Testing timed systems modeled by Stream X-machines

Abstract

Stream X-machines have been used to specify real systems requiring to represent complex data structures. They are a kind of extended finite state machine using a shared memory to specify communications between the components of systems. In this paper we introduce an extension of the Stream X-machines formalism in order to specify systems that present temporal requirements. On the one hand, we consider that (output) actions take time to be performed. On the other hand, our formalism allows to specify timeouts. Timeouts represent the time a system can wait for the environment to react. Since timeous affect the set of available actions of the system, a relation focusing on the functional behavior of systems, that is, the actions that they can perform, must explicitly take into account the possible timeouts. We also propose a formal testing methodology allowing to systematically test a system with respect to a specification. Finally, we introduce a test derivation algorithm. Given a specification, the derived test suite is sound and complete, that is, a system under test successfully passes the test suite if and only if this system conforms to the specification.

A verified and optimized Stream X‐Machine testing method, with application to cloud service certification

“…Recent developments in Stream X‐Machines include Ipate's combined method for testing component machines and their system‐level integration in parallel ; the TXStates domain‐specific language for multi‐agent systems , which supports specifying agents as Stream X‐Machines in NetLogo; and a timed extension to the SXM formalism , for which we are not yet aware of any testing method.…”

Formal Testing of Timed and Probabilistic Systems

“…In addition to the work presented in this talk, I have also participated in the development of other frameworks to test timed and probabilistic systems that I would like to briefly review. First, it is worth mentioning that the presented framework is general enough so that it can be easily modified to deal with other formalisms such as timed variants of stream X-machines [14]. The timed framework presented in this talk allows their users to express temporal requirements concerning the time elapsed between the reception of an input and the production of an output but it does not deal with timeouts.…”

Passive testing with asynchronous communications and timestamps

“…In contrast, there has been some work on active testing for models with asynchronous communications where there is a distinction between inputs and outputs [16,27,49,17,18,47]. Concerning the consideration of time, there is plenty of work on formal approaches to both active [50,41,21,29,40,23,46] and passive [42,3] testing of timed systems. However, as far as we know, these approaches assume a synchronous communications mechanism.…”