Fray: An Efficient General-Purpose Concurrency Testing Platform for the JVM

2025-01-22

AI Summary

Existing concurrent testing tools struggle to simultaneously achieve high bug-detection efficiency, reliable reproducibility, and developer-friendliness. This paper introduces a JVM-based, modification-free, one-click concurrency testing framework tailored for data-race-free programs. It precisely models all feasible executions by orchestrating thread interleavings—without replacing primitives—while introducing the novel “shadow-lock” mechanism to enable efficient, controllable scheduling with zero code intrusion, thereby breaking the traditional trade-off among expressiveness, applicability, and performance. The framework integrates bytecode instrumentation, runtime monitoring, partial-order sampling (POS), randomized search, and semantic-aware lock-behavior encoding. Evaluated on 53 benchmarks with known concurrency bugs, it detects 70% more bugs than JPF and 77% more than RR’s chaos mode. In large-scale real-world testing across Kafka, Lucene, and Guava—comprising 2,655 test cases—it successfully identifies 18 reproducible, production-grade concurrency defects.

Technology Category

• Data Mining & Knowledge Management: Scalability, Parallel & Distributed Systems
• Constraint Satisfaction and Optimization: Distributed CSP/Optimization
• Search and Optimization: Distributed Search

Application Category

• Security and Privacy: Large-scale security measurements
• Economics, Online Markets and Human Computation: The sharing economy
• Systems and Infrastructure for Web, Mobile and WoT: Web performance, measurement, and characterization

Abstract

Concurrency bugs are hard to discover and reproduce. Prior work has developed sophisticated algorithms to search for concurrency bugs, such as partial order sampling (POS); however, fundamental limitations with existing platforms for concurrency control hinder effective testing of real-world software. We observe that the design space for concurrency control on managed code involves complex trade-offs between expressibility, applicability, and maintainability on the one hand, and bug-finding efficiency on the other hand. This paper presents Fray, a platform for performing push-button concurrency testing of data-race-free JVM programs. The key insight behind Fray is that effective controlled concurrency testing requires orchestrating thread interleavings without replacing existing concurrency primitives, while encoding their semantics for faithfully expressing the set of all possible program behaviors. Fray incorporates a novel concurrency control mechanism called shadow locking, designed to make controlled concurrency testing practical and efficient for JVM programs. In an empirical evaluation on 53 benchmark programs with known bugs (SCTBench and JaConTeBe), Fray with random search finds 70% more bugs than JPF and 77% more bugs than RR's chaos mode. We also demonstrate Fray's push-button applicability on 2,655 tests from Apache Kafka, Lucene, and Google Guava. In these mature projects, Fray successfully discovered 18 real-world concurrency bugs that can cause 363 tests to fail reproducibly.

Problem

• Concurrency Control
• Software Testing
• Code Maintainability

Innovation

• Concurrent Testing
• JVM Platform
• Error Detection Efficiency