信标可控性定义及问题

Siphon Controllability Definitions and Issues

死锁是资源分配系统中极不希望出现的现象,目前死锁控制的一个重要的方法是信标控制法,信标控制法的基础是信标可控性的定义.对于普通Petri网,已有一个完善的信标可控性定义,而对于一般Petri网,这方面的工作还需改进和完善.近年来,学者们针对一般Petri网及其子类提出了不少信标可控性定义,但这些定义并不完善,仍有大量的问题亟待解决.首先回顾了文献中的各个信标可控性定义,提出了两个新的信标可控性定义,然后从可控性定义的宽松程度、应用范围以及等价性等方面分析比较了现有的信标可控性定义优缺点.最后给出了今后的研究方向.

Deadlocks are an extremely undesirable situation in resource allocation systems. Nowadays, siphon control, which is based on siphon controllability conditions, is one of the important methods to ensure that deadlocks never occur in systems. For ordinary Petri nets, the siphon controllability condition is well defined. However, it remains an open question for generalized Petri nets despite many attempts to define their siphon controllability conditions. In recent years, many such conditions have been proposed for them or their subclasses, but suffer from various problems. This paper surveys the existing siphon controllability conditions and then presents two new ones. All of them are compared in terms of their condition strictness, application scope and equivalence. ~ture research directions are also indicated.