1 /* Copyright (C) 2002,2003,2004 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3 Contributed by Ulrich Drepper <drepper@redhat.com>, 2002.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <http://www.gnu.org/licenses/>. */
18
19 #include "pthreadP.h"
20
21 #ifndef LOCK_PREFIX
22 # ifdef UP
23 # define LOCK_PREFIX /* nothing */
24 # else
25 # define LOCK_PREFIX "lock;"
26 # endif
27 #endif
28
29
30 int
pthread_spin_lock(pthread_spinlock_t * lock)31 pthread_spin_lock (
32 pthread_spinlock_t *lock)
33 {
34 __asm__ ("\n"
35 "1:\t" LOCK_PREFIX "decl %0\n\t"
36 "jne 2f\n\t"
37 ".subsection 1\n\t"
38 ".align 16\n"
39 "2:\trep; nop\n\t"
40 "cmpl $0, %0\n\t"
41 "jg 1b\n\t"
42 "jmp 2b\n\t"
43 ".previous"
44 : "=m" (*lock)
45 : "m" (*lock));
46
47 return 0;
48 }
49