Sync http handler

Author: candid82

std/http/http_native.go

@@ -7,6 +7,7 @@ import (
 	"net/http"
 	"os"
 	"strings"
+	"sync"
 
 	. "github.com/candid82/joker/core"
 )
@@ -144,8 +145,11 @@ func startServer(addr string, handler Callable) Object {
 		host = MakeString(addr[:i])
 		port = MakeString(addr[i+1:])
 	}
+	var mutex sync.Mutex
 	err := http.ListenAndServe(addr, http.HandlerFunc(func(w http.ResponseWriter, req *http.Request) {
+		mutex.Lock()
 		defer func() {
+			mutex.Unlock()
 			if r := recover(); r != nil {
 				w.WriteHeader(500)
 				io.WriteString(w, "Internal server error")