Verifying Concurrent Programs via Bounded Context-Switching and Induction

This paper presents a new approach to the problem of verifying safety properties of concurrent programs with shared memory and interleaving semantics. Our method builds on and extends contextbounded analysis (CBA), in which thread interleavings are considered only up to K context switches. In a K-induction argument, the base case establishes that the property holds for the first K steps (first K context switches in our case); the inductive case establishes that if the property held for the previous K steps (context switches), then it will hold after one more step (context switch). Our approach uses CBA directly to handle the base case, and uses CBA as a subroutine when discharging the inductive case. The account sketched out above over-simplifies; there are actually several impediments to combining CBA and K-induction. The paper identifies these challenges and introduces three techniques that, when used together, side-step the difficulties.