external_libraries/boost-lockfree/boost/lockfree/policies.hpp

   1 // boost lockfree
   2 //
   3 // Copyright (C) 2011 Tim Blechmann
   4 //
   5 // Distributed under the Boost Software License, Version 1.0. (See
   6 // accompanying file LICENSE_1_0.txt or copy at
   7 // http://www.boost.org/LICENSE_1_0.txt)
   8
   9 #ifndef BOOST_LOCKFREE_POLICIES_HPP_INCLUDED
  10 #define BOOST_LOCKFREE_POLICIES_HPP_INCLUDED
  11
  12 #include <boost/parameter.hpp>
  13 #include <boost/mpl/bool.hpp>
  14 #include <boost/mpl/size_t.hpp>
  15 #include <boost/mpl/void.hpp>
  16
  17 namespace boost {
  18 namespace lockfree {
  19
  20 #ifndef BOOST_DOXYGEN_INVOKED
  21 namespace tag { struct allocator ; }
  22 namespace tag { struct fixed_sized; }
  23 namespace tag { struct capacity; }
  24
  25 #endif
  26
  27 /** Configures a data structure as \b fixed-sized.
  28  *
  29  *  The internal nodes are stored inside an array and they are addressed by array indexing. This limits the possible size of the
  30  *  queue to the number of elements that can be addressed by the index type (usually 2**16-2), but on platforms that lack
  31  *  double-width compare-and-exchange instructions, this is the best way to achieve lock-freedom.
  32  *  This implies that a data structure is bounded.
  33  * */
  34 template <bool IsFixedSized>
  35 struct fixed_sized:
  36     boost::parameter::template_keyword<tag::fixed_sized, boost::mpl::bool_<IsFixedSized> >
  37 {};
  38
  39 /** Sets the \b capacity of a data structure at compile-time.
  40  *
  41  * This implies that a data structure is bounded and fixed-sized.
  42  * */
  43 template <size_t Size>
  44 struct capacity:
  45     boost::parameter::template_keyword<tag::capacity, boost::mpl::size_t<Size> >
  46 {};
  47
  48 /** Defines the \b allocator type of a data structure.
  49  * */
  50 template <class Alloc>
  51 struct allocator:
  52     boost::parameter::template_keyword<tag::allocator, Alloc>
  53 {};
  54
  55 }
  56 }
  57
  58 #endif /* BOOST_LOCKFREE_POLICIES_HPP_INCLUDED */
  59