Security Mechanisms and Reliable Real-time Multicast and Memory Replication with Bounded Delays for Time-triggered Message-triggered Objects

Real-Time Distributed Computing (RTDC) technology has applications in many important fields. The Time-triggered Message-triggered Object (TMO) programming scheme is a component-based approach that has been established to facilitate the development of RTDC software systems.;Many RTDC applications have tight security-enforcement requirements. We proposed the first formal extension of the TMO component model called AS-TMO which is devised to facilitate efficient construction of secure RTDC applications. We also present the execution-engine facilities being incorporated into the TMO Support Middleware (TMOSM), for providing the security-enforcement capabilities defined in the AS-TMO scheme. An application scenario is discussed to exemplify the use of the AS-TMO scheme.;Quite a few RTDC applications require a real-time reliable multicast framework that can detect message losses with tight latency bounds. One highly promising concrete formulation of a multicast framework is the Real-time Multicast and Memory Replication Channel (RMMC) scheme. We present the Delay-Bounded Reliable RMMC (DBR-RMMC) scheme which extends the basic RMMC scheme in order to yield tight latency bounds in detecting and reporting message losses. We also discuss the TMOSM extension devised to support DBR-RMMC, followed by a summary of analytical results on the latency bounds in reacting to message losses. To demonstrate the practice of DBR-RMMC, we focus on its application in networked multimedia systems with QoS adaptation capabilities. Particularly, DBR-RMMC provides timely information regarding the network condition, and a QoS adaptation support layer (QASL) is developed to take the advantage of DBR-RMMC and allow programmers to easily incorporate QoS-adaptation capabilities into TMO-based multimedia applications. Experiments have been conducted and encouraging results are presented.;TMOSM has the limitation in controlling low-level computing resources and thus achieves a timing precision around tens of milliseconds. To improve the performance, we built inside the Linux kernel the structuring principles and execution rules of the TMO programming scheme and the TMOSM. The resulting kernel is called the Time-Triggered Function Support Linux (TS-Linux). We also proposed the TTF Net programming scheme which bears the similar design philosophy and structuring principles as those of the TMO programming scheme. We discussed the high-level architecture of TS-Linux and evaluated the two-level-scheduler.