fix int64 to float64 overflow

README.md

@@ -9,13 +9,38 @@ a golang performence testing platform
 
 ## demo client
 ```go
-	perfm := perfm.New(perfm.WithBinsNumber(15), perfm.WithParallel(5), perfm.WithDuration(10))
-	j := &job{}
-	j.url = "http://www.baidu.com"
-	perfm.Regist(j)
+type job struct {
+	// job private data
+	url string
+}
 
-	perfm.Start()
-	perfm.Wait()
+// Copy will called in parallel
+func (j *job) Copy() perfm.Job {
+	jc := *j
+	return &jc
+}
+
+func (j *job) Pre() {
+	// do pre job
+}
+func (j *job) Do() error {
+	// do benchmark job
+	_, err := http.Get(j.url)
+	return err
+}
+func (j *job) After() {
+	// do clean job
+}
+
+// start perfm
+
+perfm := perfm.New(perfm.WithBinsNumber(15), perfm.WithParallel(5), perfm.WithDuration(10))
+j := &job{}
+j.url = "http://www.baidu.com"
+perfm.Regist(j)
+
+perfm.Start()
+perfm.Wait()
 
 ```
 ![test demo](./demo/screen.png)

demo/main.go

@@ -7,7 +7,7 @@ import (
 )
 
 type job struct {
-	// job data here
+	// job private data
 	url string
 }
 

perfm.go

@@ -197,10 +197,10 @@ func (p *perfmonitor) Start() {
 // Wait for the benchmark task done and caculate the result
 func (p *perfmonitor) Wait() {
 	p.wg.Wait()
-	var sum2, i, d, max, min int64
+	var sum2, i, d, max, min float64
 	min = 0x7fffffffffffffff
-	for i = 0; i < p.Total; i++ {
-		d = <-p.buffer
+	for i = 0; int64(i) < p.Total; i++ {
+		d = float64(<-p.buffer)
 		p.histogram.Add(float64(d))
 		p.Sum += float64(d)
 		sum2 += d * d