private_node_allocator.hpp

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//////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2008. 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)
//
// See http://www.boost.org/libs/interprocess for documentation.
//
//////////////////////////////////////////////////////////////////////////////

#ifndef BOOST_INTERPROCESS_PRIVATE_NODE_ALLOCATOR_HPP
#define BOOST_INTERPROCESS_PRIVATE_NODE_ALLOCATOR_HPP

#if (defined _MSC_VER) && (_MSC_VER >= 1200)
#  pragma once
#endif

#include <boost/interprocess/detail/config_begin.hpp>
#include <boost/interprocess/detail/workaround.hpp>

#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/assert.hpp>
#include <boost/utility/addressof.hpp>
#include <boost/interprocess/allocators/detail/node_pool.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/interprocess/detail/workaround.hpp>
#include <memory>
#include <algorithm>
#include <cstddef>

//!\file
//!Describes private_node_allocator_base pooled shared memory STL compatible allocator 

namespace boost {
namespace interprocess {

/// @cond

namespace detail {

template < unsigned int Version
         , class T
         , class SegmentManager
         , std::size_t NodesPerBlock
         >
class private_node_allocator_base
   : public node_pool_allocation_impl
   < private_node_allocator_base < Version, T, SegmentManager, NodesPerBlock>
   , Version
   , T
   , SegmentManager
   >
{
   public:
   //Segment manager
   typedef SegmentManager                                segment_manager;
   typedef typename SegmentManager::void_pointer         void_pointer;

   /// @cond
   private:
   typedef private_node_allocator_base
      < Version, T, SegmentManager, NodesPerBlock>       self_t;
   typedef detail::private_node_pool
      <SegmentManager
      , sizeof_value<T>::value
      , NodesPerBlock
      > node_pool_t;

   BOOST_STATIC_ASSERT((Version <=2));

   /// @endcond

   public:
   typedef typename detail::
      pointer_to_other<void_pointer, T>::type            pointer;
   typedef typename detail::
      pointer_to_other<void_pointer, const T>::type      const_pointer;
   typedef T                                             value_type;
   typedef typename detail::add_reference
                     <value_type>::type                  reference;
   typedef typename detail::add_reference
                     <const value_type>::type            const_reference;
   typedef std::size_t                                   size_type;
   typedef std::ptrdiff_t                                difference_type;
   typedef detail::version_type
      <private_node_allocator_base, Version>              version;
   typedef transform_iterator
      < typename SegmentManager::
         multiallocation_iterator
      , detail::cast_functor <T> >              multiallocation_iterator;
   typedef typename SegmentManager::
      multiallocation_chain                     multiallocation_chain;

   //!Obtains node_allocator from other node_allocator
   template<class T2>
   struct rebind
   {  
      typedef private_node_allocator_base
         <Version, T2, SegmentManager, NodesPerBlock>   other;
   };

   /// @cond
   template <int dummy>
   struct node_pool
   {
      typedef detail::private_node_pool
      <SegmentManager
      , sizeof_value<T>::value
      , NodesPerBlock
      > type;

      static type *get(void *p)
      {  return static_cast<type*>(p);  }
   };

   private:
   //!Not assignable from related private_node_allocator_base
   template<unsigned int Version2, class T2, class MemoryAlgorithm2, std::size_t N2>
   private_node_allocator_base& operator=
      (const private_node_allocator_base<Version2, T2, MemoryAlgorithm2, N2>&);

   //!Not assignable from other private_node_allocator_base
   private_node_allocator_base& operator=(const private_node_allocator_base&);
   /// @endcond

   public:
   //!Constructor from a segment manager
   private_node_allocator_base(segment_manager *segment_mngr)
      : m_node_pool(segment_mngr)
   {}

   //!Copy constructor from other private_node_allocator_base. Never throws
   private_node_allocator_base(const private_node_allocator_base &other)
      : m_node_pool(other.get_segment_manager())
   {}

   //!Copy constructor from related private_node_allocator_base. Never throws.
   template<class T2>
   private_node_allocator_base
      (const private_node_allocator_base
         <Version, T2, SegmentManager, NodesPerBlock> &other)
      : m_node_pool(other.get_segment_manager())
   {}

   //!Destructor, frees all used memory. Never throws
   ~private_node_allocator_base() 
   {}

   //!Returns the segment manager. Never throws
   segment_manager* get_segment_manager()const
   {  return m_node_pool.get_segment_manager(); }

   //!Returns the internal node pool. Never throws
   node_pool_t* get_node_pool() const
   {  return const_cast<node_pool_t*>(&m_node_pool); }

   //!Swaps allocators. Does not throw. If each allocator is placed in a
   //!different shared memory segments, the result is undefined.
   friend void swap(self_t &alloc1,self_t &alloc2)
   {  alloc1.m_node_pool.swap(alloc2.m_node_pool);  }

   /// @cond
   private:
   node_pool_t m_node_pool;
   /// @endcond
};

//!Equality test for same type of private_node_allocator_base
template<unsigned int V, class T, class S, std::size_t NPC> inline
bool operator==(const private_node_allocator_base<V, T, S, NPC> &alloc1, 
                const private_node_allocator_base<V, T, S, NPC> &alloc2)
{  return &alloc1 == &alloc2; }

//!Inequality test for same type of private_node_allocator_base
template<unsigned int V, class T, class S, std::size_t NPC> inline
bool operator!=(const private_node_allocator_base<V, T, S, NPC> &alloc1, 
                const private_node_allocator_base<V, T, S, NPC> &alloc2)
{  return &alloc1 != &alloc2; }

template < class T
         , class SegmentManager
         , std::size_t NodesPerBlock = 64
         >
class private_node_allocator_v1
   :  public private_node_allocator_base
         < 1
         , T
         , SegmentManager
         , NodesPerBlock
         >
{
   public:
   typedef detail::private_node_allocator_base
         < 1, T, SegmentManager, NodesPerBlock> base_t;

   template<class T2>
   struct rebind
   {  
      typedef private_node_allocator_v1<T2, SegmentManager, NodesPerBlock>  other;
   };

   private_node_allocator_v1(SegmentManager *segment_mngr) 
      : base_t(segment_mngr)
   {}

   template<class T2>
   private_node_allocator_v1
      (const private_node_allocator_v1<T2, SegmentManager, NodesPerBlock> &other)
      : base_t(other)
   {}
};

}  //namespace detail {

/// @endcond

//!An STL node allocator that uses a segment manager as memory 
//!source. The internal pointer type will of the same type (raw, smart) as
//!"typename SegmentManager::void_pointer" type. This allows
//!placing the allocator in shared memory, memory mapped-files, etc...
//!This allocator has its own node pool. NodesPerBlock is the number of nodes allocated