Replace std::lock_guard with std::scoped_lock. When locking a single mutex, both are functionally the same. When locking two mutexes in the operator= overload, the scoped_lock uses a deadlock avoidance algorithm to avoid deadlock. Signed-off-by: Naushir Patuck <naush@raspberrypi.com> Reviewed-by: David Plowman <david.plowman@raspberrypi.com> Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com> Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>