1// <atomic> compatibility -*- C++ -*-
2
3// Copyright (C) 2008-2022 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
36namespace
37{
38#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
39  std::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
56namespace 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
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
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
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
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
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*
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#ifdef _GLIBCXX_COMPAT_
154#define _GLIBCXX_ASM_SYMVER(cur, old, version) \
155   asm (".symver " #cur "," #old "@@" #version);
156#else
157#define _GLIBCXX_ASM_SYMVER(cur, old, version)
158#endif
159
160_GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag5clearESt12memory_order, _ZNVSt9__atomic011atomic_flag5clearESt12memory_order, GLIBCXX_3.4.11)
161
162_GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag12test_and_setESt12memory_order, _ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order, GLIBCXX_3.4.11)
163
164#endif
165