ThreadSanitizer and libfork are not compatible

[UsernameLinde]

libfork uses std::atomic_thread_fence which is not compatible with ThreadSanitizer.

If/when tracking down a problem in my code, it would be nice to not get false positives from libfork.

Has this problem been considered and is there something that can be done?

[ConorWilliams]

This is a hard problem, I think the only way forward I see is to have a macro which converts all atomics to sequential consistent and removes the barriers. Not something I'm that keen on though as it would be quite painful to maintain. Id be open to a PR

[UsernameLinde]

I've pondered over this and converting atomics is not really something that looks tempting. Don't want to increase the future maintenance burden a lot. So I searched around and looked for other ways to make tsan happy.

I haven't dug through libforks code in detail, but if there is only atomic-fence and fence-atomic synchronization,
then perhaps it can be done with some extra macros using __tsan_acquire and __tsan_release from
https://github.com/gcc-mirror/gcc/blob/master/libsanitizer/include/sanitizer/tsan_interface.h and the macros could expand to nothing unless tsan-checking is enabled at compile time.

[leha-bot]

google/sanitizers#1352