DroidCon Greece 16 - Android High Performance Apps

Presentation for the DroidCon Greece 2016 on Android High Performance Apps

1. Android High Performance Enrique López Mañas Google Developer Expert & IT Consultor
2. Ego Slide • IT Consultor • Google Developer Expert • @eenriquelopez
3. Performance "how well a person, machine, etc. does a piece of work or an activity" Cambridge
4. But what is high performance? • Strategies to create efficient software Layout Energy and battery Security Multithreading Programming patterns Debugging techniques
5. Why is important? • User Engagement • Costs • Maintenance • Quality
6. 3 Important Limits 0.1s 1s 10s [Miller 1968; Card et al. 1991]:
7. What this means in Android? ANR
8. ANR • No response for input event in 5 seconds • BroadCast receiver still executing after 10 seconds
9. How to avoid it? Background operations? Show feedback!
10. How to avoid it? Splash Screen?
11. How to avoid it? Calculations? Worker thread!
12. How to avoid it? Systrace! TraceView!
13. Debug DDMS
14. Networking
15. Layouts TV: 24fps(NTSC), 25fps(PAL) New cam-coders / slow motion: 48fps+ Blur can occur! Apps: 60fps! every 16 ms!
16. Layouts
17. Layouts
18. Reusing layouts
19. Reusing layouts
20. Reusing layouts
21. ViewStub ViewStub.inflate() View.setVisibility()
22. ViewStub
23. Hierarchy Viewer
24. Profile GPU Rendering
25. Profile GPU Rendering • Blue: draw • Purple: prepare • Red: process • Orange: execute
26. Memory “the ability to remember information, experiences, and people" Cambridge
27. Memory - Enumerations
28. Memory - Enumerations
29. Memory - Enumerations
30. Memory - Enumerations
31. Memory - Enumerations @IntDef
32. Memory - Enumerations @IntDef
33. Memory - Enumerations Summary • Unnecessary allocations • AVOID USING THEM • Change as much as possible with static final integer values
34. Memory - Constants Constants in the code should be static and final to take advantage of memory savings and to avoid initialization in Java compiler
35. Memory - Strings
36. Memory - Strings
37. Memory - Strings
38. Memory Leaks “a memory leak is a type of resource leak that occurs when a computer program incorrectly manages memory allocations in such a way that memory which is no longer needed is not released.” Wikipedia
39. Memory Leaks - static fields
40. Memory Leaks - static fields
41. Memory Leaks - non-static inner classes
42. Memory Leaks - WeakReference
43. Threading “Threading is a method of hair removal originating in Asia.” Wikipedia
44. Threading “is the smallest sequence of programmed instructions that can be managed independently by a scheduler” Wikipedia
45. Threading • AsyncTask • Loader • Threads… Know your war!
46. Threading - AsyncTask Communicate Worker Thread with UI Does not need to communicate UI? Does not need to notify user? DOES NOT NEED ASYNCTASK! If the AsyncTask has all parameters Void, you are only implementing doInBackground() and you do not need an AsyncTask
47. Threading - AsyncTaskLoader Use it to fetch data Same features as AsyncTask… …plus the Activity life-cycle independency and data caching
48. Threading - AsyncTaskLoader
49. Threading - Services • Not threads! • Executed in UI Thread by default • Never start a long running operation! • Lifecycle
50. Threading - IntentService • Particular implementation of a Service • Execute sequential operations in background • Don’t need to handle the lifecycle
51. Networking “process of communication between different terminal nodes to exchange data” Me
52. Networking - best practices Latency Gauging
53. Networking - best practices Batch connections • Wait, collect and send • (Analytics)
54. Networking - best practices Pre-fetch • Download as much as possible • (specially if idle connection)
55. Networking - best practices Queuing connections
56. Networking - best practices Caching responses
57. Networking - best practices Last modified
58. Networking - best practices Exponential back-off
59. I want your feedback! http://bit.ly/droidConGR
60. #dfist