Hello Daniel, Than you for reviewing the page! On 9/23/19 1:26 PM, Daniel Colascione wrote: > On Mon, Sep 23, 2019 at 3:53 AM Florian Weimer <fw@xxxxxxxxxxxxx> wrote: >> >> * Michael Kerrisk: >> >>> SYNOPSIS >>> int pidfd_open(pid_t pid, unsigned int flags); >> >> Should this mention <sys/types.h> for pid_t? >> >>> ERRORS >>> EINVAL flags is not 0. >>> >>> EINVAL pid is not valid. >>> >>> ESRCH The process specified by pid does not exist. >> >> Presumably, EMFILE and ENFILE are also possible errors, and so is >> ENOMEM. >> >>> A PID file descriptor can be monitored using poll(2), select(2), >>> and epoll(7). When the process that it refers to terminates, the >>> file descriptor indicates as readable. > > The phrase "becomes readable" is simpler than "indicates as readable" > and conveys the same meaning. I agree with Florian's comment on this > point below. See my reply to Florian. (I did change the text here.) >>> Note, however, that in the >>> current implementation, nothing can be read from the file descrip‐ >>> tor. >> >> “is indicated as readable” or “becomes readable”? Will reading block? >> >>> The pidfd_open() system call is the preferred way of obtaining a >>> PID file descriptor. The alternative is to obtain a file descrip‐ >>> tor by opening a /proc/[pid] directory. However, the latter tech‐ >>> nique is possible only if the proc(5) file system is mounted; fur‐ >>> thermore, the file descriptor obtained in this way is not pol‐ >>> lable. > > Referring to procfs directory FDs as pidfds will probably confuse > people. I'd just omit this paragraph. See my reply to Christian (and feel free to argue the point, please). So far, I have made no change here. >> One question is whether the glibc wrapper should fall back back to the >> /proc subdirectory if it is not available. Probably not. > > I'd prefer that glibc not provide this kind of fallback. > posix_fallocate-style emulation is, IMHO, too surprising. Agreed. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/
