This repository was archived by the owner on Jun 30, 2025. It is now read-only.
This repository was archived by the owner on Jun 30, 2025. It is now read-only.
TSan warning: a race in LOG_EVERY_N and friends #439
Description
TSan correctly warns about a race in LOG_EVERY_N macros. Consider:
#define SOME_KIND_OF_LOG_EVERY_N(severity, n, what_to_do) \
static int LOG_OCCURRENCES = 0, LOG_OCCURRENCES_MOD_N = 0; \
++LOG_OCCURRENCES; \
if (++LOG_OCCURRENCES_MOD_N > n) LOG_OCCURRENCES_MOD_N -= n; \
if (LOG_OCCURRENCES_MOD_N == 1)
...
...
This code is clearly unsafe when running in multiple threads concurrently and needs std::atomic() annotation (or an equivalent non-standard fix).