Auto hotspot implementation

PiPedalCommon/src/include/DBusDispatcher.hpp

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+#pragma once
+#include <memory>
+#include <functional>
+#include <thread>
+#include <mutex>
+#include <vector>
+#include <chrono>
+#include <atomic>
+
+namespace sdbus {
+    class IConnection;
+};
+
+
+class DBusDispatcher {
+    DBusDispatcher(const DBusDispatcher&) = delete;
+    DBusDispatcher(DBusDispatcher&&) = delete;
+    DBusDispatcher & operator=(const DBusDispatcher&) = delete;
+    DBusDispatcher & operator=(const DBusDispatcher&&) = delete;
+public:
+    DBusDispatcher(bool systemBus = true);
+    ~DBusDispatcher();
+
+    void Run();
+    // Stop everything, shutting down gracefully.
+    void Stop();
+    void Wait();
+    bool IsFinished();
+
+    // Stop, but don't wait. Suitable for use in a signal handler.
+    // The callback is executed by the dispatcher thread, and can therefore call non-signal-safe functions.
+    void SignalStop(std::function<void(void)> &&callback);
+
+    bool IsStopping();
+
+    using PostHandle = uint64_t;
+    using PostCallback = std::function<void()>;
+    PostHandle Post(PostCallback&&fn);
+
+    using clock = std::chrono::steady_clock;
+
+    template<class REP,class PERIOD> 
+    DBusDispatcher::PostHandle PostDelayed(const std::chrono::duration<REP,PERIOD>&delay,PostCallback&&fn)
+    {
+        return PostDelayed(
+            std::chrono::duration_cast<clock::duration,REP,PERIOD>(delay),
+            std::move(fn));
+    }
+
+    DBusDispatcher::PostHandle PostDelayed(const clock::duration&delay,PostCallback&&fn);
+
+    bool CancelPost(DBusDispatcher::PostHandle handle);
+
+    sdbus::IConnection&Connection() { return *busConnection;}
+
+private:
+    std::atomic<bool> isFinished;
+    std::atomic<bool> signalStopRequested;
+    bool signalStopExecuted = false;
+    std::function<void(void)> signalStopCallback;
+    uint64_t NextHandle() {
+        return nextHandle.fetch_add(1);
+    }
+    int GetEventTimeoutMs();
+    std::atomic<PostHandle> nextHandle;
+    int eventFd = -1;
+    bool closed = false;
+    void ThreadProc();
+    void WakeThread();
+    std::unique_ptr<sdbus::IConnection> busConnection;
+
+    struct CallbackEntry {
+        PostCallback callback;
+        clock::time_point time;
+        PostHandle handle;
+    };
+
+    std::atomic<bool> stopping;
+
+    std::vector<CallbackEntry> postedEvents;
+    bool threadJoined;
+    std::thread serviceThread;
+    std::mutex postMutex;
+};