xref: /freebsd/lib/librt/aio.c (revision 87569f75a91f298c52a71823c04d41cf53c88889)
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 
51 typedef void (*aio_func)(union sigval val, struct aiocb *iocb);
52 
53 extern int __sys_aio_read(struct aiocb *iocb);
54 extern int __sys_aio_write(struct aiocb *iocb);
55 extern int __sys_aio_waitcomplete(struct aiocb **iocbp, struct timespec *timeout);
56 extern int __sys_aio_return(struct aiocb *iocb);
57 extern int __sys_aio_error(struct aiocb *iocb);
58 
59 static void
60 aio_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 
67 static int
68 aio_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 
113 int
114 __aio_read(struct aiocb *iocb)
115 {
116 
117 	return aio_io(iocb, &__sys_aio_read);
118 }
119 
120 int
121 __aio_write(struct aiocb *iocb)
122 {
123 
124 	return aio_io(iocb, &__sys_aio_write);
125 }
126 
127 int
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 
146 int
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