feat(core): Ensure that all actions are compared to fixed point in time (#1236) (#1458)

i.e. world update start

src/server/game/Time/UpdateTime.h

@@ -0,0 +1,65 @@
+/*
+ * Copyright (C) 2016+     AzerothCore <www.azerothcore.org>, released under GNU GPL v2 license: https://github.com/azerothcore/azerothcore-wotlk/blob/master/LICENSE-GPL2
+ * Copyright (C) 2008-2016 TrinityCore <http://www.trinitycore.org/>
+ * Copyright (C) 2005-2009 MaNGOS <http://getmangos.com/>
+ */
+
+#ifndef __UPDATETIME_H
+#define __UPDATETIME_H
+
+#include <array>
+
+#include "Define.h"
+
+#define AVG_DIFF_COUNT 500
+
+class UpdateTime
+{
+    using DiffTableArray = std::array<uint32, AVG_DIFF_COUNT>;
+
+    public:
+        uint32 GetAverageUpdateTime() const;
+        uint32 GetTimeWeightedAverageUpdateTime() const;
+        uint32 GetMaxUpdateTime() const;
+        uint32 GetMaxUpdateTimeOfCurrentTable() const;
+        uint32 GetLastUpdateTime() const;
+
+        void UpdateWithDiff(uint32 diff);
+
+        void RecordUpdateTimeReset();
+
+    protected:
+        UpdateTime();
+
+        void _RecordUpdateTimeDuration(std::string const& text, uint32 minUpdateTime);
+
+    private:
+        DiffTableArray _updateTimeDataTable;
+        uint32 _averageUpdateTime;
+        uint32 _totalUpdateTime;
+        uint32 _updateTimeTableIndex;
+        uint32 _maxUpdateTime;
+        uint32 _maxUpdateTimeOfLastTable;
+        uint32 _maxUpdateTimeOfCurrentTable;
+
+        uint32 _recordedTime;
+};
+
+class WorldUpdateTime : public UpdateTime
+{
+    public:
+        WorldUpdateTime() : UpdateTime(), _recordUpdateTimeInverval(0), _recordUpdateTimeMin(0), _lastRecordTime(0) { }
+        void LoadFromConfig();
+        void SetRecordUpdateTimeInterval(uint32 t);
+        void RecordUpdateTime(uint32 gameTimeMs, uint32 diff, uint32 sessionCount);
+        void RecordUpdateTimeDuration(std::string const& text);
+
+    private:
+        uint32 _recordUpdateTimeInverval;
+        uint32 _recordUpdateTimeMin;
+        uint32 _lastRecordTime;
+};
+
+extern WorldUpdateTime sWorldUpdateTime;
+
+#endif