Move pagemgr to generic lock free structure.

1 files changed, 47 insertions, 0 deletions

diff --git a/src/include/util/lockfree/stack.H b/src/include/util/lockfree/stack.H
new file mode 100644
index 000000000..8f884e072
--- /dev/null
+++ b/src/include/util/lockfree/stack.H
@@ -0,0 +1,47 @@
+#ifndef __UTIL_LOCKFREE_STACK_H
+#define __UTIL_LOCKFREE_STACK_H
+
+#include <stddef.h>
+
+namespace Util
+{
+    namespace Lockfree
+    {
+	template <typename _T>
+	class Stack
+	{
+	    public:
+		Stack() : head(NULL) {};
+		
+		_T* pop();
+		void push(_T*);
+
+	    private:
+		_T* head;
+	};
+
+	template <typename _T>
+	_T* Stack<_T>::pop()
+	{
+	    _T * h = head;
+	    if (NULL == h) return h;
+	    if (!__sync_bool_compare_and_swap(&head,
+					      h,
+					      h->next))
+		return pop();
+	    return h;
+	}
+
+	template <typename _T>
+	void Stack<_T>::push(_T* p)
+	{
+	    p->next = head;
+	    if (!__sync_bool_compare_and_swap(&head,
+					      p->next,
+					      p))
+		push(p);
+	}
+    }
+}
+
+#endif