ceph/src/boost/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/aux_/template_keyword.hpp>
  13 #include <boost/mpl/bool.hpp>
  14 #include <boost/mpl/size_t.hpp>
  15
  16 namespace boost {
  17 namespace lockfree {
  18
  19 #ifndef BOOST_DOXYGEN_INVOKED
  20 namespace tag { struct allocator ; }
  21 namespace tag { struct fixed_sized; }
  22 namespace tag { struct capacity; }
  23
  24 #endif
  25
  26 /** Configures a data structure as \b fixed-sized.
  27  *
  28  *  The internal nodes are stored inside an array and they are addressed by array indexing. This limits the possible size of the
  29  *  queue to the number of elements that can be addressed by the index type (usually 2**16-2), but on platforms that lack
  30  *  double-width compare-and-exchange instructions, this is the best way to achieve lock-freedom.
  31  *  This implies that a data structure is bounded.
  32  * */
  33 template <bool IsFixedSized>
  34 struct fixed_sized:
  35     boost::parameter::template_keyword<tag::fixed_sized, boost::mpl::bool_<IsFixedSized> >
  36 {};
  37
  38 /** Sets the \b capacity of a data structure at compile-time.
  39  *
  40  * This implies that a data structure is bounded and fixed-sized.
  41  * */
  42 template <size_t Size>
  43 struct capacity:
  44     boost::parameter::template_keyword<tag::capacity, boost::mpl::size_t<Size> >
  45 {};
  46
  47 /** Defines the \b allocator type of a data structure.
  48  * */
  49 template <class Alloc>
  50 struct allocator:
  51     boost::parameter::template_keyword<tag::allocator, Alloc>
  52 {};
  53
  54 }
  55 }
  56
  57 #endif /* BOOST_LOCKFREE_POLICIES_HPP_INCLUDED */