Abstract : This paper presents a method for handling exceptional behaviour expressions in a system using RLOTOS (Reflective LOTOS), which is an extension of LOTOS (Language Of Temporal Ordering Specification). We embedded reflection or reflective computation facilities into the behaviour expressions of LOTOS and produced an RLOTOS interpreter system in the C language, which includes LOTOS executor support. The Reflective System has the concept of a meta level and an object level. The meta level system deals with object-level description as data and executes the object-level description. Users can control the meta-level system by describing a special process, called the reflective process. We also show a method of handling exceptional behaviour expressions in RLOTOS to control the Alternating Bit Protocol. We describe normal behaviour expressions at the object level and exceptional behaviour expressions at the meta level. This example will help us to clarify the usefulness of separating descriptions into the meta level and the object level.
Keywords : LOTOS, Reflection, Alternating Bit Protocol, process algebra