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
  84 /* gcc 4.1 and newer,
  85  * clang 3.3 (possibly older)
  86  *
  87  * __sync_swap isn't in gcc's documentation, but clang has it
  88  *
  89  * note __sync_synchronize()
  90  */
  91 #elif defined(HAVE___SYNC)
  92
  93 #define _Atomic volatile
  94 #define _ATOMIC_WANT_TYPEDEFS
  95
  96 #define memory_order_relaxed 0
  97 #define memory_order_consume 0
  98 #define memory_order_acquire 0
  99 #define memory_order_release 0
 100 #define memory_order_acq_rel 0
 101 #define memory_order_seq_cst 0
 102
 103 #define atomic_load_explicit(ptr, mem)                                         \
 104         ({                                                                     \
 105                 __sync_synchronize();                                          \
 106                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0);            \
 107                 __sync_synchronize();                                          \
 108                 rval;                                                          \
 109         })
 110 #define atomic_store_explicit(ptr, val, mem)                                   \
 111         ({                                                                     \
 112                 __sync_synchronize();                                          \
 113                 *(ptr) = (val);                                                \
 114                 __sync_synchronize();                                          \
 115                 (void)0;                                                       \
 116         })
 117 #ifdef HAVE___SYNC_SWAP
 118 #define atomic_exchange_explicit(ptr, val, mem)                                \
 119         ({                                                                     \
 120                 __sync_synchronize();                                          \
 121                 typeof(*ptr) rval = __sync_swap((ptr, val), 0);                \
 122                 __sync_synchronize();                                          \
 123                 rval;                                                          \
 124         })
 125 #else /* !HAVE___SYNC_SWAP */
 126 #define atomic_exchange_explicit(ptr, val, mem)                                \
 127         ({                                                                     \
 128                 typeof(ptr) _ptr = (ptr);                                      \
 129                 typeof(val) _val = (val);                                      \
 130                 __sync_synchronize();                                          \
 131                 typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0);       \
 132                 do {                                                           \
 133                         old1 = old2;                                           \
 134                         old2 = __sync_val_compare_and_swap(_ptr, old1, _val);  \
 135                 } while (old1 != old2);                                        \
 136                 __sync_synchronize();                                          \
 137                 old2;                                                          \
 138         })
 139 #endif /* !HAVE___SYNC_SWAP */
 140 #define atomic_fetch_add_explicit(ptr, val, mem)                               \
 141         ({                                                                     \
 142                 __sync_synchronize();                                          \
 143                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val));        \
 144                 __sync_synchronize();                                          \
 145                 rval;                                                          \
 146         })
 147 #define atomic_fetch_sub_explicit(ptr, val, mem)                               \
 148         ({                                                                     \
 149                 __sync_synchronize();                                          \
 150                 typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val));        \
 151                 __sync_synchronize();                                          \
 152                 rval;                                                          \
 153         })
 154
 155 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
 156                                               mem2)                            \
 157         ({                                                                     \
 158                 typeof(atom) _atom = (atom);                                   \
 159                 typeof(expect) _expect = (expect);                             \
 160                 typeof(desire) _desire = (desire);                             \
 161                 __sync_synchronize();                                          \
 162                 typeof(*atom) rval =                                           \
 163                         __sync_val_compare_and_swap(_atom, *_expect, _desire); \
 164                 __sync_synchronize();                                          \
 165                 bool ret = (rval == *_expect);                                 \
 166                 *_expect = rval;                                               \
 167                 ret;                                                           \
 168         })
 169
 170 #define atomic_fetch_and_explicit(ptr, val, mem)                               \
 171         ({                                                                     \
 172                 __sync_synchronize();                                          \
 173                 typeof(*ptr) rval = __sync_fetch_and_and(ptr, val);            \
 174                 __sync_synchronize();                                          \
 175                 rval;                                                          \
 176         })
 177 #define atomic_fetch_or_explicit(ptr, val, mem)                                \
 178         ({                                                                     \
 179                 __sync_synchronize();                                          \
 180                 typeof(*ptr) rval = __sync_fetch_and_or(ptr, val);             \
 181                 __sync_synchronize();                                          \
 182                 rval;                                                          \
 183         })
 184
 185 #define atomic_add_fetch_explicit(ptr, val, mem)                               \
 186         ({                                                                     \
 187                 __sync_synchronize();                                          \
 188                 typeof(*ptr) rval = __sync_add_and_fetch((ptr), (val));        \
 189                 __sync_synchronize();                                          \
 190                 rval;                                                          \
 191         })
 192 #define atomic_sub_fetch_explicit(ptr, val, mem)                               \
 193         ({                                                                     \
 194                 __sync_synchronize();                                          \
 195                 typeof(*ptr) rval = __sync_sub_and_fetch((ptr), (val));        \
 196                 __sync_synchronize();                                          \
 197                 rval;                                                          \
 198         })
 199
 200 #define atomic_and_fetch_explicit(ptr, val, mem)                               \
 201         ({                                                                     \
 202                 __sync_synchronize();                                          \
 203                 typeof(*ptr) rval = __sync_and_and_fetch(ptr, val);            \
 204                 __sync_synchronize();                                          \
 205                 rval;                                                          \
 206         })
 207 #define atomic_or_fetch_explicit(ptr, val, mem)                                \
 208         ({                                                                     \
 209                 __sync_synchronize();                                          \
 210                 typeof(*ptr) rval = __sync_or_and_fetch(ptr, val);             \
 211                 __sync_synchronize();                                          \
 212                 rval;                                                          \
 213         })
 214
 215 #else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
 216 #error no atomic functions...
 217 #endif
 218
 219 #ifdef _ATOMIC_WANT_TYPEDEFS
 220 #undef _ATOMIC_WANT_TYPEDEFS
 221
 222 #include <stdint.h>
 223 #include <stdbool.h>
 224
 225 typedef _Atomic bool            atomic_bool;
 226 typedef _Atomic size_t          atomic_size_t;
 227 typedef _Atomic uint_fast32_t   atomic_uint_fast32_t;
 228 #endif
 229
 230 #endif /* _FRRATOMIC_H */