Remote Debugging and Reflection in Resource Constrained Devices. Nikolaos Papoulias - December 2013

Transcription

1 Remote Debugging and Reflection in Resource Constrained Devices Nikolaos Papoulias - December 2013! 1

2 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 2

3 Context - Constrained Devices Cannot locally support an IDE & Dev-Tools Have different HW/SW Configurations from Dev-Machines 3

4 Context - Debugging Constrained Devices Emulators Post-Mortem Analysis Developer's end 5 1 Coding / Compilation Deployment 4 2 Target Devices Execution 3 Post-mortem analysis Log Collection Logging 4

5 Context - Debugging Constrained Devices Developer's end Target Devices Coding / Compilation 2 Deployment Emulators 1 4 Inspection 3 Post-Mortem Analysis Execution 5 Action / Modification Remote Debugging 5

6 Remote Debugging Is a solution that is distributed in a nature: Impact on productivity due to re-deployments [ZeroTurnAround 2011] Lacks facilities otherwise available in a local setting (e.g O-Centric Debugging [Ressia 2012b]) 6

7 Research Questions What are the properties of an ideal remote debugging solution? Given these properties which model for remote debugging can exhibit them? What are the trade-offs between this ideal model and a real world implementation? 7

8 Thesis Statement - Properties An ideal remote debugging solution should support Interactiveness Instrumentation Distribution Security 8

9 Interactiveness the ability to incrementally update all parts of a remote application without losing the running context (i.e without stopping the application). Add/Rem Packages, Add/Rem Classes, Add/Rem Fields, Edit Hierarchy, Add/Rem Methods 9

10 Instrumentation the ability to alter the semantics of a running process in order to assist debugging Method/Statement Execution, Class Instantiation/Field Read/Write Object Read/Write/Send/Receive/Argument/Store/Interact 10

11 Distribution the ability of a debugging solution to adapt its framework while debugging a remote target No-Distribution / Fixed Middleware / Extensible Middleware / Adaptable Middleware 11

12 Security the availability of prerequisites for security mechanisms such as authentication and access restriction Internal / External / Target-Side / Client-Side 12

13 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 13

14 Related Work - Overview JPDA.NET GDB DCE JREBEL SMALLTALK BIFROST Interactiveness (6) Instrumentation (13) Distribution (+++) Security (4)

15 Related Work - Overview JPDA.NET GDB DCE JREBEL SMALLTALK BIFROST (A) None of the 1 existing 1 1 solutions met all of our 4 4 criteria (B) But - reflective - debugging proved superior 0 to 0 other approaches in a local setting 15

16 Related Work - Overview JPDA.NET GDB DCE JREBEL SMALLTALK BIFROST (B) Since reflective 1debugging 1 1 proved superior to other 4approaches 4 5in a 4local setting (C) Investigate Remote 3 0 Reflection 0 Design Patterns 16

17 Remote Reflection System A Meta System System B Reflective System DATA DATA DISTRIBUTED-SELF-REPRESENTATION OF SYSTEM B PROGRAM PROGRAM Part of the world INTERPRETER INTERPRETER act upon represent Remote Proxy / Remote Facade / Mirrors 17

18 Mirrors - Explicit Meta-Objects Object ObjectMirror <<ObjectMirrorInterface>> getclass() anobject reflects on anobjectmirror Encapsulation Stratification Ont. Correspondance Mirror on: anobject Indirection 18

19 Design Patterns - Criteria Extensibility, Re-use Distribution Identity [Bracha 2010] Meta-recursion [Denker 2008] Mirrors can be seen as an extension to both the remote proxy and the remote facade patterns 19

20 Mirrors - Open Issues Mirrors and the Problem of State - debugging meta-information in cohesive language kernels Mirrors and Intercession - advanced instrumentation support while debugging 20

21 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 21

22 Our Proposals MetaTalk Α solution to the problem of Reflective-Data [Maes 1987b] in the context of mirrors [Bracha 2004] The definition of a model for remote debugging that can exhibit the properties of: interactiveness, instrumentation distribution and security Mercury 22

23 Our Proposal MetaTalk From a language design perspective metaobjects should be both: Pluggable as mirrors are and State-Full as 3-KRS meta-objects 23

24 MetaTalk Kernel AbstractMirror Object AbstractMirror Class Mirror Object Class ObjectMirror ClassMirror Point Mirror on: apoint Mirror on: Object Mirror on: Point Mirror on: Class apoint BASE LEVEL META LEVEL 24

25 MetaTalk Implementation MetaTalk-VM is written in Pharo MetaTalk-Compiler relies on Petit-Parser Object-Model inspired by ObjVLisp 25

26 Our Proposals MetaTalk Α solution to the problem of Reflective-Data [Maes 1987b] in the context of mirrors [Bracha 2004] The definition of a model for remote debugging that can exhibit the properties of: interactiveness, instrumentation distribution and security Mercury 26

27 Overview Mercury 1 DEVELOPER'S END MODEL OF THE DEBUGGED APP DEBUGGER / IDE MIDDLEWARE TARGET DEBUGGED APPLICATION RUN-TIME DEBUGGING SUPPORT MIDDLEWARE Interactiveness - through a mirror-based remote meta-level that is causally connected to its target 27

28 Core Model Development Side Target Side Mirror * reflects on 1 Object Point ObjectMirror - rtmirror: RunTimeMirror + instvarat(anivname: String): ObjectMirror +... instance of - targetobject: Object... RunTimeMirror - runtime: RTDebuggingSupport + objectinstvarat(forobject: Object, anivname: String): ObjectMirror +... M I D D L E W A R E 1 1 RTSupport RunTimeDebuggingSupport + objectinstvarat(forobject: Object, anivname: String): Object +... instance of runtimedebuggingsupp ort mirroro napoint aruntime Mirror... apoint 28

29 Interactiveness (1) Structural Reflection Mirror - targetobject: Object ObjectMirror - rtmirror: RunTimeMirror + setclass(aclassmirror: ClassMirror): ClassMirror EnvironmentMirror + newpackagenamed(apackagename: String): PackageMirror + removepackagenamed(apackagename: String): PackageMirror PackageMirror + newclassnamed(aclassname: String): ClassMirror + removeclassnamed(aclassname: String): ClassMirror ClassMirror... + setsuperclass(aclassmirror: ClassMirror): ClassMirror + addinstvarname(anivname: String): ClassMirror + deleteinstvarname(anivname: String): ClassMirror + addmethod(methodname: String, source: String): MethodMirror + deletemethod(methodname: String): MethodMirror RunTimeMirror - runtime: RunTimeDebuggingSupport (2) Computational Reflection ExceptionMirror ProcessMirror ContextMirror + saveandcontinue (newsrc: String): ContextMirror MethodMirror + recompilewithsource(src: String): MethodMirror 29

30 Our Proposal - Overview DEVELOPER'S END MODEL OF THE DEBUGGED APP DEBUGGER / IDE MIDDLEWARE 2 TARGET DEBUGGED APPLICATION RUN-TIME DEBUGGING SUPPORT MIDDLEWARE Instrumentation - through reflective intercession by reifying the underlying execution environment 30

31 Instrumentation Target Side 1 RunTimeDebuggingSupport interpreter: Interpreter values: Dictionary<Object> objecthalt(): Object + objecthaltonreceive(): Object + objectonreceive(callback: LocalCallBack) + objectonreceive(callback: RemoteCallBack) 1 Interpreter basemetadict: Dictionary 1 1 MetaEnvironment 1 * ImplicitMetaObject - onreceive: Closure - onsend: Closure - onread: Closure - onwrite: Closure. * * Object * Closure LocalCallBack RemoteCallBack 31

32 Our Proposal - Overview DEVELOPER'S END MODEL OF THE DEBUGGED APP DEBUGGER / IDE MIDDLEWARE 3 TARGET DEBUGGED APPLICATION RUN-TIME DEBUGGING SUPPORT MIDDLEWARE Distribution - through an Adaptable Middleware 32

33 Distribution DistributionPolicy Marshaller Middleware Deamon Transporter 1 SecurityPolicy 1 33

34 Our Proposal - Overview DEVELOPER'S END TARGET MODEL OF THE DEBUGGED APP DEBUGGER / IDE MIDDLEWARE 4b 4a DEBUGGED APPLICATION RUN-TIME DEBUGGING SUPPORT MIDDLEWARE Security - security by decomposing and authenticating access to reflective facilities 34

35 Security Development Side SecurityPolicy 1 1 Process is invoked by uses a RemoteEnvironment Reflection + onenvironment(environmentaddress: RemoteEnvironment) : EnvironmentMirror - address: String Mirror - targetobject: Object IntrospectionMirrorForAPoint instance of EnvironmentIntrospectionMi rror EnvironmentIntercessionMir ror ObjectMirror - rtmirror: RunTimeMirror ObjectIntrospectionMirror + instvarat(anivname: String): ObjectIntrospectionMirror +... ObjectIntercessionMirror + instvaratput(anivname: String, avalue: ObjectIntercessionMirror): ObjectIntercessionMirror RunTimeMirror - runtime: RunTimeDebuggingSupport instance of IntrercessionMirrorForAPoint ProcessIntrospectionMirror ProcessIntercessionMirror 35

36 Comparison JPDA.NET GDB DCE JREBEL SMALLTALK BIFROST MERCURY Interactiveness (6) Instrumentation (13) Distribution (+++) Security (4)

37 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 37

38 Implementation Overview Mercury-Core Seamless Mercury-Ui (Alexandria) MetaStackVM

39 Meta-Recursion - mstackvm Interpreter Ooops! on: MessageReceived for: anobject do: [:reifications anobject incrementmessagecounter. anobject perform: reifications selector witharguments: reifications arguments] 39

40 MetaStackVM - Reflectogram Interpreter on: MessageReceived for: anobject do: [:reifications :reflectogram reflectogram disable. anobject incrementmessagecounter. reflectogram enable. reflectogram returnvalue: reflectogram defaultaction] 40

41 MetaStackVM - Reflectogram Interpreter Reflectogram on: MessageReceived for: anobject +.. do: [:reifications + enable :reflectogram + reflectogram + removedisable. + anobject + defaultaction incrementmessagecounter. + returnvalue: reflectogram enable. + reflectogram + processmetalevel + objectmetalevel returnvalue: + reflectogram defaultaction] + obj:perform: 41

42 Implementation Trade-offs Supporting Interactiveness and Instrumentation Through Local Reflection Through Virtual-Machine support Through Byte-code manipulation 42

43 Benchmark Benchmark based on Tanter [Tanter 2003] Mercury No Instrumentation Disabled Instrumentation Enabled Instrumentation 1x 1x 35x 1x 1x 8x 43

44 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 44

45 Experimental Setting Constraint Device (A) Phone WIFI: USB: PORT-FWD Galaxy Nexus - (1.2 GHz / 1GB RAM) Android 4.3 Constraint Device (B) Tablet WIFI: USB: PORT-FWD Galaxy Tab - (1.0 GHz / 1GB RAM) Android 4.0 Constraint Device (C) Remote Server ETH: HP Workstation - (2.3 GHz / 4GB RAM) Ubuntu over wifi / usb over wifi / usb over ethernet Mercury IDE Running Developer-Machine ETH: WIFI: USB: PORT-FWD Mac-Mini - (2.3 GHz / 4GB RAM) Ubuntu

46 Alexandria 46

47 Experimental Setting 47

48 Objectives Verify the applicability of Mercury for these constrained debugging targets. Illustrate how a debugging session benefits from Mercury s properties Case-Study I Remote Agile Debugging Case-Study II Remote Object Instrumentation 48

49 Remote Agile Debugging Suffix Bug Phone: /charger Tablet: /default.prop Server: /User/.profile-xmind-portable

50 Remote Agile Debugging nt Device (A) IFI: SB: PORT-FWD Galaxy Nexus - (1.2 GHz / 1GB RAM) Android 4.3 Constraint Device (B) Tablet WIFI: USB: PORT-FWD Galaxy Tab - (1.0 GHz / 1GB RAM) Android 4.0 Constraint Devic Remote Server HP W Ubunt TestCase TestCase over wifi / usb FileBrowserTest + suffixof: astring + testsuffixwithdot + testsuffixwithoutdot + testlongfilepath over wifi / usb FileBrowserTest + suffixof: astring + testsuffixwithdot + testsuffixwithoutdot + testlongfilepath TestCase FileBrowserTest + suffixof: over ethernet astring + testsuffixwithdot + testsuffixwithoutdot + testlongfilepath Mercury IDE 50

51 Remote Agile Debugging 51

52 Objectives Verify the applicability of Mercury for these constrained debugging targets. Illustrate how a debugging session benefits from Mercury s properties Case-Study I Remote Agile Debugging Case-Study II Remote Object Instrumentation 52

53 Remote Object Instrumentation Suffix Bug Phone: /charger Tablet: /default.prop Server: /User/.profile-xmind-portable FileDirectory dot 53

54 Remote Object Instrumentation 54

55 Remote Object Instrumentation 55

56 Results 56

57 Outline Introduction Related Work Contributions Implementation Validation Conclusion & Future Work 57

58 Summary - Contributions Identification of four desirable properties for remote debugging: interactiveness, instrumentation, distribution and security. The definition of a model for remote debugging (Mercury) that exhibits these desirable properties. A solution to the problem of Reflective-Data [Maes 1987b] in the context of mirrors [Bracha 2004] (MetaTalk) 58

59 Contributions The reification of a previously illustrative notion (that of the reflectogram [Tanter 2003]) Prototype implementation of our model for remote debugging in the context of reflective languages. Implementation of an adaptable middleware [David 2002] for supporting distribution (Seamless). Implementation of a dedicated VM for Pharo (MetaStackVM) for advanced intercession facilities. 59

60 Diffusion of Results Submitted/Published: Nikolaos Papoulias, Noury Bouraqadi, Marcus Denker, Stéphane Ducasse and Luc Fabresse. Towards Structural Decomposition of Reflection with Mirrors}. In Proceedings of International Workshop on Smalltalk Technologies (IWST 11), Edingburgh, United Kingdom, Conference Talk: Nikolaos Papoulias. Seamless -- Let a thousand systems bloom. 20th International Smalltalk Conference, Ghent, Belgium, To Be Submitted: Nikolaos Papoulias, Noury Bouraqadi, Luc Fabresse, Marcus Denker and Stéphane Ducasse. Mercury: Live Remote Debugging in Reflective Languages. To be submitted in The Journal of Object Technology. To Be Submitted: Nikolaos Papoulias, Stéphane Ducasse, Marcus Denker, Guillermo Pollito, Noury Bouraqadi and Luc Fabresse. MetaTalk: Designing a Language with a Pluggable Meta-Level. To be submitted in The Journal for Universal Computer Science. Invited Chapter: Nikolaos Papoulias. Seamless: an Adaptable Middleware Solution. Invited Chapter to be submitted for the forthcoming book Pharo in the Enterprise, by Square Bracket Associates. 60

61 Future Work Language and Virtual-Machine Debugging in the Same Model Integration of Automated Debugging Techniques (e.g delta-debugging) in Developer-Driven Debugging 61

62 Mercury Thank you! MetaTalk! Mercury-Core Mercury-Ui Seamless MetaStackVM (Alexandria) Nick Papoulias

63 Some time left? Groovy!! 63

64 Collaborations Seamless as a library for the Continuous integration services of Pharo. The MetaTalk model as a case-study for bootstraping OO - languages. Mercury integration with the PhaROS robotic middleware (on-going effort). 64

65 Design Patterns - Mirrors Explicit meta-object Abstract class / Interface Factory Facade and Bridge 65

66 Conditional Meta-Action [:reifications :reflectogram ] reifications trigger halt. reflectogram override: true; returnvalue: reflectogram defaultaction. 66

67 Seamless Initialization SeamlessDeamon class>>newdefaultwithglobalaccess ^ self new buildwithtransporterclass: SeamlessSocketStreamTransporter transcoderclass: SeamlessFuelTranscoder proxyclass: SeamlessFastDNUProxy garbagecollectorclass: SeamlessDefaultGarbageCollector andauthenticationmanager: ((SeamlessAuthenticationManager new) addgroup: [...] withpolicy: (SeamlessDistributionPolicy newwithentrypoint: [...] classestopassbyvalue: [...] classestopassbyshallowcopy: [...] andsecuritypolicy: (SeamlessSecurityPolicy newwithclassestopassbyreference: [..] classesnottoreference: [..] includingmessages: [...] excludingmessages: [...]); adduser: [...] withpassword: [...] ingroup: [...]). 67

68 Seamless UserGroup Seamless User Seamless DistributionPolicy Seamless SecurityPolicy Seamless Seamless AuthenticationManager SeamlessSession Seamless DistributionStrategy SeamlessDeamon Seamless ObjectTransporter Seamless Protocol Seamless ProcessManager Seamless DistributionTable SeamlessTransporter SeamlessTranscoder SeamlessConnection 68

69 JMercury - Our model on top of Java JPDA + DCE VM (Interactiveness) Reflex / ASM / JavaAssist (Instrumentation) Cajo Project (Distribution) Decomposed Hierarchy of Mirrors / Closer integration with SecurityManager (Security) 69

70 Emulators - Field Experience IPhone/Android emulators (different models - versions of OSes - gyroscopes - touch gestures...) Car-Team experience -- RoboShop 2013 Demo (unanticipated changes - people walking by - glass walls...) 70