https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=194985
--- Comment #4 from Mateusz Guzik <m...@freebsd.org> --- + p = td->td_proc; + PROC_LOCK(p); + fdp = p->p_fd; + FILEDESC_SLOCK(fdp); + td->td_retval[0] = fdp->fd_openfd; + FILEDESC_SUNLOCK(fdp); + PROC_UNLOCK(p); proc lock has no useful purpose here. p_fd can change in some cases during fork, but then the process is singlethreaded. proc lock is a mutex with bound sleep, while filedesc lock has unbound sleep. As such, they cannot be taken in this order anyway. As a side note, they happen to be taken in the opposide order, so this code gives 2 different opportunities for deadlocks. The kernel would tell you that if you enabled WITNESS and INVARIANTS. Lastly, I'm not a fan of counting fds if it can be avoided. As mentioned in my previous comment, the kernel maintains a bitmap of open descriptors. I would suspect counting set bits (= open descriptors) would be fast enough for real life cases. -- You are receiving this mail because: You are the assignee for the bug. _______________________________________________ freebsd-bugs@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-bugs To unsubscribe, send any mail to "freebsd-bugs-unsubscr...@freebsd.org"
