--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/foosdk/sdk/pfc/once.h	Mon Jan 05 02:15:46 2026 -0500
@@ -0,0 +1,51 @@
+#pragma once
+
+#include <functional>
+#include "event.h"
+#include <memory>
+#include "lockless.h"
+
+#ifdef __ANDROID__
+#define PFC_CUSTOM_ONCE_FLAG 1
+#endif
+
+#ifndef PFC_CUSTOM_ONCE_FLAG
+#define PFC_CUSTOM_ONCE_FLAG 0
+#endif
+
+#if ! PFC_CUSTOM_ONCE_FLAG
+#include <mutex>
+#endif
+
+namespace pfc {
+#if PFC_CUSTOM_ONCE_FLAG
+    struct once_flag {
+        bool inProgress = false, done = false;
+        std::shared_ptr<::pfc::event> waitFor;
+    };
+    
+    void call_once( once_flag &, std::function<void () > );
+#else
+    using std::once_flag;
+    using std::call_once;
+#endif
+
+    //! Minimalist class to call some function only once. \n
+    //! Presumes low probability of concurrent run() calls actually happening, \n
+    //! but frequent calls once already initialized, hence only using basic volatile bool check. \n
+    //! If using a modern compiler you might want to use std::call_once instead. \n
+    //! The called function is not expected to throw exceptions.
+    struct once_flag_lite {
+        threadSafeInt::val_t guard = 0;
+        volatile bool done = false;
+    };
+    
+    void call_once( once_flag_lite &, std::function<void () > );
+
+    class runOnceLock {
+    public:
+        void run(std::function<void()> f) {call_once(m_flag, f);}
+    private:
+        once_flag_lite m_flag;
+    };
+}