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.