Use Thread Safety Analysis (TSA) annotations to explicitly document which mutexes protect which variables, making thread safety relationships clear to both static analyzers and code readers. Every mutex should have a clear, documented purpose with TSA annotations that specify what data it protects. This prevents issues like unused mutexes, inconsistent locking patterns, and unclear concurrent access semantics. Example using TSA annotations: ```cpp class XRayInstrumentationManager { private: mutable std::mutex functions_mutex; std::list instrumented_functions GUARDED_BY(functions_mutex); InstrumentedFunctions getInstrumentedFunctions() const REQUIRES(functions_mutex) { std::lock_guard lock(functions_mutex); return instrumented_functions; } }; ``` For read-only concurrent access, use const-correctness and shared locks with clear documentation: ```cpp // Functions can access this info in parallel for reading purposes only std::pair> getIndexInfo() const; ``` TSA macros like `GUARDED_BY`, `REQUIRES`, and `EXCLUDES` help catch threading issues early and make code self-documenting about its concurrency assumptions.