[PATCH] Fix return value on aio_read/write success

Corinna Vinschen corinna-cygwin@cygwin.com
Sat Aug 4 20:23:00 GMT 2018


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".

>  }
>  
>  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.

>  }
>  
>  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.


Thanks,
Corinna

-- 
Corinna Vinschen                  Please, send mails regarding Cygwin to
Cygwin Maintainer                 cygwin AT cygwin DOT com
Red Hat
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