Runtime Detection of Data Races in OCaml with ThreadSanitizer

on YouTube ↗19m

" summary

ThreadSanitizer is integrated into the OCaml compiler and runtime via LLVM-style instrumentation and a runtime library that records vector clocks and shadow memory for each word so it can report true happens‑before violations and backtraces. The port handles exceptions and effects by emitting function‑entry/exit events, runs on x86_64 Linux 64‑bit only, and is merged upstream (backport to 5.1 RC3, mainline in 5.2). Expect 2x–7x slowdown, higher memory use, and missed races on unexecuted paths or evicted shadow entries.

AI-written summary · about

" chapters (5)

1. 0:00ThreadSanitizer for OCaml
2. 3:35How ThreadSanitizer detects races
3. 8:11Instrumenting OCaml
4. 13:13OCaml memory model
5. 16:22Performance impact and status

" related talks

• 22mData race detectionNeven Miculinic · WebCamp Zagreb 2019
• 44m"go test -race" Under the HoodKavya Joshi · Strange Loop 2016
• 01h 04mDebugging data racesCliff Click · Hydra 2020
• 15mSound and partially-complete static analysis of data-races in GPU programsJulien Lange, Dennis Liew, Tiago Cogumbreiro · OOPSLA 2024
• 48mThreadSanitizer and Heap SamplingJaeheon Yi, Jean Christophe Beyler · JVM Language Summit 2017
• 19mEfficient Timestamping for Sampling-Based Race DetectionUmang Mathur, Mahesh Viswanathan, Minjian Zhang, Daniel Wee Soong Lim, Mosaad Al Thokair · PLDI 2025
• 16mFast Atomicity MonitoringAndreas Pavlogiannis, Hünkar Can Tunç, Yifan Dong · PLDI 2026
• 24mRacerD - Compositional Static Race DetectionSam Blackshear · OOPSLA 2018