After using scif_mmap to establish a piece of shared memory between card and host, is it possible to use a mutex (of some kind) to sync the access to the shared data in this piece of shared memory? I tried to use a portion of this shared memory range as a pthread mutex to be used by both sides(the mutex is set PTHREAD_PROCESS_SHARED attribute), but the mutex doesn't work on remote side. pthread_mutex_lock just hangs in an infinite loop. Is there any other methods that I can use as a mutex? Thanks guys!