diff --git a/starlog.go b/starlog.go
index b438183..7e5e2ae 100644
--- a/starlog.go
+++ b/starlog.go
@@ -6,6 +6,7 @@ import (
 	"path/filepath"
 	"runtime"
 	"strconv"
+	"sync"
 	"time"
 
 	"github.com/fatih/color"
@@ -60,11 +61,18 @@ var (
 	ShowLine, ShowLevel, DoWrite, DoShow, switching bool     = true, true, true, true, false
 	loghandle                                       *os.File = nil
 	HandleFunc                                      func([]color.Attribute, string)
+	lock                                            sync.WaitGroup
 )
 
 func write(logs string) {
+	var i int = 0
+	defer lock.Done()
 	for switching {
 		time.Sleep(time.Millisecond * 100)
+		i++
+		if i > 20 {
+			return
+		}
 	}
 	if loghandle == nil {
 		return
@@ -100,6 +108,7 @@ func output(level int, showline, showlv, dowrite, doshow bool, strlog string) {
 		go HandleFunc(Colors[level], logs)
 	}
 	if dowrite {
+		lock.Add(1)
 		go write(logs)
 	}
 }
@@ -284,10 +293,12 @@ func Panicln(str ...interface{}) {
 func SetLogFile(path string) error {
 	var err error
 	loghandle, err = os.Create(path)
+	switching = false
 	return err
 }
 
 func SwitchFile(path string) error {
+	switching = true
 	if loghandle != nil {
 		loghandle.Close()
 	}
@@ -295,6 +306,7 @@ func SwitchFile(path string) error {
 }
 
 func CloseLog() {
+	lock.Wait()
 	if loghandle != nil {
 		loghandle.Close()
 	}