I'm just guessing, but if a function receives a pointer, it does not store the pointer anywhere but works with the contents, and finally returns while VM is blocked, voil� :).

On Wed, Jul 3, 2013 at 10:13 PM, St�phane Ducasse <stephane.ducasse@inria.fr> wrote:

if you pass a pointer to something in object memory into function,
make sure GC cannot move the object while function uses/accessing its contents.

How?