Timed atomic commitment

Abstract

Timed atomic commitment is defined, protocols to implement it in a realistic operating environment are devised, and its usefulness is shown through an example. In a large class of hard-real-time control applications, components execute concurrently on distributed nodes and must coordinate, under timing constraints, to perform the control task. As such, they perform a type of atomic commitment. Traditional atomic commitment differs, however, because there are no timing constraints; agreement is eventual. The authors define timed atomic commitment (TAC), which requires the processes to be functionally consistent, but allows the outcome to include an exceptional state, indicating that timing constraints have been violated. Centralized and decentralized protocols to implement TAC are presented. Programming constructs for TAC are introduced, and their use is illustrated in a coordinating robots example.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>