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 HAVE_STDATOMIC_H
  30 #include <stdatomic.h>
  31
  32 /* gcc 4.7 and newer */
  33 #elif defined(HAVE___ATOMIC)
  34
  35 #define _Atomic volatile
  36
  37 #define memory_order_relaxed __ATOMIC_RELAXED
  38 #define memory_order_consume __ATOMIC_CONSUME
  39 #define memory_order_acquire __ATOMIC_ACQUIRE
  40 #define memory_order_release __ATOMIC_RELEASE
  41 #define memory_order_acq_rel __ATOMIC_ACQ_REL
  42 #define memory_order_seq_cst __ATOMIC_SEQ_CST
  43
  44 #define atomic_load_explicit __atomic_load_n
  45 #define atomic_store_explicit __atomic_store_n
  46 #define atomic_exchange_explicit __atomic_exchange_n
  47 #define atomic_fetch_add_explicit __atomic_fetch_add
  48 #define atomic_fetch_sub_explicit __atomic_fetch_sub
  49 #define atomic_fetch_and_explicit __atomic_fetch_and
  50 #define atomic_fetch_or_explicit __atomic_fetch_or
  51
  52 #define atomic_add_fetch_explicit __atomic_add_fetch
  53 #define atomic_sub_fetch_explicit __atomic_sub_fetch
  54 #define atomic_and_fetch_explicit __atomic_and_fetch
  55 #define atomic_or_fetch_explicit __atomic_or_fetch
  56
  57 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
  58                                               mem2)                            \
  59         __atomic_compare_exchange_n(atom, expect, desire, 1, mem1, mem2)
  60
  61 /* gcc 4.1 and newer,
  62  * clang 3.3 (possibly older)
  63  *
  64  * __sync_swap isn't in gcc's documentation, but clang has it
  65  *
  66  * note __sync_synchronize()
  67  */
  68 #elif defined(HAVE___SYNC)
  69
  70 #define _Atomic volatile
  71
  72 #define memory_order_relaxed 0
  73 #define memory_order_consume 0
  74 #define memory_order_acquire 0
  75 #define memory_order_release 0
  76 #define memory_order_acq_rel 0
  77 #define memory_order_seq_cst 0
  78
  79 #define atomic_load_explicit(ptr, mem)                                         \
  80         ({                                                                     \
  81                 __sync_synchronize();                                          \
  82                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), 0);            \
  83                 __sync_synchronize();                                          \
  84                 rval;                                                          \
  85         })
  86 #define atomic_store_explicit(ptr, val, mem)                                   \
  87         ({                                                                     \
  88                 __sync_synchronize();                                          \
  89                 *(ptr) = (val);                                                \
  90                 __sync_synchronize();                                          \
  91                 (void)0;                                                       \
  92         })
  93 #ifdef HAVE___SYNC_SWAP
  94 #define atomic_exchange_explicit(ptr, val, mem)                                \
  95         ({                                                                     \
  96                 __sync_synchronize();                                          \
  97                 typeof(*ptr) rval = __sync_swap((ptr, val), 0);                \
  98                 __sync_synchronize();                                          \
  99                 rval;                                                          \
 100         })
 101 #else /* !HAVE___SYNC_SWAP */
 102 #define atomic_exchange_explicit(ptr, val, mem)                                \
 103         ({                                                                     \
 104                 typeof(ptr) _ptr = (ptr);                                      \
 105                 typeof(val) _val = (val);                                      \
 106                 __sync_synchronize();                                          \
 107                 typeof(*ptr) old1, old2 = __sync_fetch_and_add(_ptr, 0);       \
 108                 do {                                                           \
 109                         old1 = old2;                                           \
 110                         old2 = __sync_val_compare_and_swap(_ptr, old1, _val);  \
 111                 } while (old1 != old2);                                        \
 112                 __sync_synchronize();                                          \
 113                 old2;                                                          \
 114         })
 115 #endif /* !HAVE___SYNC_SWAP */
 116 #define atomic_fetch_add_explicit(ptr, val, mem)                               \
 117         ({                                                                     \
 118                 __sync_synchronize();                                          \
 119                 typeof(*ptr) rval = __sync_fetch_and_add((ptr), (val));        \
 120                 __sync_synchronize();                                          \
 121                 rval;                                                          \
 122         })
 123 #define atomic_fetch_sub_explicit(ptr, val, mem)                               \
 124         ({                                                                     \
 125                 __sync_synchronize();                                          \
 126                 typeof(*ptr) rval = __sync_fetch_and_sub((ptr), (val));        \
 127                 __sync_synchronize();                                          \
 128                 rval;                                                          \
 129         })
 130
 131 #define atomic_compare_exchange_weak_explicit(atom, expect, desire, mem1,      \
 132                                               mem2)                            \
 133         ({                                                                     \
 134                 typeof(atom) _atom = (atom);                                   \
 135                 typeof(expect) _expect = (expect);                             \
 136                 typeof(desire) _desire = (desire);                             \
 137                 __sync_synchronize();                                          \
 138                 typeof(*atom) rval =                                           \
 139                         __sync_val_compare_and_swap(_atom, *_expect, _desire); \
 140                 __sync_synchronize();                                          \
 141                 bool ret = (rval == *_expect);                                 \
 142                 *_expect = rval;                                               \
 143                 ret;                                                           \
 144         })
 145
 146 #define atomic_fetch_and_explicit(ptr, val, mem)                               \
 147         ({                                                                     \
 148                 __sync_synchronize();                                          \
 149                 typeof(*ptr) rval = __sync_fetch_and_and(ptr, val);            \
 150                 __sync_synchronize();                                          \
 151                 rval;                                                          \
 152         })
 153 #define atomic_fetch_or_explicit(ptr, val, mem)                                \
 154         ({                                                                     \
 155                 __sync_synchronize();                                          \
 156                 typeof(*ptr) rval = __sync_fetch_and_or(ptr, val);             \
 157                 __sync_synchronize();                                          \
 158                 rval;                                                          \
 159         })
 160
 161 #define atomic_add_fetch_explicit(ptr, val, mem)                               \
 162         ({                                                                     \
 163                 __sync_synchronize();                                          \
 164                 typeof(*ptr) rval = __sync_add_and_fetch((ptr), (val));        \
 165                 __sync_synchronize();                                          \
 166                 rval;                                                          \
 167         })
 168 #define atomic_sub_fetch_explicit(ptr, val, mem)                               \
 169         ({                                                                     \
 170                 __sync_synchronize();                                          \
 171                 typeof(*ptr) rval = __sync_sub_and_fetch((ptr), (val));        \
 172                 __sync_synchronize();                                          \
 173                 rval;                                                          \
 174         })
 175
 176 #define atomic_and_fetch_explicit(ptr, val, mem)                               \
 177         ({                                                                     \
 178                 __sync_synchronize();                                          \
 179                 typeof(*ptr) rval = __sync_and_and_fetch(ptr, val);            \
 180                 __sync_synchronize();                                          \
 181                 rval;                                                          \
 182         })
 183 #define atomic_or_fetch_explicit(ptr, val, mem)                                \
 184         ({                                                                     \
 185                 __sync_synchronize();                                          \
 186                 typeof(*ptr) rval = __sync_or_and_fetch(ptr, val);             \
 187                 __sync_synchronize();                                          \
 188                 rval;                                                          \
 189         })
 190
 191 #else /* !HAVE___ATOMIC && !HAVE_STDATOMIC_H */
 192 #error no atomic functions...
 193 #endif
 194
 195 #endif /* _FRRATOMIC_H */