A trace simplification technique for effective debugging of concurrent programs

13 years 2 months ago

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Concurrent programs are notoriously difficult to debug. We see two main reasons for this: 1) concurrency bugs are often difficult to reproduce, 2) traces of buggy concurrent executions can be complicated by fine-grained thread interleavings. Recently, a number of efficient techniques have tried to address the former reproducibility problem; however, there is no effective solution for the latter trace simplification problem. In this paper, we formalize and prove the trace simplification problem is NP-hard. We then propose a heuristic algorithm, Tinertia, that transforms a buggy execution trace into an easier-to-understand simplified trace. Tinertia works by automatically and iteratively increasing the granularity of the thread interleavings in the buggy trace. Tinertia cannot guarantee optimal simplification; however, we empirically show that our algorithm often generates optimally simplified traces. Moreover, we show that in the simplified trace, the locations of preemptive context sw...

Nicholas Jalbert, Koushik Sen

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