Re: aio_return(3): misleading RETURN VALUE

[Alexander Holler <holler-SXC+2es9fhnfWeYVQQPykw@public.gmane.org>]

Am 18.03.2015 um 13:14 schrieb Stéphane Aulery:
> Hello Alexander,
>
> Le mercredi 18 mars 2015 à 09:03:38, Alexander Holler a écrit :
>>
>> I suggest to use the same wording as in write(2) in the paragraph RETURN
>> VALUE:
>>
>> "On error, -1 is returned, and errno is set appropriately."
>
> Like that ?
>
>      If the asynchronous I/O operation has completed, this function
>      returns the value that would have been returned in case of a
>      synchronous read(2), write(2), fsync(2) or fdatasync(2), call. On
>      error, -1 is returned, and errno is set appropriately.
>
>      If the asynchronous I/O operation has not yet completed, the return
>      value and effect of aio_return() are undefined.

Exactly. Thanks a lot if you change that.

> I think that's what you meant. What will happen if the asynchronous I/O
> operation has not yet completed please ?

It is still undefined, but I haven't looked that up in the source of glibc.

The reason is that aio_return() should only be called if the operation 
before has completed, which must be checked with calling aio_error() 
before calling aio_return().

That's how I've understood all that and how it currently seems to work 
in the SW in question I've fixed a problem.

Regards,

Alexander Holler

--
To unsubscribe from this list: send the line "unsubscribe linux-man" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html