open-nomad/vendor/github.com/shirou/gopsutil/cpu/cpu_unix.go
2016-02-12 10:02:16 -08:00

60 lines
1.2 KiB
Go

// +build linux freebsd darwin
package cpu
import (
"fmt"
"time"
)
func CPUPercent(interval time.Duration, percpu bool) ([]float64, error) {
getAllBusy := func(t CPUTimesStat) (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 CPUTimesStat) 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 := CPUTimes(percpu)
if err != nil {
return nil, err
}
if interval > 0 {
time.Sleep(interval)
}
// And at the end of the interval.
cpuTimes2, err := CPUTimes(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
}