#ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
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#define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
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//
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// boost/detail/atomic_count_pthreads.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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#include <boost/assert.hpp>
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#include <pthread.h>
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#if defined(BOOST_SP_REPORT_IMPLEMENTATION)
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#include <boost/config/pragma_message.hpp>
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BOOST_PRAGMA_MESSAGE("Using pthread_mutex atomic_count")
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#endif
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//
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// The generic pthread_mutex-based implementation sometimes leads to
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// inefficiencies. Example: a class with two atomic_count members
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// can get away with a single mutex.
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//
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// Users can detect this situation by checking BOOST_AC_USE_PTHREADS.
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//
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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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private:
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class scoped_lock
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{
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public:
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scoped_lock(pthread_mutex_t & m): m_(m)
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{
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BOOST_VERIFY( pthread_mutex_lock( &m_ ) == 0 );
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}
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~scoped_lock()
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{
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BOOST_VERIFY( pthread_mutex_unlock( &m_ ) == 0 );
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}
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private:
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pthread_mutex_t & m_;
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};
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public:
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explicit atomic_count(long v): value_(v)
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{
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BOOST_VERIFY( pthread_mutex_init( &mutex_, 0 ) == 0 );
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}
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~atomic_count()
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{
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BOOST_VERIFY( pthread_mutex_destroy( &mutex_ ) == 0 );
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}
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long operator++()
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{
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scoped_lock lock(mutex_);
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return ++value_;
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}
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long operator--()
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{
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scoped_lock lock(mutex_);
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return --value_;
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}
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operator long() const
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{
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scoped_lock lock(mutex_);
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return 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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mutable pthread_mutex_t mutex_;
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long value_;
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};
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} // namespace detail
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} // namespace boost
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#endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
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