RMagick, migrate to ImageMagick 7 #RubyKaigi #RubyKaigi2019

Transcript

1. RMagick,
   migrate to ImageMagick 7
   Shizuo Fujita
   

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

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3. What's RMagick
   

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4. "RMagick is an interface between the
   Ruby programming language and the
   ImageMagick image processing
   library."
   

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5. Active members
   ˏmockdeep
   ˏwatson1978 ˏdlemstra
   

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6. My Motivation
   

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

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

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

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10. I want to use Ruby ...
    •Web programming
    
    •iOS programming
    
    •Image processing
    
    •Machine learning, etc
    

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11. I want to use Ruby ...
    •Web programming
    
    •iOS programming
    
    •Image processing
    
    •Machine learning, etc
    To meet crazy
    great people
    at Ruby World
    

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12. Current Status of RMagick
    

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

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15. Set up problems
    

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

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17. macOS (Homebrew)
    

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18. macOS (Homebrew)
    

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19. Windows
    •Ruby has some environments
    
    • MingW
    
    • MSWin
    
    • Cygwin
    
    • Windows Subsystem for Linux
    

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20. Windows
    •Ruby has some environments
    
    • MingW
    
    • MSWin
    
    • Cygwin
    
    • Windows Subsystem for Linux
    

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21. MingW...?
    

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22. Set up : MingW
    

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

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24. MingW works
    

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25. MSWin...?
    

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26. Set up : MSWin
    

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

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

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29. MSWin works well
    

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30. Memory leak
    

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31. Fixed many memory leaks
    55 Closed
    

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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);
    }
    

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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
    

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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
    

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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
    

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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
    

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37. Case 1: Exception causes Memory Leak
    image =
    Magick::Image.read('sample.png').first
    begin
    image.shear('x', 'y')
    rescue
    end
    

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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;
    }
    

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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
    

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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
    

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41. Case 2: Missing destroy lead to
    Memory Leak
    image =
    Magick::Image.read('sample.png').first
    image.gray?
    

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

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43. Case 3: Memory Leak
    by incorrect API usage
    image =
    Magick::Image.read('sample.png').first
    image.sharpen_channel
    

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44. Case 4
    

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45. Case 4 Found
    memory leak in
    ImageMagick
    

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46. Case 4
    

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47. Case 4: Huge software has
    Memory Leak
    

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48. How to detect memory leak
    

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49. Profiler tool
    

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50. Profiler tool
    Memory leak
    detected
    

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51. Profiler tool
    

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

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

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54. SEGV
    

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55. Closed 5 SEGVs
    4 Fixed
    1 Workaround
    

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56. Workaround Case
    Help wanted
    

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57. Workaround Case
    •Call back image processing progress to
    Ruby
    User's
    Ruby code
    RMagick ImageMagick
    Callback
    

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58. ruby_stack_length() shows
    51119378542 = 47 GB
    • Invalid stack length
    • GC running
    →SEGV
    

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59. RMagick is better than ever.
    

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60. Future...
    

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61. ImageMagick 7 support
    

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62. Preparing draft code... now
    

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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
    

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64. Plan 2 : Mix both
    ImageMagick 7
    ImageMagick 7
    ImageMagick 6
    Using many #if defined
    ...
    

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65. Plan 3: Bundle both
    ImageMagick 7
    ImageMagick 6
    

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66. We welcome good ideas for
    the future
    

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67. Announcement
    •RubyData Workshop (Tomorrow, 14:20 ~)
    
    •RubyKaigi 2019 Code Party (Tomorrow, 19:00 ~)
    

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68. Thank you
    

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