Data Loss Detector: Automatically Revealing Data Loss Bugs in Android Apps Oliviero Riganelli University of Milano Bicocca joint work with Simone Paolo Mottadelli, Claudio Rota, Daniela Micucci and Leonardo Mariani Distinguished Artifact 

Recreating Android Activity https://disco.unimib.it oliviero.riganelli …………. https://disco.unimib.it oliviero.riganelli …………. 

Recreating Android Activity Running (visible) Destroyed Created Running (visible) create activity restore activity state save activity state 1 2 3 

https://disco.unimib.it oliviero.riganelli …………. Instance State https://disco.unimib.it oliviero.riganelli …………. Recreating an Activity 

https://disco.unim ib.it oliviero.riganelli …………. Running (visible) Destroyed save activity state 1 https://disco.unimib.it oliviero.riganelli …………. Instance State Recreating an Activity 

https://disco.unimib.it oliviero.riganelli …………. Created create activity 2 https://disco.unim ib.it oliviero.riganelli …………. Instance State Recreating an Activity 

https://disco.unimib.it oliviero.riganelli …………. https://disco.unimib.it oliviero.riganelli …………. Created Running (visible) restore activity state 3 Instance State Recreating an Activity 

https://disco.unimib.it oliviero.riganelli …………. Data Loss Instance State https://disco.unimib.it oliviero.riganelli …………. 

https://disco.unim ib.it Running (visible) Destroyed save activity state 1 https://disco.unimib.it oliviero.riganelli …………. Data Loss Instance State 

https://disco.unimib.it oliviero.riganelli …………. Created create activity 2 https://disco.unim ib.it Instance State Data Loss 

https://disco.unimib.it oliviero.riganelli …………. https://disco.unimib.it Created Running (visible) restore activity state 3 Instance State Data Loss 

https://disco.unimib.it oliviero.riganelli …………. https://disco.unimib.it Created Running (visible) restore activity state 3 Instance State Data Loss The metronome is frustrating. I use it when I practice but if I ever stop it, and turn off the screen, it resets to 40bpm and 4/4 time As soon as I opened a comic through this app I was really happy given its functionality and ease of use. But everytime I rotate the screen, the app exits saying " file could not be loaded" Randomly sets back to 100% and auto brightness after using camera 

Pervasiveness of Data Loss Problems APP APP APP APP APP 

Pervasiveness of Data Loss Problems 88% Apps with data loss 12% App without data loss 

Pervasiveness of Data Loss Problems 88% Apps with data loss 12% App without data loss 

Data Loss Detector (DLD) https://disco.unimib.it oliviero.riganelli …………. https://disco.unimib.it 

Data Loss Detector (DLD) Touch buttons Type text Press HOME key … 

Data Loss Detector (DLD) Touch buttons Type text Press HOME key … 

TouchEvent(“3”) GrantPermissionsActivity GrantPermissionsActivity MainActivity MainActivity Launcher TouchEvent(“ALLOW”) TouchEvent(“ALLOW”) KeyEvent(HOME) GUI Model 

TouchEvent(“3”) GrantPermissionsActivity GrantPermissionsActivity MainActivity MainActivity Launcher TouchEvent(“ALLOW”) TouchEvent(“ALLOW”) KeyEvent(HOME) GUI Model GUI: ACTIONS: KeyEvent(HOME) TouchEvent(“ALLOW”) … STATE 

TouchEvent(“3”) GrantPermissionsActivity GrantPermissionsActivity MainActivity MainActivity Launcher TouchEvent(“ALLOW”) TouchEvent(“ALLOW”) KeyEvent(HOME) GUI Model Type: Touch View: Command: adb shell input … EVENT 

https://disco.unimib.it oliviero.riganelli …………. Data Loss Detector (DLD) oliviero.riganelli Love is the answer Biased Model-Based Exploration Data Loss Oracles Data-Loss-Revealing Actions 

TouchEvent(“OK”) Sn TouchEvent(“NO THANKS”) KeyEvent(MENU) Biased Model-Based Exploration 

Sn KeyEvent(MENU) Biased Model-Based Exploration 0.9 Unexecuted event 0.1 Any event TouchEvent(“OK”) TouchEvent(“NO THANKS”) 

Sn KeyEvent(MENU) Biased Model-Based Exploration P:0.333 P:0.333 P:0.333 TouchEvent(“OK”) TouchEvent(“NO THANKS”) 0.9 Unexecuted event 0.1 Any event 

Sn KeyEvent(MENU) Biased Model-Based Exploration P:0.333 P:0.333 P:0.333 TouchEvent(“OK”) TouchEvent(“NO THANKS”) 0.9 Unexecuted event 0.1 Any event 

Sn KeyEvent(MENU) Biased Model-Based Exploration P:0.033 P:0.483 P:0.483 TouchEvent(“OK”) TouchEvent(“NO THANKS”) 0.9 Unexecuted event 0.1 Any event 

Sn KeyEvent(MENU) Biased Model-Based Exploration TouchEvent(“OK”) TouchEvent(“NO THANKS”) P:0.033 P:0.483 P:0.483 0.9 Unexecuted event 0.1 Any event 

Sn KeyEvent(HOME) Biased Model-Based Exploration P:0.033 P:0.933 P:0.033 TouchEvent(“OK”) TouchEvent(“NO THANKS”) 0.9 Unexecuted event 0.1 Any event 

Data-Loss-Revealing Actions NEW STATE Systematic Probabilistic ALREADY VISITED STATE 

Systematic data-loss-revealing action https:// oliviero.riganelli …………. 

Systematic data-loss-revealing action https:// oliviero.riganelli …………. https://disco.unimib.it oliviero.riganelli …………. https:// oliviero.riganelli …………. 

https:// oliviero.riganelli …………. https://disco.unimib.it oliviero.riganelli …………. https:// oliviero.riganelli …………. https:// oliviero.riganelli … … … … . https://disco.unim ib.it Systematic data-loss-revealing action 

Probabilistic data-loss-revealing action https:// oliviero.rig …………. https:// oliviero.rig … … … … . https:// oliviero.riganelli … … … … . https:// oliviero.rig … … … … . https:// oliviero.riganelli … … … … . 

Data Loss Oracles [ … { 'content_description': None, 'resource_id': None, 'text': 'Editing "test123"', 'visible': True, 'checkable': False, 'children': [], 'size': '720*81', 'checked': False, 'temp_id': 4, 'selected': False, 'child_count': 0, ... } ... ] Snapshot-based oracle Property-based oracle 

Data Loss Oracles Snapshot Property … ‘content_description': … … ‘content_description': ... Before double rotation After double rotation 

Data Loss Oracles Snapshot Property … ‘content_description': 'Open navigation drawer', … … ‘content_description': ‘Close navigation drawer', ... Before double rotation After double rotation 

Evaluation Evaluation Research Questions APPs Configuration Google Nexus 5 Android 6.0 RQ0 - What is the ε that provides the best exploration? RQ1 - How effective is DLD with data loss problems? RQ2 - Is DLD more effective than state- of-the-art techniques? RQ3 - What is the tradeoff between the snapshot- and property- based oracles? RQ4 - Are data loss faults relevant to developers? 110 real data loss 54 app releases Riganelli et al. "A Benchmark of Data Loss Bugs for Android Apps”, MSR 2019. 

RQ1 - How effective is DLD with data loss problems? 110 Benchmark Data Loss 

RQ1 - How effective is DLD with data loss problems? 27 83 267 Benchmark Data Loss Detected by DLD 

RQ1 - How effective is DLD with data loss problems? 27 83 267 Benchmark Data Loss Detected by DLD 90% of faults confirmed by developers, see RQ4 in the paper 

RQ2 - Is DLD more effective than state-of-the-art techniques? 0 50 100 150 200 Faulty Activity Benchmark Faults New Faults Spuriuos Violations Alaric DLD 

RQ2 - Is DLD more effective than state-of-the-art techniques? 0 50 100 150 200 Faulty Activity Benchmark Faults New Faults Spuriuos Violations Alaric DLD COMPARISON TO QUANTUM IN THE PAPER 

RQ3 - What is the tradeoff between the snapshot- and property- based oracles? 73% 18% 9% snapshot-based oracle property-based oracle both incomplete rotation 74% 21% 5% Data loss detected Spurious oracle violations 

RQ3 - What is the tradeoff between the snapshot- and property- based oracles? 73% 18% 9% snapshot-based oracle property-based oracle both incomplete rotation 74% 21% 5% Data loss detected Spurious oracle violations 0.1% 

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