There has been a recent upsurge of interest in formal, machine-checked verification of timing guarantees for C implementations of real-time system schedulers. However, prior work has only considered tick-based schedulers, which enjoy a clearly defined notion of time: the time “quantum”. In this work, we present a new approach to real-time systems verification for interrupt-free schedulers , which are commonly used in deeply embedded and resource-constrained systems but which do not enjoy a natural notion of periodic time. Our approach builds on and connects two recently developed Rocq-based systems—RefinedC (for foundational C verification) and Prosa (for verified response-time analysis)—adapting the former to reason about timed traces and the latter to reason about overheads. We apply the resulting system, which we call RefinedProsa , to verify Rössl, a simple yet representative, fixed-priority, non-preemptive, interrupt-free scheduler implemented in C.

@article{paperbot3139,
  title = {RefinedProsa: Connecting Response-Time Analysis with C Verification for Interrupt-Free Schedulers},
  author = {Kimaya Bedarkar and Laila Elbeheiry and Michael Sammler and Lennard Gäher and Björn Brandenburg and Derek Dreyer and Deepak Garg},
  journal = {Proceedings of the ACM on Programming Languages},
  volume = {9},
  number = {PLDI},
  year = {2025},
  doi = {10.1145/3729249}
}