GEEKING

Base/include/util/ScopedSingleton.h

@@ -0,0 +1,52 @@
+#pragma once
+//#include "pdh.h"
+
+#include "boost/weak_ptr.hpp"
+#include "boost/shared_ptr.hpp"
+#include "rbx/Debug.h"
+#include "rbx/threadsafe.h"
+
+namespace RBX
+{
+	template<class T>
+	class ScopedSingleton
+	{
+	private:
+		static int& initCount()
+		{
+			static int initcount = 0;
+			return initcount;
+		}
+	protected:
+		// use this to validate usage pattern.
+		// some usage patterns will want to check that this doesn't 
+		// increase more than 1.
+		static int getInitCount()
+		{
+			return initCount();
+		}
+		SAFE_STATIC(rbx::spin_mutex, sync)
+		SAFE_STATIC(boost::weak_ptr<T>, s_instance)
+	public:
+		static boost::shared_ptr<T> getInstance()
+		{
+			rbx::spin_mutex::scoped_lock lock(sync());
+			
+			shared_ptr<T> result = s_instance().lock();
+
+			if (!result)
+			{
+				initCount()++;
+				result = shared_ptr<T>(new T());
+				s_instance() = result;
+			}
+
+			return result;
+		}
+        static boost::shared_ptr<T> getInstanceOptional()
+        {
+            return s_instance().lock();
+        }
+	};
+
+}