The document discusses memory management for Android apps. It covers heap size limits which have increased over time from 16MB to 64MB on newer devices. It also discusses garbage collection, noting that earlier versions had stop-the-world pauses over 100ms while newer versions since Gingerbread are concurrent with pauses under 5ms. Bitmap management is also covered, explaining how bitmaps were freed via recycle() before Android 2.3, resulting in full garbage collections, whereas newer versions free bitmaps synchronously during concurrent garbage collection.

1. 
Memory Management
For Android Apps

2. Who am I ?
Faculty at Aiti-Aptech
Android leader at Zoo Studio

3. What will I share today ?
 Heap size
 Garbage Collection
 Bitmap management

4. 290 MB
2GB

6. Heap size
 Heap size Limits.
G1 : 16MB
Nexus One : 32MB
Galaxy S3 : 64MB

8. Heap size
 Honeycomb (3.0) support option :
 “largetHeap”
 ActivityManager.getLargeMemoryClass()

9. Garbage Collection

10. Garbage Collection
 Bigger heaps = longer pauses
 Pre- Gingerbread
 Stop all application
 Pause time > 100ms
 Gingerbread and beyond
 Concurrent
 Pause times < 5ms

11. Bitmap
 Pre Android 2.3
 Freed via recycle()
 Full, Stop the world GCs

12. Bitmap
 > Android 2.3
 Freed synchronously by GC
 Concurrent & partial GCs

13. GC_FOR_ALLOC freed <1K, 5% free 4961K/5176K,
paused 13ms, total 13ms
GC_CONCURRENT freed 0K, 5% free 4961K/5176K,
paused 8ms+0ms, total 10ms
GC_FOR_ALLOC freed 2418K, 45% free
3192K/5788K, paused 1ms, total 1ms

14. References
 http://android-developers.blogspot.com/2011/03/memory-
analysis-for-android.html.
 http://kohlerm.blogspot.com/2009/02/memory-leaks-are-
easy-to-find.html
 http://developer.android.com/training/displaying-
bitmaps/manage-memory.html

15. Thank you !!!
 Email : vietbq@moneylover.me