Add mutex interface

include/sta/mutex.hpp

@@ -0,0 +1,27 @@
+#ifndef STA_MUTEX_HPP
+#define STA_MUTEX_HPP
+
+
+namespace sta
+{
+	/**
+	 * @brief Interface for mutex objects.
+	 */
+	class Mutex
+	{
+	public:
+		/**
+		 * @brief Block until mutex has been acquired
+		 */
+		virtual void acquire() = 0;
+		/**
+		 * @brief Release mutex
+		 */
+		virtual void release() = 0;
+
+		static Mutex * ALWAYS_FREE; /**< Fake mutex that can always be acquired */
+	};
+} // namespace sta
+
+
+#endif // STA_MUTEX_HPP

src/mutex.cpp

@@ -0,0 +1,20 @@
+#include <sta/mutex.hpp>
+
+
+namespace sta
+{
+	/**
+	 * @brief Dummy mutex implementation with no access control.
+	 */
+	class DummyMutex : public Mutex
+	{
+	public:
+		void acquire() override {}
+		void release() override {}
+	};
+
+	static DummyMutex dummyMutex;
+
+
+	Mutex * Mutex::ALWAYS_FREE = &dummyMutex;
+} // namespace sta