I have been debugging a problem with ushare in FreeBSD 7.0, specifically I have tracked it down to the pthread_cond_wait call inside the libupnp library that ushare uses. UpnpInit ultimately calls the below ithread_cond_wait, which is where I am seeing the "hang". The code in question is on line 650 of: /usr/ports/devel/upnp/work/libupnp-1.6.0/threadutil/src/ThreadPool.c 648 while( tp->totalThreads < currentThreads ) { 649 650 ithread_cond_wait( &tp->start_and_shutdown, &tp->mutex ); 651 652 } The call to ithread_cond_wait (#defined to pthread_cond_wait) hangs indefinitely, causing ushare to never listen on the UPnP port. It only does this when ushare is run with the -D option, indicating it should daemonize. If I run it without -D, it works fine. Here is the tail end of a truss of ushare when run with -D, at which point it hangs and subsequently does not listen on the UPnP socket. 22539: mprotect(0x7fffff9fe000,4096,PROT_NONE) = 0 (0x0) 22539: thr_new(0x7fffffffe590,0x68,0x7fffffffe620,0x0,0xffffffffb05a9d40,0x7fffffffe538) = 0 (0x0) 22539: _umtx_op(0x40e1c160,0x6,0x0,0x0,0x0,0x7fffffffe578) ERR#1 'Operation not permitted' 22539: _umtx_op(0x40e1e160,0x8,0x1,0x40e1e140,0x0,0x7fffffffe598)# and here's the tail end of the ktrace for the same: ushare CALL mmap(0x7fffff9fe000,0x201000,PROT_READ|PROT_WRITE,MAP_STACK,0xffffffff,0) ushare RET mmap -6299648/0x7fffff9fe000 ushare CALL mprotect(0x7fffff9fe000,0x1000,PROT_NONE) ushare RET mprotect 0 ushare CALL thr_new(0x7fffffffe9c0,0x68) ushare RET thr_new 0 ushare RET fork 0 ushare CALL _umtx_op(0x40e1e160,0x8,0x1,0x40e1e140,0) ushare RET _umtx_op -1 errno 1 Operation not permitted ushare CALL _umtx_op(0x40e1e140,0x5,0,0,0) ushare CALL _umtx_op(0x40e1c160,0x5,0,0,0) ushare RET _umtx_op RESTART ushare PSIG SIGTERM SIG_DFL I pointed ushare and libupnp.so to libkse instead with libmap.conf, and it works properly with libkse. It only exhibits this behavior with libthr. For now, I am using libmap.conf as a workaround, but there seems to be a problem with libthr in this particular usage. Please let me know if any other information is required. This is 7.0-RELEASE on amd64. Thanks! Josh