Atomicity Checking in Linear Time using Vector Clocks

Abstract

Multi-threaded programs are challenging to write. Developers often need to reason about a prohibitively large number of thread interleavings to reason about the behavior of software. A non-interference property like atomicity can reduce this interleaving space by ensuring that any execution is equivalent to an execution where all atomic blocks are executed serially. We consider the well studied notion of conflict serializability for dynamically checking atomicity. Existing algorithms detect violations of conflict serializability by detecting cycles in a graph of transactions observed in a given execution. The number of edges in such a graph can grow quadratically with the length of the trace making the analysis not scalable. In this paper, we present AeroDrome, a novel single pass linear time algorithm that uses vector clocks to detect violations of conflict serializability in an online setting. Experiments show that AeroDrome scales to traces with a large number of events with significant speedup. CCS Concepts. • Software and its engineering → Dynamic analysis; Software testing and debugging.

A tree clock data structure for causal orderings in concurrent executions

“…This algebraic treatment allows to naturally lift language-inclusion problems from the verification of sequential programs to concurrent programs [7]. As such, it has been the most studied partial order in the context of concurrency, with deep applications in dynamic analyses [25,38,42], ensuring consistency [57] and stateless model checking [26]. In shared memory concurrency, the standard independence relation deems two events as dependent if they conflict, and independent otherwise [28].…”

“…Prominent examples include the widespread use of HB [19,24,30,49,60], schedulably-happens-before (SHB) [37], causally-precedes (CP) [63], weak-causally-precedes (WCP) [31], doesn't-commute (DC) [53], and strong/weak-dependently-precedes (SDP/WDP) [28], M2 [48] and SyncP [41]. Beyond race detection, partial orders are often employed to detect and reproduce other concurrency bugs such as atomicity violations [9,26,42], deadlocks [57,65], and other concurrency vulnerabilities [70]. Vector clocks in dynamic analyses.…”

“…Vector clocks, thus seamlessly capture a partial order, with the point-wise ordering of the vector timestamps of two events capturing the ordering between the events with respect to the partial order of interest. For this reason, vector clocks are instrumental in computing the HB parial order efficiently [21,22,39], and are ubiquitous in the efficient implementation of analyses based on partial orders even beyond HB [23,30,31,35,38,49,53,61].…”

Detection of Concurrency Errors in Multithreaded Applications Based on Static Source Code Analysis

“…Java, due to its unflagging popularity, is still one of the most popular languages used in research on these errors. The paper [47] presents an algorithm called AeroDrome, which was implemented in the RAPID tool, which is used for dynamic analysis of applications written for JRE (Java Runtime Environment) to detect atomicity violation. Research on the algorithm is at an early stage of development and its authors indicate that it is not good enough and should be used as part of a hybrid method.…”

Opportunistic Monitoring of Multithreaded Programs

“…Guaranteeing the correctness of concurrent programs often relies on dynamic analysis and verification approaches. Some approaches target generic concurrency errors such as data races [29,37], deadlocks [11], and atomicity violations [28,47,57]. Others target behavioral properties such as null-pointer dereferences [27], and typestate violations [36,38,55] and more generally order violations with runtime verification [42].…”