1 // Support for atomic operations -*- C++ -*-
3 // Copyright (C) 2008, 2009
4 // Free Software Foundation, Inc.
6 // This file is part of the GNU ISO C++ Library. This library is free
7 // software; you can redistribute it and/or modify it under the
8 // terms of the GNU General Public License as published by the
9 // Free Software Foundation; either version 3, or (at your option)
12 // This library is distributed in the hope that it will be useful,
13 // but WITHOUT ANY WARRANTY; without even the implied warranty of
14 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 // GNU General Public License for more details.
17 // Under Section 7 of GPL version 3, you are granted additional
18 // permissions described in the GCC Runtime Library Exception, version
19 // 3.1, as published by the Free Software Foundation.
21 // You should have received a copy of the GNU General Public License and
22 // a copy of the GCC Runtime Library Exception along with this program;
23 // see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
24 // <http://www.gnu.org/licenses/>.
34 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
38 static std::mutex atomic_mutex;
43 std::__atomic_flag_base volatile flag_table[ 1 << LOGSIZE ] =
45 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
46 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
47 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
48 ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
50 } // anonymous namespace
57 atomic_flag::test_and_set(memory_order) volatile
59 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
60 lock_guard<mutex> __lock(get_atomic_mutex());
68 atomic_flag::clear(memory_order) volatile
70 #if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
71 lock_guard<mutex> __lock(get_atomic_mutex());
80 atomic_flag_test_and_set_explicit(volatile __atomic_flag_base* __a,
83 volatile atomic_flag* d = static_cast<volatile atomic_flag*>(__a);
84 return d->test_and_set(__m);
88 atomic_flag_clear_explicit(volatile __atomic_flag_base* __a,
91 volatile atomic_flag* d = static_cast<volatile atomic_flag*>(__a);
96 __atomic_flag_wait_explicit(volatile __atomic_flag_base* __a,
99 while (atomic_flag_test_and_set_explicit(__a, __x))
103 volatile __atomic_flag_base*
104 __atomic_flag_for_address(const volatile void* __z)
106 uintptr_t __u = reinterpret_cast<uintptr_t>(__z);
107 __u += (__u >> 2) + (__u << 4);
108 __u += (__u >> 7) + (__u << 5);
109 __u += (__u >> 17) + (__u << 13);
110 if (sizeof(uintptr_t) > 4)
112 __u &= ~((~uintptr_t(0)) << LOGSIZE);
113 return flag_table + __u;