if (get_iface()) {
const auto& piface = static_cast<const s4u::Comm&>(*get_iface());
set_iface(nullptr); // reset iface to protect against multiple trigger of the on_completion signals
if (get_iface()) {
const auto& piface = static_cast<const s4u::Comm&>(*get_iface());
set_iface(nullptr); // reset iface to protect against multiple trigger of the on_completion signals