|
0
|
1 /* Copyright (C) 2005, 2008, 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 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 #include "wait.h"
|
|
|
30
|
|
|
31 long int gomp_futex_wake = FUTEX_WAKE | FUTEX_PRIVATE_FLAG;
|
|
|
32 long int gomp_futex_wait = FUTEX_WAIT | FUTEX_PRIVATE_FLAG;
|
|
|
33
|
|
|
34 void
|
|
|
35 gomp_mutex_lock_slow (gomp_mutex_t *mutex)
|
|
|
36 {
|
|
|
37 do
|
|
|
38 {
|
|
|
39 int oldval = __sync_val_compare_and_swap (mutex, 1, 2);
|
|
|
40 if (oldval != 0)
|
|
|
41 do_wait (mutex, 2);
|
|
|
42 }
|
|
|
43 while (!__sync_bool_compare_and_swap (mutex, 0, 2));
|
|
|
44 }
|
|
|
45
|
|
|
46 void
|
|
|
47 gomp_mutex_unlock_slow (gomp_mutex_t *mutex)
|
|
|
48 {
|
|
|
49 futex_wake (mutex, 1);
|
|
|
50 }
|
