This is a part of an online Codename One course published around 2017 see it all for free at https://debugagent.com/series/cn1

1. Performance & Memory Tuning - Part I

2. How This Module Is Structured
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✦Performance Tips

3. How This Module Is Structured
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✦Performance Tips
✦Root causes (profiling)

4. How This Module Is Structured
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✦Performance Tips
✦Root causes (profiling)
✦Real World Example

5. What is Performance?
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6. What is Performance?
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✦Rendering Performance
✦Logic Performance
✦Memory Thrashing & Crashes
✦Perceived Performance
✦Pareto distribution

7. Rendering Performance
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✦Framerate

8. Rendering Performance
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✦Framerate
✦Feels less smooth

9. Rendering Performance
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✦Framerate
✦Feels less smooth
✦Animations & scrolling feel jumpy

10. Rendering Performance
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✦Framerate
✦Feels less smooth
✦Animations & scrolling feel jumpy
✦Small issues

11. Rendering Performance
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✦Framerate
✦Feels less smooth
✦Animations & scrolling feel jumpy
✦Small issues
✦Need to render a frame within 16 milliseconds for 60fps

12. Logic Performance
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✦More common than rendering performance

13. Logic Performance
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✦More common than rendering performance
✦CPU Starvation

14. Logic Performance
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✦More common than rendering performance
✦CPU Starvation
✦Causes delay/bounce - not uniform impact

15. Logic Performance
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✦More common than rendering performance
✦CPU Starvation
✦Causes delay/bounce - not uniform impact
✦Use caching/threading effectively to solve

16. Memory Thrashing & Crashes
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✦GC Thrashing - rapid alloc/discard

17. Memory Thrashing & Crashes
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✦GC Thrashing - rapid alloc/discard
✦Cache clearance

18. Perceived Performance
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✦Experiment:

19. Perceived Performance
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✦Experiment:
✓ Show a button after 1 second delay with no indication

20. Perceived Performance
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✦Experiment:
✓ Show a button after 1 second delay with no indication
✓ Do the same with 2 seconds delay but write
“Loading…” on the button after the tap

21. Perceived Performance
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✦Experiment:
✓ Show a button after 1 second delay with no indication
✓ Do the same with 2 seconds delay but write
“Loading…” on the button after the tap
✦The second version feels more responsive

22. Perceived Performance
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✦Experiment:
✓ Show a button after 1 second delay with no indication
✓ Do the same with 2 seconds delay but write
“Loading…” on the button after the tap
✦The second version feels more responsive
✦Try to avoid InfiniteProgress, try to show cached data
and update in the background

23. Perceived Performance
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✦Experiment:
✓ Show a button after 1 second delay with no indication
✓ Do the same with 2 seconds delay but write
“Loading…” on the button after the tap
✦The second version feels more responsive
✦Try to avoid InfiniteProgress, try to show cached data
and update in the background
✦This is probably the most common reason for end user
performance complaints!

24. Pareto Distribution: the 80-20 Rule
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25. Pareto Distribution: the 80-20 Rule
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The real problem is that programmers have
spent far too much time worrying about
efficiency in the wrong places and at the wrong
times; premature optimization is the root of all
evil (or at least most of it) in programming

26. Pareto Distribution: the 80-20 Rule
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The real problem is that programmers have
spent far too much time worrying about
efficiency in the wrong places and at the wrong
times; premature optimization is the root of all
evil (or at least most of it) in programming

27. Pareto Distribution: the 80-20 Rule
© Codename One 2017 all rights reserved
The real problem is that programmers have
spent far too much time worrying about
efficiency in the wrong places and at the wrong
times; premature optimization is the root of all
evil (or at least most of it) in programming
Donald Knuth

28. Pareto Distribution: the 80-20 Rule
© Codename One 2017 all rights reserved
The real problem is that programmers have
spent far too much time worrying about
efficiency in the wrong places and at the wrong
times; premature optimization is the root of all
evil (or at least most of it) in programming
Donald Knuth
“

29. Pareto Distribution: the 80-20 Rule
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✦When you spend time optimizing at an early stage you
will have an unmaintainable app

30. Pareto Distribution: the 80-20 Rule
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✦When you spend time optimizing at an early stage you
will have an unmaintainable app
✦Caching is key

31. Pareto Distribution: the 80-20 Rule
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✦When you spend time optimizing at an early stage you
will have an unmaintainable app
✦Caching is key
✦In my experience performance is more of a 98% - 2%
rule