1 /* $NetBSD: mtx.c,v 1.1 2019/04/24 11:43:19 kamil Exp $ */
2
3 /*-
4 * Copyright (c) 2016 The NetBSD Foundation, Inc.
5 * All rights reserved.
6 *
7 * This code is derived from software contributed to The NetBSD Foundation
8 * by Kamil Rytarowski.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 __RCSID("$NetBSD: mtx.c,v 1.1 2019/04/24 11:43:19 kamil Exp $");
34
35 #include <assert.h>
36 #include <errno.h>
37 #include <pthread.h>
38 #include <threads.h>
39
40 void
mtx_destroy(mtx_t * mtx)41 mtx_destroy(mtx_t *mtx)
42 {
43
44 _DIAGASSERT(mtx != NULL);
45
46 /*
47 * The cnd_destroy(3) function that conforms to C11 returns no value.
48 */
49 (void)pthread_mutex_destroy(mtx);
50 }
51
52 static inline int
mtx_init_default(mtx_t * mtx)53 mtx_init_default(mtx_t *mtx)
54 {
55
56 _DIAGASSERT(mtx != NULL);
57
58 if (pthread_mutex_init(mtx, NULL) != 0)
59 return thrd_error;
60
61 return thrd_success;
62 }
63
64 static inline int
mtx_init_recursive(mtx_t * mtx)65 mtx_init_recursive(mtx_t *mtx)
66 {
67 pthread_mutexattr_t attr;
68
69 _DIAGASSERT(mtx != NULL);
70
71 if (pthread_mutexattr_init(&attr) != 0)
72 return thrd_error;
73
74 if (pthread_mutexattr_settype(&attr, PTHREAD_MUTEX_RECURSIVE) != 0) {
75 pthread_mutexattr_destroy(&attr);
76
77 return thrd_error;
78 }
79
80 if (pthread_mutex_init(mtx, &attr) == 0)
81 return thrd_success;
82
83 pthread_mutexattr_destroy(&attr);
84
85 return thrd_error;
86 }
87
88 int
mtx_init(mtx_t * mtx,int type)89 mtx_init(mtx_t *mtx, int type)
90 {
91
92 _DIAGASSERT(mtx != NULL);
93
94 switch (type) {
95 case mtx_plain:
96 case mtx_timed:
97 return mtx_init_default(mtx);
98 case mtx_plain | mtx_recursive:
99 case mtx_timed | mtx_recursive:
100 return mtx_init_recursive(mtx);
101 default:
102 return thrd_error;
103 }
104 }
105
106 int
mtx_lock(mtx_t * mtx)107 mtx_lock(mtx_t *mtx)
108 {
109
110 _DIAGASSERT(mtx != NULL);
111
112 if (pthread_mutex_lock(mtx) == 0)
113 return thrd_success;
114
115 return thrd_error;
116 }
117
118 int
mtx_timedlock(mtx_t * __restrict mtx,const struct timespec * __restrict ts)119 mtx_timedlock(mtx_t *__restrict mtx, const struct timespec *__restrict ts)
120 {
121
122 _DIAGASSERT(mtx != NULL);
123 _DIAGASSERT(ts != NULL);
124
125 switch(pthread_mutex_timedlock(mtx, ts)) {
126 case 0:
127 return thrd_success;
128 case ETIMEDOUT:
129 return thrd_timedout;
130 default:
131 return thrd_error;
132 }
133 }
134
135 int
mtx_trylock(mtx_t * mtx)136 mtx_trylock(mtx_t *mtx)
137 {
138
139 _DIAGASSERT(mtx != NULL);
140
141 switch(pthread_mutex_trylock(mtx)) {
142 case 0:
143 return thrd_success;
144 case EBUSY:
145 return thrd_busy;
146 default:
147 return thrd_error;
148 }
149 }
150
151 int
mtx_unlock(mtx_t * mtx)152 mtx_unlock(mtx_t *mtx)
153 {
154
155 _DIAGASSERT(mtx != NULL);
156
157 if (pthread_mutex_unlock(mtx) == 0)
158 return thrd_success;
159
160 return thrd_error;
161 }
162