Add a compat stdatomic.h implementation based on pthreads
[ffmpeg.git] / compat / atomics / pthread / stdatomic.h
1 /*
2  * This file is part of FFmpeg.
3  *
4  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
17  */
18
19 /*
20  * based on vlc_atomic.h from VLC
21  * Copyright (C) 2010 RĂ©mi Denis-Courmont
22  */
23
24 #ifndef FFMPEG_COMPAT_ATOMICS_PTHREAD_STDATOMIC_H
25 #define FFMPEG_COMPAT_ATOMICS_PTHREAD_STDATOMIC_H
26
27 #include <stdint.h>
28
29 #define ATOMIC_FLAG_INIT 0
30
31 #define ATOMIC_VAR_INIT(value) (value)
32
33 #define atomic_init(obj, value) \
34 do {                            \
35     *(obj) = (value);           \
36 } while(0)
37
38 #define kill_dependency(y) ((void)0)
39
40 #define atomic_signal_fence(order) \
41     ((void)0)
42
43 #define atomic_is_lock_free(obj) 0
44
45 typedef intptr_t atomic_flag;
46 typedef intptr_t atomic_bool;
47 typedef intptr_t atomic_char;
48 typedef intptr_t atomic_schar;
49 typedef intptr_t atomic_uchar;
50 typedef intptr_t atomic_short;
51 typedef intptr_t atomic_ushort;
52 typedef intptr_t atomic_int;
53 typedef intptr_t atomic_uint;
54 typedef intptr_t atomic_long;
55 typedef intptr_t atomic_ulong;
56 typedef intptr_t atomic_llong;
57 typedef intptr_t atomic_ullong;
58 typedef intptr_t atomic_wchar_t;
59 typedef intptr_t atomic_int_least8_t;
60 typedef intptr_t atomic_uint_least8_t;
61 typedef intptr_t atomic_int_least16_t;
62 typedef intptr_t atomic_uint_least16_t;
63 typedef intptr_t atomic_int_least32_t;
64 typedef intptr_t atomic_uint_least32_t;
65 typedef intptr_t atomic_int_least64_t;
66 typedef intptr_t atomic_uint_least64_t;
67 typedef intptr_t atomic_int_fast8_t;
68 typedef intptr_t atomic_uint_fast8_t;
69 typedef intptr_t atomic_int_fast16_t;
70 typedef intptr_t atomic_uint_fast16_t;
71 typedef intptr_t atomic_int_fast32_t;
72 typedef intptr_t atomic_uint_fast32_t;
73 typedef intptr_t atomic_int_fast64_t;
74 typedef intptr_t atomic_uint_fast64_t;
75 typedef intptr_t atomic_intptr_t;
76 typedef intptr_t atomic_uintptr_t;
77 typedef intptr_t atomic_size_t;
78 typedef intptr_t atomic_ptrdiff_t;
79 typedef intptr_t atomic_intmax_t;
80 typedef intptr_t atomic_uintmax_t;
81
82 void avpriv_atomic_lock(void);
83 void avpriv_atomic_unlock(void);
84
85 static inline void atomic_thread_fence(int order)
86 {
87     avpriv_atomic_lock();
88     avpriv_atomic_unlock();
89 }
90
91 static inline void atomic_store(intptr_t *object, intptr_t desired)
92 {
93     avpriv_atomic_lock();
94     *object = desired;
95     avpriv_atomic_unlock();
96 }
97
98 #define atomic_store_explicit(object, desired, order) \
99     atomic_store(object, desired)
100
101 static inline intptr_t atomic_load(intptr_t *object)
102 {
103     intptr_t ret;
104     avpriv_atomic_lock();
105     ret = *object;
106     avpriv_atomic_unlock();
107     return ret;
108 }
109
110 #define atomic_load_explicit(object, order) \
111     atomic_load(object)
112
113 static inline intptr_t atomic_exchange(intptr_t *object, intptr_t desired)
114 {
115     intptr_t ret;
116     avpriv_atomic_lock();
117     ret     = *object;
118     *object = desired;
119     avpriv_atomic_unlock();
120     return ret;
121 }
122
123 #define atomic_exchange_explicit(object, desired, order) \
124     atomic_exchange(object, desired)
125
126 static inline int atomic_compare_exchange_strong(intptr_t *object, intptr_t *expected,
127                                                  intptr_t desired)
128 {
129     int ret;
130     avpriv_atomic_lock();
131     if (*object == *expected) {
132         ret     = 1;
133         *object = desired;
134     } else {
135         ret = 0;
136         *expected = *object;
137     }
138     avpriv_atomic_unlock();
139     return ret;
140 }
141
142 #define atomic_compare_exchange_strong_explicit(object, expected, desired, success, failure) \
143     atomic_compare_exchange_strong(object, expected, desired)
144
145 #define atomic_compare_exchange_weak(object, expected, desired) \
146     atomic_compare_exchange_strong(object, expected, desired)
147
148 #define atomic_compare_exchange_weak_explicit(object, expected, desired, success, failure) \
149     atomic_compare_exchange_weak(object, expected, desired)
150
151 #define FETCH_MODIFY(opname, op)                                                   \
152 static inline intptr_t atomic_fetch_ ## opname(intptr_t *object, intptr_t operand) \
153 {                                                                                  \
154     intptr_t ret;                                                                  \
155     avpriv_atomic_lock();                                                          \
156     ret = *object;                                                                 \
157     *object = *object op operand;                                                  \
158     avpriv_atomic_unlock();                                                        \
159     return ret;                                                                    \
160 }
161
162 FETCH_MODIFY(add, +)
163 FETCH_MODIFY(sub, -)
164 FETCH_MODIFY(or,  |)
165 FETCH_MODIFY(xor, ^)
166 FETCH_MODIFY(and, &)
167
168 #undef FETCH_MODIFY
169
170 #define atomic_fetch_add_explicit(object, operand, order) \
171     atomic_fetch_add(object, operand)
172
173 #define atomic_fetch_sub_explicit(object, operand, order) \
174     atomic_fetch_sub(object, operand)
175
176 #define atomic_fetch_or_explicit(object, operand, order) \
177     atomic_fetch_or(object, operand)
178
179 #define atomic_fetch_xor_explicit(object, operand, order) \
180     atomic_fetch_sub(object, operand)
181
182 #define atomic_fetch_and_explicit(object, operand, order) \
183     atomic_fetch_and(object, operand)
184
185 #define atomic_flag_test_and_set(object) \
186     atomic_exchange(object, 1)
187
188 #define atomic_flag_test_and_set_explicit(object, order) \
189     atomic_flag_test_and_set(object)
190
191 #define atomic_flag_clear(object) \
192     atomic_store(object, 0)
193
194 #define atomic_flag_clear_explicit(object, order) \
195     atomic_flag_clear(object)
196
197 #endif /* FFMPEG_COMPAT_ATOMICS_PTHREAD_STDATOMIC_H */