A Flexible Multiprocessor Resource Sharing Framework for Ada

Lock-based resource sharing protocols for single processor systems are well understood and supported in programming languages such as Ada and the Real-Time Specification for Java, and in Real-Time Operating Systems, and those that conform to the Real-Time POSIX standard. In contrast, multiprocessor resource sharing protocols are still in their infancy with no agreed best practices, and yet current real-time programming languages and operating systems claim to be suitable for supporting multiprocessor applications. This thesis argues that, instead of supporting a single resource sharing protocol, a resource sharing framework should be provided that allows application-defined resource sharing protocols to be implemented. The framework should be flexible and adaptive so that a wide range of protocols with different design characteristics can be integrated and implemented effectively with minimum runtime overheads. The thesis reviews the currently available multiprocessor resource allocation policies and analyzes their applicability to the main industry standard real-time programming languages. It then proposes a framework that allows programmers to define and implement their own locking policy for monitor based concurrent control mechanisms. Instantiation of the framework is illustrated for the Real-Time Specification for Java and POSIX. A prototype implementation of the full framework for Ada is developed and evaluated.