in dnsdist maintenance thread we'd lock up trying to lock g_luamutex twice

diff --git a/pdns/dnsdist.cc b/pdns/dnsdist.cc
index a793a15d92a07cfc01bd2ba1135a6717359b6102..b0447bb9cd44e028857c3e4fdc5f09ab4d6e2d7c 100644 (file)
--- a/pdns/dnsdist.cc
+++ b/pdns/dnsdist.cc
@@ -1012,10 +1012,12 @@ void* maintThread()
   for(;;) {
     sleep(interval);
 
-    std::lock_guard<std::mutex> lock(g_luamutex);
-    auto f =g_lua.readVariable<boost::optional<std::function<void()> > >("maintenance");
-    if(f)
-      (*f)();
+    {
+      std::lock_guard<std::mutex> lock(g_luamutex);
+      auto f =g_lua.readVariable<boost::optional<std::function<void()> > >("maintenance");
+      if(f)
+        (*f)();
+    }
 
     counter++;
     if (counter >= g_cacheCleaningDelay) {