A programming environment with runtime energy characterization for energy-aware applications

System-level power management has been studied extensively. For further energy reduction, the collaboration from user applications becomes critical. This paper presents a programming environment to ease the construction of energy-aware applications. We observe that energy-aware programs may identify different ways (called options) to achieve the desired functionalities and choose the most energy-efficient option at runtime. Our framework provides a programming interface to obtain the estimated energy consumption for choosing a particular option. The energy is estimated based on runtime energy characterization that records a set of runtime conditions correlated with the energy consumption of the options. We provide the procedure and general guidelines for using the environment to construct energy-aware programs. The prototype demonstrates that (a) energy-aware applications can be programmed easily with our interface, (b) accurate estimates are achieved by integrating multiple runtime conditions, and (c) the framework can make multiple devices collaborate for significant energy savings (15% to 41%) with negligible time and energy overhead (<0.35%).