print message when starting api server

example/syncx/sharedcalls/main.go

@@ -0,0 +1,34 @@
+package main
+
+import (
+	"fmt"
+	"sync"
+	"time"
+
+	"github.com/tal-tech/go-zero/core/stringx"
+	"github.com/tal-tech/go-zero/core/syncx"
+)
+
+func main() {
+	const round = 5
+	var wg sync.WaitGroup
+	barrier := syncx.NewSharedCalls()
+
+	wg.Add(round)
+	for i := 0; i < round; i++ {
+		go func() {
+			defer wg.Done()
+			val, err := barrier.Do("once", func() (interface{}, error) {
+				time.Sleep(time.Second)
+				return stringx.RandId(), nil
+			})
+			if err != nil {
+				fmt.Println(err)
+			} else {
+				fmt.Println(val)
+			}
+		}()
+	}
+
+	wg.Wait()
+}