Extracts from "Memory Management for Android Apps"

Slide 1

Slide 1 text

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

Slide 2

Slide 2 text

2 @wuman  David Wu  [email protected]  blog.wu-man.com  #tossug, #h4  HTC

Slide 3

Slide 3 text

3 In 10 Minutes...

Slide 4

Slide 4 text

4 Purpose  Avoid OOM errors

Slide 5

Slide 5 text

5 Breakdown API Changes  Heap size  Garbage collection  Bitmap allocations Understanding heap usage  Memory leaks  Logcat  Memory Analyzer (MAT)

Slide 6

Slide 6 text

6 Heap Size  Heap size limits  G1: 16MB  Droid: 24MB  Nexus One: 32MB  Xoom: 48MB  ActivityManager.getMemoryClass()

Slide 7

Slide 7 text

7 Large Heaps 

Slide 8

Slide 8 text

8 Garbage Collection

Slide 9

Slide 9 text

9 Garbage Collection

Slide 10

Slide 10 text

10 Garbage Collection

Slide 11

Slide 11 text

11 Garbage Collection

Slide 12

Slide 12 text

12 Garbage Collection  < Gingerbread  Stop-the-world  Full heap collection  Pause times often > 100ms  >= Gingerbread  Concurrent (mostly)  Partial collections  Pause times usually < 5ms

Slide 13

Slide 13 text

13 Bitmaps (Old)

Slide 14

Slide 14 text

14 Bitmaps (New)

Slide 15

Slide 15 text

15 Memory Leaks

Slide 16

Slide 16 text

16 Logcat

Slide 17

Slide 17 text

17 Logcat

Slide 18

Slide 18 text

18 Logcat

Slide 19

Slide 19 text

19 Logcat

Slide 20

Slide 20 text

20 Logcat

Slide 21

Slide 21 text

21 Logcat

Slide 22

Slide 22 text

22 Heap Dumps  Create with  DDMS  andorid.os.Debug.dumpHprofData()  Conversion  hprof-conv orig.hprof converted.hprof  Analyze with MAT

Slide 23

Slide 23 text

23 Shallow and Retained Heap

Slide 24

Slide 24 text

24 Dominator Tree

Slide 25

Slide 25 text

25 Demo Debugging a memory leak with MAT

Slide 26

Slide 26 text

26 Demo

Slide 27

Slide 27 text

27 References  Video of the session http://goo.gl/KRrx7  Original slides http://goo.gl/0RqIZ  Patrick Dubroy's blog http://dubroy.com/blog/