aio_return.3

xen 3.2.2 源码

.TH aio_return 3 2002-09-12 "Linux 2.4" Linux AIO"
.SH NAME
aio_return \- Retrieve status of asynchronous I/O operation
.SH SYNOPSYS
.nf
.B #include <errno.h>
.sp
.br 
.B #include <aio.h>
.sp
.br
.BI "ssize_t aio_return (const struct aiocb *aiocbp)"
.fi
.SH DESCRIPTION
This function can be used to retrieve the return status of the operation
carried out by the request described in the variable pointed to by
.IR aiocbp
.  As long as the error status of this request as returned
by 
.IR aio_error
is 
.IR EINPROGRESS
the return of this function is
undefined.

Once the request is finished this function can be used exactly once to
retrieve the return value.  Following calls might lead to undefined
behavior.  
When the sources are compiled with 
.B "_FILE_OFFSET_BITS == 64"
this function is in fact 
.IR aio_return64
since the LFS interface
transparently replaces the normal implementation.
.SH "RETURN VALUES"
The return value itself is the value which would have been
returned by the 
.IR read
,
.IR write
, or 
.IR fsync
call.
.SH ERRORS
The function can return 
.TP
.B ENOSYS
if it is not implemented.
.TP
.B EINVAL 
if the 
.IR aiocbp 
parameter does not
refer to an asynchronous operation whose return status is not yet known.
.SH "SEE ALSO"
.BR aio(3),
.BR aio_cancel(3),
.BR aio_cancel64(3),
.BR aio_error(3),
.BR aio_error64(3),
.BR aio_fsync(3),
.BR aio_fsync64(3),
.BR aio_init(3),
.BR aio_read(3),
.BR aio_read64(3),
.BR aio_return64(3),
.BR aio_suspend(3),
.BR aio_suspend64(3),
.BR aio_write(3),
.BR aio_write64(3),
.BR errno(3),