xref: /freebsd/contrib/llvm-project/clang/lib/Headers/stdatomic.h (revision 911f0260390e18cf85f3dbf2c719b593efdc1e3c)
1 /*===---- stdatomic.h - Standard header for atomic types and operations -----===
2  *
3  * Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4  * See https://llvm.org/LICENSE.txt for license information.
5  * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6  *
7  *===-----------------------------------------------------------------------===
8  */
9 
10 #ifndef __CLANG_STDATOMIC_H
11 #define __CLANG_STDATOMIC_H
12 
13 /* If we're hosted, fall back to the system's stdatomic.h. FreeBSD, for
14  * example, already has a Clang-compatible stdatomic.h header.
15  *
16  * Exclude the MSVC path as well as the MSVC header as of the 14.31.30818
17  * explicitly disallows `stdatomic.h` in the C mode via an `#error`.  Fallback
18  * to the clang resource header until that is fully supported.  The
19  * `stdatomic.h` header requires C++ 23 or newer.
20  */
21 #if __STDC_HOSTED__ &&                                                         \
22     __has_include_next(<stdatomic.h>) &&                                       \
23     (!defined(_MSC_VER) || (defined(__cplusplus) && __cplusplus >= 202002L))
24 # include_next <stdatomic.h>
25 #else
26 
27 #include <stddef.h>
28 #include <stdint.h>
29 
30 #ifdef __cplusplus
31 extern "C" {
32 #endif
33 
34 /* 7.17.1 Introduction */
35 
36 #define ATOMIC_BOOL_LOCK_FREE       __CLANG_ATOMIC_BOOL_LOCK_FREE
37 #define ATOMIC_CHAR_LOCK_FREE       __CLANG_ATOMIC_CHAR_LOCK_FREE
38 #define ATOMIC_CHAR16_T_LOCK_FREE   __CLANG_ATOMIC_CHAR16_T_LOCK_FREE
39 #define ATOMIC_CHAR32_T_LOCK_FREE   __CLANG_ATOMIC_CHAR32_T_LOCK_FREE
40 #define ATOMIC_WCHAR_T_LOCK_FREE    __CLANG_ATOMIC_WCHAR_T_LOCK_FREE
41 #define ATOMIC_SHORT_LOCK_FREE      __CLANG_ATOMIC_SHORT_LOCK_FREE
42 #define ATOMIC_INT_LOCK_FREE        __CLANG_ATOMIC_INT_LOCK_FREE
43 #define ATOMIC_LONG_LOCK_FREE       __CLANG_ATOMIC_LONG_LOCK_FREE
44 #define ATOMIC_LLONG_LOCK_FREE      __CLANG_ATOMIC_LLONG_LOCK_FREE
45 #define ATOMIC_POINTER_LOCK_FREE    __CLANG_ATOMIC_POINTER_LOCK_FREE
46 
47 /* 7.17.2 Initialization */
48 
49 #define ATOMIC_VAR_INIT(value) (value)
50 #if ((defined(__STDC_VERSION__) && __STDC_VERSION__ >= 201710L) ||             \
51      (defined(__cplusplus) && __cplusplus >= 202002L)) &&                      \
52     !defined(_CLANG_DISABLE_CRT_DEPRECATION_WARNINGS)
53 /* ATOMIC_VAR_INIT was deprecated in C17 and C++20. */
54 #pragma clang deprecated(ATOMIC_VAR_INIT)
55 #endif
56 #define atomic_init __c11_atomic_init
57 
58 /* 7.17.3 Order and consistency */
59 
60 typedef enum memory_order {
61   memory_order_relaxed = __ATOMIC_RELAXED,
62   memory_order_consume = __ATOMIC_CONSUME,
63   memory_order_acquire = __ATOMIC_ACQUIRE,
64   memory_order_release = __ATOMIC_RELEASE,
65   memory_order_acq_rel = __ATOMIC_ACQ_REL,
66   memory_order_seq_cst = __ATOMIC_SEQ_CST
67 } memory_order;
68 
69 #define kill_dependency(y) (y)
70 
71 /* 7.17.4 Fences */
72 
73 /* These should be provided by the libc implementation. */
74 void atomic_thread_fence(memory_order);
75 void atomic_signal_fence(memory_order);
76 
77 #define atomic_thread_fence(order) __c11_atomic_thread_fence(order)
78 #define atomic_signal_fence(order) __c11_atomic_signal_fence(order)
79 
80 /* 7.17.5 Lock-free property */
81 
82 #define atomic_is_lock_free(obj) __c11_atomic_is_lock_free(sizeof(*(obj)))
83 
84 /* 7.17.6 Atomic integer types */
85 
86 #ifdef __cplusplus
87 typedef _Atomic(bool)               atomic_bool;
88 #else
89 typedef _Atomic(_Bool)              atomic_bool;
90 #endif
91 typedef _Atomic(char)               atomic_char;
92 typedef _Atomic(signed char)        atomic_schar;
93 typedef _Atomic(unsigned char)      atomic_uchar;
94 typedef _Atomic(short)              atomic_short;
95 typedef _Atomic(unsigned short)     atomic_ushort;
96 typedef _Atomic(int)                atomic_int;
97 typedef _Atomic(unsigned int)       atomic_uint;
98 typedef _Atomic(long)               atomic_long;
99 typedef _Atomic(unsigned long)      atomic_ulong;
100 typedef _Atomic(long long)          atomic_llong;
101 typedef _Atomic(unsigned long long) atomic_ullong;
102 typedef _Atomic(uint_least16_t)     atomic_char16_t;
103 typedef _Atomic(uint_least32_t)     atomic_char32_t;
104 typedef _Atomic(wchar_t)            atomic_wchar_t;
105 typedef _Atomic(int_least8_t)       atomic_int_least8_t;
106 typedef _Atomic(uint_least8_t)      atomic_uint_least8_t;
107 typedef _Atomic(int_least16_t)      atomic_int_least16_t;
108 typedef _Atomic(uint_least16_t)     atomic_uint_least16_t;
109 typedef _Atomic(int_least32_t)      atomic_int_least32_t;
110 typedef _Atomic(uint_least32_t)     atomic_uint_least32_t;
111 typedef _Atomic(int_least64_t)      atomic_int_least64_t;
112 typedef _Atomic(uint_least64_t)     atomic_uint_least64_t;
113 typedef _Atomic(int_fast8_t)        atomic_int_fast8_t;
114 typedef _Atomic(uint_fast8_t)       atomic_uint_fast8_t;
115 typedef _Atomic(int_fast16_t)       atomic_int_fast16_t;
116 typedef _Atomic(uint_fast16_t)      atomic_uint_fast16_t;
117 typedef _Atomic(int_fast32_t)       atomic_int_fast32_t;
118 typedef _Atomic(uint_fast32_t)      atomic_uint_fast32_t;
119 typedef _Atomic(int_fast64_t)       atomic_int_fast64_t;
120 typedef _Atomic(uint_fast64_t)      atomic_uint_fast64_t;
121 typedef _Atomic(intptr_t)           atomic_intptr_t;
122 typedef _Atomic(uintptr_t)          atomic_uintptr_t;
123 typedef _Atomic(size_t)             atomic_size_t;
124 typedef _Atomic(ptrdiff_t)          atomic_ptrdiff_t;
125 typedef _Atomic(intmax_t)           atomic_intmax_t;
126 typedef _Atomic(uintmax_t)          atomic_uintmax_t;
127 
128 /* 7.17.7 Operations on atomic types */
129 
130 #define atomic_store(object, desired) __c11_atomic_store(object, desired, __ATOMIC_SEQ_CST)
131 #define atomic_store_explicit __c11_atomic_store
132 
133 #define atomic_load(object) __c11_atomic_load(object, __ATOMIC_SEQ_CST)
134 #define atomic_load_explicit __c11_atomic_load
135 
136 #define atomic_exchange(object, desired) __c11_atomic_exchange(object, desired, __ATOMIC_SEQ_CST)
137 #define atomic_exchange_explicit __c11_atomic_exchange
138 
139 #define atomic_compare_exchange_strong(object, expected, desired) __c11_atomic_compare_exchange_strong(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
140 #define atomic_compare_exchange_strong_explicit __c11_atomic_compare_exchange_strong
141 
142 #define atomic_compare_exchange_weak(object, expected, desired) __c11_atomic_compare_exchange_weak(object, expected, desired, __ATOMIC_SEQ_CST, __ATOMIC_SEQ_CST)
143 #define atomic_compare_exchange_weak_explicit __c11_atomic_compare_exchange_weak
144 
145 #define atomic_fetch_add(object, operand) __c11_atomic_fetch_add(object, operand, __ATOMIC_SEQ_CST)
146 #define atomic_fetch_add_explicit __c11_atomic_fetch_add
147 
148 #define atomic_fetch_sub(object, operand) __c11_atomic_fetch_sub(object, operand, __ATOMIC_SEQ_CST)
149 #define atomic_fetch_sub_explicit __c11_atomic_fetch_sub
150 
151 #define atomic_fetch_or(object, operand) __c11_atomic_fetch_or(object, operand, __ATOMIC_SEQ_CST)
152 #define atomic_fetch_or_explicit __c11_atomic_fetch_or
153 
154 #define atomic_fetch_xor(object, operand) __c11_atomic_fetch_xor(object, operand, __ATOMIC_SEQ_CST)
155 #define atomic_fetch_xor_explicit __c11_atomic_fetch_xor
156 
157 #define atomic_fetch_and(object, operand) __c11_atomic_fetch_and(object, operand, __ATOMIC_SEQ_CST)
158 #define atomic_fetch_and_explicit __c11_atomic_fetch_and
159 
160 /* 7.17.8 Atomic flag type and operations */
161 
162 typedef struct atomic_flag { atomic_bool _Value; } atomic_flag;
163 
164 #define ATOMIC_FLAG_INIT { 0 }
165 
166 /* These should be provided by the libc implementation. */
167 #ifdef __cplusplus
168 bool atomic_flag_test_and_set(volatile atomic_flag *);
169 bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
170 #else
171 _Bool atomic_flag_test_and_set(volatile atomic_flag *);
172 _Bool atomic_flag_test_and_set_explicit(volatile atomic_flag *, memory_order);
173 #endif
174 void atomic_flag_clear(volatile atomic_flag *);
175 void atomic_flag_clear_explicit(volatile atomic_flag *, memory_order);
176 
177 #define atomic_flag_test_and_set(object) __c11_atomic_exchange(&(object)->_Value, 1, __ATOMIC_SEQ_CST)
178 #define atomic_flag_test_and_set_explicit(object, order) __c11_atomic_exchange(&(object)->_Value, 1, order)
179 
180 #define atomic_flag_clear(object) __c11_atomic_store(&(object)->_Value, 0, __ATOMIC_SEQ_CST)
181 #define atomic_flag_clear_explicit(object, order) __c11_atomic_store(&(object)->_Value, 0, order)
182 
183 #ifdef __cplusplus
184 }
185 #endif
186 
187 #endif /* __STDC_HOSTED__ */
188 #endif /* __CLANG_STDATOMIC_H */
189 
190