性能优化4，修复编译bug

src/media_server_app.h

@@ -1,5 +1,7 @@
 #pragma once
 
+#include <atomic>
+#include <thread>
 #include <string>
 
 #include "graph_manager.h"
@@ -15,6 +17,9 @@ public:
 private:
     std::string config_path_;
     GraphManager graph_manager_{};
+
+    std::atomic<bool> stop_signal_thread_{false};
+    std::thread signal_thread_;
 };
 
 }  // namespace rk3588