Android High Performance - Droidcon VN 2017

Android High Performance - Droidcon VN 2017

Transcript

1. Android High Performance Enrique López Mañas Google Developer Expert
2. Ego Slide • Indie Dev • Google Developer Expert • @eenriquelopez
3. How it did start?
4. Performance "how well a person, machine, etc. does a piece of work or an activity" Cambridge
5. But what is high performance? • Strategies to create efficient software Layout Energy and battery Security Multithreading Programming patterns Debugging techniques
6. Why is important? • User Engagement • Costs • Maintenance • Quality
7. 3 Important Limits 0.1s 1s 10s [Miller 1968; Card et al. 1991]:
8. What this means in Android? ANR
9. ANR • No response for input event in 5 seconds • BroadCast receiver still executing after 10 seconds
10. How to avoid it? Background operations? Show feedback!
11. How to avoid it? Splash Screen?
12. How to avoid it? Calculations? Worker thread!
13. How to avoid it? Systrace! TraceView!
14. Debug DDMS
15. Networking
16. Layouts TV: 24fps(NTSC), 25fps(PAL) New cam-coders / slow motion: 48fps+ Blur can occur! Apps: 60fps! every 16 ms!
17. Layouts
18. Layouts
19. Reusing layouts
20. Reusing layouts
21. Reusing layouts
22. ViewStub ViewStub.inflate() View.setVisibility()
23. ViewStub
24. Hierarchy Viewer
25. Profile GPU Rendering
26. Profile GPU Rendering • Blue: draw • Purple: prepare • Red: process • Orange: execute
27. Memory “the ability to remember information, experiences, and people" Cambridge
28. Memory - Enumerations
29. Memory - Enumerations
30. Memory - Enumerations
31. Memory - Enumerations
32. Memory - Enumerations @IntDef
33. Memory - Enumerations @IntDef
34. Memory - Enumerations Summary • Unnecessary allocations • AVOID USING THEM • Change as much as possible with static final integer values
35. Memory - Constants Constants in the code should be static and final to take advantage of memory savings and to avoid initialization in Java compiler
36. Memory - Strings
37. Memory - Strings
38. Memory - Strings
39. 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
40. Memory Leaks - static fields
41. Memory Leaks - static fields
42. Memory Leaks - non-static inner classes
43. Memory Leaks - WeakReference
44. Threading “Threading is a method of hair removal originating in Asia.” Wikipedia
45. Threading “is the smallest sequence of programmed instructions that can be managed independently by a scheduler” Wikipedia
46. Threading • AsyncTask • Loader • Threads… Know your war!
47. 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
48. Threading - AsyncTaskLoader Use it to fetch data Same features as AsyncTask… …plus the Activity life-cycle independency and data caching
49. Threading - AsyncTaskLoader
50. Threading - Services • Not threads! • Executed in UI Thread by default • Never start a long running operation! • Lifecycle
51. Threading - IntentService • Particular implementation of a Service • Execute sequential operations in background • Don’t need to handle the lifecycle
52. Networking “process of communication between different terminal nodes to exchange data” Me
53. Networking - best practices Latency Gauging
54. Networking - best practices Batch connections • Wait, collect and send • (Analytics)
55. Networking - best practices Pre-fetch • Download as much as possible • (specially if idle connection)
56. Networking - best practices Queuing connections
57. Networking - best practices Caching responses
58. Networking - best practices Last modified
59. Networking - best practices Exponential back-off
60. I want your feedback! http://bit.ly/droidconIT17
61. #Droidconvn