0
|
1 /* Copyright (C) 2008, 2009 Free Software Foundation, Inc.
|
|
2 Contributed by Jakub Jelinek <jakub@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 a Linux specific implementation of a mutex synchronization
|
|
26 mechanism for libgomp. This type is private to the library. This
|
|
27 implementation uses atomic instructions and the futex syscall. */
|
|
28
|
|
29 #ifndef GOMP_WAIT_H
|
|
30 #define GOMP_WAIT_H 1
|
|
31
|
|
32 #include "libgomp.h"
|
|
33 #include <errno.h>
|
|
34
|
|
35 #define FUTEX_WAIT 0
|
|
36 #define FUTEX_WAKE 1
|
|
37 #define FUTEX_PRIVATE_FLAG 128L
|
|
38
|
|
39 #ifdef HAVE_ATTRIBUTE_VISIBILITY
|
|
40 # pragma GCC visibility push(hidden)
|
|
41 #endif
|
|
42
|
|
43 extern long int gomp_futex_wait, gomp_futex_wake;
|
|
44
|
|
45 #include "futex.h"
|
|
46
|
|
47 static inline void do_wait (int *addr, int val)
|
|
48 {
|
|
49 unsigned long long i, count = gomp_spin_count_var;
|
|
50
|
|
51 if (__builtin_expect (gomp_managed_threads > gomp_available_cpus, 0))
|
|
52 count = gomp_throttled_spin_count_var;
|
|
53 for (i = 0; i < count; i++)
|
|
54 if (__builtin_expect (*addr != val, 0))
|
|
55 return;
|
|
56 else
|
|
57 cpu_relax ();
|
|
58 futex_wait (addr, val);
|
|
59 }
|
|
60
|
|
61 #ifdef HAVE_ATTRIBUTE_VISIBILITY
|
|
62 # pragma GCC visibility pop
|
|
63 #endif
|
|
64
|
|
65 #endif /* GOMP_WAIT_H */
|