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RMagick,
migrate to ImageMagick 7
Shizuo Fujita
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self.inspect
• @watson1978
• Ubiregi, Inc
• Ruby committer
• RMagick maintainer
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What's RMagick
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"RMagick is an interface between the
Ruby programming language and the
ImageMagick image processing
library."
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Active members
ˏmockdeep
ˏwatson1978 ˏdlemstra
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My Motivation
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I want to use Ruby ...
•Web programming
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I want to use Ruby ...
•Web programming
•iOS programming
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I want to use Ruby ...
•Web programming
•iOS programming
•Image processing
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I want to use Ruby ...
•Web programming
•iOS programming
•Image processing
•Machine learning, etc
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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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Current Status of RMagick
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No content
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Fixed major problems
since v2.16.0
•Set up
•Memory leaks
•SEGVs
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Set up problems
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Set up problems
•macOS (Homebrew)
•Windows
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macOS (Homebrew)
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macOS (Homebrew)
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Windows
•Ruby has some environments
• MingW
• MSWin
• Cygwin
• Windows Subsystem for Linux
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Windows
•Ruby has some environments
• MingW
• MSWin
• Cygwin
• Windows Subsystem for Linux
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MingW...?
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Set up : MingW
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Solution
https://github.com/oneclick/rubyinstaller2/wiki/For-gem-developers
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MingW works
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MSWin...?
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Set up : MSWin
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MSWin supported...?
Looks like MSWin
supporting code...
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Not supported...
Why !?
For MSWin
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MSWin works well
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Memory leak
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Fixed many memory leaks
55 Closed
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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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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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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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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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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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Case 1: Exception causes Memory Leak
image =
Magick::Image.read('sample.png').first
begin
image.shear('x', 'y')
rescue
end
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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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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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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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Case 2: Missing destroy lead to
Memory Leak
image =
Magick::Image.read('sample.png').first
image.gray?
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Case 3
Unnecessary clone
API returns NEW image
in allocated memory
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Case 3: Memory Leak
by incorrect API usage
image =
Magick::Image.read('sample.png').first
image.sharpen_channel
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Case 4
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Case 4 Found
memory leak in
ImageMagick
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Case 4
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Case 4: Huge software has
Memory Leak
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How to detect memory leak
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Profiler tool
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Profiler tool
Memory leak
detected
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Profiler tool
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Profiler tool...
•Detects at executed code only
•unit-test
•RSpec
•Needs better coverage...
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Code reading...
•To find same pattern that profiler detects
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SEGV
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Closed 5 SEGVs
4 Fixed
1 Workaround
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Workaround Case
Help wanted
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Workaround Case
•Call back image processing progress to
Ruby
User's
Ruby code
RMagick ImageMagick
Callback
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ruby_stack_length() shows
51119378542 = 47 GB
• Invalid stack length
• GC running
→SEGV
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RMagick is better than ever.
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Future...
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ImageMagick 7 support
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Preparing draft code... now
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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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Plan 2 : Mix both
ImageMagick 7
ImageMagick 7
ImageMagick 6
Using many #if defined
...
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Plan 3: Bundle both
ImageMagick 7
ImageMagick 6
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We welcome good ideas for
the future
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Announcement
•RubyData Workshop (Tomorrow, 14:20 ~)
•RubyKaigi 2019 Code Party (Tomorrow, 19:00 ~)
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Thank you