LOLA: Runtime Monitoring of Synchronous Systems

Abstract

Abstract-We present a specification language and algorithms for the online and offline monitoring of synchronous systems including circuits and embedded systems. Such monitoring is useful not only for testing, but also under actual deployment. The specification language is simple and expressive; it can describe both correctness/failure assertions along with interesting statistical measures that are useful for system profiling and coverage analysis. The algorithm for online monitoring of queries in this language follows a partial evaluation strategy: it incrementally constructs output streams from input streams, while maintaining a store of partially evaluated expressions for forward references. We identify a class of specifications, characterized syntactically, for which the algorithm's memory requirement is independent of the length of the input streams. Being able to bound memory requirements is especially important in online monitoring of large input streams. We extend the concepts used in the online algorithm to construct an efficient offline monitoring algorithm for large traces.We have implemented our algorithm and applied it to two industrial systems, the PCI bus protocol and a memory controller. The results demonstrate that our algorithms are practical and that our specification language is sufficiently expressive to handle specifications of interest to industry.

Synthesising Correct Concurrent Runtime Monitors

“…Despite the typical drawbacks associated with asynchrony, e.g., late detections, our monitoring setup is in line with the asynchrony advocated by the actor concurrency model, which facilitates scalable coding techniques such as fail-fast design patterns [11]. Asynchronous monitoring has also been used in other RV tools, e.g., [14,17], and has proved to be less intrusive and easier to instrument than synchronous monitoring setups. It is also the more feasible alternative when monitoring distributed systems [19,16].…”

Rapidly Adjustable Non-intrusive Online Monitoring for Multi-core Systems

“…TeSSLa can be seen as an asynchronous extension of the stream based language LOLA [8]. LOLA is based on synchronous streams, but as we want to observe multi-core systems, we can not assume synchronization between the streams coming in from different cores.…”

“…The syntax of TeSSLa is inspired by existing stream-based specification languages like LOLA [8] and the underlying concept of functional reactive programming [11]. TeSSLa is built around the basic concept of deriving internal or output streams by applying functions to input streams or already derived internal streams.…”

On Temporal Logic and Signal Processing

“…Rather than taking the logic as a primary object and put all the numerical predicates and functions as part of domain-specific signature (as in [21]), we take a general framework of a data-flow network (as has been done in [4]) and add the temporal operators (until and since) as a special type of signal transducers. This approach is also close to [24], where AMS-LTL is extended with auxiliary functions that allow to embed arbitrary signal transducers in the body of property specifications.…”