1169695Skan/* Copyright (C) 2005 Free Software Foundation, Inc.
2169695Skan   Contributed by Richard Henderson <rth@redhat.com>.
3169695Skan
4169695Skan   This file is part of the GNU OpenMP Library (libgomp).
5169695Skan
6169695Skan   Libgomp is free software; you can redistribute it and/or modify it
7169695Skan   under the terms of the GNU Lesser General Public License as published by
8169695Skan   the Free Software Foundation; either version 2.1 of the License, or
9169695Skan   (at your option) any later version.
10169695Skan
11169695Skan   Libgomp is distributed in the hope that it will be useful, but WITHOUT ANY
12169695Skan   WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
13169695Skan   FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public License for
14169695Skan   more details.
15169695Skan
16169695Skan   You should have received a copy of the GNU Lesser General Public License
17169695Skan   along with libgomp; see the file COPYING.LIB.  If not, write to the
18169695Skan   Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
19169695Skan   MA 02110-1301, USA.  */
20169695Skan
21169695Skan/* As a special exception, if you link this library with other files, some
22169695Skan   of which are compiled with GCC, to produce an executable, this library
23169695Skan   does not by itself cause the resulting executable to be covered by the
24169695Skan   GNU General Public License.  This exception does not however invalidate
25169695Skan   any other reasons why the executable file might be covered by the GNU
26169695Skan   General Public License.  */
27169695Skan
28169695Skan/* This is a Linux specific implementation of a semaphore synchronization
29169695Skan   mechanism for libgomp.  This type is private to the library.  This
30169695Skan   implementation uses atomic instructions and the futex syscall.  */
31169695Skan
32169695Skan#ifndef GOMP_SEM_H
33169695Skan#define GOMP_SEM_H 1
34169695Skan
35169695Skantypedef int gomp_sem_t;
36169695Skan
37169695Skanstatic inline void gomp_sem_init (gomp_sem_t *sem, int value)
38169695Skan{
39169695Skan  *sem = value;
40169695Skan}
41169695Skan
42169695Skanextern void gomp_sem_wait_slow (gomp_sem_t *);
43169695Skanstatic inline void gomp_sem_wait (gomp_sem_t *sem)
44169695Skan{
45169695Skan  if (!__sync_bool_compare_and_swap (sem, 1, 0))
46169695Skan    gomp_sem_wait_slow (sem);
47169695Skan}
48169695Skan
49169695Skanextern void gomp_sem_post_slow (gomp_sem_t *);
50169695Skanstatic inline void gomp_sem_post (gomp_sem_t *sem)
51169695Skan{
52169695Skan  if (!__sync_bool_compare_and_swap (sem, 0, 1))
53169695Skan    gomp_sem_post_slow (sem);
54169695Skan}
55169695Skan
56169695Skanstatic inline void gomp_sem_destroy (gomp_sem_t *sem)
57169695Skan{
58169695Skan}
59169695Skan
60169695Skan#endif /* GOMP_SEM_H */
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