CGAL users discussion list

["Sebastien Loriot (GeometryFactory)" <>]

Hi Tom,

Try patching the file include/CGAL/Polynomial/Polynomial_type.h
as follow.

Sebastien.

@@ -44,6 +44,10 @@
 #include <sstream>
 #include <CGAL/Polynomial/misc.h>

+#ifdef CGAL_HAS_THREADS
+#  include <boost/thread/tss.hpp>
+#endif
+
 namespace CGAL {

 template <class NT> class Polynomial;
@@ -261,8 +265,15 @@
 //
 private:
     static Self& get_default_instance(){
-      static Self x = Self(0);
-      return x;
+      #ifdef CGAL_HAS_THREADS
+        static boost::thread_specific_ptr< Self > safe_x_ptr;
+          if (safe_x_ptr.get() == NULL)
+            safe_x_ptr.reset(new Self(0));
+        return *safe_x_ptr.get();
+      #else
+        static Self x = Self(0);
+        return x;
+      #endif
     }
 public:
     //! \name Constructors




Tom Dreyfus wrote:
> Hello,
>
> I use the Algebraic_kernel_d_1 of CGAL for solving degree 4 equations.
>
> When I use the solver in a *#pragma omp parallel for* directive,  I have 
> a segmentation fault.
> However, I have no issue when there is only one thread.
>
> I attached an example.
>
> Thank you.
>
> Tom.