Description
fatal error: concurrent map read and map write
goroutine 4030 [running]: github.com/gin-gonic/gin/binding.setByForm({0xf41cd0, 0x7703a18, 0x18e}, {{0xf6336c, 0xe}, {0x0, 0x0}, {0x14d4ad4, 0xf41cd0}, {0xf6337b, ...}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:168 +0x34 github.com/gin-gonic/gin/binding.formSource.TrySet(0x7e78080, {0xf41cd0, 0x7703a18, 0x18e}, {{0xf6336c, 0xe}, {0x0, 0x0}, {0x14d4ad4, 0xf41cd0}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:73 +0x68 github.com/gin-gonic/gin/binding.tryToSetValue({0xf41cd0, 0x7703a18, 0x18e}, {{0xf6336c, 0xe}, {0x0, 0x0}, {0x14d4ad4, 0xf41cd0}, {0xf6337b, ...}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:164 +0x200 github.com/gin-gonic/gin/binding.mapping({0xf41cd0, 0x7703a18, 0x18e}, {{0xf6336c, 0xe}, {0x0, 0x0}, {0x14d4ad4, 0xf41cd0}, {0xf6337b, ...}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:106 +0xec github.com/gin-gonic/gin/binding.mapping({0x101f760, 0x77039e0, 0x199}, {{0x0, 0x0}, {0x0, 0x0}, {0x0, 0x0}, {0x0, ...}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:124 +0x46c github.com/gin-gonic/gin/binding.mapping({0xee59d0, 0x77039e0, 0x16}, {{0x0, 0x0}, {0x0, 0x0}, {0x0, 0x0}, {0x0, ...}, ...}, ...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:95 +0x2ec github.com/gin-gonic/gin/binding.mappingByPtr({0xee59d0, 0x77039e0}, {0x14cb214, 0x7e78080}, {0x10886a7, 0x4}) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:77 +0xf8 github.com/gin-gonic/gin/binding.mapFormByTag({0xee59d0, 0x77039e0}, 0x7e78080, {0x10886a7, 0x4}) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:59 +0x238 github.com/gin-gonic/gin/binding.mapForm(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:34 github.com/gin-gonic/gin/binding.formBinding.Bind({}, 0x7a5ea00, {0xee59d0, 0x77039e0}) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/binding/form.go:29 +0xc4 github.com/gin-gonic/gin.(Context).ShouldBindWith(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:741 github.com/gin-gonic/gin.(Context).ShouldBind(0x6c18870, {0xee59d0, 0x77039e0}) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:696 +0x2b4 code.iflytek.com/EBG_WB_Osaka/elstStudentApi/pkg/app.(core).ShouldBind(0x80d79f8, {0xee59d0, 0x77039e0}) D:/go/src/EBG_WB_Osaka/elstStudentApi/pkg/app/response.go:75 +0x74 code.iflytek.com/EBG_WB_Osaka/elstStudentApi/controllers/studentapi.(eikenSpeaking).PostEikenExaminationLog(0x1e0e5d0, 0x6c18870) D:/go/src/EBG_WB_Osaka/elstStudentApi/controllers/studentapi/eiken.go:189 +0x60 github.com/gin-gonic/gin.(Context).Next(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174 code.iflytek.com/EBG_WB_Osaka/elstStudentApi/routers.checkStudentToken.func1(0x6c18870) D:/go/src/EBG_WB_Osaka/elstStudentApi/routers/check_token.go:18 +0x80 github.com/gin-gonic/gin.(Context).Next(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174 code.iflytek.com/EBG_WB_Osaka/elstStudentApi/routers.CorsDomain.func1(0x6c18870) D:/go/src/EBG_WB_Osaka/elstStudentApi/routers/cors_domain.go:19 +0x1b4 github.com/gin-gonic/gin.(Context).Next(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174 github.com/gin-gonic/gin.CustomRecoveryWithWriter.func1(0x6c18870) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/recovery.go:102 +0x94 github.com/gin-gonic/gin.(Context).Next(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174 github.com/gin-gonic/gin.LoggerWithConfig.func1(0x6c18870) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/logger.go:240 +0x9c github.com/gin-gonic/gin.(Context).Next(...) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/context.go:174 github.com/gin-gonic/gin.(Engine).handleHTTPRequest(0x3d10b60, 0x6c18870) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/gin.go:620 +0x554 github.com/gin-gonic/gin.(Engine).ServeHTTP(0x3d10b60, {0x14ce2a4, 0x7e1efa0}, 0x7a5ea00) C:/Users/yangwu11/go/pkg/mod/github.com/gin-gonic/gin@v1.9.1/gin.go:576 +0x1f8 net/http.serverHandler.ServeHTTP({0x46c2280}, {0x14ce2a4, 0x7e1efa0}, 0x7a5ea00) D:/Program Files/Go/src/net/http/server.go:2947 +0x2f0 net/http.(conn).serve(0x63d78c0, {0x14cf058, 0x58a1e90}) D:/Program Files/Go/src/net/http/server.go:1991 +0x654 created by net/http.(*Server).Serve D:/Program Files/Go/src/net/http/server.go:3102 +0x4e0
How to reproduce
1. form bind script:
var form FormEkExaminationLog
if err := c.ShouldBind(&form); err != nil {
g.Error(err.Error())
return
}
2. self define the bind func
func (g *core) ShouldBind(data interface{}) (err error) {
if g.ctx.ContentType() == "application/json" {
return g.ctx.ShouldBindBodyWith(data, binding.JSON)
}
return g.ctx.ShouldBind(data)
}
Expectations
When press test, the fatal error coccur.
Why?
func (c *Context) ShouldBind(obj any) error {
b := binding.Default(c.Request.Method, c.ContentType())
return c.ShouldBindWith(obj, b)
}
the gin built map is not safe concurrent?
Environment
- go version: 1.18
- gin version (or commit ref): 1.9.1
- operating system:
Comment From: zhuzaiye
func setByForm(value reflect.Value, field reflect.StructField, form map[string][]string, tagValue string, opt setOptions) (isSet bool, err error) {
vs, ok := form[tagValue]
if !ok && !opt.isDefaultExists {
return false, nil
}
switch value.Kind() {
case reflect.Slice:
if !ok {
vs = []string{opt.defaultValue}
}
return true, setSlice(vs, value, field)
case reflect.Array:
if !ok {
vs = []string{opt.defaultValue}
}
if len(vs) != value.Len() {
return false, fmt.Errorf("%q is not valid value for %s", vs, value.Type().String())
}
return true, setArray(vs, value, field)
default:
var val string
if !ok {
val = opt.defaultValue
}
if len(vs) > 0 {
val = vs[0]
}
return true, setWithProperType(val, value, field)
}
}
github.com/gin-gonic/gin@v1.9.1/binding/form_mapping.go:167
the setByForm func's input param form is map type, the map instance is unsafe.
The reason is here?
Comment From: zhuzaiye
This is my one route:
api.POST("eiken/training-log", studentapi.EikenSpeakingController.PostEikenTrainingLog, integral.PushIntegralOfSelfExeWithResType12, integral.PushIntegralOfEikenSpeak)
The form shoud bind operation in the 1st handler function, the left function in the route chain will should bind to get the post data for working.
The shoud bind in the route chain will occur the bug "[fatal error: concurrent map read and map write]"
Comment From: zhuzaiye
Using the single-factor method, determine the problem occurring in the handlesfunc chain.
Example:
api.POST("eiken/training-log", studentapi.EikenSpeakingController.PostEikenTrainingLog, integral.PushIntegralOfSelfExeWithResType12, integral.PushIntegralOfEikenSpeak)
-- PostEikenTrainingLog
var form FormEkExaminationLog
if err := g.ShouldBind(&form); err != nil {
g.Error(err.Error())
return
}
-- PushIntegralOfSelfExeWithResType12
func PushIntegralOfSelfExeWithResType12(c *gin.Context) {
go func() {
integralOfBaseExercise(c, modelOfSelfExercise, generalModeOfType12)
}()
}
func integralOfBaseExercise(c *gin.Context, exerciseType, exerciseModule int) {
studentId := v4.GetStudentIdByToken(c)
if studentId == 0 {
return
}
g := app.Gin(c)
var form exerciseForm
if err := g.ShouldBind(&form); err != nil {
logging.Error(err.Error())
return
}
The error will not occur if PushIntegralOfSelfExeWithResType12 is not executed using the goroutine.
Currently, my solution is to either not use the goroutine method in the handlerfuncs chain, or to start it in a handlerfunc and use goroutine within a transaction.
PS: handlerfuncs chain+ shouldbind+goroutine will not trigger this error????
Comment From: zhuzaiye
using context is correct way!!!
Comment From: zhuzaiye
The following is my guess reson and fix my bug solution.
sence:
router handler_chains: api.POST("test/goroutine-chain", v4.ContestController.SubmitResult, integral.NewPushIntegralOfWriteContest)
// first handled chain
func (s *contest) SubmitResult(c *gin.Context) {
g := app.Gin{C: c}
studentId := GetStudentIdByToken(c)
var form constants.ScoreLog
if err := g.ShouldBind(&form); err != nil {
g.Error("form param_missing")
logging.Error(err.Error())
return
}
}
// second handled chain
func NewPushIntegralOfWriteContest(c *gin.Context) {
go func() {
studentId := v4.GetStudentIdByToken(c)
var form FormIntegral
// second handler chain get the request data
if err := c.ShouldBind(&form); err != nil {
logging.Error(err.Error())
return
}
// Main business code
...
}
}
github.com/gin-gonic/gin@v1.7.7/context.go:705
func (c *Context) ShouldBindWith(obj interface{}, b binding.Binding) error {
return b.Bind(c.Request, obj)
}
github.com/gin-gonic/gin@v1.7.7/binding/form.go:54
func (formMultipartBinding) Bind(req *http.Request, obj interface{}) error {
if err := req.ParseMultipartForm(defaultMemory); err != nil {
return err
}
if err := mappingByPtr(obj, (*multipartRequest)(req), "form"); err != nil {
return err
}
return validate(obj)
}
go1.18/src/net/http/request.go:1299
func (r *Request) ParseMultipartForm(maxMemory int64) error {
if r.MultipartForm == multipartByReader {
return errors.New("http: multipart handled by MultipartReader")
}
var parseFormErr error
if r.Form == nil {
// Let errors in ParseForm fall through, and just
// return it at the end.
parseFormErr = r.ParseForm()
}
if r.MultipartForm != nil {
return nil
}
mr, err := r.multipartReader(false)
if err != nil {
return err
}
f, err := mr.ReadForm(maxMemory)
if err != nil {
return err
}
// Point: 1
if r.PostForm == nil {
r.PostForm = make(url.Values)
}
// The reason: fatal error: concurrent map writes
// here will write the r.PostForm
// the type of r.PostForm is map[string][]string in `go1.18/src/net/url/url.go:865`, which is unsafe concurrent map
for k, v := range f.Value {
r.Form[k] = append(r.Form[k], v...)
// r.PostForm should also be populated. See Issue 9305.
r.PostForm[k] = append(r.PostForm[k], v...)
}
r.MultipartForm = f
return parseFormErr
}
go1.18/src/net/url/url.go:865
// no safe cocurrent
type Values map[string][]string
To fix:
// second handled chain
func NewPushIntegralOfWriteContest(c *gin.Context) {
studentId := v4.GetStudentIdByToken(c)
var form FormIntegral
// the scond bind the PostForm cannot be used in goroutine and must be executed sequentially
if err := c.ShouldBind(&form); err != nil {
logging.Error(err.Error())
return
}
go func() {
// Main business code
...
}
}