RMagick, migrate to ImageMagick 7 #RubyKaigi #RubyKaigi2019

Transcript

1. RMagick, migrate to ImageMagick 7 Shizuo Fujita

2. self.inspect • @watson1978 • Ubiregi, Inc • Ruby committer •

   RMagick maintainer

3. What's RMagick

4. "RMagick is an interface between the Ruby programming language and

   the ImageMagick image processing library."

5. Active members ˏmockdeep ˏwatson1978 ˏdlemstra

6. My Motivation

7. I want to use Ruby ... •Web programming

8. I want to use Ruby ... •Web programming •iOS programming

9. I want to use Ruby ... •Web programming •iOS programming

   •Image processing

10. I want to use Ruby ... •Web programming •iOS programming

    •Image processing •Machine learning, etc

11. I want to use Ruby ... •Web programming •iOS programming

    •Image processing •Machine learning, etc To meet crazy great people at Ruby World

12. Current Status of RMagick

13. None

14. Fixed major problems since v2.16.0 •Set up •Memory leaks •SEGVs

15. Set up problems

16. Set up problems •macOS (Homebrew) •Windows

17. macOS (Homebrew)

18. macOS (Homebrew)

19. Windows •Ruby has some environments • MingW • MSWin •

    Cygwin • Windows Subsystem for Linux

20. Windows •Ruby has some environments • MingW • MSWin •

    Cygwin • Windows Subsystem for Linux

21. MingW...?

22. Set up : MingW

23. Solution https://github.com/oneclick/rubyinstaller2/wiki/For-gem-developers

24. MingW works

25. MSWin...?

26. Set up : MSWin

27. MSWin supported...? Looks like MSWin supporting code...

28. Not supported... Why !? For MSWin

29. MSWin works well

30. Memory leak

31. Fixed many memory leaks 55 Closed

32. Case 1 VALUE Image_shear(VALUE self, VALUE x_shear, VALUE y_shear) {

    Image *image, *new_image; ExceptionInfo *exception; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), exception); rm_check_exception(exception, new_image, DestroyOnError); (void) DestroyExceptionInfo(exception); rm_ensure_result(new_image); return rm_image_new(new_image); }

33. VALUE Image_shear(VALUE self, VALUE x_shear, VALUE y_shear) { Image *image,

    *new_image; ExceptionInfo *exception; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), exception); rm_check_exception(exception, new_image, DestroyOnError); (void) DestroyExceptionInfo(exception); rm_ensure_result(new_image); return rm_image_new(new_image); } Case 1 Allocate memory

34. VALUE Image_shear(VALUE self, VALUE x_shear, VALUE y_shear) { Image *image,

    *new_image; ExceptionInfo *exception; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), exception); rm_check_exception(exception, new_image, DestroyOnError); (void) DestroyExceptionInfo(exception); rm_ensure_result(new_image); return rm_image_new(new_image); } Case 1 Allocate memory Destroy memory

35. VALUE Image_shear(VALUE self, VALUE x_shear, VALUE y_shear) { Image *image,

    *new_image; ExceptionInfo *exception; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), exception); rm_check_exception(exception, new_image, DestroyOnError); (void) DestroyExceptionInfo(exception); rm_ensure_result(new_image); return rm_image_new(new_image); } Case 1 Allocate memory Destroy memory Raise exception with unexpected value

36. VALUE Image_shear(VALUE self, VALUE x_shear, VALUE y_shear) { Image *image,

    *new_image; ExceptionInfo *exception; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); new_image = ShearImage(image, NUM2DBL(x_shear), NUM2DBL(y_shear), exception); rm_check_exception(exception, new_image, DestroyOnError); (void) DestroyExceptionInfo(exception); rm_ensure_result(new_image); return rm_image_new(new_image); } Case 1 Allocate memory Destroy memory Raise exception with unexpected value Unreachable by exception

37. Case 1: Exception causes Memory Leak image = Magick::Image.read('sample.png').first begin

    image.shear('x', 'y') rescue end

38. Case 2 static VALUE has_attribute(VALUE self, MagickBooleanType....[snip]) { Image *image;

    ExceptionInfo *exception; MagickBooleanType r; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); r = (attr_test)(image, exception); CHECK_EXCEPTION() return r ? Qtrue : Qfalse; }

39. static VALUE has_attribute(VALUE self, MagickBooleanType....[snip]) { Image *image; ExceptionInfo *exception;

    MagickBooleanType r; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); r = (attr_test)(image, exception); CHECK_EXCEPTION() return r ? Qtrue : Qfalse; } Case 2 Allocate memory

40. static VALUE has_attribute(VALUE self, MagickBooleanType....[snip]) { Image *image; ExceptionInfo *exception;

    MagickBooleanType r; image = rm_check_destroyed(self); exception = AcquireExceptionInfo(); r = (attr_test)(image, exception); CHECK_EXCEPTION() return r ? Qtrue : Qfalse; } Case 2 Allocate memory Missing destroy

41. Case 2: Missing destroy lead to Memory Leak image =

    Magick::Image.read('sample.png').first image.gray?

42. Case 3 Unnecessary clone API returns NEW image in allocated

    memory

43. Case 3: Memory Leak by incorrect API usage image =

    Magick::Image.read('sample.png').first image.sharpen_channel

44. Case 4

45. Case 4 Found memory leak in ImageMagick

46. Case 4

47. Case 4: Huge software has Memory Leak

48. How to detect memory leak

49. Profiler tool

50. Profiler tool Memory leak detected

51. Profiler tool

52. Profiler tool... •Detects at executed code only •unit-test •RSpec •Needs

    better coverage...

53. Code reading... •To find same pattern that profiler detects

54. SEGV

55. Closed 5 SEGVs 4 Fixed 1 Workaround

56. Workaround Case Help wanted

57. Workaround Case •Call back image processing progress to Ruby User's

    Ruby code RMagick ImageMagick Callback

58. ruby_stack_length() shows 51119378542 = 47 GB • Invalid stack length

    • GC running →SEGV

59. RMagick is better than ever.

60. Future...

61. ImageMagick 7 support

62. Preparing draft code... now

63. Plan 1: Split RMagick ver 4.x RMagick ver 3.x ver

    3.0 ver 3.1 ver 2.16.1 ImageMagick 7 ImageMagick 6

64. Plan 2 : Mix both ImageMagick 7 ImageMagick 7 ImageMagick

    6 Using many #if defined ...

65. Plan 3: Bundle both ImageMagick 7 ImageMagick 6

66. We welcome good ideas for the future

67. Announcement •RubyData Workshop (Tomorrow, 14:20 ~) •RubyKaigi 2019 Code Party

    (Tomorrow, 19:00 ~)

68. Thank you