Implementing AUTOSAR scheduling and resource management on an embedded SMT processor

Abstract

The AUTOSAR specification provides a common standard for software development in the automotive domain. Its functional definition is based on the concept of single-threaded processors. Recent trends in embedded processors provide new possibilities for more powerful processors using parallel execution techniques like multithreading and multi-cores. We discuss the implementation of the AUTOSAR operating system interface on a modern simultaneous multithreaded (SMT) processor. Several problems in resource management arise when AUTOSAR tasks are executed concurrently on a multithreaded processor. Especially deadlocks, which should be averted through the priority ceiling protocol, can reoccur. We solve this problems by extending AUTOSAR OS by the Task Filtering Method to avoid deadlocks in multithreaded processors. Other synchronisation problems arising through the parallel execution of tasks are solved through the use of lock-free data structures. In the end, we propose some extensions to the AUTOSAR specification so it can be used in software development for SMT processors. We develop some additional requirements on such SMT processors to enable the use of the Task Filtering Method. Our work gives also perspectives for software development on upcoming multi-core processors in the automotive domain.