xref: /dflybsd-src/contrib/gcc-4.7/libgomp/config/posix/sem.c (revision 94b98a915ba84699b2a2adab9146fbc2cf617459)
1*629ff9f7SJohn Marino /* Copyright (C) 2005, 2006, 2009 Free Software Foundation, Inc.
2*629ff9f7SJohn Marino    Contributed by Richard Henderson <rth@redhat.com>.
3*629ff9f7SJohn Marino 
4*629ff9f7SJohn Marino    This file is part of the GNU OpenMP Library (libgomp).
5*629ff9f7SJohn Marino 
6*629ff9f7SJohn Marino    Libgomp is free software; you can redistribute it and/or modify it
7*629ff9f7SJohn Marino    under the terms of the GNU General Public License as published by
8*629ff9f7SJohn Marino    the Free Software Foundation; either version 3, or (at your option)
9*629ff9f7SJohn Marino    any later version.
10*629ff9f7SJohn Marino 
11*629ff9f7SJohn Marino    Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12*629ff9f7SJohn Marino    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13*629ff9f7SJohn Marino    FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
14*629ff9f7SJohn Marino    more details.
15*629ff9f7SJohn Marino 
16*629ff9f7SJohn Marino    Under Section 7 of GPL version 3, you are granted additional
17*629ff9f7SJohn Marino    permissions described in the GCC Runtime Library Exception, version
18*629ff9f7SJohn Marino    3.1, as published by the Free Software Foundation.
19*629ff9f7SJohn Marino 
20*629ff9f7SJohn Marino    You should have received a copy of the GNU General Public License and
21*629ff9f7SJohn Marino    a copy of the GCC Runtime Library Exception along with this program;
22*629ff9f7SJohn Marino    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
23*629ff9f7SJohn Marino    <http://www.gnu.org/licenses/>.  */
24*629ff9f7SJohn Marino 
25*629ff9f7SJohn Marino /* This is the default POSIX 1003.1b implementation of a semaphore
26*629ff9f7SJohn Marino    synchronization mechanism for libgomp.  This type is private to
27*629ff9f7SJohn Marino    the library.
28*629ff9f7SJohn Marino 
29*629ff9f7SJohn Marino    This is a bit heavy weight for what we need, in that we're not
30*629ff9f7SJohn Marino    interested in sem_wait as a cancelation point, but it's not too
31*629ff9f7SJohn Marino    bad for a default.  */
32*629ff9f7SJohn Marino 
33*629ff9f7SJohn Marino #include "libgomp.h"
34*629ff9f7SJohn Marino 
35*629ff9f7SJohn Marino #ifdef HAVE_BROKEN_POSIX_SEMAPHORES
36*629ff9f7SJohn Marino #include <stdlib.h>
37*629ff9f7SJohn Marino 
gomp_sem_init(gomp_sem_t * sem,int value)38*629ff9f7SJohn Marino void gomp_sem_init (gomp_sem_t *sem, int value)
39*629ff9f7SJohn Marino {
40*629ff9f7SJohn Marino   int ret;
41*629ff9f7SJohn Marino 
42*629ff9f7SJohn Marino   ret = pthread_mutex_init (&sem->mutex, NULL);
43*629ff9f7SJohn Marino   if (ret)
44*629ff9f7SJohn Marino     return;
45*629ff9f7SJohn Marino 
46*629ff9f7SJohn Marino   ret = pthread_cond_init (&sem->cond, NULL);
47*629ff9f7SJohn Marino   if (ret)
48*629ff9f7SJohn Marino     return;
49*629ff9f7SJohn Marino 
50*629ff9f7SJohn Marino   sem->value = value;
51*629ff9f7SJohn Marino }
52*629ff9f7SJohn Marino 
gomp_sem_wait(gomp_sem_t * sem)53*629ff9f7SJohn Marino void gomp_sem_wait (gomp_sem_t *sem)
54*629ff9f7SJohn Marino {
55*629ff9f7SJohn Marino   int ret;
56*629ff9f7SJohn Marino 
57*629ff9f7SJohn Marino   ret = pthread_mutex_lock (&sem->mutex);
58*629ff9f7SJohn Marino   if (ret)
59*629ff9f7SJohn Marino     return;
60*629ff9f7SJohn Marino 
61*629ff9f7SJohn Marino   if (sem->value > 0)
62*629ff9f7SJohn Marino     {
63*629ff9f7SJohn Marino       sem->value--;
64*629ff9f7SJohn Marino       ret = pthread_mutex_unlock (&sem->mutex);
65*629ff9f7SJohn Marino       return;
66*629ff9f7SJohn Marino     }
67*629ff9f7SJohn Marino 
68*629ff9f7SJohn Marino   while (sem->value <= 0)
69*629ff9f7SJohn Marino     {
70*629ff9f7SJohn Marino       ret = pthread_cond_wait (&sem->cond, &sem->mutex);
71*629ff9f7SJohn Marino       if (ret)
72*629ff9f7SJohn Marino 	{
73*629ff9f7SJohn Marino 	  pthread_mutex_unlock (&sem->mutex);
74*629ff9f7SJohn Marino 	  return;
75*629ff9f7SJohn Marino 	}
76*629ff9f7SJohn Marino     }
77*629ff9f7SJohn Marino 
78*629ff9f7SJohn Marino   sem->value--;
79*629ff9f7SJohn Marino   ret = pthread_mutex_unlock (&sem->mutex);
80*629ff9f7SJohn Marino   return;
81*629ff9f7SJohn Marino }
82*629ff9f7SJohn Marino 
gomp_sem_post(gomp_sem_t * sem)83*629ff9f7SJohn Marino void gomp_sem_post (gomp_sem_t *sem)
84*629ff9f7SJohn Marino {
85*629ff9f7SJohn Marino   int ret;
86*629ff9f7SJohn Marino 
87*629ff9f7SJohn Marino   ret = pthread_mutex_lock (&sem->mutex);
88*629ff9f7SJohn Marino   if (ret)
89*629ff9f7SJohn Marino     return;
90*629ff9f7SJohn Marino 
91*629ff9f7SJohn Marino   sem->value++;
92*629ff9f7SJohn Marino 
93*629ff9f7SJohn Marino   ret = pthread_mutex_unlock (&sem->mutex);
94*629ff9f7SJohn Marino   if (ret)
95*629ff9f7SJohn Marino     return;
96*629ff9f7SJohn Marino 
97*629ff9f7SJohn Marino   ret = pthread_cond_signal (&sem->cond);
98*629ff9f7SJohn Marino 
99*629ff9f7SJohn Marino   return;
100*629ff9f7SJohn Marino }
101*629ff9f7SJohn Marino 
gomp_sem_destroy(gomp_sem_t * sem)102*629ff9f7SJohn Marino void gomp_sem_destroy (gomp_sem_t *sem)
103*629ff9f7SJohn Marino {
104*629ff9f7SJohn Marino   int ret;
105*629ff9f7SJohn Marino 
106*629ff9f7SJohn Marino   ret = pthread_mutex_destroy (&sem->mutex);
107*629ff9f7SJohn Marino   if (ret)
108*629ff9f7SJohn Marino     return;
109*629ff9f7SJohn Marino 
110*629ff9f7SJohn Marino   ret = pthread_cond_destroy (&sem->cond);
111*629ff9f7SJohn Marino 
112*629ff9f7SJohn Marino   return;
113*629ff9f7SJohn Marino }
114*629ff9f7SJohn Marino #else /* HAVE_BROKEN_POSIX_SEMAPHORES  */
115*629ff9f7SJohn Marino void
gomp_sem_wait(gomp_sem_t * sem)116*629ff9f7SJohn Marino gomp_sem_wait (gomp_sem_t *sem)
117*629ff9f7SJohn Marino {
118*629ff9f7SJohn Marino   /* With POSIX, the wait can be canceled by signals.  We don't want that.
119*629ff9f7SJohn Marino      It is expected that the return value here is -1 and errno is EINTR.  */
120*629ff9f7SJohn Marino   while (sem_wait (sem) != 0)
121*629ff9f7SJohn Marino     continue;
122*629ff9f7SJohn Marino }
123*629ff9f7SJohn Marino #endif
124