Research On Scheduling Strategies Of Safety Embedded Real-Time Operating Systems

Real-time systems are mainly designed to satisfy the timing requirements of applications in the real world. They are widely adopted in many areas, such as industrial controls, aerospace electronics, military equipments, and so on. The real-time system concerns not only the logic correctness of the computing results, but also the time when the results come out. With the application of real-time system continually developing, it has spread into areas such as military affairs, medical treatment and so on, which require the real-time systems with high security. To meet the requirements, embedded safety real-time operating system is proposed.First, the basic theory of scheduling real-time systems and its security issues are described. The concept of real-time systems, classification criteria of the real-time system scheduling strategy, research status of the basic real-time scheduling strategy are described. Then current status of security scheduling strategy is described by introducing two different security scheduling strategy. By researching and analyzing the advantages and disadvantages of different scheduling strategy, of the traditional, the research issue of this paper is proposed to resolve the problem of the deficiency of the security and flexibility of scheduling strategy.Secondly, by analyzing the general task scheduling model of real-time system and researching on the security risk of traditional scheduling models, it comes to the conclusion that the real-time system can not effectively prevent the risk of high-priority task. The whole system's security and reliability were under threat. A new scheduling strategy named double-level scheduling strategy was proposed in the paper. Experiments show that the double-level scheduling strategy can effectively enhance system's security and reliability without additional high overhead. Finally, for the sake of absence of flexibility and elasticity of the traditional real-time system's scheduling strategy, the replacement or upgrade of hardware configuration of real-time system easily lead to a scheduling anomaly. Two different strategies were proposed in this paper to prevent the scheduling anomalies when the system configuration was changed. The new strategies had good flexibility and elasticity while ensuring the security and reliability.