LC

Reproduce and Diagnose Race Condition Using Thread Sanitizer

easy9/10

Reproduce and Diagnose Deadlock; Fix Using Lock Ordering Implement Barriers for Thread Synchronization

Language

Compiler

2.0s Limit 256MB

Implementation

Create race condition and detect with ThreadSanitizer.

Requirements:

Write buggy code with data race
Demonstrate non-deterministic behavior
Compile with -fsanitize=thread
Fix race condition with mutex or atomic
Show TSan output
Show fix eliminates race

Success Criteria:

Race detected by TSan
Fix eliminates race
TSan reports no issues after fix

Why This Matters

ThreadSanitizer, the tool this task exercises, was built at Google after data races caused real, hard-to-reproduce production incidents in Chrome's multi-process renderer and is now standard in Go's `-race` flag and Rust's Miri. The double-checked-locking bug shown here is a famous real pattern (formalized as broken by the 'C++ and the Perils of Double-Checked Locking' paper) that misled a generation of C++ programmers into shipping racy singleton initialization.

Hints

0 / 3 revealed

Validation Suite

main.c

Workspace 1.0