Message Passing on a Time-predictable Multicore Processor

Real-time systems need time-predictable computing platforms. For a multicore processor to be time-predictable, communication between processor cores needs to be time-predictable as well. This paper presents a time-predictable message-passing library for such a platform. We show how to build up abstraction layers from a simple, time-division multiplexed hardware push channel. We develop these time-predictable abstractions and implement them in software. To prove the time-predictability of these functions we analyze their worst-case execution time (WCET) with the aiT WCET analysis tool. We combine these WCET numbers with the calculation of the network latency of a message and then provide a statically computed end-to-end latency for this core-to-core message.