據我所知， net/http 包使用 goroutine 作為處理程序。我是否有必要鎖定地圖，sync.Mutex以防止nextId函數中可能出現錯誤，因為該函數可能會計算地圖的舊狀態？這是我的示例代碼：package mainimport (    "net/http"    "github.com/gorilla/mux"    "io/ioutil"    "fmt")var testData = map[int]string {    1: "foo",    2: "bar",}func main() {    r := mux.NewRouter()    r.HandleFunc("/data", getData).Methods("GET")    r.HandleFunc("/data", addData).Methods("POST")    http.ListenAndServe(":3000", r)}func getData(writer http.ResponseWriter, request *http.Request) {    for k, v := range testData {        fmt.Fprintf(writer, "Key: %d\tValue: %v\n", k, v)    }}func addData(writer http.ResponseWriter, request *http.Request) {    if data, err := ioutil.ReadAll(request.Body); err == nil {        if len(data) == 0 {            writer.WriteHeader(http.StatusBadRequest)            return        }        id := nextId()        testData[id] = string(data)        url := request.URL.String()        writer.Header().Set("Location", fmt.Sprintf("%s", url))        writer.WriteHeader(http.StatusCreated)    } else {        writer.WriteHeader(http.StatusBadRequest)    }}func nextId() int {    id := 1    for k, _ := range testData {        if k >= id {            id = k + 1;        }    }    return id}