Hi Josh, On 23 August 2015 at 09:32, Josh Triplett <josh@xxxxxxxxxxxxxxxx> wrote: > On some systems (reported by Jeremy Sequoia as occurring on Darwin), > poll(2) and select(2) can spuriously return EAGAIN if they fail to > allocate kernel-internal resources, rather than ENOMEM as Linux does. > The spec allows this for poll(2): > http://pubs.opengroup.org/onlinepubs/9699919799/functions/poll.html says > poll may return EAGAIN if "The allocation of internal data structures > failed but a subsequent request may succeed." The spec for select(2) > at http://pubs.opengroup.org/onlinepubs/9699919799/functions/select.html > doesn't specify EAGAIN, but apparently Darwin can return it in that case > too. > > I'd suggest the following text for poll(2)'s NOTES section: > > Some other UNIX systems can return EAGAIN if they fail to allocate > kernel-internal resources, rather than ENOMEM as Linux does. The Single > Unix Specification allows this behavior for poll(2). Portable programs > may wish to check for EAGAIN and loop, just as with EINTR. > > > And the following text for select(2)'s NOTES section: > > Some other UNIX systems can return EAGAIN if they fail to allocate > kernel-internal resources, rather than ENOMEM as Linux does. The Single > Unix Specification allows this behavior for poll(2), but not for > select(2); nonetheless, some systems do return EAGAIN from select(2). > Portable programs may wish to check for EAGAIN and loop, just as with > EINTR. I've added text to both pages similar to what you proposed above. Cheers, Michael -- Michael Kerrisk Linux man-pages maintainer; http://www.kernel.org/doc/man-pages/ Linux/UNIX System Programming Training: http://man7.org/training/ -- To unsubscribe from this list: send the line "unsubscribe linux-man" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
