Mercurial > hg > CbC > CbC_gcc
comparison libgomp/config/posix/sem.c @ 0:a06113de4d67
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author | kent <kent@cr.ie.u-ryukyu.ac.jp> |
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date | Fri, 17 Jul 2009 14:47:48 +0900 |
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children | 04ced10e8804 |
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1 /* Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc. | |
2 Contributed by Richard Henderson <rth@redhat.com>. | |
3 | |
4 This file is part of the GNU OpenMP Library (libgomp). | |
5 | |
6 Libgomp is free software; you can redistribute it and/or modify it | |
7 under the terms of the GNU General Public License as published by | |
8 the Free Software Foundation; either version 3, or (at your option) | |
9 any later version. | |
10 | |
11 Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY | |
12 WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS | |
13 FOR A PARTICULAR PURPOSE. See the GNU General Public License for | |
14 more details. | |
15 | |
16 Under Section 7 of GPL version 3, you are granted additional | |
17 permissions described in the GCC Runtime Library Exception, version | |
18 3.1, as published by the Free Software Foundation. | |
19 | |
20 You should have received a copy of the GNU General Public License and | |
21 a copy of the GCC Runtime Library Exception along with this program; | |
22 see the files COPYING3 and COPYING.RUNTIME respectively. If not, see | |
23 <http://www.gnu.org/licenses/>. */ | |
24 | |
25 /* This is the default POSIX 1003.1b implementation of a semaphore | |
26 synchronization mechanism for libgomp. This type is private to | |
27 the library. | |
28 | |
29 This is a bit heavy weight for what we need, in that we're not | |
30 interested in sem_wait as a cancelation point, but it's not too | |
31 bad for a default. */ | |
32 | |
33 #include "libgomp.h" | |
34 | |
35 #ifdef HAVE_BROKEN_POSIX_SEMAPHORES | |
36 #include <stdlib.h> | |
37 | |
38 void gomp_sem_init (gomp_sem_t *sem, int value) | |
39 { | |
40 int ret; | |
41 | |
42 ret = pthread_mutex_init (&sem->mutex, NULL); | |
43 if (ret) | |
44 return; | |
45 | |
46 ret = pthread_cond_init (&sem->cond, NULL); | |
47 if (ret) | |
48 return; | |
49 | |
50 sem->value = value; | |
51 } | |
52 | |
53 void gomp_sem_wait (gomp_sem_t *sem) | |
54 { | |
55 int ret; | |
56 | |
57 ret = pthread_mutex_lock (&sem->mutex); | |
58 if (ret) | |
59 return; | |
60 | |
61 if (sem->value > 0) | |
62 { | |
63 sem->value--; | |
64 ret = pthread_mutex_unlock (&sem->mutex); | |
65 return; | |
66 } | |
67 | |
68 while (sem->value <= 0) | |
69 { | |
70 ret = pthread_cond_wait (&sem->cond, &sem->mutex); | |
71 if (ret) | |
72 { | |
73 pthread_mutex_unlock (&sem->mutex); | |
74 return; | |
75 } | |
76 } | |
77 | |
78 sem->value--; | |
79 ret = pthread_mutex_unlock (&sem->mutex); | |
80 return; | |
81 } | |
82 | |
83 void gomp_sem_post (gomp_sem_t *sem) | |
84 { | |
85 int ret; | |
86 | |
87 ret = pthread_mutex_lock (&sem->mutex); | |
88 if (ret) | |
89 return; | |
90 | |
91 sem->value++; | |
92 | |
93 ret = pthread_mutex_unlock (&sem->mutex); | |
94 if (ret) | |
95 return; | |
96 | |
97 ret = pthread_cond_signal (&sem->cond); | |
98 | |
99 return; | |
100 } | |
101 | |
102 void gomp_sem_destroy (gomp_sem_t *sem) | |
103 { | |
104 int ret; | |
105 | |
106 ret = pthread_mutex_destroy (&sem->mutex); | |
107 if (ret) | |
108 return; | |
109 | |
110 ret = pthread_cond_destroy (&sem->cond); | |
111 | |
112 return; | |
113 } | |
114 #else /* HAVE_BROKEN_POSIX_SEMAPHORES */ | |
115 void | |
116 gomp_sem_wait (gomp_sem_t *sem) | |
117 { | |
118 /* With POSIX, the wait can be canceled by signals. We don't want that. | |
119 It is expected that the return value here is -1 and errno is EINTR. */ | |
120 while (sem_wait (sem) != 0) | |
121 continue; | |
122 } | |
123 #endif |