CGAL users discussion list

["Laurent Rineau (CGAL/GeometryFactory)" <>]

Le Monday, January 23, 2017 6:34:02 AM CET mistafunk a ?crit :
> hi
> 
> i am seeing an access violation in Handle.h:56. for some reason, the
> returned reference by Lazy::zero() does not seem to be valid. the problem
> is reproducible with cgal 4.9 and apple clang 7.3 (-std=c++14). the 
> stacktrace
> <http://cgal-discuss.949826.n4.nabble.com/file/n4662484/stacktrace.txt>  
> is attached.
> 
> in Lazy::zero(), the macro CGAL_STATIC_THREAD_LOCAL_VARIABLE is used and
> its definition looks like this (tss.h:34, note that apple clang 7.3 does
> not yet support thread_local):
> 
> # define CGAL_STATIC_THREAD_LOCAL_VARIABLE(TYPE, VAR, ARG1) \
> static boost::thread_specific_ptr<TYPE> VAR##_ptr; \
> if(VAR##_ptr.get() == NULL) {VAR##_ptr.reset(new TYPE(ARG1));} \
> TYPE& VAR = * VAR##_ptr.get()
> 
> so i am basically trying to understand how Lazy::zero() can return an
> invalid reference.
> 
> thanks & best,
> simon

How can you tell that it is `Lazy::zero()` that triggers the error? I do not 
see that from the backtrace.

Do you have multiple threads?


It could be that a bad JNI call, or a double-free, or a use-after-free, has 
corrupted the heap or stack. You should try to reproduce the same issue in a 
standalone C++ file, without Java. Doing that, you will probably find out the 
issue by yourself. Otherwise, post your code to an online web service, like 
gist.github.com and show us the code.

-- 
Laurent Rineau, PhD
R&D Engineer at GeometryFactory           http://www.geometryfactory.com/
Release Manager of the CGAL Project       http://www.cgal.org/