RE: [PATCH v4 4/4] make poll() work on platforms that can't recv() on a non-socket

From: Joachim Schmitz <jojo@schmitz-digital.de>
Date: Sep 8, 2012, 13:53 UTC
Message-ID: <001b01cd8dc9$5c6ca7a0$1545f6e0$@schmitz-digital.de>
In-Reply-To: <CABPQNSY1+3X3LE19mSm2398Kr9EvOxbmsoRLzo4fFTytiA3B+Q@mail.gmail.com>

Show 26 quoted lines

> From: Erik Faye-Lund [mailto:kusmabite@gmail.com]
> Sent: Saturday, September 08, 2012 1:32 PM
> To: Joachim Schmitz
> Cc: Junio C Hamano; git@vger.kernel.org
> Subject: Re: [PATCH v4 4/4] make poll() work on platforms that can't recv() on a non-socket
> 
> On Fri, Sep 7, 2012 at 5:43 PM, Joachim Schmitz <jojo@schmitz-digital.de> wrote:
> > This way it gets added to gnulib too.
> >
> > Signed-off-by: Joachim Schmitz <jojo@schmitz-digital.de>
> > ---
> >  compat/poll/poll.c | 5 +++++
> >  1 file changed, 4 insertions(+)
> >
> > diff --git a/compat/poll/poll.c b/compat/poll/poll.c
> > index e4b8319..10a204e 100644
> > --- a/compat/poll/poll.c
> > +++ b/compat/poll/poll.c
> > @@ -306,6 +306,10 @@ compute_revents (int fd, int sought, fd_set *rfds, fd_set *wfds, fd_set *efds)
> >                || socket_errno == ECONNABORTED || socket_errno == ENETRESET)
> >         happened |= POLLHUP;
> >
> > +      /* some systems can't use recv() on non-socket, including HP NonStop */
> > +      else if (/* (r == -1) && */ socket_errno == ENOTSOCK)
> 
> Why add commented-out code ("(r == -1) && ")?

I'm not really sure whether it may be needed, esp. for Mac OS X, where en ENOTSOCK is expected from a recv() but then dealt with by an ioctl(), which does not resert socket_errno, but does set r to something not -1. And wouldn't need this code path? There's some similar code a few lines up, which too has that part commented out:

      /* If the event happened on an unconnected server socket,
         that's fine. */
      else if (r > 0 || ( /* (r == -1) && */ socket_errno == ENOTCONN))
        happened |= (POLLIN | POLLRDNORM) & sought;

Bye, Jojo