Accelerating Delta Debugging through Probabilistic Monotonicity Assessment

Delta debugging assumes search space monotonicity: if a program causes a failure, any supersets of that program will also induce the same failure, permitting the exclusion of subsets of non-failure-inducing programs. However, this assumption does not always hold in practice. This paper introduces Probabilistic Monotonicity Assessment (PMA), enhancing the efficiency of DDMIN-style algorithms without sacrificing effectiveness. PMA dynamically models and assesses the search space's monotonicity based on prior tests tried during the debugging process and uses a confidence function to quantify monotonicity, thereby enabling the probabilistic exclusion of subsets of non-failure-inducing programs. Our approach significantly reduces redundant tests that would otherwise be performed, without compromising the quality of the reduction. We evaluated PMA against two leading DDMIN-style tools, CHISEL and ProbDD. Our findings indicate that PMA cuts processing time by 59.2% compared to CHISEL, accelerates the reduction process (i.e., the number of tokens deleted per second) by 3.32x, and decreases the sizes of the final reduced programs by 6.7%. Against ProbDD, PMA reduces processing time by 22.0%, achieves a 1.34x speedup in the reduction process, and further decreases the sizes of the final reduced programs by 3.0%. These findings affirm PMA's role in significantly improving delta debugging's efficiency while maintaining or enhancing its effectiveness.