1. named_mutex.hpp has some serious issues on the pthread side including: mp_mut is declared of type sem_t and is expected to be of type pthread_mutex_t The timed_lock function operates a sem_timedwait with a pthread_mutex_t. 2. shared_read_write_mutex.hpp has a possible issue with its exceptions: The exception used is a lock_error which is defined in boost::thread (and not included in shared_read_write_mutex.hpp) vs. using the boost::shmem::lock_exception as is used in all other boost::shmem sync primitives. Paul Ryan and Shumin Wu SAIC