aio.c revision 156383 
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 156383 2006-03-07 08:28:07Z 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 <stddef.h>
38#include <signal.h>
39#include "sigev_thread.h"
40#include "un-namespace.h"
41
42__weak_reference(__aio_read, _aio_read);
43__weak_reference(__aio_read, aio_read);
44__weak_reference(__aio_write, _aio_write);
45__weak_reference(__aio_write, aio_write);
46__weak_reference(__aio_return, _aio_return);
47__weak_reference(__aio_return, aio_return);
48__weak_reference(__aio_waitcomplete, _aio_waitcomplete);
49__weak_reference(__aio_waitcomplete, aio_waitcomplete);
50
51typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
52
53extern int __sys_aio_read(struct aiocb *iocb);
54extern int __sys_aio_write(struct aiocb *iocb);
55extern int __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
56extern int __sys_aio_return(struct aiocb *iocb);
57extern int __sys_aio_error(struct aiocb *iocb);
58
59static void
60aio_dispatch(struct sigev_node *sn)
61{
62	aio_func f = sn->sn_func;
63
64	f(sn->sn_value, (struct aiocb *)sn->sn_id);
65}
66
67static int
68aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
69{
70	struct sigev_node *sn;
71	struct sigevent saved_ev;
72	int ret, err;
73
74	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
75		ret = sysfunc(iocb);
76		return (ret);
77	}
78
79	if (__sigev_check_init()) {
80		/* This might be that thread library is not enabled. */
81		errno = EINVAL;
82		return (-1);
83	}
84
85	sn = __sigev_alloc(SI_ASYNCIO, &iocb->aio_sigevent, NULL, 1);
86	if (sn == NULL) {
87		errno = EAGAIN;
88		return (-1);
89	}
90
91	saved_ev = iocb->aio_sigevent;
92	sn->sn_id = (sigev_id_t)iocb;
93	__sigev_get_sigevent(sn, &iocb->aio_sigevent, sn->sn_id);
94
95	__sigev_list_lock();
96	__sigev_register(sn);
97	__sigev_list_unlock();
98
99	sn->sn_dispatch = aio_dispatch;
100	ret = sysfunc(iocb);
101	iocb->aio_sigevent = saved_ev;
102
103	if (ret != 0) {
104		err = errno;
105		__sigev_list_lock();
106		__sigev_delete_node(sn);
107		__sigev_list_unlock();
108		errno = err;
109	}
110	return (ret);
111}
112
113int
114__aio_read(struct aiocb *iocb)
115{
116
117	return aio_io(iocb, &__sys_aio_read);
118}
119
120int
121__aio_write(struct aiocb *iocb)
122{
123
124	return aio_io(iocb, &__sys_aio_write);
125}
126
127int
128__aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
129{
130	int err;
131	int ret = __sys_aio_waitcomplete(iocbp, timeout);
132
133	if (*iocbp) {
134		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
135			err = errno;
136			__sigev_list_lock();
137			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
138			__sigev_list_unlock();
139			errno = err;
140		}
141	}
142
143	return (ret);
144}
145
146int
147__aio_return(struct aiocb *iocb)
148{
149
150	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
151		if (__sys_aio_error(iocb) == EINPROGRESS)
152			return (EINPROGRESS);
153		__sigev_list_lock();
154		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
155		__sigev_list_unlock();
156	}
157
158	return __sys_aio_return(iocb);
159}
160