UNMAP_NOTIFY_SEND_EVENT
if (notify->action & UNMAP_NOTIFY_SEND_EVENT) {
if (source->action & UNMAP_NOTIFY_SEND_EVENT)
if (destination->action & UNMAP_NOTIFY_SEND_EVENT)
if (arg->action & ~(UNMAP_NOTIFY_CLEAR_BYTE|UNMAP_NOTIFY_SEND_EVENT))