A novel framework for design and analysis of embedded software with variable constraints

现代嵌入式系统需要对可能需要随时间改变其行为的应用程序进行设计考虑。为了在不同的情况下运行应用程序，嵌入式系统需要考虑不同的用户驱动的约束条件，如安全性、安全性或可用性，以及面向系统的约束条件，如成本、时间、能耗和吞吐量。然而，这些限制可能相互对立，因此改善一个意味着接受另一个的恶化。例如，物理冗余可能会增加安全性，同时也会增加受攻击面，从而降低安全性。平衡约束可以提供良好的系统性能；但是，在需要优化特定约束或约束组合的情况下，这可能不适用于应用程序。嵌入式系统在不同配置下运行与可变约束相关的需求促进了由一套创新的设计和分析方法和工具组成的新框架的发展。首先，由于应用程序中任务和消息的不断变化的需求以及各种嵌入式系统的存在，选择一组有效的设计元素及其配置是具有挑战性的。其次，需要对可变约束的可容忍延迟进行适当的分析，以减少资源的过度配置。该框架将工作负载映射到不同的配置或模式，其中每个配置优化特定的约束或约束的组合。然而，将变量约束映射到多个模式可能需要适应现有的调度策略或新的调度策略。此外，应用程序可以在多处理器平台上加速性能，但将工作负载映射到处理器需要进行严格的分析。最后，分析对于识别不确定性并为配置更改或调整生成建议是必要的。提出的嵌入式软件设计与分析框架包括以下研究活动：(1)有效地选择设计元素及其配置；(2)分析具有可变约束的工作负载的延迟；(3)将可变约束映射到多个模式；(4)事件和分析的处理。通过研究过程，学生将接受高需求嵌入式软件的专门培训，并获得引入新的嵌入式软件设计实践的技能，实现面向用户和面向系统的约束的更紧密耦合。这些成果有望提高加拿大人从从消费电子到物联网等领域的经济和社会重要案例研究中获得洞察力的能力。

Modern embedded systems need design considerations for applications that may require changing their behavior over time. To run an application in different situations, embedded systems need to consider different user-driven constraints such as safety, security, or usability, and system-oriented constraints such as cost, timing, energy consumption, and throughput. However, these constraints may oppose each other, and therefore improving one means accepting deterioration in another. For example, physical redundancy might increase safety while also increasing the attack surface and thereby reducing security. Balancing the constraints provides a good performance of the system; however this might not work well for applications in situations that require optimization of a particular constraint or a combination of constraints. The requirement to operate an embedded system in different configurations associated with variable constraints fosters the development of a novel framework composed of a set of innovative design and analysis methods and tools.Several research problems exist in designing an embedded software with variable constraints. First, selecting an efficient set of design elements and their configurations is challenging because of the evolving requirements of tasks and messages in an application and the presence of a wide variety of embedded systems. Secondly, proper analysis on tolerable delays for variable constraints is required to reduce overprovisioning of resources. The framework will map workloads into different configurations or modes, where each configuration optimizes a particular or a combination of constraints. However, mapping variable constraints to multiple modes may require adaptation of an existing scheduling strategy or a new one. Moreover, an application can provide acceleration of performance upon multiprocessor platforms, but the mapping of workloads to processors requires rigorous analysis. Finally, analytics is necessary to identify uncertainties and generate recommendations for configuration changes or adaptations. The proposed framework for design and analysis of embedded software comprises the following research activities: (1) efficient selection of design elements and their configurations, (2) analyzing delays for workloads with variable constraints, (3) mapping variable constraints to multiple modes, and (4) processing of events and analytics.Throughout the research process, students will receive specialized training in high-demand embedded software and gain skills which will introduce new embedded software design practices, achieving a closer coupling of user- and system-oriented constraints. The outcomes promise to improve Canadians' ability to gain insights from economically and socially important case studies in domains from consumer electronics to the Internet of Things.