fixed #689 potential race condition

.travis.yml

@@ -21,7 +21,7 @@ env:
 
 script:
   - env GO111MODULE=on go vet ./...
-  - env GO111MODULE=on go test ./... -v -race -coverprofile=coverage.txt -covermode=atomic
+  - env GO111MODULE=on go test -v -race ./... -coverprofile=coverage.txt -covermode=atomic
 
 after_success:
   - bash <(curl -s https://codecov.io/bash)

cell.go

@@ -178,8 +178,6 @@ func setCellDuration(value time.Duration) (t string, v string) {
 // SetCellInt provides a function to set int type value of a cell by given
 // worksheet name, cell coordinates and cell value.
 func (f *File) SetCellInt(sheet, axis string, value int) error {
-	f.Lock()
-	defer f.Unlock()
 	xlsx, err := f.workSheetReader(sheet)
 	if err != nil {
 		return err
@@ -201,8 +199,6 @@ func setCellInt(value int) (t string, v string) {
 // SetCellBool provides a function to set bool type value of a cell by given
 // worksheet name, cell name and cell value.
 func (f *File) SetCellBool(sheet, axis string, value bool) error {
-	f.Lock()
-	defer f.Unlock()
 	xlsx, err := f.workSheetReader(sheet)
 	if err != nil {
 		return err
@@ -236,8 +232,6 @@ func setCellBool(value bool) (t string, v string) {
 //    f.SetCellFloat("Sheet1", "A1", float64(x), 2, 32)
 //
 func (f *File) SetCellFloat(sheet, axis string, value float64, prec, bitSize int) error {
-	f.Lock()
-	defer f.Unlock()
 	xlsx, err := f.workSheetReader(sheet)
 	if err != nil {
 		return err
@@ -259,19 +253,15 @@ func setCellFloat(value float64, prec, bitSize int) (t string, v string) {
 // SetCellStr provides a function to set string type value of a cell. Total
 // number of characters that a cell can contain 32767 characters.
 func (f *File) SetCellStr(sheet, axis, value string) error {
-	f.Lock()
 	xlsx, err := f.workSheetReader(sheet)
 	if err != nil {
-		f.Unlock()
 		return err
 	}
 	cellData, col, _, err := f.prepareCell(xlsx, sheet, axis)
 	if err != nil {
-		f.Unlock()
 		return err
 	}
 	cellData.S = f.prepareCellStyle(xlsx, col, cellData.S)
-	f.Unlock()
 	cellData.T, cellData.V = f.setCellString(value)
 	return err
 }
@@ -372,8 +362,6 @@ type FormulaOpts struct {
 // SetCellFormula provides a function to set cell formula by given string and
 // worksheet name.
 func (f *File) SetCellFormula(sheet, axis, formula string, opts ...FormulaOpts) error {
-	f.Lock()
-	defer f.Unlock()
 	xlsx, err := f.workSheetReader(sheet)
 	if err != nil {
 		return err
@@ -698,6 +686,8 @@ func (f *File) SetSheetRow(sheet, axis string, slice interface{}) error {
 
 // getCellInfo does common preparation for all SetCell* methods.
 func (f *File) prepareCell(xlsx *xlsxWorksheet, sheet, cell string) (*xlsxC, int, int, error) {
+	xlsx.Lock()
+	defer xlsx.Unlock()
 	var err error
 	cell, err = f.mergeCellsParser(xlsx, cell)
 	if err != nil {

cell_test.go

@@ -18,6 +18,7 @@ func TestConcurrency(t *testing.T) {
 		wg.Add(1)
 		go func(val int) {
 			f.SetCellValue("Sheet1", fmt.Sprintf("A%d", val), val)
+			f.SetCellValue("Sheet1", fmt.Sprintf("B%d", val), strconv.Itoa(val))
 			f.GetCellValue("Sheet1", fmt.Sprintf("A%d", val))
 			wg.Done()
 		}(i)

excelize.go

@@ -155,6 +155,8 @@ func (f *File) setDefaultTimeStyle(sheet, axis string, format int) error {
 // workSheetReader provides a function to get the pointer to the structure
 // after deserialization by given worksheet name.
 func (f *File) workSheetReader(sheet string) (xlsx *xlsxWorksheet, err error) {
+	f.Lock()
+	defer f.Unlock()
 	var (
 		name string
 		ok   bool