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
|
/*************************************************************************/
/* safe_refcount.cpp */
/*************************************************************************/
/* This file is part of: */
/* GODOT ENGINE */
/* http://www.godotengine.org */
/*************************************************************************/
/* Copyright (c) 2007-2017 Juan Linietsky, Ariel Manzur. */
/* Copyright (c) 2014-2017 Godot Engine contributors (cf. AUTHORS.md) */
/* */
/* Permission is hereby granted, free of charge, to any person obtaining */
/* a copy of this software and associated documentation files (the */
/* "Software"), to deal in the Software without restriction, including */
/* without limitation the rights to use, copy, modify, merge, publish, */
/* distribute, sublicense, and/or sell copies of the Software, and to */
/* permit persons to whom the Software is furnished to do so, subject to */
/* the following conditions: */
/* */
/* The above copyright notice and this permission notice shall be */
/* included in all copies or substantial portions of the Software. */
/* */
/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, */
/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF */
/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY */
/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, */
/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE */
/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. */
/*************************************************************************/
#include "safe_refcount.h"
// Atomic functions, these are used for multithread safe reference counters!
#ifdef NO_THREADS
/* Bogus implementation unaware of multiprocessing */
template <class T>
static _ALWAYS_INLINE_ T _atomic_conditional_increment_impl(register T *pw) {
if (*pw == 0)
return 0;
(*pw)++;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_decrement_impl(register T *pw) {
(*pw)--;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) {
(*pw)++;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) {
(*pw) -= val;
return *pw;
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
(*pw) += val;
return *pw;
}
#elif defined(__GNUC__)
/* Implementation for GCC & Clang */
// GCC guarantees atomic intrinsics for sizes of 1, 2, 4 and 8 bytes.
// Clang states it supports GCC atomic builtins.
template <class T>
static _ALWAYS_INLINE_ T _atomic_conditional_increment_impl(register T *pw) {
while (true) {
T tmp = static_cast<T const volatile &>(*pw);
if (tmp == 0)
return 0; // if zero, can't add to it anymore
if (__sync_val_compare_and_swap(pw, tmp, tmp + 1) == tmp)
return tmp + 1;
}
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_decrement_impl(register T *pw) {
return __sync_sub_and_fetch(pw, 1);
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_increment_impl(register T *pw) {
return __sync_add_and_fetch(pw, 1);
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_sub_impl(register T *pw, register T val) {
return __sync_sub_and_fetch(pw, val);
}
template <class T>
static _ALWAYS_INLINE_ T _atomic_add_impl(register T *pw, register T val) {
return __sync_add_and_fetch(pw, val);
}
#elif defined(_MSC_VER)
/* Implementation for MSVC-Windows */
// don't pollute my namespace!
#include <windows.h>
#define ATOMIC_CONDITIONAL_INCREMENT_BODY(m_pw, m_win_type, m_win_cmpxchg, m_cpp_type) \
/* try to increment until it actually works */ \
/* taken from boost */ \
while (true) { \
m_cpp_type tmp = static_cast<m_cpp_type const volatile &>(*(m_pw)); \
if (tmp == 0) \
return 0; /* if zero, can't add to it anymore */ \
if (m_win_cmpxchg((m_win_type volatile *)(m_pw), tmp + 1, tmp) == tmp) \
return tmp + 1; \
}
static _ALWAYS_INLINE_ uint32_t _atomic_conditional_increment_impl(register uint32_t *pw) {
ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONG, InterlockedCompareExchange, uint32_t)
}
static _ALWAYS_INLINE_ uint32_t _atomic_decrement_impl(register uint32_t *pw) {
return InterlockedDecrement((LONG volatile *)pw);
}
static _ALWAYS_INLINE_ uint32_t _atomic_increment_impl(register uint32_t *pw) {
return InterlockedIncrement((LONG volatile *)pw);
}
static _ALWAYS_INLINE_ uint32_t _atomic_sub_impl(register uint32_t *pw, register uint32_t val) {
#if _WIN32_WINNT >= 0x0601 // Windows 7+
return InterlockedExchangeSubtract(pw, val) - val;
#else
return InterlockedExchangeAdd((LONG volatile *)pw, -(int32_t)val) - val;
#endif
}
static _ALWAYS_INLINE_ uint32_t _atomic_add_impl(register uint32_t *pw, register uint32_t val) {
return InterlockedAdd((LONG volatile *)pw, val);
}
static _ALWAYS_INLINE_ uint64_t _atomic_conditional_increment_impl(register uint64_t *pw) {
ATOMIC_CONDITIONAL_INCREMENT_BODY(pw, LONGLONG, InterlockedCompareExchange64, uint64_t)
}
static _ALWAYS_INLINE_ uint64_t _atomic_decrement_impl(register uint64_t *pw) {
return InterlockedDecrement64((LONGLONG volatile *)pw);
}
static _ALWAYS_INLINE_ uint64_t _atomic_increment_impl(register uint64_t *pw) {
return InterlockedIncrement64((LONGLONG volatile *)pw);
}
static _ALWAYS_INLINE_ uint64_t _atomic_sub_impl(register uint64_t *pw, register uint64_t val) {
#if _WIN32_WINNT >= 0x0601 && !defined(UWP_ENABLED) // Windows 7+ except UWP
return InterlockedExchangeSubtract64(pw, val) - val;
#else
return InterlockedExchangeAdd64((LONGLONG volatile *)pw, -(int64_t)val) - val;
#endif
}
static _ALWAYS_INLINE_ uint64_t _atomic_add_impl(register uint64_t *pw, register uint64_t val) {
return InterlockedAdd64((LONGLONG volatile *)pw, val);
}
#else
//no threads supported?
#error Must provide atomic functions for this platform or compiler!
#endif
// The actual advertised functions; they'll call the right implementation
uint32_t atomic_conditional_increment(register uint32_t *counter) {
return _atomic_conditional_increment_impl(counter);
}
uint32_t atomic_decrement(register uint32_t *pw) {
return _atomic_decrement_impl(pw);
}
uint32_t atomic_increment(register uint32_t *pw) {
return _atomic_increment_impl(pw);
}
uint32_t atomic_sub(register uint32_t *pw, register uint32_t val) {
return _atomic_sub_impl(pw, val);
}
uint32_t atomic_add(register uint32_t *pw, register uint32_t val) {
return _atomic_add_impl(pw, val);
}
uint64_t atomic_conditional_increment(register uint64_t *counter) {
return _atomic_conditional_increment_impl(counter);
}
uint64_t atomic_decrement(register uint64_t *pw) {
return _atomic_decrement_impl(pw);
}
uint64_t atomic_increment(register uint64_t *pw) {
return _atomic_increment_impl(pw);
}
uint64_t atomic_sub(register uint64_t *pw, register uint64_t val) {
return _atomic_sub_impl(pw, val);
}
uint64_t atomic_add(register uint64_t *pw, register uint64_t val) {
return _atomic_add_impl(pw, val);
}
|