aio.c revision 156267 
1/*
2 * Copyright (c) 2005 David Xu <davidxu@freebsd.org>
3 * All rights reserved.
4 *
5 * Redistribution and use in source and binary forms, with or without
6 * modification, are permitted provided that the following conditions
7 * are met:
8 * 1. Redistributions of source code must retain the above copyright
9 *    notice unmodified, this list of conditions, and the following
10 *    disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 *    notice, this list of conditions and the following disclaimer in the
13 *    documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
16 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
17 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
18 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
19 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
20 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
21 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
22 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
23 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
24 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
25 *
26 * $FreeBSD: head/lib/librt/aio.c 156267 2006-03-04 00:18:19Z davidxu $
27 *
28 */
29
30#include <sys/cdefs.h>
31#include <sys/types.h>
32#include <sys/syscall.h>
33#include <sys/aio.h>
34
35#include "namespace.h"
36#include <errno.h>
37#include <pthread.h>
38#include <stddef.h>
39#include <signal.h>
40#include <unistd.h>
41#include "sigev_thread.h"
42#include "un-namespace.h"
43
44__weak_reference(__aio_read, _aio_read);
45__weak_reference(__aio_read, aio_read);
46__weak_reference(__aio_write, _aio_write);
47__weak_reference(__aio_write, aio_write);
48__weak_reference(__aio_return, _aio_return);
49__weak_reference(__aio_return, aio_return);
50__weak_reference(__aio_waitcomplete, _aio_waitcomplete);
51__weak_reference(__aio_waitcomplete, aio_waitcomplete);
52
53typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
54
55extern int __sys_aio_read(struct aiocb *iocb);
56extern int __sys_aio_write(struct aiocb *iocb);
57extern int __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
58extern int __sys_aio_return(struct aiocb *iocb);
59extern int __sys_aio_error(struct aiocb *iocb);
60
61static void
62aio_dispatch(struct sigev_node *sn)
63{
64	aio_func f = sn->sn_func;
65
66	f(sn->sn_value, (struct aiocb *)sn->sn_id);
67}
68
69static int
70aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
71{
72	struct sigev_node *sn;
73	struct sigevent saved_ev;
74	int ret, err;
75
76	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
77		ret = sysfunc(iocb);
78		return (ret);
79	}
80
81	if (__sigev_check_init()) {
82		/* This might be that thread library is not enabled. */
83		errno = EINVAL;
84		return (-1);
85	}
86
87	sn = __sigev_alloc(SI_ASYNCIO, &iocb->aio_sigevent, NULL, 1);
88	if (sn == NULL) {
89		errno = EAGAIN;
90		return (-1);
91	}
92
93	saved_ev = iocb->aio_sigevent;
94	sn->sn_id = (sigev_id_t)iocb;
95	sn->sn_flags |= SNF_ONESHOT;
96	__sigev_get_sigevent(sn, &iocb->aio_sigevent, sn->sn_id);
97
98	__sigev_list_lock();
99	__sigev_register(sn);
100	__sigev_list_unlock();
101
102	sn->sn_dispatch = aio_dispatch;
103	ret = sysfunc(iocb);
104	iocb->aio_sigevent = saved_ev;
105
106	if (ret != 0) {
107		err = errno;
108		__sigev_list_lock();
109		__sigev_delete_node(sn);
110		__sigev_list_unlock();
111		errno = err;
112	}
113	return (ret);
114}
115
116int
117__aio_read(struct aiocb *iocb)
118{
119
120	return aio_io(iocb, &__sys_aio_read);
121}
122
123int
124__aio_write(struct aiocb *iocb)
125{
126
127	return aio_io(iocb, &__sys_aio_write);
128}
129
130int
131__aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
132{
133	int err;
134	int ret = __sys_aio_waitcomplete(iocbp, timeout);
135
136	if (*iocbp) {
137		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
138			err = errno;
139			__sigev_list_lock();
140			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
141			__sigev_list_unlock();
142			errno = err;
143		}
144	}
145
146	return (ret);
147}
148
149int
150__aio_return(struct aiocb *iocb)
151{
152
153	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
154		if (__sys_aio_error(iocb) == EINPROGRESS)
155			return (EINPROGRESS);
156		__sigev_list_lock();
157		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
158		__sigev_list_unlock();
159	}
160
161	return __sys_aio_return(iocb);
162}
163