arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 0912.2553cs.LOcs.DCcs.SE
收藏

一种有效的时间模型检验的显式时间描述方法

An Efficient Explicit-time Description Method for Timed Model Checking

Hao Wang, Wendy MacCaull

摘要:

时间模型检验作为一种形式化验证实时系统的方法,正受到模型检验界和实时界的广泛关注。显式时间描述方法使用标准非定时模型检查器中的一般模型构造来验证实时系统。Lamport提出了一种显式时间描述方法,使用时钟滴答过程(Tick)来模拟时间的流逝,并使用一组全局变量来建模时间需求。提出了两种方法,基于同步的显式时间描述方法和基于信号量的显式时间描述方法,这两种方法在建模实时系统时都比Lamport方法具有更好的模块性。与基于时间自动机的模型检查器(如UPPAAL)相比,显式时间描述方法可以访问和存储当前时刻,以便许多实时系统(特别是具有抢先调度的系统)将来进行必要的计算。然而,上述三种方法中的Tick过程在每个Tick中增加一个单位的时间;因此,状态空间随着时间参数的增加而相对快速地增长,当系统的时间周期相对较长时会出现问题。在本文中,我们提出了一个更有效的方法,使滴答过程跨越多个时间单位在一个滴答。在高性能计算环境下的初步实验结果表明,该方法显著地减少了状态空间,提高了时间和内存效率。

英文摘要:

Timed model checking, the method to formally verify real-time systems, is attracting increasing attention from both the model checking community and the real-time community. Explicit-time description methods verify real-time systems using general model constructs found in standard un-timed model checkers. Lamport proposed an explicit-time description method using a clock-ticking process (Tick) to simulate the passage of time together with a group of global variables to model time requirements. Two methods, the Sync-based Explicit-time Description Method using rendezvous synchronization steps and the Semaphore-based Explicit-time Description Method using only one global variable were proposed; they both achieve better modularity than Lamport's method in modeling the real-time systems. In contrast to timed automata based model checkers like UPPAAL, explicit-time description methods can access and store the current time instant for future calculations necessary for many real-time systems, especially those with pre-emptive scheduling. However, the Tick process in the above three methods increments the time by one unit in each tick; the state spaces therefore grow relatively fast as the time parameters increase, a problem when the system's time period is relatively long. In this paper, we propose a more efficient method which enables the Tick process to leap multiple time units in one tick. Preliminary experimental results in a high performance computing environment show that this new method significantly reduces the state space and improves both the time and memory efficiency.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

↑