1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
|
/* POSIX spinlock implementation. hppa version.
Copyright (C) 2000 Free Software Foundation, Inc.
This file is part of the GNU C Library.
The GNU C Library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public License as
published by the Free Software Foundation; either version 2.1 of the
License, or (at your option) any later version.
The GNU C Library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with the GNU C Library; see the file COPYING.LIB. If
not, see <http://www.gnu.org/licenses/>. */
#include <errno.h>
#include <pthread.h>
#include "internals.h"
int
__pthread_spin_lock (pthread_spinlock_t *lock)
{
unsigned int val;
do
__asm__ __volatile__ ("ldcw %1,%0"
: "=r" (val), "=m" (*lock)
: "m" (*lock));
while (!val);
return 0;
}
weak_alias (__pthread_spin_lock, pthread_spin_lock)
int
__pthread_spin_trylock (pthread_spinlock_t *lock)
{
unsigned int val;
__asm__ __volatile__ ("ldcw %1,%0"
: "=r" (val), "=m" (*lock)
: "m" (*lock));
return val ? 0 : EBUSY;
}
weak_alias (__pthread_spin_trylock, pthread_spin_trylock)
int
__pthread_spin_unlock (pthread_spinlock_t *lock)
{
*lock = 1;
return 0;
}
weak_alias (__pthread_spin_unlock, pthread_spin_unlock)
int
__pthread_spin_init (pthread_spinlock_t *lock, int pshared)
{
/* We can ignore the `pshared' parameter. Since we are busy-waiting
all processes which can access the memory location `lock' points
to can use the spinlock. */
*lock = 1;
return 0;
}
weak_alias (__pthread_spin_init, pthread_spin_init)
int
__pthread_spin_destroy (pthread_spinlock_t *lock)
{
/* Nothing to do. */
return 0;
}
weak_alias (__pthread_spin_destroy, pthread_spin_destroy)
|
