On Sun, Nov 06, 2016 at 05:42:48PM +0700, Robert Elz wrote: > Date: Sun, 6 Nov 2016 10:39:22 +0100 > From: Nicolas Joly <nj...@pasteur.fr> > Message-ID: <20161106093922.ga10...@issan.sis.pasteur.fr> > > | Just tested it on 7.0.2 NetBSD/amd64 under qemu, and it works as > | expected. Looks like a -current regression. > > In -current, the primary wait*() interface is wait6() - which is > posix waitid() (also available) plus the extra args needed to allow > it to also implement wait() wait3() waitpid() and wait4(). > > Posix is less clear on whether waitid() is supposed to return 0 or > ECHILD when WNOHANG is set, and there are no (applicable) children > (none that match the pid/flags specified - which includes no children > at all of course.) > > If WNOHANG was specified and status is not available for any > process specified by idtype and id, 0 shall be returned. > > but also ... > > [ECHILD] > The calling process has no existing unwaited-for child processes. > > but generally, the error values only apply when the sys call is stated > to return an error, which waitid() does not specify when WNOHANG is > set (unlike it does for waitpid()).
Don't we need to report an error because of the "shall" wording in the ERRORS section. [...] The waitid() function shall fail if: [ECHILD] The calling process has no existing unwaited-for child processes. [...] http://pubs.opengroup.org/onlinepubs/9699919799/functions/waitid.html -- Nicolas Joly Cluster & Computing Group Biology IT Center Institut Pasteur, Paris.