AllenRV: An Extensible Monitor for Multiple Complex Specifications with High Reactivity

Abstract

AllenRV is a tool for monitoring temporal specifications, designed for ensuring good scalability in terms of size and number of formulae, and high reactivity. Its features reflect this design goal. For ensuring scalability in the number of formulae, it can simultaneously monitor a set of formulae written in past and future, next-free LTL, with some metric extensions; their efficient simultaneous monitoring is supported by a let construct allowing to share computations between formulae. For ensuring scalability in the size of formulae, it allows defining new abstractions as user-defined operators, which take discrete time boolean signals as arguments, but also constant parameters such as delays. For ensuring high reactivity, its monitoring algorithm does not require clock tick events, unlike many other tools. This is achieved by recomputing output signals both upon input signals changes and upon internally generated timeout events relative to such changes. As a consequence, monitoring remains efficient on arbitrarily fine-grained time domains. AllenRV is implemented by extending the existing Allen language and compiler, initially targeting ubiquitous applications using binary sensors, with temporal logic operators and a comprehensive library of user-defined operators on top of them. The most complex of these operators, including a complete adaptation of Allen-logic relations as selection operators, are proven correct with respect to their defined semantics. Thus, AllenRV offers an open platform for cooperatively developing increasingly complex libraries of high level, general or domain-specific, temporal operators and abstractions, without compromising correctness.

STAn: analysis of data traces using an event-driven interval temporal logic

“…In the recent years, some works have focused specifically on stream runtime verification (SRV), in which the trace of events is in fact a set of (possibly infinite) streams or signals (numerical or boolean) and the specifications represent the temporal and data manipulation dependencies between input and output streams. These works can be classified into those that assume that the input streams are synchronous (all streams are produced following a global clock and thus the sequence of data is not timestamped), such as Hallé (2016), and those that assume asynchronous input streams, such as Volanschi and Serpette (2019), Faymonville et al (2019) and Convent18TeSSLa. In general, SRV tools use very expressive specification languages in order to describe the complex relation between input and output streams.…”

“…In eLTL, we could analyze a property ψ in a time window of fixed size with [ p,q] ψ formula, where p and q are events triggered at the beginning and end of each temporal window. On the other hand, some SRV tools (Hallé 2016;Volanschi and Serpette 2019;Gorostiaga and Sánchez 2021) implement monitors in such a way that they can support customized or user-defined operations to deal with their rich input language. In this sense, eLTL maintains a balance between the fixed set of operators and the interval formulae that can be defined by the user.…”