Asynchronous data sharing in multiprocessor real-time systems using process consensus

Abstract

The paper presents an approach to implementing fully asynchronous reader/writer mechanisms which addresses the problems of priority inversion and blocking among tasks within multiprocessor real time systems. The approach is conceived from the concept of process consensus that the writer and the reader come to an agreement on accessing the shared data before proceeding to carry out their respective data operations. Because neither locking operations nor repeated actions of read and check are involved, the shared data can be accessed at any time by the writer and all the readers in a manner not only wait-free but also loop-free. In addition, sharing data via this approach introduces no impact upon either timing behaviour or schedulability of any task in the system. Hence the approach helps to remove priority inversion and blocking incurred by the commonly used lock based synchronization mechanisms.