Generalized Weakly-Hard Constraints
Generalized Weakly-Hard Constraints
复制标题
广义弱硬约束
DOI：
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发表时间：
2012
期刊：
影响因子：
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通讯作者：
R. Ernst
中科院分区：
文献类型：
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作者：
Sophie Quinton;R. Ernst
实时系统除了满足其功能要求外，还必须满足有关其定时行为的要求。在硬实时系统的情况下，这样的要求包括没有最后期限错过。相比之下，对于软实时系统，“合理”数量的截止日期错过可能会发生，而不会导致系统故障。通常对“合理”数量的截止日期错过的正式定义是基于概率分布的。另一种选择是使用弱硬约束，它描述了给定时间窗口内允许的最后期限错过次数的界限。
在本文中，我们展示了使用弱硬约束的兴趣，用于其他目的，而不是描述最后期限错过，例如，描述执行时间或抖动。我们深入讨论了弱硬约束的语义，重点是它们如何从其他弱硬约束中推断出来，并与概率约束进行比较。
Real-time systems must meet, in addition to their functional requirements, requirements regarding their timing behavior. In the case of hard real-time systems, such requirements include the absence of deadline misses. In contrast, for soft real-time systems, a "reasonable" number of deadline misses may happen without leading to a system failure. The usual definition of what a "reasonable" number of deadline misses formally means is based on probability distributions. Another option is to use weakly-hard constraints, which describe bounds on the number of allowed deadline misses in a given time window.
In this paper we show the interest of using weakly-hard constraints for other purposes than describing deadline misses, e.g. to describe execution times or jitter. We discuss in depth the semantics of weakly-hard constraints with an emphasis on how they can be inferred from other weakly-hard constraints and compared to probabilistic constraints.