boost/atomic/detail/lockpool.hpp
#ifndef BOOST_ATOMIC_DETAIL_LOCKPOOL_HPP
#define BOOST_ATOMIC_DETAIL_LOCKPOOL_HPP
// Copyright (c) 2011 Helge Bahmann
//
// 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 <boost/atomic/detail/config.hpp>
#ifndef BOOST_ATOMIC_FLAG_LOCK_FREE
#include <boost/thread/mutex.hpp>
#endif
#ifdef BOOST_ATOMIC_HAS_PRAGMA_ONCE
#pragma once
#endif
namespace boost {
namespace atomics {
namespace detail {
#ifndef BOOST_ATOMIC_FLAG_LOCK_FREE
class lockpool
{
public:
typedef mutex lock_type;
class scoped_lock
{
private:
lock_type& mtx_;
scoped_lock(scoped_lock const&) /* = delete */;
scoped_lock& operator=(scoped_lock const&) /* = delete */;
public:
explicit
scoped_lock(const volatile void * addr) : mtx_(get_lock_for(addr))
{
mtx_.lock();
}
~scoped_lock()
{
mtx_.unlock();
}
};
private:
static BOOST_ATOMIC_DECL lock_type& get_lock_for(const volatile void * addr);
};
#else
class lockpool
{
public:
typedef atomic_flag lock_type;
class scoped_lock
{
private:
atomic_flag& flag_;
scoped_lock(const scoped_lock &) /* = delete */;
scoped_lock& operator=(const scoped_lock &) /* = delete */;
public:
explicit
scoped_lock(const volatile void * addr) : flag_(get_lock_for(addr))
{
for (; flag_.test_and_set(memory_order_acquire);)
{
#if defined(BOOST_ATOMIC_X86_PAUSE)
BOOST_ATOMIC_X86_PAUSE();
#endif
}
}
~scoped_lock(void)
{
flag_.clear(memory_order_release);
}
};
private:
static BOOST_ATOMIC_DECL lock_type& get_lock_for(const volatile void * addr);
};
#endif
}
}
}
#endif