On Sun, Feb 05, 2012 at 01:32:42PM -0500, Daniel Eischen wrote: > On Sun, 5 Feb 2012, Ivan Voras wrote: > > On 5 February 2012 11:44, Garrett Cooper <yaneg...@gmail.com> wrote:
> >> 'make MAKE_JOBS_NUMBER=1' is the workground used right now.. > > David Xu suggested that it is a bug in Python - it doesn't set > > process-shared attribute when it calls sem_init(), but i've tried > > patching it (replacing the port patchfile file the one I've attached) > > and I still get the hang. > I don't understand how process shared semaphores can work. Perhaps > I'm dumb and ignorant, but a sem_id_t is an allocated struct. The > actual kernel sem_id is inside the struct. Isn't this the same > reason pthread_mutex_t and pthread_cond_t cannot be process-shared? That's how the old implementation works. It does not support process-shared semaphores although they may happen to work in some specific cases. However, in 9.0, sem_t works differently and contains the actual lock word directly, so that process-shared semaphores work. The implementation is in lib/libc/gen/sem_new.c. The pshared flag to sem_init() is not a no-op because it tells the kernel to allow for use from multiple processes. Note that the old implementation is still present as well, for compatibility with old binaries. -- Jilles Tjoelker _______________________________________________ freebsd-hackers@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hackers To unsubscribe, send any mail to "freebsd-hackers-unsubscr...@freebsd.org"
