[cpu] Fix #599 cap percent values returned by Percent() between 0 and 100

See https://github.com/shirou/gopsutil/issues/599#issuecomment-491942842 for a repoduction case
2019-06-23 16:14:14 +02:00 · 2019-06-23 16:14:14 +02:00 · 946c9ce6ea
parent 2ac72f1fa1
commit 946c9ce6ea
1 changed files with 2 additions and 1 deletions
--- a/cpu/cpu.go
+++ b/cpu/cpu.go
@ -4,6 +4,7 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
+	"math"
 	"strconv"
 	"strings"
 	"sync"
@ -112,7 +113,7 @@ func calculateBusy(t1, t2 TimesStat) float64 {
 	if t2All <= t1All {
 		return 1
 	}
-	return (t2Busy - t1Busy) / (t2All - t1All) * 100
+	return math.Min(100, math.Max(0, (t2Busy-t1Busy)/(t2All-t1All)*100))
 }

 func calculateAllBusy(t1, t2 []TimesStat) ([]float64, error) {