xref: /freebsd/lib/librt/aio.c (revision 5dae51da3da0cc94d17bd67b308fad304ebec7e0)
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  * $FreeBSD$
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 __weak_reference(__aio_fsync, _aio_fsync);
51 __weak_reference(__aio_fsync, aio_fsync);
52 
53 typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
54 
55 extern int __sys_aio_read(struct aiocb *iocb);
56 extern int __sys_aio_write(struct aiocb *iocb);
57 extern ssize_t __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
58 extern ssize_t __sys_aio_return(struct aiocb *iocb);
59 extern int __sys_aio_error(struct aiocb *iocb);
60 extern int __sys_aio_fsync(int op, struct aiocb *iocb);
61 
62 static void
63 aio_dispatch(struct sigev_node *sn)
64 {
65 	aio_func f = sn->sn_func;
66 
67 	f(sn->sn_value, (struct aiocb *)sn->sn_id);
68 }
69 
70 static int
71 aio_sigev_alloc(struct aiocb *iocb, struct sigev_node **sn,
72 	struct sigevent *saved_ev)
73 {
74 	if (__sigev_check_init()) {
75 		/* This might be that thread library is not enabled. */
76 		errno = EINVAL;
77 		return (-1);
78 	}
79 
80 	*sn = __sigev_alloc(SI_ASYNCIO, &iocb->aio_sigevent, NULL, 1);
81 	if (*sn == NULL) {
82 		errno = EAGAIN;
83 		return (-1);
84 	}
85 
86 	*saved_ev = iocb->aio_sigevent;
87 	(*sn)->sn_id = (sigev_id_t)iocb;
88 	__sigev_get_sigevent(*sn, &iocb->aio_sigevent, (*sn)->sn_id);
89 	(*sn)->sn_dispatch = aio_dispatch;
90 
91 	__sigev_list_lock();
92 	__sigev_register(*sn);
93 	__sigev_list_unlock();
94 
95 	return (0);
96 }
97 
98 static int
99 aio_io(struct aiocb *iocb, int (*sysfunc)(struct aiocb *iocb))
100 {
101 	struct sigev_node *sn;
102 	struct sigevent saved_ev;
103 	int ret, err;
104 
105 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD) {
106 		ret = sysfunc(iocb);
107 		return (ret);
108 	}
109 
110 	ret = aio_sigev_alloc(iocb, &sn, &saved_ev);
111 	if (ret)
112 		return (ret);
113 	ret = sysfunc(iocb);
114 	iocb->aio_sigevent = saved_ev;
115 	if (ret != 0) {
116 		err = errno;
117 		__sigev_list_lock();
118 		__sigev_delete_node(sn);
119 		__sigev_list_unlock();
120 		errno = err;
121 	}
122 	return (ret);
123 }
124 
125 int
126 __aio_read(struct aiocb *iocb)
127 {
128 
129 	return aio_io(iocb, &__sys_aio_read);
130 }
131 
132 int
133 __aio_write(struct aiocb *iocb)
134 {
135 
136 	return aio_io(iocb, &__sys_aio_write);
137 }
138 
139 ssize_t
140 __aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout)
141 {
142 	ssize_t ret;
143 	int err;
144 
145 	ret = __sys_aio_waitcomplete(iocbp, timeout);
146 	if (*iocbp) {
147 		if ((*iocbp)->aio_sigevent.sigev_notify == SIGEV_THREAD) {
148 			err = errno;
149 			__sigev_list_lock();
150 			__sigev_delete(SI_ASYNCIO, (sigev_id_t)(*iocbp));
151 			__sigev_list_unlock();
152 			errno = err;
153 		}
154 	}
155 
156 	return (ret);
157 }
158 
159 ssize_t
160 __aio_return(struct aiocb *iocb)
161 {
162 
163 	if (iocb->aio_sigevent.sigev_notify == SIGEV_THREAD) {
164 		if (__sys_aio_error(iocb) == EINPROGRESS) {
165 			/*
166 			 * Fail with EINVAL to match the semantics of
167 			 * __sys_aio_return() for an in-progress
168 			 * request.
169 			 */
170 			errno = EINVAL;
171 			return (-1);
172 		}
173 		__sigev_list_lock();
174 		__sigev_delete(SI_ASYNCIO, (sigev_id_t)iocb);
175 		__sigev_list_unlock();
176 	}
177 
178 	return __sys_aio_return(iocb);
179 }
180 
181 int
182 __aio_fsync(int op, struct aiocb *iocb)
183 {
184 	struct sigev_node *sn;
185 	struct sigevent saved_ev;
186 	int ret, err;
187 
188 	if (iocb->aio_sigevent.sigev_notify != SIGEV_THREAD)
189 		return __sys_aio_fsync(op, iocb);
190 
191 	ret = aio_sigev_alloc(iocb, &sn, &saved_ev);
192 	if (ret)
193 		return (ret);
194 	ret = __sys_aio_fsync(op, iocb);
195 	iocb->aio_sigevent = saved_ev;
196 	if (ret != 0) {
197 		err = errno;
198 		__sigev_list_lock();
199 		__sigev_delete_node(sn);
200 		__sigev_list_unlock();
201 		errno = err;
202 	}
203 	return (ret);
204 }
205