[apple/xnu.git] / bsd / man / man2 / aio_return.2

.\"
.\" Copyright (c) 2008 Apple Inc.  All rights reserved.
.\"
.\" @APPLE_LICENSE_HEADER_START@
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.\" This file contains Original Code and/or Modifications of Original Code
.\" as defined in and that are subject to the Apple Public Source License
.\" Version 2.0 (the 'License'). You may not use this file except in
.\" compliance with the License. Please obtain a copy of the License at
.\" http://www.opensource.apple.com/apsl/ and read it before using this
.\" file.
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.\" The Original Code and all software distributed under the License are
.\" distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
.\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
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.\" FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
.\" Please see the License for the specific language governing rights and
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.\"
.\" Copyright (c) 1999 Softweyr LLC.
.\" All rights reserved.
.\"
.\" Redistribution and use in source and binary forms, with or without
.\" modification, are permitted provided that the following conditions
.\" are met:
.\" 1. Redistributions of source code must retain the above copyright
.\"    notice, this list of conditions and the following disclaimer.
.\" 2. Redistributions in binary form must reproduce the above copyright
.\"    notice, this list of conditions and the following disclaimer in the
.\"    documentation and/or other materials provided with the distribution.
.\"
.\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
.\" ARE DISCLAIMED.  IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
.\" SUCH DAMAGE.
.\"
.\" $FreeBSD: src/lib/libc/sys/aio_return.2,v 1.17 2003/01/13 10:37:11 tjr Exp $
.\"
.Dd September 26, 2008
.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
.Fo aio_return
.Fa "struct aiocb *aiocbp"
.Fc
.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 aiocbp .
.Pp
The
.Fn aio_return
system call
should only be called once, to obtain the final status of an asynchronous
I/O operation (once
.Xr aio_error 2
returns something other than
.Er EINPROGRESS) and to clean up system resources.
However, if
.Fn aio_return
is not called at all,
.Xr aio 4
will leak resources.
.Sh RETURN VALUES
If the asynchronous I/O request has completed,
the status is returned as described in
.Xr read 2 ,
.Xr write 2 ,
or
.Xr fsync 2 .
On failure,
.Fn aio_return
returns
.Dv -1
and sets
.Dv 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 aiocbp
argument
does not reference an outstanding asynchronous I/O request.
.\" ==========
.It Bq Er EINPROGRESS
The asynchronous I/O request is still in progress.
.El
.Sh LEGACY SYNOPSIS
.Fd #include <aio.h>
.Pp
.Ft int
.br
.Fo aio_return
.Fa "struct aiocb *aiocbp"
.Fc ;
.Pp
The type of the return value has changed.
.Sh SEE ALSO
.Xr aio_cancel 2 ,
.Xr aio_error 2 ,
.Xr aio_suspend 2 ,
.Xr aio_write 2 ,
.Xr fsync 2 ,
.Xr read 2 ,
.Xr write 2 ,
.Xr aio 4 ,
.Xr compat 5
.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 wes@softweyr.com .
Commit	Line	Data
b0d623f7 A	1	.\"
	2	.\" Copyright (c) 2008 Apple Inc. All rights reserved.
	3	.\"
	4	.\" @APPLE_LICENSE_HEADER_START@
	5	.\"
	6	.\" This file contains Original Code and/or Modifications of Original Code
	7	.\" as defined in and that are subject to the Apple Public Source License
	8	.\" Version 2.0 (the 'License'). You may not use this file except in
	9	.\" compliance with the License. Please obtain a copy of the License at
	10	.\" http://www.opensource.apple.com/apsl/ and read it before using this
	11	.\" file.
	12	.\"
	13	.\" The Original Code and all software distributed under the License are
	14	.\" distributed on an 'AS IS' basis, WITHOUT WARRANTY OF ANY KIND, EITHER
	15	.\" EXPRESS OR IMPLIED, AND APPLE HEREBY DISCLAIMS ALL SUCH WARRANTIES,
	16	.\" INCLUDING WITHOUT LIMITATION, ANY WARRANTIES OF MERCHANTABILITY,
	17	.\" FITNESS FOR A PARTICULAR PURPOSE, QUIET ENJOYMENT OR NON-INFRINGEMENT.
	18	.\" Please see the License for the specific language governing rights and
	19	.\" limitations under the License.
	20	.\"
	21	.\" @APPLE_LICENSE_HEADER_END@
	22	.\"
	23	.\"
91447636 A	24	.\" Copyright (c) 1999 Softweyr LLC.
	25	.\" All rights reserved.
	26	.\"
	27	.\" Redistribution and use in source and binary forms, with or without
	28	.\" modification, are permitted provided that the following conditions
	29	.\" are met:
	30	.\" 1. Redistributions of source code must retain the above copyright
	31	.\" notice, this list of conditions and the following disclaimer.
	32	.\" 2. Redistributions in binary form must reproduce the above copyright
	33	.\" notice, this list of conditions and the following disclaimer in the
	34	.\" documentation and/or other materials provided with the distribution.
	35	.\"
	36	.\" THIS SOFTWARE IS PROVIDED BY Softweyr LLC AND CONTRIBUTORS ``AS IS'' AND
	37	.\" ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
	38	.\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
	39	.\" ARE DISCLAIMED. IN NO EVENT SHALL Softweyr LLC OR CONTRIBUTORS BE LIABLE
	40	.\" FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
	41	.\" DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
	42	.\" OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
	43	.\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
	44	.\" LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
	45	.\" OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
	46	.\" SUCH DAMAGE.
	47	.\"
	48	.\" $FreeBSD: src/lib/libc/sys/aio_return.2,v 1.17 2003/01/13 10:37:11 tjr Exp $
	49	.\"
b0d623f7	50	.Dd September 26, 2008
91447636 A	51	.Dt AIO_RETURN 2
	52	.Os
	53	.Sh NAME
	54	.Nm aio_return
	55	.Nd retrieve return status of asynchronous I/O operation (REALTIME)
	56	.Sh LIBRARY
	57	.Lb libc
	58	.Sh SYNOPSIS
	59	.In aio.h
2d21ac55 A	60	.Ft ssize_t
	61	.Fo aio_return
	62	.Fa "struct aiocb *aiocbp"
	63	.Fc
91447636 A	64	.Sh DESCRIPTION
	65	The
	66	.Fn aio_return
	67	system call returns the final status of the asynchronous I/O request
	68	associated with the structure pointed to by
2d21ac55	69	.Fa aiocbp .
91447636 A	70	.Pp
	71	The
	72	.Fn aio_return
	73	system call
	74	should only be called once, to obtain the final status of an asynchronous
b0d623f7	75	I/O operation (once
91447636 A	76	.Xr aio_error 2
91447636 A	77	returns something other than
b0d623f7 A	78	.Er EINPROGRESS) and to clean up system resources.
	79	However, if
	80	.Fn aio_return
	81	is not called at all,
	82	.Xr aio 4
	83	will leak resources.
91447636	84	.Sh RETURN VALUES
2d21ac55 A	85	If the asynchronous I/O request has completed,
2d21ac55 A	86	the status is returned as described in
91447636 A	87	.Xr read 2 ,
	88	.Xr write 2 ,
	89	or
	90	.Xr fsync 2 .
	91	On failure,
	92	.Fn aio_return
	93	returns
	94	.Dv -1
	95	and sets
	96	.Dv errno
	97	to indicate the error condition.
	98	.Sh ERRORS
	99	The
	100	.Fn aio_return
	101	system call will fail if:
	102	.Bl -tag -width Er
2d21ac55	103	.\" ==========
91447636 A	104	.It Bq Er EINVAL
91447636 A	105	The
2d21ac55	106	.Fa aiocbp
91447636 A	107	argument
91447636 A	108	does not reference an outstanding asynchronous I/O request.
b0d623f7 A	109	.\" ==========
	110	.It Bq Er EINPROGRESS
	111	The asynchronous I/O request is still in progress.
91447636	112	.El
2d21ac55 A	113	.Sh LEGACY SYNOPSIS
	114	.Fd #include <aio.h>
	115	.Pp
	116	.Ft int
	117	.br
	118	.Fo aio_return
	119	.Fa "struct aiocb *aiocbp"
	120	.Fc ;
	121	.Pp
	122	The type of the return value has changed.
91447636 A	123	.Sh SEE ALSO
	124	.Xr aio_cancel 2 ,
	125	.Xr aio_error 2 ,
	126	.Xr aio_suspend 2 ,
	127	.Xr aio_write 2 ,
	128	.Xr fsync 2 ,
	129	.Xr read 2 ,
	130	.Xr write 2 ,
2d21ac55 A	131	.Xr aio 4 ,
2d21ac55 A	132	.Xr compat 5
91447636 A	133	.Sh STANDARDS
	134	The
	135	.Fn aio_return
	136	system call
	137	is expected to conform to the
	138	.St -p1003.1
	139	standard.
	140	.Sh HISTORY
	141	The
	142	.Fn aio_return
	143	system call first appeared in
	144	.Fx 3.0 .
	145	.Sh AUTHORS
	146	This
	147	manual page was written by
	148	.An Wes Peters Aq wes@softweyr.com .