1 #ifndef BOOST_MEMORY_ORDER_HPP_INCLUDED
2 #define BOOST_MEMORY_ORDER_HPP_INCLUDED
4 // MS compatible compilers support #pragma once
6 #if defined(_MSC_VER) && (_MSC_VER >= 1020)
10 // boost/memory_order.hpp
12 // Defines enum boost::memory_order per the C++0x working draft
14 // Copyright (c) 2008, 2009 Peter Dimov
16 // Distributed under the Boost Software License, Version 1.0.
17 // See accompanying file LICENSE_1_0.txt or copy at
18 // http://www.boost.org/LICENSE_1_0.txt)
25 // Enum values are chosen so that code that needs to insert
26 // a trailing fence for acquire semantics can use a single
29 // if( mo & memory_order_acquire ) { ...fence... }
31 // For leading fences one can use:
33 // if( mo & memory_order_release ) { ...fence... }
35 // Architectures such as Alpha that need a fence on consume
38 // if( mo & ( memory_order_acquire | memory_order_consume ) ) { ...fence... }
43 memory_order_relaxed = 0,
44 memory_order_acquire = 1,
45 memory_order_release = 2,
46 memory_order_acq_rel = 3, // acquire | release
47 memory_order_seq_cst = 7, // acq_rel | 4
48 memory_order_consume = 8
53 #endif // #ifndef BOOST_MEMORY_ORDER_HPP_INCLUDED