Introduce tls_ptr_t

This is a lightweight wrapper around the pthread methods to access thread local memory.

Shared/include/oak/tls_ptr.h

@@ -0,0 +1,36 @@
+#ifndef TLS_PTR_H_186F0BAB
+#define TLS_PTR_H_186F0BAB
+
+namespace oak
+{
+	template<typename T>
+	struct tls_ptr_t
+	{
+		tls_ptr_t () { pthread_key_create(&_key, destructor); }
+		~tls_ptr_t () { }
+
+		tls_ptr_t (tls_ptr_t const& rhs) = delete;
+		tls_ptr_t& operator= (tls_ptr_t const& rhs) = delete;
+
+		T& operator*  () const { return *get(); }
+		T* operator-> () const { return  get(); }
+
+	private:
+		T* get () const
+		{
+			T* valuePtr = static_cast<T*>(pthread_getspecific(_key));
+			if(!valuePtr)
+			{
+				pthread_setspecific(_key, new T);
+				valuePtr = static_cast<T*>(pthread_getspecific(_key));
+			}
+			return valuePtr;
+		}
+
+		static void destructor (void* valuePtr) { delete static_cast<T*>(valuePtr); }
+
+		pthread_key_t _key;
+	};
+} /* oak */
+
+#endif /* end of include guard: TLS_PTR_H_186F0BAB */