Automatic Symmetry Detection for Promela

Abstract

We introduce a specification language, Promela-Lite, which captures the essential features of Promela but which, unlike Promela, has a formally defined semantics. We show how we can detect symmetry in specifications defined in Promela-lite by constructing a directed, coloured bipartite digraph called a static channel diagram, and applying computational group theoretic techniques. We extend our approach to Promela and introduce a tool, SymmExtractor, for automatically detecting symmetries of Promela specifications. We demonstrate the effectiveness of our approach via experimental results for a suite of Promela specifications. Unlike previous approaches our technique is fully automatic, and not restricted to fully symmetric systems.

Counterexample-guided abstraction refinement for symmetric concurrent programs

“…To fully automate the application of our method to source code, we additionally need a technique for detecting the presence of thread symmetry. Existing approaches try to identify symmetries in PROMELA models [13] or in fact multi-threaded C code [31]. In practice, there are two options: one can focus on full symmetry, checking that the code of the replicated function does not use thread ids in a symmetry-breaking way.…”

Replication and Abstraction: Symmetry in Automated Formal Verification

“…Instead, symmetry is automatically detected by extracting a communication graph, the static channel diagram, from a PROMELA program, and computing automorphisms of this graph, which induce automorphisms of the model associated with the program [43,44]. We describe this approach to symmetry detection in more detail in Section 7.3 TOPSPIN is not limited to full symmetry, and computes orbit representatives for a wider variety of symmetry groups by generalizing the reduction techniques employed by SYMMSPIN [30,31,34].…”

“…Static channel diagram analysis is the basis of automatic symmetry detection techniques for PROMELA [43,44] and is implemented in the TOPSPIN symmetry reduction tool [41]. The SAUCY tool [90] is used to compute the group Aut(SCD).…”

Constraint-based automatic symmetry detection

“…All values that belongs to this type are equivalent. Although there are automatic approaches which do not need expert insights, they are designed for specific languages [24], [23], or require models to be written in specific patterns [13], [14]. Thus they trade off generality for efficiency, and consequently a user has to transform his problem into a form amenable to the approach.…”

“…Although values of all label variables are fully symmetric in this case, that is, permuting the values 1 to 0 and 0 to 1 for all label variables together over all the states and transitions of the state space results in the same state space, the arithmetic operations on the variables prohibit the use of scalarsets. Further, the protocol does not take message-passing paradigm, so the approaches [13], [14], [24], [23] for detecting process symmetries are not applicable. Moreover, as far as we know, there is no approach that considers process and data symmetries which are not both full symmetries at the same time, i.e., no existing approaches can find all symmetries in this example.…”