freebsd/lib/libsys/aio_return.2

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.Dd January 11, 2021
.Dt AIO_RETURN 2
.Os
.Sh NAME
.Nm aio_return
.Nd retrieve return status of asynchronous I/O operation (REALTIME)
.Sh LIBRARY
.Lb libc
.Sh SYNOPSIS
.In aio.h
.Ft ssize_t
.Fn aio_return "struct aiocb *iocb"
.Sh DESCRIPTION
The
.Fn aio_return
system call returns the final status of the asynchronous I/O request
associated with the structure pointed to by
.Fa iocb .
.Pp
The
.Fn aio_return
system call
should only be called once, to obtain the final status of an asynchronous
I/O operation once it has completed
.Xr ( aio_error 2
returns something other than
.Er EINPROGRESS ) .
.Sh RETURN VALUES
If the asynchronous I/O request has completed, the status is returned
as described in
.Xr read 2 ,
.Xr readv 2 ,
.Xr write 2 ,
.Xr writev 2 ,
or
.Xr fsync 2 .
Otherwise,
.Fn aio_return
returns \-1 and sets
.Va errno
to indicate the error condition.
.Sh ERRORS
The
.Fn aio_return
system call will fail if:
.Bl -tag -width Er
.It Bq Er EINVAL
The
.Fa iocb
argument
does not reference a completed asynchronous I/O request.
.It Bq Er EINVAL
The I/O operation was submitted with
.Fn lio_listio ,
and the value of the
.Fa aio_lio_opcode
is invalid.
.El
.Sh SEE ALSO
.Xr aio_cancel 2 ,
.Xr aio_error 2 ,
.Xr aio_suspend 2 ,
.Xr aio_waitcomplete 2 ,
.Xr aio_write 2 ,
.Xr fsync 2 ,
.Xr read 2 ,
.Xr write 2 ,
.Xr aio 4
.Sh STANDARDS
The
.Fn aio_return
system call
is expected to conform to the
.St -p1003.1
standard.
.Sh HISTORY
The
.Fn aio_return
system call first appeared in
.Fx 3.0 .
.Sh AUTHORS
This
manual page was written by
.An Wes Peters Aq Mt wes@softweyr.com .