lib/frratomic.h

   1 /*
   2  * Copyright (c) 2015-16  David Lamparter, for NetDEF, Inc.
   3  *
   4  * Permission to use, copy, modify, and distribute this software for any
   5  * purpose with or without fee is hereby granted, provided that the above
   6  * copyright notice and this permission notice appear in all copies.
   7  *
   8  * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
   9  * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
  10  * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
  11  * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
  12  * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
  13  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  14  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  15  */
  16
  17 #ifndef _FRRATOMIC_H
  18 #define _FRRATOMIC_H
  19
  20 #ifdef HAVE_CONFIG_H
  21 #include "config.h"
  22 #endif
  23
  24 #ifndef FRR_AUTOCONF_ATOMIC
  25 #error autoconf checks for atomic functions were not properly run
  26 #endif
  27
  28 /* ISO C11 */
  29 #ifdef __cplusplus
  30 #include <stdint.h>
  31 #include <atomic>
  32 using std::atomic_int;
  33 using std::memory_order;
  34 using std::memory_order_relaxed;
  35 using std::memory_order_acquire;
  36 using std::memory_order_release;
  37 using std::memory_order_acq_rel;
  38 using std::memory_order_consume;
  39 using std::memory_order_seq_cst;
  40
  41 typedef std::atomic<bool>               atomic_bool;
  42 typedef std::atomic<size_t>             atomic_size_t;
  43 typedef std::atomic<uint_fast32_t>      atomic_uint_fast32_t;
  44
  45 #elif defined(HAVE_STDATOMIC_H)
  46 #include <stdatomic.h>
  47
  48 /* These are available in gcc, but not in stdatomic */
  49 #define atomic_add_fetch_explicit __atomic_add_fetch
  50 #define atomic_sub_fetch_explicit __atomic_sub_fetch
  51 #define atomic_and_fetch_explicit __atomic_and_fetch
  52 #define atomic_or_fetch_explicit __atomic_or_fetch
  53
  54 /* gcc 4.7 and newer */
  55 #elif defined(HAVE___ATOMIC)
  56
  57 #define _Atomic volatile
  58 #define _ATOMIC_WANT_TYPEDEFS
  59
  60 #define memory_order_relaxed __ATOMIC_RELAXED
  61 #define memory_order_consume __ATOMIC_CONSUME
  62 #define memory_order_acquire __ATOMIC_ACQUIRE
  63 #define memory_order_release __ATOMIC_RELEASE
  64 #define memory_order_acq_rel __ATOMIC_ACQ_REL
  65 #define memory_order_seq_cst __ATOMIC_SEQ_CST
  66
  67 #define atomic_load_explicit __atomic_load_n
  68 #define atomic_store_explicit __atomic_store_n
  69 #define atomic_exchange_explicit __atomic_exchange_n
  70 #define atomic_fetch_add_explicit __atomic_fetch_add
  71 #define atomic_fetch_sub_explicit __atomic_fetch_sub
  72 #define atomic_fetch_and_explicit __atomic_fetch_and
  73 #define atomic_fetch_or_explicit __atomic_fetch_or
  74
  75 #define atomic_add_fetch_explicit __atomic_add_fetch
  76 #define atomic_sub_fetch_explicit __atomic_sub_fetch
  77 #define atomic_and_fetch_explicit __atomic_and_fetch
  78 #define atomic_or_fetch_explicit __atomic_or_fetch
  79
  80 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
  81                                               mem2)                            \
  82         __atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)
  83 #define atomic_compare_exchange_strong_explicit(atom, expect, desire, mem1,    \
  84                                               mem2)                            \
  85         __atomic_compare_exchange_n(atom, expect, desire, 0, mem1, mem2)
  86
  87 /* gcc 4.1 and newer,
  88  * clang 3.3 (possibly older)
  89  *
  90  * __sync_swap isn't in gcc's documentation, but clang has it
  91  *
  92  * note __sync_synchronize()
  93  */
  94 #elif defined(HAVE___SYNC)
  95
  96 #define _Atomic volatile
  97 #define _ATOMIC_WANT_TYPEDEFS
  98
  99 #define memory_order_relaxed 0
 100 #define memory_order_consume 0
 101 #define memory_order_acquire 0
 102 #define memory_order_release 0
 103 #define memory_order_acq_rel 0
 104 #define memory_order_seq_cst 0
 105
 106 #define atomic_load_explicit(ptr, mem)                                         \
 107         ({                                                                     \
 108                 __sync_synchronize();                                          \
 109                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0);            \
 110                 __sync_synchronize();                                          \
 111                 rval;                                                          \
 112         })
 113 #define atomic_store_explicit(ptr, val, mem)                                   \
 114         ({                                                                     \
 115                 __sync_synchronize();                                          \
 116                 *(ptr) = (val);                                                \
 117                 __sync_synchronize();                                          \
 118                 (void)0;                                                       \
 119         })
 120 #ifdef HAVE___SYNC_SWAP
 121 #define atomic_exchange_explicit(ptr, val, mem)                                \
 122         ({                                                                     \
 123                 __sync_synchronize();                                          \
 124                 typeof(*ptr) rval = __sync_swap((ptr, val), 0);                \
 125                 __sync_synchronize();                                          \
 126                 rval;                                                          \
 127         })
 128 #else /* !HAVE___SYNC_SWAP */
 129 #define atomic_exchange_explicit(ptr, val, mem)                                \
 130         ({                                                                     \
 131                 typeof(ptr) _ptr = (ptr);                                      \
 132                 typeof(val) _val = (val);                                      \
 133                 __sync_synchronize();                                          \
 134                 typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0);       \
 135                 do {                                                           \
 136                         old1 = old2;                                           \
 137                         old2 = __sync_val_compare_and_swap(_ptr, old1, _val);  \
 138                 } while (old1 != old2);                                        \
 139                 __sync_synchronize();                                          \
 140                 old2;                                                          \
 141         })
 142 #endif /* !HAVE___SYNC_SWAP */
 143 #define atomic_fetch_add_explicit(ptr, val, mem)                               \
 144         ({                                                                     \
 145                 __sync_synchronize();                                          \
 146                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val));        \
 147                 __sync_synchronize();                                          \
 148                 rval;                                                          \
 149         })
 150 #define atomic_fetch_sub_explicit(ptr, val, mem)                               \
 151         ({                                                                     \
 152                 __sync_synchronize();                                          \
 153                 typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val));        \
 154                 __sync_synchronize();                                          \
 155                 rval;                                                          \
 156         })
 157
 158 #define atomic_compare_exchange_strong_explicit(atom, expect, desire, mem1,    \
 159                                               mem2)                            \
 160         ({                                                                     \
 161                 typeof(atom) _atom = (atom);                                   \
 162                 typeof(expect) _expect = (expect);                             \
 163                 typeof(desire) _desire = (desire);                             \
 164                 __sync_synchronize();                                          \
 165                 typeof(*atom) rval =                                           \
 166                         __sync_val_compare_and_swap(_atom, *_expect, _desire); \
 167                 __sync_synchronize();                                          \
 168                 bool ret = (rval == *_expect);                                 \
 169                 *_expect = rval;                                               \
 170                 ret;                                                           \
 171         })
 172 #define atomic_compare_exchange_weak_explicit \
 173         atomic_compare_exchange_strong_explicit
 174
 175 #define atomic_fetch_and_explicit(ptr, val, mem)                               \
 176         ({                                                                     \
 177                 __sync_synchronize();                                          \
 178                 typeof(*ptr) rval = __sync_fetch_and_and(ptr, val);            \
 179                 __sync_synchronize();                                          \
 180                 rval;                                                          \
 181         })
 182 #define atomic_fetch_or_explicit(ptr, val, mem)                                \
 183         ({                                                                     \
 184                 __sync_synchronize();                                          \
 185                 typeof(*ptr) rval = __sync_fetch_and_or(ptr, val);             \
 186                 __sync_synchronize();                                          \
 187                 rval;                                                          \
 188         })
 189
 190 #define atomic_add_fetch_explicit(ptr, val, mem)                               \
 191         ({                                                                     \
 192                 __sync_synchronize();                                          \
 193                 typeof(*ptr) rval = __sync_add_and_fetch((ptr), (val));        \
 194                 __sync_synchronize();                                          \
 195                 rval;                                                          \
 196         })
 197 #define atomic_sub_fetch_explicit(ptr, val, mem)                               \
 198         ({                                                                     \
 199                 __sync_synchronize();                                          \
 200                 typeof(*ptr) rval = __sync_sub_and_fetch((ptr), (val));        \
 201                 __sync_synchronize();                                          \
 202                 rval;                                                          \
 203         })
 204
 205 #define atomic_and_fetch_explicit(ptr, val, mem)                               \
 206         ({                                                                     \
 207                 __sync_synchronize();                                          \
 208                 typeof(*ptr) rval = __sync_and_and_fetch(ptr, val);            \
 209                 __sync_synchronize();                                          \
 210                 rval;                                                          \
 211         })
 212 #define atomic_or_fetch_explicit(ptr, val, mem)                                \
 213         ({                                                                     \
 214                 __sync_synchronize();                                          \
 215                 typeof(*ptr) rval = __sync_or_and_fetch(ptr, val);             \
 216                 __sync_synchronize();                                          \
 217                 rval;                                                          \
 218         })
 219
 220 #else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
 221 #error no atomic functions...
 222 #endif
 223
 224 #ifdef _ATOMIC_WANT_TYPEDEFS
 225 #undef _ATOMIC_WANT_TYPEDEFS
 226
 227 #include <stdint.h>
 228 #include <stdbool.h>
 229
 230 typedef _Atomic bool            atomic_bool;
 231 typedef _Atomic size_t          atomic_size_t;
 232 typedef _Atomic uint_fast32_t   atomic_uint_fast32_t;
 233 #endif
 234
 235 #endif /* _FRRATOMIC_H */