/[pcsx2_0.9.7]/trunk/3rdparty/w32pthreads/pthread_rwlock_destroy.c
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Contents of /trunk/3rdparty/w32pthreads/pthread_rwlock_destroy.c

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Revision 31 - (show annotations) (download)
Tue Sep 7 03:24:11 2010 UTC (9 years, 11 months ago) by william
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committing r3113 initial commit again...
1 /*
2 * pthread_rwlock_destroy.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 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
35 */
36
37 #include "ptw32pch.h"
38
39 int
40 pthread_rwlock_destroy (pthread_rwlock_t * rwlock)
41 {
42 pthread_rwlock_t rwl;
43 int result = 0, result1 = 0, result2 = 0;
44
45 if (rwlock == NULL || *rwlock == NULL)
46 {
47 return EINVAL;
48 }
49
50 if (*rwlock != PTHREAD_RWLOCK_INITIALIZER)
51 {
52 rwl = *rwlock;
53
54 if (rwl->nMagic != PTW32_RWLOCK_MAGIC)
55 {
56 return EINVAL;
57 }
58
59 if ((result = pthread_mutex_lock (&(rwl->mtxExclusiveAccess))) != 0)
60 {
61 return result;
62 }
63
64 if ((result =
65 pthread_mutex_lock (&(rwl->mtxSharedAccessCompleted))) != 0)
66 {
67 (void) pthread_mutex_unlock (&(rwl->mtxExclusiveAccess));
68 return result;
69 }
70
71 /*
72 * Check whether any threads own/wait for the lock (wait for ex.access);
73 * report "BUSY" if so.
74 */
75 if (rwl->nExclusiveAccessCount > 0
76 || rwl->nSharedAccessCount > rwl->nCompletedSharedAccessCount)
77 {
78 result = pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted));
79 result1 = pthread_mutex_unlock (&(rwl->mtxExclusiveAccess));
80 result2 = EBUSY;
81 }
82 else
83 {
84 rwl->nMagic = 0;
85
86 if ((result =
87 pthread_mutex_unlock (&(rwl->mtxSharedAccessCompleted))) != 0)
88 {
89 pthread_mutex_unlock (&rwl->mtxExclusiveAccess);
90 return result;
91 }
92
93 if ((result =
94 pthread_mutex_unlock (&(rwl->mtxExclusiveAccess))) != 0)
95 {
96 return result;
97 }
98
99 *rwlock = NULL; /* Invalidate rwlock before anything else */
100 result = pthread_cond_destroy (&(rwl->cndSharedAccessCompleted));
101 result1 = pthread_mutex_destroy (&(rwl->mtxSharedAccessCompleted));
102 result2 = pthread_mutex_destroy (&(rwl->mtxExclusiveAccess));
103 (void) free (rwl);
104 }
105 }
106 else
107 {
108 /*
109 * See notes in ptw32_rwlock_check_need_init() above also.
110 */
111 EnterCriticalSection (&ptw32_rwlock_test_init_lock);
112
113 /*
114 * Check again.
115 */
116 if (*rwlock == PTHREAD_RWLOCK_INITIALIZER)
117 {
118 /*
119 * This is all we need to do to destroy a statically
120 * initialised rwlock that has not yet been used (initialised).
121 * If we get to here, another thread
122 * waiting to initialise this rwlock will get an EINVAL.
123 */
124 *rwlock = NULL;
125 }
126 else
127 {
128 /*
129 * The rwlock has been initialised while we were waiting
130 * so assume it's in use.
131 */
132 result = EBUSY;
133 }
134
135 LeaveCriticalSection (&ptw32_rwlock_test_init_lock);
136 }
137
138 return ((result != 0) ? result : ((result1 != 0) ? result1 : result2));
139 }

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