[util] Add Singleton helper

src/util/util_singleton.h

@@ -0,0 +1,43 @@
+#pragma once
+
+#include "rc/util_rc_ptr.h"
+
+#include "thread.h"
+
+namespace dxvk {
+
+/**
+ * \brief Singleton helper
+ *
+ * Class that manages a dynamically created 
+ */
+template<typename T>
+class Singleton {
+
+public:
+
+  Rc<T> acquire() {
+    std::lock_guard lock(m_mutex);
+
+    if (!(m_useCount++))
+      m_object = new T();
+
+    return m_object;
+  }
+
+  void release() {
+    std::lock_guard lock(m_mutex);
+
+    if (!(--m_useCount))
+      m_object = nullptr;
+  }
+
+private:
+
+  dxvk::mutex m_mutex;
+  size_t      m_useCount  = 0;
+  Rc<T>       m_object    = nullptr;;
+
+};
+
+}