1 /* Copyright (C) 2003-2022 Free Software Foundation, Inc.
2 This file is part of the GNU C Library.
3
4 The GNU C Library is free software; you can redistribute it and/or
5 modify it under the terms of the GNU Lesser General Public
6 License as published by the Free Software Foundation; either
7 version 2.1 of the License, or (at your option) any later version.
8
9 The GNU C Library is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 Lesser General Public License for more details.
13
14 You should have received a copy of the GNU Lesser General Public
15 License along with the GNU C Library; if not, see
16 <https://www.gnu.org/licenses/>. */
17
18 #include <errno.h>
19 #include "pthreadP.h"
20 #include <shlib-compat.h>
21
22 int
__pthread_spin_trylock(pthread_spinlock_t * lock)23 __pthread_spin_trylock (pthread_spinlock_t *lock)
24 {
25 unsigned int old;
26 int err = EBUSY;
27
28 asm ("1: lwarx %0,0,%2" MUTEX_HINT_ACQ "\n"
29 " cmpwi 0,%0,0\n"
30 " bne 2f\n"
31 " stwcx. %3,0,%2\n"
32 " bne- 1b\n"
33 " li %1,0\n"
34 __ARCH_ACQ_INSTR "\n"
35 "2: "
36 : "=&r" (old), "=&r" (err)
37 : "r" (lock), "r" (1), "1" (err)
38 : "cr0", "memory");
39
40 return err;
41 }
42 versioned_symbol (libc, __pthread_spin_trylock, pthread_spin_trylock,
43 GLIBC_2_34);
44
45 #if OTHER_SHLIB_COMPAT (libpthread, GLIBC_2_2, GLIBC_2_34)
46 compat_symbol (libpthread, __pthread_spin_trylock, pthread_spin_trylock,
47 GLIBC_2_2);
48 #endif
49