An Abstraction Technique for Describing Concurrent Program Behaviour

Abstract

This paper presents a technique to reason about functional properties of shared-memory concurrent software by means of abstraction. The abstract behaviour of the program is described using process algebras. In the program we indicate which concrete atomic steps correspond to the actions that are used in the process algebra term. Each action comes with a specification that describes its effect on the shared state. Program logics are used to show that the concrete program steps adhere to this specification. Separately, we also use program logics to prove that the program behaves as described by the process algebra term. Finally, via process algebraic reasoning we derive properties that hold for the program from its abstraction. This technique allows reasoning about the behaviour of highly concurrent, non-deterministic and possibly nonterminating programs. The paper discusses various verification examples to illustrate our approach. The verification technique is implemented as part of the VerCors toolset. We demonstrate that our technique is capable of verifying data-and control-flow properties that are hard to verify with alternative approaches, especially with mechanised tool support.

Static Code Verification Through Process Models

“…Abstract Models. This paper generalizes previous work on abstract models as proposed by Oortwijn et al [10,11]. In the work of Oortwijn, the contract for a method states which actions may or will be taken by that thread.…”

On Models and Code

“…Within the VerCors tool set, we have started to develop techniques to support this idea. In particular, we allow to specify an abstract model view of a component using process algebra, and then we use an extension of concurrent separation logic to prove that the concrete code behaves according to this model [23], while model checking technology can be used to derive global properties of the program from the process algebra models.…”

“…Thread t1 = new Mult(); Thread t2 = new Add(); 5 t1.fork(); t2.fork(); 6 t1.join(); t2.join(); 7 } This example is very simple, but we have used the same approach on larger and non-terminating programs [2,23,27].…”

Cloud computing based load balancing algorithm for erlang concurrent traffic

“…The evaluation based on benchmark software confirms that the overhead due to execution time is practical to existing theoretical frameworks. Another article treats a memory for concurrent software by restricting the abstraction level [5]. Hanxleden, et al [6] mention that the synchronous language confirms fixed concurrency but the cost of restrictions on concurrent programs is considered whether it is constructive or valid.…”