Function starpu_data_pack_node 

pub unsafe extern "C" fn starpu_data_pack_node(
    handle: starpu_data_handle_t,
    node: c_uint,
    ptr: *mut *mut c_void,
    count: *mut starpu_ssize_t,
) -> c_int

Execute the packing operation of the interface of the data registered at \p handle (see starpu_data_interface_ops). This packing operation must allocate a buffer large enough at \p ptr on node \p node and copy into the newly allocated buffer the data associated to \p handle. \p count will be set to the size of the allocated buffer. If \p ptr is NULL, the function should not copy the data in the buffer but just set \p count to the size of the buffer which would have been allocated. The special value -1 indicates the size is yet unknown. See \ref DataHandlesHelpers for more details.