hi all, i did some performance tests of boost::shared_mutex and a wrapper class to posix pthread_rwlock_t, which provides most of the interface from the sharedlockable concept (without the timed locking, which should be easy to add). i am not sure, whether the boost::shared_mutex class is supposed to give some guaranties (like fairness), that my wrapper implementation doesn't provide ... it does outperform the boost::shared_mutex implementation by a factor of about 2.5, though (linux, x86_64) benchmark code and wrapper class are attached. seeing these speedups, would it be reasonable to introduce a boost::native_shared_mutex class, based on a native implementation? best, tim -- tim@klingt.org http://tim.klingt.org The first question I ask myself when something doesn't seem to be beautiful is why do I think it's not beautiful. And very shortly you discover that there is no reason. John Cage.