[Boost-users] [Boost.thread] Interruption points ?

Hi there, just a short question: http://www.boost.org/doc/libs/1_35_0/doc/html/thread/thread_management.html#... lists the following interruption points: * boost::thread::join() * boost::thread::timed_join() * boost::condition_variable::wait() * boost::condition_variable::timed_wait() * boost::condition_variable_any::wait() * boost::condition_variable_any::timed_wait() * boost::thread::sleep() * boost::this_thread::sleep() * boost::this_thread::interruption_point() Is (and if so: why is) a lock on a mutex no interruption point ? Thanks and Best Regards, Ruediger