Date: Thu, 10 Jul 2014 18:10:26 +0200 From: Baptiste Daroussin <bapt@FreeBSD.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: svn-src-head@freebsd.org, svn-src-all@freebsd.org, src-committers@freebsd.org Subject: Re: svn commit: r268493 - head/lib/libfetch Message-ID: <20140710161026.GC93051@ivaldir.etoilebsd.net> In-Reply-To: <20140710160807.GR93733@kib.kiev.ua> References: <201407101304.s6AD4rne079137@svn.freebsd.org> <20140710132813.GQ93733@kib.kiev.ua> <20140710135253.GA93051@ivaldir.etoilebsd.net> <20140710160807.GR93733@kib.kiev.ua>
next in thread | previous in thread | raw e-mail | index | archive | help
--rQ2U398070+RC21q Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Thu, Jul 10, 2014 at 07:08:07PM +0300, Konstantin Belousov wrote: > On Thu, Jul 10, 2014 at 03:52:53PM +0200, Baptiste Daroussin wrote: > > On Thu, Jul 10, 2014 at 04:28:13PM +0300, Konstantin Belousov wrote: > > > On Thu, Jul 10, 2014 at 01:04:53PM +0000, Baptiste Daroussin wrote: > > > > Author: bapt > > > > Date: Thu Jul 10 13:04:52 2014 > > > > New Revision: 268493 > > > > URL: http://svnweb.freebsd.org/changeset/base/268493 > > > >=20 > > > > Log: > > > > Support EAGAIN in fetch_writev > > > > =20 > > > > Reviewed by: des > > > > Approved by: des > > > >=20 > > > > Modified: > > > > head/lib/libfetch/common.c > > > >=20 > > > > Modified: head/lib/libfetch/common.c > > > > =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D= =3D=3D=3D=3D=3D=3D > > > > --- head/lib/libfetch/common.c Thu Jul 10 12:41:58 2014 (r268492) > > > > +++ head/lib/libfetch/common.c Thu Jul 10 13:04:52 2014 (r268493) > > > > @@ -1110,6 +1110,8 @@ fetch_writev(conn_t *conn, struct iovec=20 > > > > errno =3D 0; > > > > pfd.revents =3D 0; > > > > if (poll(&pfd, 1, deltams) < 0) { > > > > + if (errno =3D=3D EAGAIN) > > > > + continue; > > > > if (errno =3D=3D EINTR && fetchRestartCalls) > > > > continue; > > > > return (-1); > > >=20 > > > How is this error possible ? poll(2) converts EAGAIN from seltdwait(9) > > > to no error. > >=20 > > For posix compliance, libfetch is not only used on FreeBSD, reading at: > > http://pubs.opengroup.org/onlinepubs/009695399/functions/poll.html I ca= n read: > >=20 > > [EAGAIN] > > The allocation of internal data structures failed but a subsequent = request > > may succeed. > >=20 > > Am I missing something? >=20 > At least for me, it was very surprising. I accustomed to the facts that > poll(2) is never restarted after signal, and that you only should test > for EINTR as the error condition. >=20 > Apparently, the behaviour of converting EAGAIN to no error can be tracked > back to at least 4.4 lite. On the other hand, just looking into the man > page for poll(2) on STREAMS-based systems indeed mention EAGAIN. >=20 > My suggestion is to add a comment, noting that FreeBSD does not return > EAGAIN from poll(2), but SUSv4 allows it. This way, the addition would > be not removed in some code cleanup. Does it sound reasonable ? More that reasonable (I was thinking something like this as well) I will do= it tomorrow. regards, Bapt --rQ2U398070+RC21q Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEARECAAYFAlO+uvIACgkQ8kTtMUmk6EwRagCeIIKz7YvRKpSwReQZYOOc0UW/ MpUAoKbff+G4wXKDurmvEqaSZpr0TbN5 =NzBW -----END PGP SIGNATURE----- --rQ2U398070+RC21q--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20140710161026.GC93051>