Re: [PATCH] Fix return value on aio_read/write success

[Mark Geisert <mark at maxrnd dot com>]

Corinna Vinschen wrote:
> On Aug  4 01:44, Mark Geisert wrote:
> > Oops. Something that iozone testing had found but I regarded as an
> > iozone bug.  Re-reading the man pages set me straight.
> > ---
> >  winsup/cygwin/aio.cc | 4 ++--
> >  1 file changed, 2 insertions(+), 2 deletions(-)
> >
> > diff --git a/winsup/cygwin/aio.cc b/winsup/cygwin/aio.cc
> > index fe63dec04..571a9621b 100644
> > --- a/winsup/cygwin/aio.cc
> > +++ b/winsup/cygwin/aio.cc
> > @@ -712,7 +712,7 @@ aio_read (struct aiocb *aio)
> >        ; /* I think this is not possible */
> >      }
> >
> > -  return res;
> > +  return res < 0 ? res : 0; /* Return 0 on success, not byte count */
>
> The comment only makes sense in comparison to the former code.
> I'd reduce this to just "Return 0 on success".

OKWD (Okay, will do).

> >  }
> >
> >  ssize_t
> > @@ -902,7 +902,7 @@ aio_write (struct aiocb *aio)
> >        ; /* I think this is not possible */
> >      }
> >
> > -  return res;
> > +  return res < 0 ? res : 0; /* Return 0 on success, not byte count */
>
> Ditto.

Yup.

> >  }
> >
> >  int
> > --
> > 2.17.0
>
> While we're at it, I just found that asyncread/asyncwrite return int.
> Shouldn't they return ssize_t?  That's 32 vs. 64 bit on x86_64.

Oops++.  Yes, of course.  Will do.  Saw no compiler warning for this.
Thanks,

..mark