Concurrency in Dependable Computing

This text focuses on concurrency related issues in the area of dependable computing. Failures of system components, whether hardware units or software modules, can be viewed as undesirable events occurring concurrently with a set of normal system events. Achieving dependability therefore is closely related to, and also benefits from, concurrency theory and formalisms. This beneficial relationship appears to manifest into three strands of work. Concepts such as atomic actions, conversations, exception handling, view synchrony, and so forth, are useful in structuring concurrent activities so as to facilitate attempts at coping with the effects of component failures. The text discusses three main areas: replication induced concurrency management; the application of concurrency formalisms for dependability assurance; and CSP and Petri nets. Replication is a widely used technique for achieving reliability. Replication management essentially involves ensuring that replicas perceive concurrent events identically. Fault-tolerant algorithms are harder to verify than their fault-free counterparts due to the fact that the impact of component faults at each state need to be considered in addition to valid state transitions. CCS are useful tools to specify and verify fault-tolerant designs and protocols. This work explores many significant issues in all three strands. To this end, it is composed as a collection of papers written by authors well-known in their respective areas of reseach. To ensure quality, the papers are reviewd by a panel of at least three experts in the relelvent area.