Formal Semantics of Runtime Monitoring, Verification, Enforcement and Control

Runtime monitoring can be used to verify, enforce and control the dynamic execution of a target program at runtime to detect property violations, enforce desired properties and actively correct the execution, respectively. However, the state-of-the-art study lacks an appropriate formal program semantics of runtime monitoring. In this paper, we propose a theory of runtime control at an appropriate level of formalization to provide a formal program semantics of instrumented target programs under the control of controlling programs. Our theory provides a complete formal semantics for real implementations of runtime monitoring and control, but still retains a good balance between implementation and generality. Indeed, the theory encompasses the formalization of key implementation techniques, such as program instrumentation, synchronization on passively monitored actions, and synthesis of controlling programs from specifications. On the other hand, the theory is so generic and expressive that many existing formalisms about runtime monitoring can be considered as special cases of our theory.