Increasing the Efficiency and Responsiveness of Mobile Applications with Preemptable Code Offloading

Mobile applications are getting more and more sophisticated and demanding. Although the processing, memory, and storage resources of mobile devices are constantly increasing to enable such resource-demanding mobile applications, battery capacity is still the main limiting factor. To solve this problem, mobile code offloading approaches can be used to offload parts of a mobile application to remote servers and utilize the resources of cloud services. In this paper, we propose a novel code offloading approach that makes code offloading robust against communication link failures, which are still a major problem of mobile systems. To this end, we propose preemptable code offloading. It allows for interrupting the offloading process and continuing the remote execution locally after a link failure, without abandoning the complete result calculated remotely so far. The basic idea of our approach is to create safe-points of the remote execution and transmit these intermediate results back to the mobile device. After a link failure, the mobile device can now continue execution from the last transmitted safe-point. Although safe-points induce communication and energy overhead, our evaluations show that using an optimized safe-point schedule this overhead quickly pays off under link failures. Besides reducing the overall energy consumption significantly, responsiveness also benefits from safe-points by meeting given execution deadlines after link failures.