minio/pkg/cpu/cpu.go

91 lines
2.2 KiB
Go

/*
* Minio Cloud Storage, (C) 2019 Minio, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package cpu
import (
"fmt"
"sync"
"time"
)
const (
// cpuLoadWindow is the interval of time for which the
// cpu utilization is measured
cpuLoadWindow = 200 * time.Millisecond
// cpuLoadSampleSize is the number of samples measured
// for calculating cpu utilization
cpuLoadSampleSize = 3
// endOfTime represents the end of time
endOfTime = time.Duration(1<<63 - 1)
)
// Load holds CPU utilization % measured in three intervals of 200ms each
type Load struct {
Avg string `json:"avg"`
Max string `json:"max"`
Min string `json:"min"`
Error string `json:"error,omitempty"`
}
type counter struct{}
// GetLoad returns the CPU utilization % of the current process
func GetLoad() Load {
vals := make(chan time.Duration, 3)
wg := sync.WaitGroup{}
for i := 0; i < cpuLoadSampleSize; i++ {
cpuCounter, err := newCounter()
if err != nil {
return Load{
Error: err.Error(),
}
}
wg.Add(1)
go func() {
start := cpuCounter.now()
time.Sleep(cpuLoadWindow)
end := cpuCounter.now()
vals <- end.Sub(start)
wg.Done()
}()
}
wg.Wait()
sum := time.Duration(0)
max := time.Duration(0)
min := (endOfTime)
for i := 0; i < cpuLoadSampleSize; i++ {
val := <-vals
sum = sum + val
if val > max {
max = val
}
if val < min {
min = val
}
}
close(vals)
avg := sum / 3
return Load{
Avg: fmt.Sprintf("%.2f%%", toFixed4(float64(avg)/float64(200*time.Millisecond))*100),
Max: fmt.Sprintf("%.2f%%", toFixed4(float64(max)/float64(200*time.Millisecond))*100),
Min: fmt.Sprintf("%.2f%%", toFixed4(float64(min)/float64(200*time.Millisecond))*100),
Error: "",
}
}