How can I correctly free a pointer in unmanaged memory from managed code?

[ankofl]

Is this example correct?

extern "C" {
    __declspec(dllexport) void extern_solid_release(void* ptr) {
        if (ptr) { // Проверяем, что указатель не нулевой
            Mesh* mesh = reinterpret_cast<Mesh*>(ptr);
            delete mesh;
            mesh = nullptr; // Обнуляем указатель после удаления
        }
    }
}

  [DllImport(CallerCGAL.pathDll, CallingConvention = CallingConvention.Cdecl)]
  private static extern void extern_solid_release(IntPtr ptr);

[lrineau]

Hi @ankofl. That is difficult to understand why that is related to CGAL. I see the word CallerCGAL in your code, but I do not know what it is.

Actually, I do not even know which language you are programming into. I doubt anybody here can help you. Maybe ask on StackOverflow?

[ankofl]

I apologize for the ambiguity

I write in C# NET.9 and I call C++ libraries compiled using header libraries via DllImport .h-files of CGAL. I am interested in the question: when I created a Mesh object (Polyhedron_3) in C++ code and sent a pointer to this object to C# code, how would it be correct to free memory from C# inside the unmanaged C++ code in which the Mesh object was created?

I tried to do it via:

delete mesh;
mesh = null ptr;

But I am not sure that this will be correct.

Maybe Polyhedron_3 and Surface_Mesh objects have specialized methods to free up the memory they occupy?

Thanks!

[lrineau]

When you call delete that way, the destructor method of the pointed object is called, and the the memory freed. That should be fine.

[ankofl]

Thank you very much!