Cost Analysis of Nondeterministic Probabilistic Programs

Krishnendu Chatterjee (1) , Hongfei Fu (2) , Amir Kafshdar Goharshady (1) , Peixin Wang (2) , Xudong Qin (3) , Wenjun Shi (3)

1 IST Austria - Institute of Science and Technology [Klosterneuburg, Austria]
2 Shanghai Jiao Tong University [Shanghai]
3 ECNU - East China Normal University [Shangaï]

We consider the problem of expected cost analysis over non-deterministic probabilistic programs, which aims at automated methods for analyzing the resource-usage of such programs. Previous approaches for this problem could only handle nonnegative bounded costs. However, in many scenarios, such as queuing networks or analysis of cryptocurrency protocols , both positive and negative costs are necessary and the costs are unbounded as well. In this work, we present a sound and efficient approach to obtain polynomial bounds on the expected accumulated cost of nondeterministic probabilistic programs. Our approach can handle (a) general positive and negative costs with bounded updates in variables; and (b) nonnegative costs with general updates to variables. We show that several natural examples which could not be handled by previous approaches are captured in our framework. Moreover, our approach leads to an efficient polynomial-time algorithm, while no previous approach for cost analysis of probabilistic programs could guarantee polynomial run-time. Finally, we show the effectiveness of our approach by presenting experimental results on a variety of programs, motivated by real-world applications, for which we efficiently synthesize tight resource-usage bounds.

Domains: Programming Languages [cs.PL]; Software Engineering [cs.SE]

Krishnendu Chatterjee, Hongfei Fu, Amir Kafshdar Goharshady, Peixin Wang, Xudong Qin, et al.. Cost Analysis of Nondeterministic Probabilistic Programs. 2019. ⟨hal-02016018v1⟩