1 /*
2 * ptw32_cond_check_need_init.c
3 *
4 * Description:
5 * This translation unit implements condition variables and their primitives.
6 *
7 *
8 * --------------------------------------------------------------------------
9 *
10 * Pthreads-win32 - POSIX Threads Library for Win32
11 * Copyright(C) 1998 John E. Bossom
12 * Copyright(C) 1999,2005 Pthreads-win32 contributors
13 *
14 * Contact Email: rpj@callisto.canberra.edu.au
15 *
16 * The current list of contributors is contained
17 * in the file CONTRIBUTORS included with the source
18 * code distribution. The list can also be seen at the
19 * following World Wide Web location:
20 * http://sources.redhat.com/pthreads-win32/contributors.html
21 *
22 * This library is free software; you can redistribute it and/or
23 * modify it under the terms of the GNU Lesser General Public
24 * License as published by the Free Software Foundation; either
25 * version 2 of the License, or (at your option) any later version.
26 *
27 * This library is distributed in the hope that it will be useful,
28 * but WITHOUT ANY WARRANTY; without even the implied warranty of
29 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
30 * Lesser General Public License for more details.
31 *
32 * You should have received a copy of the GNU Lesser General Public
33 * License along with this library in the file COPYING.LIB;
34 * if not, write to the Free Software Foundation, Inc.,
35 * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA
36 */
37
38 #include "pthread.h"
39 #include "implement.h"
40
41
42 INLINE int
ptw32_cond_check_need_init(pthread_cond_t * cond)43 ptw32_cond_check_need_init (pthread_cond_t * cond)
44 {
45 int result = 0;
46 ptw32_mcs_local_node_t node;
47
48 /*
49 * The following guarded test is specifically for statically
50 * initialised condition variables (via PTHREAD_OBJECT_INITIALIZER).
51 */
52 ptw32_mcs_lock_acquire(&ptw32_cond_test_init_lock, &node);
53
54 /*
55 * We got here possibly under race
56 * conditions. Check again inside the critical section.
57 * If a static cv has been destroyed, the application can
58 * re-initialise it only by calling pthread_cond_init()
59 * explicitly.
60 */
61 if (*cond == PTHREAD_COND_INITIALIZER)
62 {
63 result = pthread_cond_init (cond, NULL);
64 }
65 else if (*cond == NULL)
66 {
67 /*
68 * The cv has been destroyed while we were waiting to
69 * initialise it, so the operation that caused the
70 * auto-initialisation should fail.
71 */
72 result = EINVAL;
73 }
74
75 ptw32_mcs_lock_release(&node);
76
77 return result;
78 }
79