[zion/glacier] Move RefCounted to glacier.

lib/glacier/memory/ref_counted.h

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <stdint.h>
+
+namespace glcr {
+
+template <typename T>
+class RefCounted {
+ public:
+  RefCounted() {}
+  virtual ~RefCounted() {}
+  // FIXME: Rethink error handling in these cases now that we can't panic the
+  // kernel.
+  void Adopt() { ref_count_ = 1; }
+
+  void Acquire() { ref_count_++; }
+  bool Release() { return (--ref_count_) == 0; }
+
+ private:
+  // FIXME: This should be an atomic type.
+  uint64_t ref_count_ = -1;
+  // Disallow copy and move.
+  RefCounted(RefCounted&) = delete;
+  RefCounted(RefCounted&&) = delete;
+  RefCounted& operator=(RefCounted&) = delete;
+  RefCounted& operator=(RefCounted&&) = delete;
+};
+
+}  // namespace glcr