func getDragonFlyCPUTimes() ([]float64, error) {
	// We want time spent per-cpu per CPUSTATE.
	// CPUSTATES (number of CPUSTATES) is defined as 5U.
	// States: CP_USER | CP_NICE | CP_SYS | CP_IDLE | CP_INTR
	//
	// Each value is a counter incremented at frequency
	//   kern.cputimer.freq
	//
	// Look into sys/kern/kern_clock.c for details.

	var (
		cpuTimesC      *C.uint64_t
		cpuTimerFreq   C.long
		cpuTimesLength C.size_t
	)

	if C.getCPUTimes(&cpuTimesC, &cpuTimesLength, &cpuTimerFreq) == -1 {
		return nil, errors.New("could not retrieve CPU times")
	}
	defer C.free(unsafe.Pointer(cpuTimesC))

	cput := (*[maxCPUTimesLen]C.uint64_t)(unsafe.Pointer(cpuTimesC))[:cpuTimesLength:cpuTimesLength]

	cpuTimes := make([]float64, cpuTimesLength)
	for i, value := range cput {
		cpuTimes[i] = float64(value) / float64(cpuTimerFreq)
	}
	return cpuTimes, nil
}
// Expose CPU stats using sysctl.
func (c *statCollector) Update(ch chan<- prometheus.Metric) (err error) {

	// We want time spent per-cpu per CPUSTATE.
	// CPUSTATES (number of CPUSTATES) is defined as 5U.
	// Order: CP_USER | CP_NICE | CP_SYS | CP_IDLE | CP_INTR
	// sysctl kern.cp_times provides hw.ncpu * CPUSTATES long integers:
	//   hw.ncpu * (space-separated list of the above variables)
	//
	// Each value is a counter incremented at frequency
	//   kern.clockrate.(stathz | hz)
	//
	// Look into sys/kern/kern_clock.c for details.

	var ncpu C.int
	var cpuTimesC *C.double
	var cpuTimesLength C.size_t
	if C.getCPUTimes(&ncpu, &cpuTimesC, &cpuTimesLength) == -1 {
		return errors.New("could not retrieve CPU times")
	}
	defer C.freeCPUTimes(cpuTimesC)
	if cpuTimesLength > maxCPUTimesLen {
		return errors.New("more CPU's than MAXCPU?")
	}

	// Convert C.double array to Go array (https://github.com/golang/go/wiki/cgo#turning-c-arrays-into-go-slices).
	cpuTimes := (*[maxCPUTimesLen]C.double)(unsafe.Pointer(cpuTimesC))[:cpuTimesLength:cpuTimesLength]

	for cpu := 0; cpu < int(ncpu); cpu++ {
		base_idx := C.CPUSTATES * cpu
		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(cpu), "mode": "user"}).Set(float64(cpuTimes[base_idx+C.CP_USER]))
		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(cpu), "mode": "nice"}).Set(float64(cpuTimes[base_idx+C.CP_NICE]))
		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(cpu), "mode": "system"}).Set(float64(cpuTimes[base_idx+C.CP_SYS]))
		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(cpu), "mode": "interrupt"}).Set(float64(cpuTimes[base_idx+C.CP_INTR]))
		c.cpu.With(prometheus.Labels{"cpu": strconv.Itoa(cpu), "mode": "idle"}).Set(float64(cpuTimes[base_idx+C.CP_IDLE]))
	}

	c.cpu.Collect(ch)
	return err
}