Fix errors when compiling Argos with the latest Cython #494
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| # Color expression namespace | ||
| EXPR_NAMESPACE = {'re':re, 'colorsys':colorsys, 'math':math, 'extract':extract_value} | ||
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Just needed to move this after extract_value was defined - I have no idea why this ever worked to begin with.
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That was my temporal fix as well!
| def setFontFromDC(self, dc): | ||
| self.c_font = getFont(dc.GetFont())[0] | ||
| py_font = dc.GetFont() | ||
| self.c_font = getFont(py_font)[0] | ||
| self.c_bold_font = wxFont(self.c_font) |
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Quick explainer of what's happening here:
dc.GetFont()returns a Pythonwx.Fontobject- We call
getFontto unwrap it and grab a pointer to the C++wxFontobject underneath it - We dereference that pointer and store a copy of the object in this class
The latest version of Cython decided it was a good idea to garbage collect the Python object returned from dc.GetFont() right before it dereferences the C++ pointer and tries to copy the C++ object, which means we end up trying to make a copy of a freed object and we get a segfault.
By storing the result of dc.GetFont() in a temporary variable, we can ensure it lives long enough for the copy to succeed.
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Wow that’s Python internals 🐍
The latest version of Cython decided it was a good idea to garbage collect the Python object returned from dc.GetFont() right before it dereferences the C++ pointer
Dunno why it’s a good idea ... isn’t that usual to collect dynamic object at the end of the function? From what you describe, it’s immdiately collected right after dc.GetFont() ...
klingaard
added
the
component: pipeViewer
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@bdutro @klingaard Just verified it, It works pretty fine!!! Thank you!!! |
Fixes
NameError: name 'extract_value' is not definederror and a segfault when trying to start Argos.Fixes #465, #490, #492