[Caml] Call caml_to_c
[C] Enter caml_to_c
[C] Call c_to_caml
[Caml] Enter c_to_caml
0
ok
[Caml] Leave c_to_caml
[C] Return from c_to_caml
[C] Leave caml_to_c
[Caml] Return from caml_to_c