File: memory_order.hpp

package info (click to toggle)
boost1.62 1.62.0+dfsg-10
  • links: PTS, VCS
  • area: main
  • in suites: sid
  • size: 687,152 kB
  • sloc: cpp: 2,613,639; xml: 972,558; ansic: 53,674; python: 32,448; sh: 9,305; asm: 3,071; cs: 2,121; makefile: 967; perl: 859; yacc: 472; php: 132; ruby: 94; f90: 55; sql: 13; csh: 6
file content (57 lines) | stat: -rw-r--r-- 1,445 bytes parent folder | download | duplicates (15)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
#ifndef BOOST_MEMORY_ORDER_HPP_INCLUDED
#define BOOST_MEMORY_ORDER_HPP_INCLUDED

// MS compatible compilers support #pragma once

#if defined(_MSC_VER) && (_MSC_VER >= 1020)
# pragma once
#endif

//  boost/memory_order.hpp
//
//  Defines enum boost::memory_order per the C++0x working draft
//
//  Copyright (c) 2008, 2009 Peter Dimov
//
//  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)


namespace boost
{

//
// Enum values are chosen so that code that needs to insert
// a trailing fence for acquire semantics can use a single
// test such as:
//
// if( mo & memory_order_acquire ) { ...fence... }
//
// For leading fences one can use:
//
// if( mo & memory_order_release ) { ...fence... }
//
// Architectures such as Alpha that need a fence on consume
// can use:
//
// if( mo & ( memory_order_acquire | memory_order_consume ) ) { ...fence... }
//
// The values are also in the order of increasing "strength"
// of the fences so that success/failure orders can be checked
// efficiently in compare_exchange methods.
//

enum memory_order
{
    memory_order_relaxed = 0,
    memory_order_consume = 1,
    memory_order_acquire = 2,
    memory_order_release = 4,
    memory_order_acq_rel = 6, // acquire | release
    memory_order_seq_cst = 14 // acq_rel | 8
};

} // namespace boost

#endif // #ifndef BOOST_MEMORY_ORDER_HPP_INCLUDED