Well, my complete example is in the previous post,
how can I ensure my MemoryPointer don't get garbage collected in a
neat way? (not using some crappy global variable?)

And by the way, what is the most easy way to deallocate some memory
that was allocated by the native code (like code returning a pointer
to a malloc),
should I link the libc free function, or is it already somewhere in
FFI?