xref: /freebsd/lib/librt/mq.c (revision 984485a02eb3e63b4170dd911b72de38b35b2289)
1 /*-
2  * Copyright (c) 2006 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, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  */
28 
29 #include <sys/cdefs.h>
30 #include <sys/types.h>
31 #include <sys/syscall.h>
32 #include <sys/mqueue.h>
33 
34 #include "namespace.h"
35 #include <errno.h>
36 #include <pthread.h>
37 #include <stddef.h>
38 #include <stdlib.h>
39 #include <signal.h>
40 #include "sigev_thread.h"
41 #include "un-namespace.h"
42 
43 extern int	__sys_kmq_notify(int, const struct sigevent *);
44 extern int	__sys_kmq_open(const char *, int, mode_t,
45 		    const struct mq_attr *);
46 extern int	__sys_kmq_setattr(int, const struct mq_attr *__restrict,
47 		    struct mq_attr *__restrict);
48 extern ssize_t	__sys_kmq_timedreceive(int, char *__restrict, size_t,
49 		    unsigned *__restrict, const struct timespec *__restrict);
50 extern int	__sys_kmq_timedsend(int, const char *, size_t, unsigned,
51 		    const struct timespec *);
52 extern int	__sys_kmq_unlink(const char *);
53 extern int	__sys_close(int fd);
54 
55 struct __mq {
56 	int oshandle;
57 	struct sigev_node *node;
58 };
59 
60 __weak_reference(__mq_open, mq_open);
61 __weak_reference(__mq_open, _mq_open);
62 __weak_reference(__mq_close, mq_close);
63 __weak_reference(__mq_close, _mq_close);
64 __weak_reference(__mq_notify, mq_notify);
65 __weak_reference(__mq_notify, _mq_notify);
66 __weak_reference(__mq_getattr, mq_getattr);
67 __weak_reference(__mq_getattr, _mq_getattr);
68 __weak_reference(__mq_setattr, mq_setattr);
69 __weak_reference(__mq_setattr, _mq_setattr);
70 __weak_reference(__mq_timedreceive_cancel, mq_timedreceive);
71 __weak_reference(__mq_timedreceive, _mq_timedreceive);
72 __weak_reference(__mq_timedsend_cancel, mq_timedsend);
73 __weak_reference(__mq_timedsend, _mq_timedsend);
74 __weak_reference(__mq_unlink, mq_unlink);
75 __weak_reference(__mq_unlink, _mq_unlink);
76 __weak_reference(__mq_send_cancel, mq_send);
77 __weak_reference(__mq_send, _mq_send);
78 __weak_reference(__mq_receive_cancel, mq_receive);
79 __weak_reference(__mq_receive, _mq_receive);
80 
81 mqd_t
82 __mq_open(const char *name, int oflag, mode_t mode,
83 	const struct mq_attr *attr)
84 {
85 	struct __mq *mq;
86 	int err;
87 
88 	mq = malloc(sizeof(struct __mq));
89 	if (mq == NULL)
90 		return (NULL);
91 
92 	mq->oshandle = __sys_kmq_open(name, oflag, mode, attr);
93 	if (mq->oshandle != -1) {
94 		mq->node = NULL;
95 		return (mq);
96 	}
97 	err = errno;
98 	free(mq);
99 	errno = err;
100 	return ((mqd_t)-1L);
101 }
102 
103 int
104 __mq_close(mqd_t mqd)
105 {
106 	int h;
107 
108 	if (mqd->node != NULL) {
109 		__sigev_list_lock();
110 		__sigev_delete_node(mqd->node);
111 		__sigev_list_unlock();
112 	}
113 	h = mqd->oshandle;
114 	free(mqd);
115 	return (__sys_close(h));
116 }
117 
118 typedef void (*mq_func)(union sigval val);
119 
120 static void
121 mq_dispatch(struct sigev_node *sn)
122 {
123 	mq_func f = sn->sn_func;
124 
125 	/*
126 	 * Check generation before calling user function,
127 	 * this should avoid expired notification.
128 	 */
129 	if (sn->sn_gen == sn->sn_info.si_value.sival_int)
130 		f(sn->sn_value);
131 }
132 
133 int
134 __mq_notify(mqd_t mqd, const struct sigevent *evp)
135 {
136 	struct sigevent ev;
137 	struct sigev_node *sn;
138 	int ret;
139 
140 	if (evp == NULL || evp->sigev_notify != SIGEV_THREAD) {
141 		if (mqd->node != NULL) {
142 			__sigev_list_lock();
143 			__sigev_delete_node(mqd->node);
144 			mqd->node = NULL;
145 			__sigev_list_unlock();
146 		}
147 		return __sys_kmq_notify(mqd->oshandle, evp);
148 	}
149 
150 	if (__sigev_check_init()) {
151 		/*
152 		 * Thread library is not enabled.
153 		 */
154 		errno = EINVAL;
155 		return (-1);
156 	}
157 
158 	sn = __sigev_alloc(SI_MESGQ, evp, mqd->node, 1);
159 	if (sn == NULL) {
160 		errno = EAGAIN;
161 		return (-1);
162 	}
163 
164 	sn->sn_id = mqd->oshandle;
165 	sn->sn_dispatch = mq_dispatch;
166 	__sigev_get_sigevent(sn, &ev, sn->sn_gen);
167 	__sigev_list_lock();
168 	if (mqd->node != NULL)
169 		__sigev_delete_node(mqd->node);
170 	mqd->node = sn;
171 	__sigev_register(sn);
172 	ret = __sys_kmq_notify(mqd->oshandle, &ev);
173 	__sigev_list_unlock();
174 	return (ret);
175 }
176 
177 int
178 __mq_getattr(mqd_t mqd, struct mq_attr *attr)
179 {
180 
181 	return __sys_kmq_setattr(mqd->oshandle, NULL, attr);
182 }
183 
184 int
185 __mq_setattr(mqd_t mqd, const struct mq_attr *newattr, struct mq_attr *oldattr)
186 {
187 
188 	return __sys_kmq_setattr(mqd->oshandle, newattr, oldattr);
189 }
190 
191 ssize_t
192 __mq_timedreceive(mqd_t mqd, char *buf, size_t len,
193 	unsigned *prio, const struct timespec *timeout)
194 {
195 
196 	return __sys_kmq_timedreceive(mqd->oshandle, buf, len, prio, timeout);
197 }
198 
199 ssize_t
200 __mq_timedreceive_cancel(mqd_t mqd, char *buf, size_t len,
201 	unsigned *prio, const struct timespec *timeout)
202 {
203 	int oldtype;
204 	int ret;
205 
206 	_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);
207 	ret = __sys_kmq_timedreceive(mqd->oshandle, buf, len, prio, timeout);
208 	_pthread_setcanceltype(oldtype, NULL);
209 	return (ret);
210 }
211 
212 ssize_t
213 __mq_receive(mqd_t mqd, char *buf, size_t len, unsigned *prio)
214 {
215 
216 	return __sys_kmq_timedreceive(mqd->oshandle, buf, len, prio, NULL);
217 }
218 
219 ssize_t
220 __mq_receive_cancel(mqd_t mqd, char *buf, size_t len, unsigned *prio)
221 {
222 	int oldtype;
223 	int ret;
224 
225 	_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);
226 	ret = __sys_kmq_timedreceive(mqd->oshandle, buf, len, prio, NULL);
227 	_pthread_setcanceltype(oldtype, NULL);
228 	return (ret);
229 }
230 ssize_t
231 __mq_timedsend(mqd_t mqd, char *buf, size_t len,
232 	unsigned prio, const struct timespec *timeout)
233 {
234 
235 	return __sys_kmq_timedsend(mqd->oshandle, buf, len, prio, timeout);
236 }
237 
238 ssize_t
239 __mq_timedsend_cancel(mqd_t mqd, char *buf, size_t len,
240 	unsigned prio, const struct timespec *timeout)
241 {
242 	int oldtype;
243 	int ret;
244 
245 	_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);
246 	ret = __sys_kmq_timedsend(mqd->oshandle, buf, len, prio, timeout);
247 	_pthread_setcanceltype(oldtype, NULL);
248 	return (ret);
249 }
250 
251 ssize_t
252 __mq_send(mqd_t mqd, char *buf, size_t len, unsigned prio)
253 {
254 
255 	return __sys_kmq_timedsend(mqd->oshandle, buf, len, prio, NULL);
256 }
257 
258 
259 ssize_t
260 __mq_send_cancel(mqd_t mqd, char *buf, size_t len, unsigned prio)
261 {
262 	int oldtype;
263 	int ret;
264 
265 	_pthread_setcanceltype(PTHREAD_CANCEL_ASYNCHRONOUS, &oldtype);
266 	ret = __sys_kmq_timedsend(mqd->oshandle, buf, len, prio, NULL);
267 	_pthread_setcanceltype(oldtype, NULL);
268 	return (ret);
269 }
270 
271 int
272 __mq_unlink(const char *path)
273 {
274 
275 	return __sys_kmq_unlink(path);
276 }
277 
278 int
279 __mq_oshandle(mqd_t mqd)
280 {
281 
282 	return (mqd->oshandle);
283 }
284