func cpuUsageOf(pid int, waitHandler func()) float32 {
// as explained in http://goo.gl/fjrV16
stat1 := procfs.StatOf(pid)
utime1 := stat1.UTime
stime1 := stat1.STime
cputime1 := procfs.CpuTimeTotal()
waitHandler()
stat2 := procfs.StatOf(pid)
utime2 := stat2.UTime
stime2 := stat2.STime
cputime2 := procfs.CpuTimeTotal()
return float32(cpuCount()*((utime2+stime2)-(utime1+stime1))*100) / float32(cputime2-cputime1)
}
func propertiesOf(pid int, keys []Property) PropertyMap {
result := make(PropertyMap)
stat := procfs.StatOf(pid)
for _, key := range keys {
switch key {
case VmUsage:
result[VmUsage] = stat.VSize
case CpuUsage:
result[CpuUsage] = cpuUsageOf(pid, func() { time.Sleep(time.Second) })
}
}
return result
}
func nameOf(pid int) string {
return procfs.StatOf(pid).Name
}