The document discusses memory management in Android, highlighting issues like OutOfMemoryError, memory leaks, and user experience lags due to inadequate memory handling. It details concepts of garbage collection, heap structures, and tools available for monitoring memory usage such as Android Studio Memory Monitor and Eclipse Memory Analyzer. Recommendations for avoiding common pitfalls include avoiding static references, inner classes, and improper context handling.

1. Memory Management
in Android
Hirbod Kamalinia
Keyhan Asghari

2. Why?
• OutOfMemoryError
• Bad user experiences
• Lags
• ...

3. Memory Structure

4. Memory Structure

5. Memory Handling
• C++, manual handling
• Java, Garbage Collection
• Android, Improved GC

6. Garbage Collection
GC Roots

7. Garbage Collection
GC Roots

8. Garbage Collection
GC Roots

9. Garbage Collection
GC Roots

10. Garbage Collection
GC Roots

11. Everything OK?
NO!

12. Remaining Problems?
• Memory Churn
• Memory Leak

13. Memory Leak
GC Roots

14. Memory Leak
GC Roots

15. How?
• Concepts
• Useful Tools

16. Objects in Heap
• Shallow Heap
• Retained Heap

17. Shallow heap & Retained heap

18. Shallow heap & Retained heap
100
100
100
100

19. Shallow heap & Retained heap
100
100
100
100

20. Shallow heap & Retained heap
100
100
100
100
Retained = 100

21. Shallow heap & Retained heap
100
100
100
100

22. Shallow heap & Retained heap
100
100
100
100
Retained = 100

23. Shallow heap & Retained heap
100
100
100
100

24. Shallow heap & Retained heap
100
100
100
100

25. Shallow heap & Retained heap
100
100
100
100
Retained = 100 + 100

26. Shallow heap & Retained heap
100
100
100
100
Retained = 200

27. Shallow heap & Retained heap
100
100
100
100

28. Shallow heap & Retained heap
100
100
100
100
Retained = 100
+ 100
+ 100
+ 100

29. Shallow heap & Retained heap
100
100
100
100
Retained = 400

30. Dominator Tree
How to find these relations?

31. Dominator Tree
A
C
B
E
D
Dominator: closest object on every path to node
A
B DC
E

32. Useful Tools
• Android Studio Memory Monitor
• DDMS Heap tools and Allocation Tracker
• Eclipse Memory Analyzer (MAT)
• ...

33. Android Studio
Memory Monitor

34. Android Studio
Memory Monitor
Free and Allocated Memory

35. Android Studio
Memory Monitor
GC Executions

36. Android Studio
Memory Monitor
Memory Allocation Level Changed
Memory Allocation Level Changed

37. Android Studio
Memory Monitor
Call GC Explicitly

38. Android DDMS

39. Android DDMS
Useful Tools!

40. Android DDMS
Call GC Explicitly

41. Android DDMS
Dump Java Heap

42. Eclipse Memory Analyzer
(MAT)
DEMO...

43. What NOT to do?
• Static References
• Inner Classes
• Reference to Context
• Adapters
• ....

44. Memory matters!
Thanks for your interest...

45. Useful links
• http://goo.gl/xb57Df
• http://goo.gl/o5O2ON
• http://goo.gl/8BqmCB