97 lines
1.7 KiB
C++
97 lines
1.7 KiB
C++
#ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
|
|
#define BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
|
|
|
|
//
|
|
// boost/detail/atomic_count_pthreads.hpp
|
|
//
|
|
// Copyright (c) 2001, 2002 Peter Dimov and Multi Media Ltd.
|
|
//
|
|
// Distributed under the Boost Software License, Version 1.0. (See
|
|
// accompanying file LICENSE_1_0.txt or copy at
|
|
// http://www.boost.org/LICENSE_1_0.txt)
|
|
//
|
|
|
|
#include <pthread.h>
|
|
|
|
//
|
|
// The generic pthread_mutex-based implementation sometimes leads to
|
|
// inefficiencies. Example: a class with two atomic_count members
|
|
// can get away with a single mutex.
|
|
//
|
|
// Users can detect this situation by checking BOOST_AC_USE_PTHREADS.
|
|
//
|
|
|
|
namespace boost
|
|
{
|
|
|
|
namespace detail
|
|
{
|
|
|
|
class atomic_count
|
|
{
|
|
private:
|
|
|
|
class scoped_lock
|
|
{
|
|
public:
|
|
|
|
scoped_lock(pthread_mutex_t & m): m_(m)
|
|
{
|
|
pthread_mutex_lock(&m_);
|
|
}
|
|
|
|
~scoped_lock()
|
|
{
|
|
pthread_mutex_unlock(&m_);
|
|
}
|
|
|
|
private:
|
|
|
|
pthread_mutex_t & m_;
|
|
};
|
|
|
|
public:
|
|
|
|
explicit atomic_count(long v): value_(v)
|
|
{
|
|
pthread_mutex_init(&mutex_, 0);
|
|
}
|
|
|
|
~atomic_count()
|
|
{
|
|
pthread_mutex_destroy(&mutex_);
|
|
}
|
|
|
|
long operator++()
|
|
{
|
|
scoped_lock lock(mutex_);
|
|
return ++value_;
|
|
}
|
|
|
|
long operator--()
|
|
{
|
|
scoped_lock lock(mutex_);
|
|
return --value_;
|
|
}
|
|
|
|
operator long() const
|
|
{
|
|
scoped_lock lock(mutex_);
|
|
return value_;
|
|
}
|
|
|
|
private:
|
|
|
|
atomic_count(atomic_count const &);
|
|
atomic_count & operator=(atomic_count const &);
|
|
|
|
mutable pthread_mutex_t mutex_;
|
|
long value_;
|
|
};
|
|
|
|
} // namespace detail
|
|
|
|
} // namespace boost
|
|
|
|
#endif // #ifndef BOOST_SMART_PTR_DETAIL_ATOMIC_COUNT_PTHREADS_HPP_INCLUDED
|