Apps World 2013 talk on how to improve APK size, runtime performance and memory consumption.

1. Of Bytes, Cycles and Battery Life

2. Who am I?
[2]
[1]
@badlogicgames
http://www.badlogicgames.com

3. What i‘ll talk about
• How to reduce your APK size
• Memory Analysis Tools
• Performance Analysis Tools

4. How to reduce your APK size
• Reduce asset size
– pngcrush your PNGs [3]
– SVG (YMMV) [4]
– lower bit-rates for audio
• Reduce code size
– Remove unnecessary dependencies!
– Proguard, for Class files [5] [6]
– Dexguard, for Dex files [7]

5. „But i can‘t reduce my APK size“
• Multiple-APKs to the „rescue“ [8]
–
–
–
–
One APK per screen density
One APK per texture compression algorithm
Use Google Play filters
Easier with new Android Gradle build system
• APK Expansion files [9]
– hosted by Google
• Roll your own „Expansion files“
– Avoid if you can!

6. Memory Analysis Tools
• „But we have a Garbage Collector!“
– You can still „leak“ memory
– Nasty static vars referencing unused objects
– Hidden object references
– Native memory allocated by Java classes
• If you write games, GC kills your steady
framerate

7. DDMS [10] Heap View

8. DDMS Allocation Tracker

9. HPROF/Eclipse MAT [11]
•
•
•
•
Select the process
Click
Save to a location of your choice
Convert to „real“ HPROF file
• Open in Eclipse MAT [12]

10. HPROF/Eclipse MAT

11. HPROF/Eclipse MAT

12. HPROF/Eclipse MAT

13. Performance Analysis Tools
• Why do we want to analyse?
– Jerky animations
– Do less, conserve battery
– Better user Experience
• What do we want to analyse?
– Time spent in Java code
– Time spent in Native code
– Time spent drawing stuff

14. Before we start...
• Never use the emulator!
– Ever, think of the kittens
• Identify hotspots in your app, not in
microbenchmarks
• Only spend time if you have a real problem

15. Java Profilers
• DDMS
– Quite capable method level profiler
– Good enough for 99% of use cases
– Works with any Android version
• 4.1+ Profiling tools
– Systrace [13], More powerful, also tracks OS calls
• Needs root and Android 4.1+
– We‘ll check out the graphical parts later

16. DDMS
•
•
•
•
Start app
Navigate to problematic activity, hit
Wait a bit, hit
View profiling data
– Ignore absolute time, only care for relative timings
– Ignore trivial getters/setters, instrumentation messes
with timings

17. DDMS

18. Native Code Profilers
• Android NDK Profiler [14]
– Not an official NDK tool
– Setup a bit involved
• Device specific CPU profilers
– NVIDIA Nsight [15], ...
• Roll your own
– Instrument manually
– Track down hotspots

19. Graphics Profilers
• What do we analyse?
– Overdraw, your biggest enemy
– Draw calls, your second biggest enemy
• Use DDMS/systrace
– Related to memory
• Textures on VRAM (which is usually RAM)
• Bitmaps in RAM

20. Graphics Profilers
• 4.1+ Profiling tools
• GPU Vendor Specific
– NVIDIA [16], Qualcomm [17], Imagination
Technologies [18]
– Outside of scope of this talk

21. Visualize Overdraw [19]

22. Visualize Overdraw
•
•
•
•
•
Normal Color – 0 Overdraw
Blue – 1x Overdraw
Green – 2x Overdraw
Light Red – 3x Overdraw
Dark Red – +4x Overdraw

23. Visualize Overdraw
• Hierarchy View [20]
• Window -> Open Perspective -> Other...

24. Visualize Overdraw

25. Visualize Overdraw
•
•
•
•
•
Tracer for OpenGL [21]
Window -> Open Perspective -> Other ...
Click
Enter package name
Wait

26. Visualize Overdraw

27. Visualize Overdraw

28. Closing Words
• So much to tell, so little time
• See Dalvik Performance Tips [22]
• Read all references
– Your users will thank you for excellent battery life
and buttery smooth UIs

29. FIN
Thanks for Listening
Questions?

30. References
[1] http://www.amazon.com/Beginning-Android-Games-Mario-Zechner/dp/1430246774
[2] http://libgdx.badlogicgames.com/
[3] http://pmt.sourceforge.net/pngcrush/
[4] https://code.google.com/p/svg-android/
[5] http://developer.android.com/tools/help/proguard.html
[6] http://proguard.sourceforge.net/index.html
[7] http://www.saikoa.com/dexguard
[8] http://developer.android.com/google/play/publishing/multiple-apks.html
[9] http://developer.android.com/google/play/expansion-files.html
[10] http://developer.android.com/tools/debugging/ddms.html
[11] http://android-developers.blogspot.co.at/2011/03/memory-analysis-for-android.html

31. References
[12] http://www.eclipse.org/mat/
[13] http://developer.android.com/tools/help/systrace.html
[14] https://code.google.com/p/android-ndk-profiler/
[15] http://www.nvidia.com/object/nsight.html
[16] https://developer.nvidia.com/tegra-profiler
[17] https://developer.qualcomm.com/mobile-development/mobile-technologies/gaming-graphics-optimization-adreno/toolsand-resources
[18] http://www.imgtec.com/powervr/insider/sdkdownloads/
[19] http://www.curious-creature.org/2012/12/01/android-performance-case-study/
[20] http://developer.android.com/tools/debugging/debugging-ui.html
[21] http://developer.android.com/tools/help/gltracer.html
[22] http://developer.android.com/training/articles/perf-tips.html