Performance analysis of a LibGDX game on Android devices and possible solution against memory leaks.

1. Memory Leak Analysis
in
Android Games
Heghine Hakobyan
Software Engineer

2. Why we need memory analysis?
● Low FPS
● Frequent Freezes
● Out of Memories

3. Why we need memory analysis?
Improved Performance
Happy Users
No Memory Leaks

4. Problems to Consider
● A lot of consequent GC calls
- because of temporary allocations
● Not enough memory
- for permanent objects

5. Garbage Collector
GC_CONCURENT freed 24K, 18% free 1572K/19207K, paused 1ms+4ms

6. How GC works?
exampleA
exampleB
......
exampleA is dominator of exampleB

7. Dominator Tree in GC
exampleA
exampleB
......
r
...
a
...
......

8. Dominator Tree in GC
exampleA
exampleB
......
r
...
a
...
......

9. Allocation Tracker
Shows where and what type of objects are being
allocated at current time

10. Going Deeper: Heap Dump
Gives huge amount of statistical information
about your game’s current heap state
Use it with
Eclipse Memory Analyzer (MAT)

11. Heap Dump Components
Dominator
Tree
Histogram
View
Heap Dump

12. Heap Dump Example

13. Example Game

14. Obstacle
Target
Soldiers
Vikings Battle

15. The Problem
● A lot of soldiers (~300)
● Moving from start position to target
● Using A* path finding algorithm
Low Performance

16. Soldier Statistics
Type Bowman
Shallow Heap 312 b
Retained
Heap
~22 kb
Animation
Component
Retained Heap
~20 kb

17. Solution: Object Pooling
Bowman b = getSoldierFromPool();
b.initialize();
Use object
as you need
b.reset();
Heap

18. Thank You!!!
Remember!
Memory Analysis are
IMPORTANT!
Questions?