some bug fixes

pkg/core/helper.go

@@ -3,6 +3,7 @@
 package core
 
 import (
+	"sync"
 	"time"
 )
 
@@ -10,6 +11,13 @@ const (
 	fileFmt = "20060102_150405"
 )
 
+var m sync.Mutex
+
 func FileName() string {
+	m.Lock()
+	defer func() {
+		time.Sleep(time.Millisecond * 1100)
+		m.Unlock()
+	}()
 	return time.Now().Format(fileFmt)
 }