On intermittence bugs in the battery-less internet of things

The resource-constrained devices of the battery-less Internet of Things are powered off energy harvesting and compute intermittently, as energy is available. Forward progress of programs is ensured by creating persistent state. Mixed-volatile platforms are thus an asset, as they map slices of the address space onto non-volatile memory. However, these platforms also possibly introduce intermittence bugs, where intermittent and continuous executions differ. Our ongoing work on intermittence bugs includes (i) an analysis that demonstrates their presence in settings that current literature overlooks; (ii) the design of efficient testing techniques to check their presence in arbitrary code, which would be otherwise prohibitive given the sheer number of different executions to check; (iii) the implementation of an offline tool called ScEpTIC that implements these techniques. ScEpTIC finds the same bugs as a brute-force approach, but is six orders of magnitude faster.