golang

golang - mem 使用量

./memLimit 0.35 （限制使用率35%，使用0.35 作为参数）

• memLimit

`
package main

import (
"fmt"
"io"
"io/ioutil"
"log"
"math"
"os"
"os/exec"
"runtime"
"runtime/debug"
"strconv"
"strings"
// "syscall"
"time"
)

func main() {

//	limitPer := 0.9
limitPer, _ := strconv.ParseFloat(os.Args[1], 64)
if limitPer <= 0 {
	os.Exit(1)
}
_, total := getMEMSample()
var chArr []chan bool = make([]chan bool, int(math.Floor(float64(total)/512)))
var fileNameArr []string = make([]string, int(math.Floor(float64(total)/512)))
for i := 0; i < int(math.Floor(float64(total)/512)); i++ {
	chArr[i] = make(chan bool)
	fileNameArr[i] = "fileName"
}
err := os.Mkdir("./memCmd", 0755)
if err != nil {
	fmt.Println("create memCmd file  error")
}
defer killAllFile(fileNameArr)
tag := 0

for {
	free, total := getMEMSample()

	memUsage, _ := strconv.ParseFloat(fmt.Sprintf("%.3f", float64(total-free)/float64(total)), 64)
	//fmt.Println(free/1024, total/1024)
	fmt.Println("memUsage: ", memUsage)

	if tag > 0 && memUsage > limitPer {
		//fmt.Println("tag---: ", tag)
		chArr[tag-1] <- true
		fileNameArr[tag-1] = "fileName"
		tag -= 1
	} else if memUsage < limitPer {
		//fmt.Println("tag++++: ", tag)

		newFileName := "./memCmd/" + strconv.FormatInt(time.Now().Unix(), 10)
		CopyFile("./mem-base", newFileName)
		fileNameArr[tag] = newFileName
		go RunSomething(chArr[tag], newFileName)
		tag += 1
	}
	time.Sleep(time.Duration(10) * time.Second)
	fmt.Println("now thread: ", tag)
	runtime.GC()
	debug.FreeOSMemory()
}

}

func RunSomething(endTag chan bool, cmdFileName string) {
cmd := exec.Command(cmdFileName)
// fmt.Println("cmdFileName: ", cmdFileName)
// defer cmd.Process.Kill()
err := cmd.Start()
fmt.Println("PID: ", cmd.Process.Pid)
if err != nil {
fmt.Println(err)
}
for {
select {
case ag := <-endTag:
fmt.Println(ag)
goto end
default:
time.Sleep(time.Duration(1) * time.Second)
}
}
end:
cmd.Process.Kill()
cmd.Wait()
// cmd.Process.Signal(syscall.SIGINT)
err = os.Remove(cmdFileName)
if err != nil {
fmt.Println("删除", cmdFileName, "失败: ", err)
}
}

func killAllFile(fileNameArr []string) {
for _, v := range fileNameArr {
fmt.Println("fileName: ", v)
if v != "fileName" {
os.Remove(v)
}
time.Sleep(time.Duration(1) * time.Second)
}

}

func getMEMSample() (free, total uint64) {
contents, err := ioutil.ReadFile("/proc/meminfo")
if err != nil {
return
}
lines := strings.Split(string(contents), " ")
for _, line := range lines {
fields := strings.Fields(line)
if len(fields) > 0 && fields[0] == "MemFree:" {
free, err = strconv.ParseUint(fields[1], 10, 64)
if err != nil {
fmt.Println("Error: ", 1, fields[1], err)
}
} else if len(fields) > 0 && fields[0] == "MemTotal:" {
total, err = strconv.ParseUint(fields[1], 10, 64)
if err != nil {
fmt.Println("Error: ", 1, fields[1], err)
}

	}
}
return

}

func CopyFile(srcFileName string, dstFileName string) {
//打开源文件
srcFile, err := os.Open(srcFileName)
if err != nil {
log.Fatalf("源文件读取失败,原因是:%v ", err)
}
defer func() {
err = srcFile.Close()
if err != nil {
log.Fatalf("源文件关闭失败,原因是:%v ", err)
}
}()

//创建目标文件,稍后会向这个目标文件写入拷贝内容
distFile, err := os.Create(dstFileName)
os.Chmod(distFile.Name(), 0755)
if err != nil {
	log.Fatalf("目标文件创建失败,原因是:%v
", err)
}
defer func() {
	err = distFile.Close()
	if err != nil {
		log.Fatalf("目标文件关闭失败,原因是:%v
", err)
	}
}()
//定义指定长度的字节切片,每次最多读取指定长度
var tmp = make([]byte, 1024*4)
//循环读取并写入
for {
	n, err := srcFile.Read(tmp)
	n, _ = distFile.Write(tmp[:n])
	if err != nil {
		if err == io.EOF { //读到了文件末尾,并且写入完毕,任务完成返回(关闭文件的操作由defer来完成)
			return
		} else {
			log.Fatalf("拷贝过程中发生错误,错误原因为:%v
", err)
		}
	}
}

}

`

• mem-base

`
package main

import (
"math/rand"
"time"
)

func main() {
tmpChan := make(chan int, 50010241024)
defer close(tmpChan)
for i := 0; i < 50010241024-10; i++ {
tmpChan <- rand.Intn(10)
}

for {
	time.Sleep(time.Duration(1) * time.Second)
}

}

`