1 /*
2 * ptw32_mutex_check_need_init.c
3 *
4 * Description:
5 * This translation unit implements mutual exclusion (mutex) 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 "pthread.h"
38 #include "implement.h"
39
40 static struct pthread_mutexattr_t_ ptw32_recursive_mutexattr_s =
41 {PTHREAD_PROCESS_PRIVATE, PTHREAD_MUTEX_RECURSIVE};
42 static struct pthread_mutexattr_t_ ptw32_errorcheck_mutexattr_s =
43 {PTHREAD_PROCESS_PRIVATE, PTHREAD_MUTEX_ERRORCHECK};
44 static pthread_mutexattr_t ptw32_recursive_mutexattr = &ptw32_recursive_mutexattr_s;
45 static pthread_mutexattr_t ptw32_errorcheck_mutexattr = &ptw32_errorcheck_mutexattr_s;
46
47
48 INLINE int
ptw32_mutex_check_need_init(pthread_mutex_t * mutex)49 ptw32_mutex_check_need_init (pthread_mutex_t * mutex)
50 {
51 register int result = 0;
52 register pthread_mutex_t mtx;
53 ptw32_mcs_local_node_t node;
54
55 ptw32_mcs_lock_acquire(&ptw32_mutex_test_init_lock, &node);
56
57 /*
58 * We got here possibly under race
59 * conditions. Check again inside the critical section
60 * and only initialise if the mutex is valid (not been destroyed).
61 * If a static mutex has been destroyed, the application can
62 * re-initialise it only by calling pthread_mutex_init()
63 * explicitly.
64 */
65 mtx = *mutex;
66
67 if (mtx == PTHREAD_MUTEX_INITIALIZER)
68 {
69 result = pthread_mutex_init (mutex, NULL);
70 }
71 else if (mtx == PTHREAD_RECURSIVE_MUTEX_INITIALIZER)
72 {
73 result = pthread_mutex_init (mutex, &ptw32_recursive_mutexattr);
74 }
75 else if (mtx == PTHREAD_ERRORCHECK_MUTEX_INITIALIZER)
76 {
77 result = pthread_mutex_init (mutex, &ptw32_errorcheck_mutexattr);
78 }
79 else if (mtx == NULL)
80 {
81 /*
82 * The mutex has been destroyed while we were waiting to
83 * initialise it, so the operation that caused the
84 * auto-initialisation should fail.
85 */
86 result = EINVAL;
87 }
88
89 ptw32_mcs_lock_release(&node);
90
91 return (result);
92 }
93