basic functions

Signed-off-by: FingerLeader <[email protected]>

Author: FingerLeader

main.go

@@ -0,0 +1,53 @@
+package main
+
+import (
+	"flag"
+	"fmt"
+	"os"
+	"runtime"
+	"strconv"
+	"syscall"
+	"time"
+)
+
+var (
+	memSize string
+)
+
+func bToMb(b uint64) uint64 {
+	return b / 1024 / 1024
+}
+
+func PrintMemUsage() {
+	var m runtime.MemStats
+	runtime.ReadMemStats(&m)
+	fmt.Printf("Alloc = %v MiB", bToMb(m.Alloc))
+	fmt.Printf("\tTotalAlloc = %v MiB", bToMb(m.TotalAlloc))
+	fmt.Printf("\tSys = %v MiB", bToMb(m.Sys))
+	fmt.Printf("\tNumGC = %v\n", m.NumGC)
+}
+
+func init() {
+	flag.StringVar(&memSize, "size", "0KB", "")
+	flag.Parse()
+}
+
+func main() {
+	length, err := strconv.Atoi(memSize)
+	if err != nil {
+		// TODO
+		print(err)
+	}
+
+	data, err := syscall.Mmap(-1, 0, length*1024*1024*1024, syscall.PROT_READ|syscall.PROT_WRITE, syscall.MAP_PRIVATE|syscall.MAP_ANONYMOUS)
+	if err != nil {
+		// TODO
+		print(err)
+	}
+	for i := 0; i < len(data); i += os.Getpagesize() {
+		data[i] = 1
+	}	
+	for {
+		time.Sleep(time.Second * 2)
+	}
+}