1 /*
2 * pthread_rwlock_init.c
3 *
4 * Description:
5 * This translation unit implements read/write lock primitives.
6 *
7 * --------------------------------------------------------------------------
8 *
9 * Pthreads-win32 - POSIX Threads Library for Win32
10 * Copyright(C) 1998 John E. Bossom
11 * Copyright(C) 1999,2005 Pthreads-win32 contributors
12 *
13 * Contact Email: rpj@callisto.canberra.edu.au
14 *
15 * The current list of contributors is contained
16 * in the file CONTRIBUTORS included with the source
17 * code distribution. The list can also be seen at the
18 * following World Wide Web location:
19 * http://sources.redhat.com/pthreads-win32/contributors.html
20 *
21 * This library is free software; you can redistribute it and/or
22 * modify it under the terms of the GNU Lesser General Public
23 * License as published by the Free Software Foundation; either
24 * version 2 of the License, or (at your option) any later version.
25 *
26 * This library is distributed in the hope that it will be useful,
27 * but WITHOUT ANY WARRANTY; without even the implied warranty of
28 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
29 * Lesser General Public License for more details.
30 *
31 * You should have received a copy of the GNU Lesser General Public
32 * License along with this library in the file COPYING.LIB;
33 * if not, write to the Free Software Foundation, Inc.,
34 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
35 */
36
37 #include <limits.h>
38
39 #include "pthread.h"
40 #include "implement.h"
41
42 int
pthread_rwlock_init(pthread_rwlock_t * rwlock,const pthread_rwlockattr_t * attr)43 pthread_rwlock_init (pthread_rwlock_t * rwlock,
44 const pthread_rwlockattr_t * attr)
45 {
46 int result;
47 pthread_rwlock_t rwl = 0;
48
49 if (rwlock == NULL)
50 {
51 return EINVAL;
52 }
53
54 if (attr != NULL && *attr != NULL)
55 {
56 result = EINVAL; /* Not supported */
57 goto DONE;
58 }
59
60 rwl = (pthread_rwlock_t) calloc (1, sizeof (*rwl));
61
62 if (rwl == NULL)
63 {
64 result = ENOMEM;
65 goto DONE;
66 }
67
68 rwl->nSharedAccessCount = 0;
69 rwl->nExclusiveAccessCount = 0;
70 rwl->nCompletedSharedAccessCount = 0;
71
72 result = pthread_mutex_init (&rwl->mtxExclusiveAccess, NULL);
73 if (result != 0)
74 {
75 goto FAIL0;
76 }
77
78 result = pthread_mutex_init (&rwl->mtxSharedAccessCompleted, NULL);
79 if (result != 0)
80 {
81 goto FAIL1;
82 }
83
84 result = pthread_cond_init (&rwl->cndSharedAccessCompleted, NULL);
85 if (result != 0)
86 {
87 goto FAIL2;
88 }
89
90 rwl->nMagic = PTW32_RWLOCK_MAGIC;
91
92 result = 0;
93 goto DONE;
94
95 FAIL2:
96 (void) pthread_mutex_destroy (&(rwl->mtxSharedAccessCompleted));
97
98 FAIL1:
99 (void) pthread_mutex_destroy (&(rwl->mtxExclusiveAccess));
100
101 FAIL0:
102 (void) free (rwl);
103 rwl = NULL;
104
105 DONE:
106 *rwlock = rwl;
107
108 return result;
109 }
110