Initial community commit

Src/replicant/nu/LockFreeItem.h

@@ -0,0 +1,35 @@
+#pragma once
+#include "foundation/atomics.h"
+#include "lfitem.h"
+/* This data structure holds one item, and returns you the old item when you replace it 
+   it's sort of a "stack of 1" */
+
+template <class value_t>
+class LockFreeItem
+{
+public:
+	typedef value_t *ptr_t;
+	LockFreeItem() 
+	{
+	lfitem_init(&item);
+	}
+	
+	value_t *GetItem()
+	{
+		return (value_t *)lfitem_get(&item);
+	}
+
+	// returns the previous value
+	value_t *SetItem(value_t *new_item)
+	{
+		return (value_t *)lfitem_set(&item, new_item);
+	}
+
+	// if there's already a value, returns what you passed in
+	value_t *SetItemIfZero(value_t *new_item)
+	{
+		return (value_t *)lfitem_set_if_zero(&item, new_item);
+	}
+
+	lfitem_value_t item;
+};