src/shims/atomic.h

   1 /*
   2  * Copyright (c) 2008-2016 Apple Inc. All rights reserved.
   3  *
   4  * @APPLE_APACHE_LICENSE_HEADER_START@
   5  *
   6  * Licensed under the Apache License, Version 2.0 (the "License");
   7  * you may not use this file except in compliance with the License.
   8  * You may obtain a copy of the License at
   9  *
  10  *     http://www.apache.org/licenses/LICENSE-2.0
  11  *
  12  * Unless required by applicable law or agreed to in writing, software
  13  * distributed under the License is distributed on an "AS IS" BASIS,
  14  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15  * See the License for the specific language governing permissions and
  16  * limitations under the License.
  17  *
  18  * @APPLE_APACHE_LICENSE_HEADER_END@
  19  */
  20
  21 /*
  22  * IMPORTANT: This header file describes INTERNAL interfaces to libdispatch
  23  * which are subject to change in future releases of Mac OS X. Any applications
  24  * relying on these interfaces WILL break.
  25  */
  26
  27 #ifndef __DISPATCH_SHIMS_ATOMIC__
  28 #define __DISPATCH_SHIMS_ATOMIC__
  29
  30 #if !__has_extension(c_atomic) || \
  31                 !__has_extension(c_generic_selections) || \
  32                 !__has_include(<stdatomic.h>)
  33 #error libdispatch requires C11 with <stdatomic.h> and generic selections
  34 #endif
  35
  36 #include <stdatomic.h>
  37
  38 #define memory_order_ordered memory_order_seq_cst
  39
  40 #define _os_atomic_basetypeof(p) \
  41                 typeof(*_Generic((p), \
  42                 char*: (char*)(p), \
  43                 volatile char*: (char*)(p), \
  44                 signed char*: (signed char*)(p), \
  45                 volatile signed char*: (signed char*)(p), \
  46                 unsigned char*: (unsigned char*)(p), \
  47                 volatile unsigned char*: (unsigned char*)(p), \
  48                 short*: (short*)(p), \
  49                 volatile short*: (short*)(p), \
  50                 unsigned short*: (unsigned short*)(p), \
  51                 volatile unsigned short*: (unsigned short*)(p), \
  52                 int*: (int*)(p), \
  53                 volatile int*: (int*)(p), \
  54                 unsigned int*: (unsigned int*)(p), \
  55                 volatile unsigned int*: (unsigned int*)(p), \
  56                 long*: (long*)(p), \
  57                 volatile long*: (long*)(p), \
  58                 unsigned long*: (unsigned long*)(p), \
  59                 volatile unsigned long*: (unsigned long*)(p), \
  60                 long long*: (long long*)(p), \
  61                 volatile long long*: (long long*)(p), \
  62                 unsigned long long*: (unsigned long long*)(p), \
  63                 volatile unsigned long long*: (unsigned long long*)(p), \
  64                 const void**: (const void**)(p), \
  65                 const void*volatile*: (const void**)(p), \
  66                 default: (void**)(p)))
  67
  68 #define _os_atomic_c11_atomic(p) \
  69                 _Generic((p), \
  70                 char*: (_Atomic(char)*)(p), \
  71                 volatile char*: (volatile _Atomic(char)*)(p), \
  72                 signed char*: (_Atomic(signed char)*)(p), \
  73                 volatile signed char*: (volatile _Atomic(signed char)*)(p), \
  74                 unsigned char*: (_Atomic(unsigned char)*)(p), \
  75                 volatile unsigned char*: (volatile _Atomic(unsigned char)*)(p), \
  76                 short*: (_Atomic(short)*)(p), \
  77                 volatile short*: (volatile _Atomic(short)*)(p), \
  78                 unsigned short*: (_Atomic(unsigned short)*)(p), \
  79                 volatile unsigned short*: (volatile _Atomic(unsigned short)*)(p), \
  80                 int*: (_Atomic(int)*)(p), \
  81                 volatile int*: (volatile _Atomic(int)*)(p), \
  82                 unsigned int*: (_Atomic(unsigned int)*)(p), \
  83                 volatile unsigned int*: (volatile _Atomic(unsigned int)*)(p), \
  84                 long*: (_Atomic(long)*)(p), \
  85                 volatile long*: (volatile _Atomic(long)*)(p), \
  86                 unsigned long*: (_Atomic(unsigned long)*)(p), \
  87                 volatile unsigned long*: (volatile _Atomic(unsigned long)*)(p), \
  88                 long long*: (_Atomic(long long)*)(p), \
  89                 volatile long long*: (volatile _Atomic(long long)*)(p), \
  90                 unsigned long long*: (_Atomic(unsigned long long)*)(p), \
  91                 volatile unsigned long long*: \
  92                                 (volatile _Atomic(unsigned long long)*)(p), \
  93                 const void**: (_Atomic(const void*)*)(p), \
  94                 const void*volatile*: (volatile _Atomic(const void*)*)(p), \
  95                 default: (volatile _Atomic(void*)*)(p))
  96
  97 #define os_atomic_thread_fence(m)  atomic_thread_fence(memory_order_##m)
  98 // see comment in dispatch_once.c
  99 #define os_atomic_maximally_synchronizing_barrier() \
 100                 atomic_thread_fence(memory_order_seq_cst)
 101
 102 #define os_atomic_load(p, m) \
 103                 ({ _os_atomic_basetypeof(p) _r = \
 104                 atomic_load_explicit(_os_atomic_c11_atomic(p), \
 105                 memory_order_##m); (typeof(*(p)))_r; })
 106 #define os_atomic_store(p, v, m) \
 107                 ({ _os_atomic_basetypeof(p) _v = (v); \
 108                 atomic_store_explicit(_os_atomic_c11_atomic(p), _v, \
 109                 memory_order_##m); })
 110 #define os_atomic_xchg(p, v, m) \
 111                 ({ _os_atomic_basetypeof(p) _v = (v), _r = \
 112                 atomic_exchange_explicit(_os_atomic_c11_atomic(p), _v, \
 113                 memory_order_##m); (typeof(*(p)))_r; })
 114 #define os_atomic_cmpxchg(p, e, v, m) \
 115                 ({ _os_atomic_basetypeof(p) _v = (v), _r = (e); \
 116                 atomic_compare_exchange_strong_explicit(_os_atomic_c11_atomic(p), \
 117                 &_r, _v, memory_order_##m, \
 118                 memory_order_relaxed); })
 119 #define os_atomic_cmpxchgv(p, e, v, g, m) \
 120                 ({ _os_atomic_basetypeof(p) _v = (v), _r = (e); _Bool _b = \
 121                 atomic_compare_exchange_strong_explicit(_os_atomic_c11_atomic(p), \
 122                 &_r, _v, memory_order_##m, \
 123                 memory_order_relaxed); *(g) = (typeof(*(p)))_r; _b; })
 124 #define os_atomic_cmpxchgvw(p, e, v, g, m) \
 125                 ({ _os_atomic_basetypeof(p) _v = (v), _r = (e); _Bool _b = \
 126                 atomic_compare_exchange_weak_explicit(_os_atomic_c11_atomic(p), \
 127                 &_r, _v, memory_order_##m, \
 128                 memory_order_relaxed); *(g) = (typeof(*(p)))_r;  _b; })
 129
 130 #define _os_atomic_c11_op(p, v, m, o, op) \
 131                 ({ _os_atomic_basetypeof(p) _v = (v), _r = \
 132                 atomic_fetch_##o##_explicit(_os_atomic_c11_atomic(p), _v, \
 133                 memory_order_##m); (typeof(*(p)))(_r op _v); })
 134 #define _os_atomic_c11_op_orig(p, v, m, o, op) \
 135                 ({ _os_atomic_basetypeof(p) _v = (v), _r = \
 136                 atomic_fetch_##o##_explicit(_os_atomic_c11_atomic(p), _v, \
 137                 memory_order_##m); (typeof(*(p)))_r; })
 138 #define os_atomic_add(p, v, m) \
 139                 _os_atomic_c11_op((p), (v), m, add, +)
 140 #define os_atomic_add_orig(p, v, m) \
 141                 _os_atomic_c11_op_orig((p), (v), m, add, +)
 142 #define os_atomic_sub(p, v, m) \
 143                 _os_atomic_c11_op((p), (v), m, sub, -)
 144 #define os_atomic_sub_orig(p, v, m) \
 145                 _os_atomic_c11_op_orig((p), (v), m, sub, -)
 146 #define os_atomic_and(p, v, m) \
 147                 _os_atomic_c11_op((p), (v), m, and, &)
 148 #define os_atomic_and_orig(p, v, m) \
 149                 _os_atomic_c11_op_orig((p), (v), m, and, &)
 150 #define os_atomic_or(p, v, m) \
 151                 _os_atomic_c11_op((p), (v), m, or, |)
 152 #define os_atomic_or_orig(p, v, m) \
 153                 _os_atomic_c11_op_orig((p), (v), m, or, |)
 154 #define os_atomic_xor(p, v, m) \
 155                 _os_atomic_c11_op((p), (v), m, xor, ^)
 156 #define os_atomic_xor_orig(p, v, m) \
 157                 _os_atomic_c11_op_orig((p), (v), m, xor, ^)
 158
 159 #define os_atomic_rmw_loop(p, ov, nv, m, ...)  ({ \
 160                 bool _result = false; \
 161                 typeof(p) _p = (p); \
 162                 ov = os_atomic_load(_p, relaxed); \
 163                 do { \
 164                         __VA_ARGS__; \
 165                         _result = os_atomic_cmpxchgvw(_p, ov, nv, &ov, m); \
 166                 } while (os_unlikely(!_result)); \
 167                 _result; \
 168         })
 169 #define os_atomic_rmw_loop2o(p, f, ov, nv, m, ...) \
 170                 os_atomic_rmw_loop(&(p)->f, ov, nv, m, __VA_ARGS__)
 171 #define os_atomic_rmw_loop_give_up_with_fence(m, expr) \
 172                 ({ os_atomic_thread_fence(m); expr; __builtin_unreachable(); })
 173 #define os_atomic_rmw_loop_give_up(expr) \
 174                 os_atomic_rmw_loop_give_up_with_fence(relaxed, expr)
 175
 176 #define os_atomic_load2o(p, f, m) \
 177                 os_atomic_load(&(p)->f, m)
 178 #define os_atomic_store2o(p, f, v, m) \
 179                 os_atomic_store(&(p)->f, (v), m)
 180 #define os_atomic_xchg2o(p, f, v, m) \
 181                 os_atomic_xchg(&(p)->f, (v), m)
 182 #define os_atomic_cmpxchg2o(p, f, e, v, m) \
 183                 os_atomic_cmpxchg(&(p)->f, (e), (v), m)
 184 #define os_atomic_cmpxchgv2o(p, f, e, v, g, m) \
 185                 os_atomic_cmpxchgv(&(p)->f, (e), (v), (g), m)
 186 #define os_atomic_cmpxchgvw2o(p, f, e, v, g, m) \
 187                 os_atomic_cmpxchgvw(&(p)->f, (e), (v), (g), m)
 188 #define os_atomic_add2o(p, f, v, m) \
 189                 os_atomic_add(&(p)->f, (v), m)
 190 #define os_atomic_add_orig2o(p, f, v, m) \
 191                 os_atomic_add_orig(&(p)->f, (v), m)
 192 #define os_atomic_sub2o(p, f, v, m) \
 193                 os_atomic_sub(&(p)->f, (v), m)
 194 #define os_atomic_sub_orig2o(p, f, v, m) \
 195                 os_atomic_sub_orig(&(p)->f, (v), m)
 196 #define os_atomic_and2o(p, f, v, m) \
 197                 os_atomic_and(&(p)->f, (v), m)
 198 #define os_atomic_and_orig2o(p, f, v, m) \
 199                 os_atomic_and_orig(&(p)->f, (v), m)
 200 #define os_atomic_or2o(p, f, v, m) \
 201                 os_atomic_or(&(p)->f, (v), m)
 202 #define os_atomic_or_orig2o(p, f, v, m) \
 203                 os_atomic_or_orig(&(p)->f, (v), m)
 204 #define os_atomic_xor2o(p, f, v, m) \
 205                 os_atomic_xor(&(p)->f, (v), m)
 206 #define os_atomic_xor_orig2o(p, f, v, m) \
 207                 os_atomic_xor_orig(&(p)->f, (v), m)
 208
 209 #define os_atomic_inc(p, m) \
 210                 os_atomic_add((p), 1, m)
 211 #define os_atomic_inc_orig(p, m) \
 212                 os_atomic_add_orig((p), 1, m)
 213 #define os_atomic_inc2o(p, f, m) \
 214                 os_atomic_add2o(p, f, 1, m)
 215 #define os_atomic_inc_orig2o(p, f, m) \
 216                 os_atomic_add_orig2o(p, f, 1, m)
 217 #define os_atomic_dec(p, m) \
 218                 os_atomic_sub((p), 1, m)
 219 #define os_atomic_dec_orig(p, m) \
 220                 os_atomic_sub_orig((p), 1, m)
 221 #define os_atomic_dec2o(p, f, m) \
 222                 os_atomic_sub2o(p, f, 1, m)
 223 #define os_atomic_dec_orig2o(p, f, m) \
 224                 os_atomic_sub_orig2o(p, f, 1, m)
 225
 226 #if defined(__x86_64__) || defined(__i386__)
 227 #undef os_atomic_maximally_synchronizing_barrier
 228 #ifdef __LP64__
 229 #define os_atomic_maximally_synchronizing_barrier() \
 230                 ({ unsigned long _clbr; __asm__ __volatile__( \
 231                 "cpuid" \
 232                 : "=a" (_clbr) : "0" (0) : "rbx", "rcx", "rdx", "cc", "memory"); })
 233 #else
 234 #ifdef __llvm__
 235 #define os_atomic_maximally_synchronizing_barrier() \
 236                 ({ unsigned long _clbr; __asm__ __volatile__( \
 237                 "cpuid" \
 238                 : "=a" (_clbr) : "0" (0) : "ebx", "ecx", "edx", "cc", "memory"); })
 239 #else // gcc does not allow inline i386 asm to clobber ebx
 240 #define os_atomic_maximally_synchronizing_barrier() \
 241                 ({ unsigned long _clbr; __asm__ __volatile__( \
 242                 "pushl  %%ebx\n\t" \
 243                 "cpuid\n\t" \
 244                 "popl   %%ebx" \
 245                 : "=a" (_clbr) : "0" (0) : "ecx", "edx", "cc", "memory"); })
 246 #endif
 247 #endif
 248 #endif // defined(__x86_64__) || defined(__i386__)
 249
 250 #endif // __DISPATCH_SHIMS_ATOMIC__