Marcel Köppen, Jana Traue, Christoph Borchert, Jörg Nolte, Olaf Spinczyk (Universität Osnabrück / Cyberus Technology GmbH / BTU Cottbus)
With the availability of systems that contain large amounts of byte-addressable non-volatile memory (NVRAM), there is a growing need for data structures that can be mapped into a process's address space and be used without data (de-)serialization. While NVRAM's ability to retain memory contents during system failure and power loss allows fast system startup and recovery, data consistency has to be preserved by using transactional operations for data manipulation.
We describe a lightweight and efficient transaction mechanism for small data structures in memory-mapped NVRAM. The size per data structure is limited to half a cache-line, so that the approach cannot serve as a general purpose mechanism for arbitrary applications, but could be used within an operating system as a low-level building block for more complex data structures. By using aspect-oriented programming with AspectC++, the mechanism can be used in an almost transparent manner, which helps to avoid many possible sources for bugs.