Mercurial > hg > CbC > CbC_gcc

comparison libgomp/config/linux/ptrlock.c @ 0:a06113de4d67

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
first commit
author kent <kent@cr.ie.u-ryukyu.ac.jp>
date Fri, 17 Jul 2009 14:47:48 +0900
parents
children 04ced10e8804
comparison
equal deleted inserted replaced
-1:000000000000 0:a06113de4d67
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 #include <endian.h>
30 #include <limits.h>
31 #include "wait.h"
32
33 void *
34 gomp_ptrlock_get_slow (gomp_ptrlock_t *ptrlock)
35 {
36 int *intptr;
37 __sync_bool_compare_and_swap (ptrlock, 1, 2);
38
39 /* futex works on ints, not pointers.
40 But a valid work share pointer will be at least
41 8 byte aligned, so it is safe to assume the low
42 32-bits of the pointer won't contain values 1 or 2. */
43 __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
44 #if __BYTE_ORDER == __BIG_ENDIAN
45 if (sizeof (*ptrlock) > sizeof (int))
46 intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
47 #endif
48 do
49 do_wait (intptr, 2);
50 while (*intptr == 2);
51 __asm volatile ("" : : : "memory");
52 return *ptrlock;
53 }
54
55 void
56 gomp_ptrlock_set_slow (gomp_ptrlock_t *ptrlock, void *ptr)
57 {
58 int *intptr;
59
60 *ptrlock = ptr;
61 __asm volatile ("" : "=r" (intptr) : "0" (ptrlock));
62 #if __BYTE_ORDER == __BIG_ENDIAN
63 if (sizeof (*ptrlock) > sizeof (int))
64 intptr += (sizeof (*ptrlock) / sizeof (int)) - 1;
65 #endif
66 futex_wake (intptr, INT_MAX);
67 }