Analysis of MrsP Protocol in RTEMS Operating System
The technological world is becoming increasingly familiarized with the usage of multiprocessing platforms on several types of devices. The capabilities provided by multiprocessor systems allow for the increase of the overall system 19s performance, enabling the execution of several tasks in a concurrent and parallel way. While this behaviour is beneficial for most systems, it has to be handled with care in the real time systems domain. Real time systems are well known for their challenging requirements, the most important of them being the need to guarantee that operations are completed within a given deadline. Thus, several efforts are being made in order to be possible to execute them in multiprocessor environments. However, there are several barriers that make the transition difficult, notably at the level of resource sharing mechanisms and process scheduling on a system.One of such efforts is the added support brought by the inclusion of several scheduling and task synchronization mechanisms to RTEMS (Real time Executive for Multiprocessor Systems) an open source real time operating system widely used by the space industry worldwide.RTEMS supports two multiprocessor shared resource protocols, OMIP (O(m) Independence Preserving Protocol) and MrsP (Multiprocessor Resource Sharing Protocol) From these two, MrsP is considered rather promising, largely covering the requirements imposed by real time multiprocessing systems. This protocol was successfully implemented in RTEMS but recently it was subject to some refinements in order to cover some flaws on its initial proposal.In the project presented in this report, the MrsP protocol is analysed from a theoretical point of view and this view is compared against the implementation of the protocol on RTEMS. The goal is to evaluate the correctness of the implementation, according to the proposed requirements. Additionally, a testbed is developed to test the protocol in its integrity in order to serve as a regression test platform and in some cases, where it makes sense, comparisons with the OMIP protocol are established. Analysis of MrsP Protocol in RTEMS Operating System CISTER