Add persistent_data/lock_tracker for more sanity checking.

persistent-data/lock_tracker.h

@@ -0,0 +1,56 @@
+// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
+//
+// This file is part of the thin-provisioning-tools source.
+//
+// thin-provisioning-tools is free software: you can redistribute it
+// and/or modify it under the terms of the GNU General Public License
+// as published by the Free Software Foundation, either version 3 of
+// the License, or (at your option) any later version.
+//
+// thin-provisioning-tools is distributed in the hope that it will be
+// useful, but WITHOUT ANY WARRANTY; without even the implied warranty
+// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU General Public License for more details.
+//
+// You should have received a copy of the GNU General Public License along
+// with thin-provisioning-tools.  If not, see
+// <http://www.gnu.org/licenses/>.
+
+#ifndef LOCK_TRACKER_H
+#define LOCK_TRACKER_H
+
+#include <boost/noncopyable.hpp>
+#include <map>
+#include <stdint.h>
+
+
+//----------------------------------------------------------------
+
+namespace persistent_data {
+	class lock_tracker : private boost::noncopyable {
+	public:
+		lock_tracker(uint64_t low, uint64_t high);
+
+		void read_lock(uint64_t key);
+		void write_lock(uint64_t key);
+		void unlock(uint64_t key);
+
+	private:
+		typedef std::map<uint64_t, int> LockMap;
+
+		bool found(LockMap::const_iterator it) const;
+
+		bool valid_key(uint64_t key) const;
+		void check_key(uint64_t key) const;
+
+		// Positive for read lock, negative for write lock
+		LockMap locks_;
+
+		uint64_t low_;
+		uint64_t high_;
+	};
+}
+
+//----------------------------------------------------------------
+
+#endif