Extracts from "Memory Management for Android Apps"

Extracts from "Memory Management for Android Apps"

Transcript

1. Extracts from "Memory Management for Android Apps" Taipei GTUG 20110706 Meetup (http://goo.gl/VdfLK) Original Presenter Patrick Dubroy @dubroy Extract Presenter David Wu @wuman blog.wu-man.com
2. 2 @wuman  David Wu  david@wu-man.com  blog.wu-man.com  #tossug, #h4  HTC
3. 3 In 10 Minutes...
4. 4 Purpose  Avoid OOM errors
5. 5 Breakdown API Changes  Heap size  Garbage collection  Bitmap allocations Understanding heap usage  Memory leaks  Logcat  Memory Analyzer (MAT)
6. 6 Heap Size  Heap size limits  G1: 16MB  Droid: 24MB  Nexus One: 32MB  Xoom: 48MB  ActivityManager.getMemoryClass()
7. 7 Large Heaps  <application android:name=”com.example.foobar” andorid:largeHeap=”true” … </application>
8. 8 Garbage Collection
9. 9 Garbage Collection
10. 10 Garbage Collection
11. 11 Garbage Collection
12. 12 Garbage Collection  < Gingerbread  Stop-the-world  Full heap collection  Pause times often > 100ms  >= Gingerbread  Concurrent (mostly)  Partial collections  Pause times usually < 5ms
13. 13 Bitmaps (Old)
14. 14 Bitmaps (New)
15. 15 Memory Leaks
16. 16 Logcat
17. 17 Logcat
18. 18 Logcat
19. 19 Logcat
20. 20 Logcat
21. 21 Logcat
22. 22 Heap Dumps  Create with  DDMS  andorid.os.Debug.dumpHprofData()  Conversion  hprof-conv orig.hprof converted.hprof  Analyze with MAT
23. 23 Shallow and Retained Heap
24. 24 Dominator Tree
25. 25 Demo Debugging a memory leak with MAT
26. 26 Demo
27. 27 References  Video of the session http://goo.gl/KRrx7  Original slides http://goo.gl/0RqIZ  Patrick Dubroy's blog http://dubroy.com/blog/