container/detail/block_slist.hpp

0001 //////////////////////////////////////////////////////////////////////////////
0002 //
0003 // (C) Copyright Ion Gaztanaga 2015-2015. Distributed under the Boost
0004 // Software License, Version 1.0. (See accompanying file
0005 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
0006 //
0007 // See http://www.boost.org/libs/container for documentation.
0008 //
0009 //////////////////////////////////////////////////////////////////////////////
0010
0011 #ifndef BOOST_CONTAINER_DETAIL_BLOCK_SLIST_HEADER
0012 #define BOOST_CONTAINER_DETAIL_BLOCK_SLIST_HEADER
0013
0014 #ifndef BOOST_CONFIG_HPP
0015 #  include <boost/config.hpp>
0016 #endif
0017
0018 #if defined(BOOST_HAS_PRAGMA_ONCE)
0019 #  pragma once
0020 #endif
0021
0022
0023 #include <boost/container/detail/config_begin.hpp>
0024 #include <boost/container/detail/workaround.hpp>
0025 #include <boost/container/container_fwd.hpp>
0026 #include <boost/container/pmr/memory_resource.hpp>
0027 #include <boost/container/throw_exception.hpp>
0028 #include <boost/container/detail/placement_new.hpp>
0029
0030 #include <boost/move/detail/type_traits.hpp>
0031 #include <boost/intrusive/linear_slist_algorithms.hpp>
0032 #include <boost/assert.hpp>
0033
0034 #include <cstddef>
0035
0036 namespace boost {
0037 namespace container {
0038 namespace pmr {
0039
0040 struct slist_node
0041 {
0042    slist_node *next;
0043 };
0044
0045 struct slist_node_traits
0046 {
0047    typedef slist_node         node;
0048    typedef slist_node*        node_ptr;
0049    typedef const slist_node*  const_node_ptr;
0050
0051    static node_ptr get_next(const_node_ptr n)
0052    {  return n->next;  }
0053
0054    static void set_next(const node_ptr & n, const node_ptr & next)
0055    {  n->next = next;  }
0056 };
0057
0058 struct block_slist_header
0059    : public slist_node
0060 {
0061    std::size_t size;
0062 };
0063
0064 typedef bi::linear_slist_algorithms<slist_node_traits> slist_algo;
0065
0066 template<class DerivedFromBlockSlistHeader = block_slist_header>
0067 class block_slist_base
0068 {
0069    slist_node m_slist;
0070
0071    static const std::size_t MaxAlignMinus1 = memory_resource::max_align-1u;
0072
0073    public:
0074
0075    static const std::size_t header_size = std::size_t(sizeof(DerivedFromBlockSlistHeader) + MaxAlignMinus1) & std::size_t(~MaxAlignMinus1);
0076
0077    explicit block_slist_base()
0078    {  slist_algo::init_header(&m_slist);  }
0079
0080    #if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
0081    block_slist_base(const block_slist_base&) = delete;
0082    block_slist_base operator=(const block_slist_base&) = delete;
0083    #else
0084    private:
0085    block_slist_base          (const block_slist_base&);
0086    block_slist_base operator=(const block_slist_base&);
0087    public:
0088    #endif
0089
0090    ~block_slist_base()
0091    {}
0092
0093    void *allocate(std::size_t size, memory_resource &mr)
0094    {
0095       if((size_t(-1) - header_size) < size)
0096          throw_bad_alloc();
0097       void *p = mr.allocate(size+header_size);
0098       block_slist_header &mb  = *::new((void*)p, boost_container_new_t()) DerivedFromBlockSlistHeader;
0099       mb.size = size+header_size;
0100       slist_algo::link_after(&m_slist, &mb);
0101       return (char *)p + header_size;
0102    }
0103
0104    void release(memory_resource &mr) BOOST_NOEXCEPT
0105    {
0106       slist_node *n = slist_algo::node_traits::get_next(&m_slist);
0107       while(n){
0108          DerivedFromBlockSlistHeader &d = static_cast<DerivedFromBlockSlistHeader&>(*n);
0109          n = slist_algo::node_traits::get_next(n);
0110          std::size_t size = d.block_slist_header::size;
0111          d.~DerivedFromBlockSlistHeader();
0112          mr.deallocate(reinterpret_cast<char*>(&d), size, memory_resource::max_align);
0113       }
0114       slist_algo::init_header(&m_slist);
0115    }
0116 };
0117
0118 class block_slist
0119    : public block_slist_base<>
0120 {
0121    memory_resource &m_upstream_rsrc;
0122
0123    public:
0124
0125    explicit block_slist(memory_resource &upstream_rsrc)
0126       : block_slist_base<>(), m_upstream_rsrc(upstream_rsrc)
0127    {}
0128
0129    #if !defined(BOOST_NO_CXX11_DELETED_FUNCTIONS) || defined(BOOST_CONTAINER_DOXYGEN_INVOKED)
0130    block_slist(const block_slist&) = delete;
0131    block_slist operator=(const block_slist&) = delete;
0132    #else
0133    private:
0134    block_slist          (const block_slist&);
0135    block_slist operator=(const block_slist&);
0136    public:
0137    #endif
0138
0139    ~block_slist()
0140    {  this->release();  }
0141
0142    void *allocate(std::size_t size)
0143    {  return this->block_slist_base<>::allocate(size, m_upstream_rsrc);  }
0144
0145    void release() BOOST_NOEXCEPT
0146    {  return this->block_slist_base<>::release(m_upstream_rsrc);  }
0147
0148    memory_resource& upstream_resource() const BOOST_NOEXCEPT
0149    {  return m_upstream_rsrc;   }
0150 };
0151
0152 }  //namespace pmr {
0153 }  //namespace container {
0154 }  //namespace boost {
0155
0156 #include <boost/container/detail/config_end.hpp>
0157
0158 #endif   //BOOST_CONTAINER_DETAIL_BLOCK_SLIST_HEADER