1 // <atomic> compatibility -*- C++ -*- 2 3 // Copyright (C) 2008-2017 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 #include "gstdint.h" 26 #include <atomic> 27 #include <mutex> 28 29 // XXX GLIBCXX_ABI Deprecated 30 // gcc-4.7.0 31 32 #ifdef _GLIBCXX_SHARED 33 34 #define LOGSIZE 4 35 36 namespace 37 { 38 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 39 std::mutex& get_atomic_mutex()40 get_atomic_mutex() 41 { 42 static std::mutex atomic_mutex; 43 return atomic_mutex; 44 } 45 #endif 46 47 std::__atomic_flag_base flag_table[ 1 << LOGSIZE ] = 48 { 49 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, 50 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, 51 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, 52 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, 53 }; 54 } // anonymous namespace 55 56 namespace std _GLIBCXX_VISIBILITY(default) 57 { 58 _GLIBCXX_BEGIN_NAMESPACE_VERSION 59 60 namespace __atomic0 61 { 62 63 struct atomic_flag : public __atomic_flag_base 64 { 65 bool 66 test_and_set(memory_order) noexcept; 67 68 void 69 clear(memory_order) noexcept; 70 }; 71 72 bool test_and_set(memory_order)73 atomic_flag::test_and_set(memory_order) noexcept 74 { 75 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 76 lock_guard<mutex> __lock(get_atomic_mutex()); 77 #endif 78 bool result = _M_i; 79 _M_i = true; 80 return result; 81 } 82 83 void clear(memory_order)84 atomic_flag::clear(memory_order) noexcept 85 { 86 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1) 87 lock_guard<mutex> __lock(get_atomic_mutex()); 88 #endif 89 _M_i = false; 90 } 91 } // namespace __atomic0 92 93 _GLIBCXX_BEGIN_EXTERN_C 94 95 bool atomic_flag_test_and_set_explicit(__atomic_flag_base * __a,memory_order __m)96 atomic_flag_test_and_set_explicit(__atomic_flag_base* __a, 97 memory_order __m) _GLIBCXX_NOTHROW 98 { 99 atomic_flag* d = static_cast<atomic_flag*>(__a); 100 return d->test_and_set(__m); 101 } 102 103 void atomic_flag_clear_explicit(__atomic_flag_base * __a,memory_order __m)104 atomic_flag_clear_explicit(__atomic_flag_base* __a, 105 memory_order __m) _GLIBCXX_NOTHROW 106 { 107 atomic_flag* d = static_cast<atomic_flag*>(__a); 108 return d->clear(__m); 109 } 110 111 void __atomic_flag_wait_explicit(__atomic_flag_base * __a,memory_order __x)112 __atomic_flag_wait_explicit(__atomic_flag_base* __a, 113 memory_order __x) _GLIBCXX_NOTHROW 114 { 115 while (atomic_flag_test_and_set_explicit(__a, __x)) 116 { }; 117 } 118 119 _GLIBCXX_CONST __atomic_flag_base* __atomic_flag_for_address(const volatile void * __z)120 __atomic_flag_for_address(const volatile void* __z) _GLIBCXX_NOTHROW 121 { 122 uintptr_t __u = reinterpret_cast<uintptr_t>(__z); 123 __u += (__u >> 2) + (__u << 4); 124 __u += (__u >> 7) + (__u << 5); 125 __u += (__u >> 17) + (__u << 13); 126 if (sizeof(uintptr_t) > 4) 127 __u += (__u >> 31); 128 __u &= ~((~uintptr_t(0)) << LOGSIZE); 129 return flag_table + __u; 130 } 131 132 _GLIBCXX_END_EXTERN_C 133 134 _GLIBCXX_END_NAMESPACE_VERSION 135 } // namespace std 136 137 #endif 138 139 // XXX GLIBCXX_ABI Deprecated 140 // gcc-4.5.0 141 // <atomic> signature changes 142 143 // The rename syntax for default exported names is 144 // asm (".symver name1,exportedname@GLIBCXX_3.4") 145 // asm (".symver name2,exportedname@@GLIBCXX_3.4.5") 146 // In the future, GLIBCXX_ABI > 6 should remove all uses of 147 // _GLIBCXX_*_SYMVER macros in this file. 148 149 #if defined(_GLIBCXX_SYMVER_GNU) && defined(_GLIBCXX_SHARED) \ 150 && defined(_GLIBCXX_HAVE_AS_SYMVER_DIRECTIVE) \ 151 && defined(_GLIBCXX_HAVE_SYMVER_SYMBOL_RENAMING_RUNTIME_SUPPORT) 152 153 #define _GLIBCXX_ASM_SYMVER(cur, old, version) \ 154 asm (".symver " #cur "," #old "@@" #version); 155 156 _GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag5clearESt12memory_order, _ZNVSt9__atomic011atomic_flag5clearESt12memory_order, GLIBCXX_3.4.11) 157 158 _GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag12test_and_setESt12memory_order, _ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order, GLIBCXX_3.4.11) 159 160 #endif 161