libstdc++-v3/include/c_compatibility/stdatomic.h

   1 // -*- C++ -*- compatibility header.
   2
   3 // Copyright (C) 2008, 2009 Free Software Foundation, Inc.
   4 //
   5 // This file is part of the GNU ISO C++ Library.  This library is free
   6 // software; you can redistribute it and/or modify it under the
   7 // terms of the GNU General Public License as published by the
   8 // Free Software Foundation; either version 3, or (at your option)
   9 // any later version.
  10
  11 // This library is distributed in the hope that it will be useful,
  12 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 // GNU General Public License for more details.
  15
  16 // Under Section 7 of GPL version 3, you are granted additional
  17 // permissions described in the GCC Runtime Library Exception, version
  18 // 3.1, as published by the Free Software Foundation.
  19
  20 // You should have received a copy of the GNU General Public License and
  21 // a copy of the GCC Runtime Library Exception along with this program;
  22 // see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23 // <http://www.gnu.org/licenses/>.
  24
  25 /** @file stdatomic.h
  26  *  This is a Standard C++ Library header.
  27  */
  28
  29 #include <bits/c++config.h>
  30 #include <stddef.h>
  31 #include <stdbool.h> // XXX need to define bool w/o stdbool.h in tr1/cstdbool
  32
  33 #ifndef _GLIBCXX_STDATOMIC_H
  34 #define _GLIBCXX_STDATOMIC_H 1
  35
  36 _GLIBCXX_BEGIN_NAMESPACE(std)
  37 _GLIBCXX_BEGIN_EXTERN_C
  38
  39   /**
  40    * @defgroup atomics Atomics
  41    *
  42    * Components for performing atomic operations.
  43    * @{
  44    */
  45
  46   /// Enumeration for memory_order
  47   typedef enum memory_order
  48     {
  49       memory_order_relaxed,
  50       memory_order_consume,
  51       memory_order_acquire,
  52       memory_order_release,
  53       memory_order_acq_rel,
  54       memory_order_seq_cst
  55     } memory_order;
  56
  57   // Base for atomic_flag.
  58   typedef struct __atomic_flag_base
  59   {
  60     bool _M_i;
  61   } __atomic_flag_base;
  62
  63 #define ATOMIC_FLAG_INIT { false }
  64
  65   /// 29.2 Lock-free Property
  66 #if defined(_GLIBCXX_ATOMIC_BUILTINS_1) && defined(_GLIBCXX_ATOMIC_BUILTINS_2) \
  67   && defined(_GLIBCXX_ATOMIC_BUILTINS_4) && defined(_GLIBCXX_ATOMIC_BUILTINS_8)
  68 # define _GLIBCXX_ATOMIC_PROPERTY 2
  69 # define _GLIBCXX_ATOMIC_NAMESPACE __atomic2
  70 #elif defined(_GLIBCXX_ATOMIC_BUILTINS_1)
  71 # define _GLIBCXX_ATOMIC_PROPERTY 1
  72 # define _GLIBCXX_ATOMIC_NAMESPACE __atomic1
  73 #else
  74 # define _GLIBCXX_ATOMIC_PROPERTY 0
  75 # define _GLIBCXX_ATOMIC_NAMESPACE __atomic0
  76 #endif
  77
  78 #define ATOMIC_INTEGRAL_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY
  79 #define ATOMIC_ADDRESS_LOCK_FREE _GLIBCXX_ATOMIC_PROPERTY
  80
  81   // Switch atomic integral base types based on C or C++.  In
  82   // addition, for "C" only provide type-generic macros for atomic
  83   // operations. (As C++ accomplishes the same thing with sets of
  84   // overloaded functions.
  85 #ifdef __cplusplus
  86   inline namespace _GLIBCXX_ATOMIC_NAMESPACE { }
  87 # include <bits/atomicfwd_cxx.h>
  88 #else
  89 # include <bits/atomicfwd_c.h>
  90 #endif
  91
  92   // Typedefs for other atomic integral types.
  93   typedef atomic_schar          atomic_int_least8_t;
  94   typedef atomic_uchar          atomic_uint_least8_t;
  95   typedef atomic_short          atomic_int_least16_t;
  96   typedef atomic_ushort         atomic_uint_least16_t;
  97   typedef atomic_int            atomic_int_least32_t;
  98   typedef atomic_uint           atomic_uint_least32_t;
  99   typedef atomic_llong          atomic_int_least64_t;
 100   typedef atomic_ullong         atomic_uint_least64_t;
 101
 102   typedef atomic_schar          atomic_int_fast8_t;
 103   typedef atomic_uchar          atomic_uint_fast8_t;
 104   typedef atomic_short          atomic_int_fast16_t;
 105   typedef atomic_ushort         atomic_uint_fast16_t;
 106   typedef atomic_int            atomic_int_fast32_t;
 107   typedef atomic_uint           atomic_uint_fast32_t;
 108   typedef atomic_llong          atomic_int_fast64_t;
 109   typedef atomic_ullong         atomic_uint_fast64_t;
 110
 111   typedef atomic_long           atomic_intptr_t;
 112   typedef atomic_ulong          atomic_uintptr_t;
 113
 114   typedef atomic_long           atomic_ssize_t;
 115   typedef atomic_ulong          atomic_size_t;
 116
 117   typedef atomic_llong          atomic_intmax_t;
 118   typedef atomic_ullong         atomic_uintmax_t;
 119
 120   typedef atomic_long           atomic_ptrdiff_t;
 121
 122   // Accessor functions for base atomic_flag type.
 123   bool
 124   atomic_flag_test_and_set_explicit(volatile __atomic_flag_base*, memory_order);
 125
 126   inline bool
 127   atomic_flag_test_and_set(volatile __atomic_flag_base* __a)
 128   { return atomic_flag_test_and_set_explicit(__a, memory_order_seq_cst); }
 129
 130   void
 131   atomic_flag_clear_explicit(volatile __atomic_flag_base*, memory_order);
 132
 133   inline void
 134   atomic_flag_clear(volatile __atomic_flag_base* __a)
 135   { atomic_flag_clear_explicit(__a, memory_order_seq_cst); }
 136
 137   void
 138   __atomic_flag_wait_explicit(volatile __atomic_flag_base*, memory_order);
 139
 140   volatile __atomic_flag_base*
 141   __atomic_flag_for_address(const volatile void* __z) __attribute__((const));
 142
 143   // Implementation specific defines.
 144 #define _ATOMIC_LOAD_(__a, __x)                                         \
 145   ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_;       \
 146      volatile atomic_flag* __g = __atomic_flag_for_address(__p);        \
 147     __atomic_flag_wait_explicit(__g, __x);                              \
 148     __typeof__ _ATOMIC_MEMBER_ __r = *__p;                              \
 149     atomic_flag_clear_explicit(__g, __x);                               \
 150     __r; })
 151
 152 #define _ATOMIC_STORE_(__a, __m, __x)                                   \
 153   ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_;       \
 154     __typeof__(__m) __v = (__m);                                        \
 155     volatile atomic_flag* __g = __atomic_flag_for_address(__p);         \
 156     __atomic_flag_wait_explicit(__g, __x);                              \
 157     *__p = __v;                                                         \
 158     atomic_flag_clear_explicit(__g, __x);                               \
 159     __v; })
 160
 161 #define _ATOMIC_MODIFY_(__a, __o, __m, __x)                             \
 162   ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_;       \
 163     __typeof__(__m) __v = (__m);                                        \
 164     volatile atomic_flag* __g = __atomic_flag_for_address(__p);         \
 165     __atomic_flag_wait_explicit(__g, __x);                              \
 166     __typeof__ _ATOMIC_MEMBER_ __r = *__p;                              \
 167     *__p __o __v;                                                       \
 168     atomic_flag_clear_explicit(__g, __x);                               \
 169     __r; })
 170
 171 #define _ATOMIC_CMPEXCHNG_(__a, __e, __m, __x)                          \
 172   ({ volatile __typeof__ _ATOMIC_MEMBER_* __p = &_ATOMIC_MEMBER_;       \
 173     __typeof__(__e) __q = (__e);                                        \
 174     __typeof__(__m) __v = (__m);                                        \
 175     bool __r;                                                           \
 176     volatile atomic_flag* __g = __atomic_flag_for_address(__p);         \
 177     __atomic_flag_wait_explicit(__g, __x);                              \
 178     __typeof__ _ATOMIC_MEMBER_ __t__ = *__p;                            \
 179     if (__t__ == *__q) { *__p = __v; __r = true; }                      \
 180     else { *__q = __t__; __r = false; }                                 \
 181     atomic_flag_clear_explicit(__g, __x);                               \
 182     __r; })
 183
 184   // @} group atomics
 185
 186 _GLIBCXX_END_EXTERN_C
 187 _GLIBCXX_END_NAMESPACE
 188
 189 // Inject into global namespace. XXX
 190 #if defined(__cplusplus) && !defined(_GLIBCXX_STDATOMIC)
 191 using std::memory_order;
 192 using std::memory_order_relaxed;
 193 using std::memory_order_consume;
 194 using std::memory_order_acquire;
 195 using std::memory_order_release;
 196 using std::memory_order_acq_rel;
 197 using std::memory_order_seq_cst;
 198 using std::atomic_flag;
 199 using std::atomic_bool;
 200 using std::atomic_char;
 201 using std::atomic_schar;
 202 using std::atomic_uchar;
 203 using std::atomic_short;
 204 using std::atomic_ushort;
 205 using std::atomic_int;
 206 using std::atomic_uint;
 207 using std::atomic_long;
 208 using std::atomic_ulong;
 209 using std::atomic_llong;
 210 using std::atomic_ullong;
 211 using std::atomic_wchar_t;
 212 using std::atomic_char16_t;
 213 using std::atomic_char32_t;
 214 using std::atomic_address;
 215 using std::atomic;
 216 #endif
 217
 218 #endif