Function enif_dynamic_resource_call 

pub unsafe extern "C" fn enif_dynamic_resource_call(
    env: *mut ErlNifEnv,
    module: ERL_NIF_TERM,
    name: ERL_NIF_TERM,
    rsrc: ERL_NIF_TERM,
    call_data: *const c_void,
) -> c_int

See enif_dynamic_resource_call in the Erlang docs.