Having followed the discussion about the availability of direct locking of mutexes, I am somewhat surprised that there are free functions available for this purpose. Is this by intent? Is using them simply bad practice? I.e.: boost::mutex m1; boost::detail::thread::lock_ops<boost::mutex>::lock(&m1); is e legal statement. (And indeed is locking the mutex.) Yes I've seen the "detail". Does this imply: Anything that is detail definitely should not go into user programs? I am asking this not for pure 'academic' reasons. What I am trying to do is to find out whether it is possible to write a small wrapper over the existing classes to support a kind of cancellability for my threads, until the "real thing" will be available. Thank you. Roland