Title :
Response-time bounds of EQL rule-based programs under rule priority structure
Author :
Wang, Rwo-hsi ; Mok, Aloysius K.
Author_Institution :
Dept. of Comput. Sci., Texas Univ., Austin, TX, USA
fDate :
7/1/1995 12:00:00 AM
Abstract :
A key index of the performance of a rule based program used in real time monitoring and control is its response time, defined by the longest program execution time before a fixed point of the program is reached from a start state. Previous work in computing the response time bounds for rule based programs effectively assumes that all rules take the same amount of firing time. It is also assumed that if two rules are enabled, then either one of them may be scheduled first for firing. These assumptions can result in loose bounds, especially in the case programmers choose to impose a priority structure on the set of rules. We remove the uniform firing cost assumption and discuss how to get tighter bounds by taking rule priority information into account. We show that the rule suppression relation we previously introduced can be extended to incorporate rule priority information. A bound derivation algorithm for programs whose potential trigger relations satisfy an acyclicity condition is presented, followed by its correctness proof and an analysis example
Keywords :
decision support systems; knowledge based systems; logic programming; program verification; real-time systems; software performance evaluation; EQL rule based programs; EQL rule-based programs; acyclicity condition; bound derivation algorithm; correctness proof; equational rule based program; potential trigger relations; priority; priority structure; program execution time; real time decision systems; real time monitoring; response time bounds; response-time bounds; rule based program; rule priority information; rule priority structure; rule suppression relation; timing analysis; uniform firing cost assumption; Algorithm design and analysis; Artificial intelligence; Delay; Equations; Knowledge based systems; Monitoring; Processor scheduling; State-space methods; Time factors; Timing;
Journal_Title :
Software Engineering, IEEE Transactions on