The inclusion of dynamic ceiling priorities in Ada is a topic of discussion in the Real-Time Ada community. Several approaches have been discussed in previous editions of the International Real-Time Ada Workshop, which have allowed to identify the problems associated with this issue, mainly the interaction of such feature with tasking, consistency and efficiency of implementation. In this paper, a new approach for dynamic ceilings is presented. It is based on implementing the ceiling change as a predefined protected operation itself, which allows to eliminate the potential for data corruption that other approaches introduce, without the need for additional locks.The paper also discusses the use of the proposed operation in the context of mode changes.
/lp/association-for-computing-machinery/protected-ceiling-changes-KPbPF2VcNu