CPAHR: an concurrency control protocol against hard real-time transactions

When a hard real-time transaction conflicts with some un-hard real-time transactions, the traditional concurrency control protocols make the hard real-time transaction prior obtain system resources through enhancing its priority and preemption. They ignore how to deal with confliction between some hard real-time transactions. This paper aims at resolving this problem. It proposes a concurrency control protocol CPaHR. One hard real-time transaction includes some alternatives, an alternative describes one execution routine. Any alternative success means the hard real-time transaction can commit, otherwise. If new hard real-time transaction conflicts with some alternatives of running hard real-time transaction, it aborts these alternatives but the transactions. Our experiment shows that CPaHR can improve success-ratio of hard real-time transactions obviously.