kubernetes/vendor/github.com/coreos/go-systemd/v22/daemon/watchdog.go

// SdWatchdogEnabled returns watchdog information for a service.
// Processes should call daemon.SdNotify(false, daemon.SdNotifyWatchdog) every
// time / 2.
// If `unsetEnvironment` is true, the environment variables `WATCHDOG_USEC` and
// `WATCHDOG_PID` will be unconditionally unset.
//
// It returns one of the following:
// (0, nil) - watchdog isn't enabled or we aren't the watched PID.
// (0, err) - an error happened (e.g. error converting time).
// (time, nil) - watchdog is enabled and we can send ping.  time is delay
// before inactive service will be killed.
func SdWatchdogEnabled(unsetEnvironment bool) (time.Duration, error) { … }