140 lines
4.1 KiB
C++
140 lines
4.1 KiB
C++
// Support for atomic operations -*- C++ -*-
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// Copyright (C) 2008, 2009
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// Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 3, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// Under Section 7 of GPL version 3, you are granted additional
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// permissions described in the GCC Runtime Library Exception, version
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// 3.1, as published by the Free Software Foundation.
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// You should have received a copy of the GNU General Public License and
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// a copy of the GCC Runtime Library Exception along with this program;
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// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
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// <http://www.gnu.org/licenses/>.
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#include "gstdint.h"
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#include <atomic>
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#include <mutex>
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#define LOGSIZE 4
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namespace
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{
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#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
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std::mutex&
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get_atomic_mutex()
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{
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static std::mutex atomic_mutex;
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return atomic_mutex;
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}
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#endif
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std::__atomic_flag_base flag_table[ 1 << LOGSIZE ] =
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{
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ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
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ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
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ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
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ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT, ATOMIC_FLAG_INIT,
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};
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} // anonymous namespace
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namespace std
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{
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namespace __atomic0
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{
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bool
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atomic_flag::test_and_set(memory_order)
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{
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#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
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lock_guard<mutex> __lock(get_atomic_mutex());
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#endif
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bool result = _M_i;
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_M_i = true;
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return result;
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}
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void
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atomic_flag::clear(memory_order)
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{
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#if defined(_GLIBCXX_HAS_GTHREADS) && defined(_GLIBCXX_USE_C99_STDINT_TR1)
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lock_guard<mutex> __lock(get_atomic_mutex());
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#endif
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_M_i = false;
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}
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}
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extern "C"
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{
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bool
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atomic_flag_test_and_set_explicit(__atomic_flag_base* __a,
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memory_order __m) throw()
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{
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atomic_flag* d = static_cast<volatile atomic_flag*>(__a);
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return d->test_and_set(__m);
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}
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void
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atomic_flag_clear_explicit(__atomic_flag_base* __a,
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memory_order __m) throw()
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{
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atomic_flag* d = static_cast<volatile atomic_flag*>(__a);
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return d->clear(__m);
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}
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void
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__atomic_flag_wait_explicit(__atomic_flag_base* __a,
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memory_order __x) throw()
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{
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while (atomic_flag_test_and_set_explicit(__a, __x))
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{ };
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}
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__atomic_flag_base*
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__atomic_flag_for_address(const void* __z) throw()
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{
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uintptr_t __u = reinterpret_cast<uintptr_t>(__z);
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__u += (__u >> 2) + (__u << 4);
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__u += (__u >> 7) + (__u << 5);
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__u += (__u >> 17) + (__u << 13);
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if (sizeof(uintptr_t) > 4)
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__u += (__u >> 31);
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__u &= ~((~uintptr_t(0)) << LOGSIZE);
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return flag_table + __u;
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}
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} // extern "C"
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} // namespace std
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// XXX GLIBCXX_ABI Deprecated
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// gcc-4.5.0
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// <atomic> signature changes
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// The rename syntax for default exported names is
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// asm (".symver name1,exportedname@GLIBCXX_3.4")
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// asm (".symver name2,exportedname@@GLIBCXX_3.4.5")
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// In the future, GLIBCXX_ABI > 6 should remove all uses of
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// _GLIBCXX_*_SYMVER macros in this file.
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#if defined(_GLIBCXX_SYMVER_GNU) && defined(PIC) \
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&& defined(_GLIBCXX_HAVE_AS_SYMVER_DIRECTIVE)
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#define _GLIBCXX_ASM_SYMVER(cur, old, version) \
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asm (".symver " #cur "," #old "@@" #version);
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_GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag5clearESt12memory_order, _ZNVSt9__atomic011atomic_flag5clearESt12memory_order, GLIBCXX_3.4.11)
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_GLIBCXX_ASM_SYMVER(_ZNSt9__atomic011atomic_flag12test_and_setESt12memory_order, _ZNVSt9__atomic011atomic_flag12test_and_setESt12memory_order, GLIBCXX_3.4.11)
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#endif
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