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70 lines
1.4 KiB
C++
70 lines
1.4 KiB
C++
#ifndef BOOST_DETAIL_ATOMIC_COUNT_LINUX_HPP_INCLUDED
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#define BOOST_DETAIL_ATOMIC_COUNT_LINUX_HPP_INCLUDED
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//
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// boost/detail/atomic_count_linux.hpp
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//
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// Copyright (c) 2001, 2002 Peter Dimov and Multi Media Ltd.
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//
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// Distributed under the Boost Software License, Version 1.0. (See
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// accompanying file LICENSE_1_0.txt or copy at
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// http://www.boost.org/LICENSE_1_0.txt)
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//
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//
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// This implementation uses <asm/atomic.h>. This is a kernel header;
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// using kernel headers in a user program may cause a number of problems,
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// and not all flavors of Linux provide the atomic instructions.
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//
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// This file is only provided because the performance of this implementation
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// is significantly higher than the pthreads version. Use at your own risk
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// (by defining BOOST_USE_ASM_ATOMIC_H.)
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//
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#include <asm/atomic.h>
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namespace boost
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{
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namespace detail
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{
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class atomic_count
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{
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public:
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explicit atomic_count(long v)
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{
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atomic_t init = ATOMIC_INIT(v);
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value_ = init;
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}
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void operator++()
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{
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atomic_inc(&value_);
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}
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long operator--()
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{
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return !atomic_dec_and_test(&value_);
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}
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operator long() const
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{
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return atomic_read(&value_);
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}
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private:
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atomic_count(atomic_count const &);
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atomic_count & operator=(atomic_count const &);
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atomic_t value_;
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};
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} // namespace detail
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} // namespace boost
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#endif // #ifndef BOOST_DETAIL_ATOMIC_COUNT_LINUX_HPP_INCLUDED
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