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
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
|
/**
* Many similar implementations exist. See for example libwsbm
* or the linux kernel include/atomic.h
*
* No copyright claimed on this file.
*
*/
#ifndef U_ATOMIC_H
#define U_ATOMIC_H
#include "pipe/p_compiler.h"
#include "pipe/p_defines.h"
/* Favor OS-provided implementations.
*
* Where no OS-provided implementation is available, fall back to
* locally coded assembly, compiler intrinsic or ultimately a
* mutex-based implementation.
*/
#if (defined(PIPE_SUBSYSTEM_WINDOWS_DISPLAY) || \
defined(PIPE_SUBSYSTEM_WINDOWS_MINIPORT))
#define PIPE_ATOMIC_OS_UNLOCKED
#elif defined(PIPE_CC_MSVC)
#define PIPE_ATOMIC_MSVC_INTRINSIC
#elif (defined(PIPE_CC_MSVC) && defined(PIPE_ARCH_X86))
#define PIPE_ATOMIC_ASM_MSVC_X86
#elif (defined(PIPE_CC_GCC) && defined(PIPE_ARCH_X86))
#define PIPE_ATOMIC_ASM_GCC_X86
#elif defined(PIPE_CC_GCC)
#define PIPE_ATOMIC_GCC_INTRINSIC
#else
#error "Unsupported platform"
#endif
#if defined(PIPE_ATOMIC_ASM_GCC_X86)
#define PIPE_ATOMIC "GCC x86 assembly"
#ifdef __cplusplus
extern "C" {
#endif
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
static INLINE boolean
p_atomic_dec_zero(int32_t *v)
{
unsigned char c;
__asm__ __volatile__("lock; decl %0; sete %1":"+m"(*v), "=qm"(c)
::"memory");
return c != 0;
}
static INLINE void
p_atomic_inc(int32_t *v)
{
__asm__ __volatile__("lock; incl %0":"+m"(*v));
}
static INLINE void
p_atomic_dec(int32_t *v)
{
__asm__ __volatile__("lock; decl %0":"+m"(*v));
}
static INLINE int32_t
p_atomic_cmpxchg(int32_t *v, int32_t old, int32_t _new)
{
return __sync_val_compare_and_swap(v, old, _new);
}
#ifdef __cplusplus
}
#endif
#endif
/* Implementation using GCC-provided synchronization intrinsics
*/
#if defined(PIPE_ATOMIC_GCC_INTRINSIC)
#define PIPE_ATOMIC "GCC Sync Intrinsics"
#ifdef __cplusplus
extern "C" {
#endif
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
static INLINE boolean
p_atomic_dec_zero(int32_t *v)
{
return (__sync_sub_and_fetch(v, 1) == 0);
}
static INLINE void
p_atomic_inc(int32_t *v)
{
(void) __sync_add_and_fetch(v, 1);
}
static INLINE void
p_atomic_dec(int32_t *v)
{
(void) __sync_sub_and_fetch(v, 1);
}
static INLINE int32_t
p_atomic_cmpxchg(int32_t *v, int32_t old, int32_t _new)
{
return __sync_val_compare_and_swap(v, old, _new);
}
#ifdef __cplusplus
}
#endif
#endif
/* Unlocked version for single threaded environments, such as some
* windows kernel modules.
*/
#if defined(PIPE_ATOMIC_OS_UNLOCKED)
#define PIPE_ATOMIC "Unlocked"
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
#define p_atomic_dec_zero(_v) ((boolean) --(*(_v)))
#define p_atomic_inc(_v) ((void) (*(_v))++)
#define p_atomic_dec(_v) ((void) (*(_v))--)
#define p_atomic_cmpxchg(_v, old, _new) (*(_v) == old ? *(_v) = (_new) : *(_v))
#endif
/* Locally coded assembly for MSVC on x86:
*/
#if defined(PIPE_ATOMIC_ASM_MSVC_X86)
#define PIPE_ATOMIC "MSVC x86 assembly"
#ifdef __cplusplus
extern "C" {
#endif
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
static INLINE boolean
p_atomic_dec_zero(int32_t *v)
{
unsigned char c;
__asm {
mov eax, [v]
lock dec dword ptr [eax]
sete byte ptr [c]
}
return c != 0;
}
static INLINE void
p_atomic_inc(int32_t *v)
{
__asm {
mov eax, [v]
lock inc dword ptr [eax]
}
}
static INLINE void
p_atomic_dec(int32_t *v)
{
__asm {
mov eax, [v]
lock dec dword ptr [eax]
}
}
static INLINE int32_t
p_atomic_cmpxchg(int32_t *v, int32_t old, int32_t _new)
{
int32_t orig;
__asm {
mov ecx, [v]
mov eax, [old]
mov edx, [_new]
lock cmpxchg [ecx], edx
mov [orig], eax
}
return orig;
}
#ifdef __cplusplus
}
#endif
#endif
#if defined(PIPE_ATOMIC_MSVC_INTRINSIC)
#define PIPE_ATOMIC "MSVC Intrinsics"
#include <intrin.h>
#pragma intrinsic(_InterlockedIncrement)
#pragma intrinsic(_InterlockedDecrement)
#pragma intrinsic(_InterlockedCompareExchange)
#ifdef __cplusplus
extern "C" {
#endif
#define p_atomic_set(_v, _i) (*(_v) = (_i))
#define p_atomic_read(_v) (*(_v))
static INLINE boolean
p_atomic_dec_zero(int32_t *v)
{
return _InterlockedDecrement((long *)v) == 0;
}
static INLINE void
p_atomic_inc(int32_t *v)
{
_InterlockedIncrement((long *)v);
}
static INLINE void
p_atomic_dec(int32_t *v)
{
_InterlockedDecrement((long *)v);
}
static INLINE int32_t
p_atomic_cmpxchg(int32_t *v, int32_t old, int32_t _new)
{
return _InterlockedCompareExchange((long *)v, _new, old);
}
#ifdef __cplusplus
}
#endif
#endif
#ifndef PIPE_ATOMIC
#error "No pipe_atomic implementation selected"
#endif
#endif /* U_ATOMIC_H */
|
