| // +build linux freebsd darwin |
| |
| package cpu |
| |
| import ( |
| "fmt" |
| "time" |
| ) |
| |
| func Percent(interval time.Duration, percpu bool) ([]float64, error) { |
| getAllBusy := func(t TimesStat) (float64, float64) { |
| busy := t.User + t.System + t.Nice + t.Iowait + t.Irq + |
| t.Softirq + t.Steal + t.Guest + t.GuestNice + t.Stolen |
| return busy + t.Idle, busy |
| } |
| |
| calculate := func(t1, t2 TimesStat) float64 { |
| t1All, t1Busy := getAllBusy(t1) |
| t2All, t2Busy := getAllBusy(t2) |
| |
| if t2Busy <= t1Busy { |
| return 0 |
| } |
| if t2All <= t1All { |
| return 1 |
| } |
| return (t2Busy - t1Busy) / (t2All - t1All) * 100 |
| } |
| |
| // Get CPU usage at the start of the interval. |
| cpuTimes1, err := Times(percpu) |
| if err != nil { |
| return nil, err |
| } |
| |
| if interval > 0 { |
| time.Sleep(interval) |
| } |
| |
| // And at the end of the interval. |
| cpuTimes2, err := Times(percpu) |
| if err != nil { |
| return nil, err |
| } |
| |
| // Make sure the CPU measurements have the same length. |
| if len(cpuTimes1) != len(cpuTimes2) { |
| return nil, fmt.Errorf( |
| "received two CPU counts: %d != %d", |
| len(cpuTimes1), len(cpuTimes2), |
| ) |
| } |
| |
| ret := make([]float64, len(cpuTimes1)) |
| for i, t := range cpuTimes2 { |
| ret[i] = calculate(cpuTimes1[i], t) |
| } |
| return ret, nil |
| } |