Created attachment 143936 [details]
helgrind/freebsd

I was looking fort examples that exercise the new pthread_clock APIS. The template code is a bit hard to read between the templates and conditional compilation but it seems to me that

std::timed_mutex (and timed_recursive_mutex) may use pthread_mutex_clocklock
std::shared_timed_mutex may use pthread_rwlock_clockwrlock and pthread_rwlock_clockrdlock

I started with this example https://en.cppreference.com/w/cpp/thread/condition_variable/wait_until
(need to check that it really is using some of the above functions. It generates several errors with both helgrind and drd.

I also need to try
https://en.cppreference.com/w/cpp/thread/shared_timed_mutex/try_lock_until
and
https://en.cppreference.com/w/cpp/thread/timed_mutex/try_lock_until

There seems to be a fair bit going wrong here. For comparison here are logs from FreeBSD (which I know has other issues, but the cv.wait_until used the timed rather than the clock version).