f2 f3 f1 f2 f3 f1 f2 f3 f1 f2 f Average of 10 executions with variance 0.5% ~ 1% 41

42 Analysis Energy 1. CAreDroid consumes only 6.73% more energy compared with the non-context aware implementation and 2. CAreDroid gives 69.33% energy saving compared to the pure Java implementation. 3. Measurements are taken every 5 seconds. Average is shown with variance < 1% Energy [J] 5,000 4,000 3,000 2,000 1, Pure Java Best fit Time [hr] Must fit Non-context aware 42

43 Future Work 1. Migrate to new versions of Android that are based on ART instead of Dalvik (Kitkat and Lollipop). 2. Add support for more abstract contexts, for example, stress, smoking, fitness, etc 3. The adaptation can be privacy-aware. 4. Time of the day is another axis that can be used to enhancing the adaptation support 43

44 Thank you! 44

45 Keeping the developer/user in the loop Make the user not fully obfuscated Why this adaptation takes place? Special CAreDroid API - read_operating_point() 45