ceph/src/boost/libs/interprocess/include/boost/interprocess/allocators/allocator.hpp

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 // (C) Copyright Ion Gaztanaga 2005-2012. Distributed under the Boost
   4 // Software License, Version 1.0. (See accompanying file
   5 // LICENSE_1_0.txt or copy at http://www.boost.org/LICENSE_1_0.txt)
   6 //
   7 // See http://www.boost.org/libs/interprocess for documentation.
   8 //
   9 ///////////////////////////////////////////////////////////////////////////////
  10
  11 #ifndef BOOST_INTERPROCESS_ALLOCATOR_HPP
  12 #define BOOST_INTERPROCESS_ALLOCATOR_HPP
  13
  14 #ifndef BOOST_CONFIG_HPP
  15 #  include <boost/config.hpp>
  16 #endif
  17 #
  18 #if defined(BOOST_HAS_PRAGMA_ONCE)
  19 #  pragma once
  20 #endif
  21
  22 #include <boost/interprocess/detail/config_begin.hpp>
  23 #include <boost/interprocess/detail/workaround.hpp>
  24
  25 #include <boost/intrusive/pointer_traits.hpp>
  26
  27 #include <boost/interprocess/interprocess_fwd.hpp>
  28 #include <boost/interprocess/containers/allocation_type.hpp>
  29 #include <boost/container/detail/multiallocation_chain.hpp>
  30 #include <boost/interprocess/allocators/detail/allocator_common.hpp>
  31 #include <boost/interprocess/detail/utilities.hpp>
  32 #include <boost/interprocess/containers/version_type.hpp>
  33 #include <boost/interprocess/exceptions.hpp>
  34 #include <boost/assert.hpp>
  35 #include <boost/utility/addressof.hpp>
  36 #include <boost/interprocess/detail/type_traits.hpp>
  37 #include <boost/container/detail/placement_new.hpp>
  38
  39 #include <cstddef>
  40 #include <stdexcept>
  41
  42 //!\file
  43 //!Describes an allocator that allocates portions of fixed size
  44 //!memory buffer (shared memory, mapped file...)
  45
  46 namespace boost {
  47 namespace interprocess {
  48
  49
  50 //!An STL compatible allocator that uses a segment manager as
  51 //!memory source. The internal pointer type will of the same type (raw, smart) as
  52 //!"typename SegmentManager::void_pointer" type. This allows
  53 //!placing the allocator in shared memory, memory mapped-files, etc...
  54 template<class T, class SegmentManager>
  55 class allocator
  56 {
  57    public:
  58    //Segment manager
  59    typedef SegmentManager                                segment_manager;
  60    typedef typename SegmentManager::void_pointer         void_pointer;
  61
  62    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
  63    private:
  64
  65    //Self type
  66    typedef allocator<T, SegmentManager>   self_t;
  67
  68    //Pointer to void
  69    typedef typename segment_manager::void_pointer  aux_pointer_t;
  70
  71    //Typedef to const void pointer
  72    typedef typename boost::intrusive::
  73       pointer_traits<aux_pointer_t>::template
  74          rebind_pointer<const void>::type          cvoid_ptr;
  75
  76    //Pointer to the allocator
  77    typedef typename boost::intrusive::
  78       pointer_traits<cvoid_ptr>::template
  79          rebind_pointer<segment_manager>::type          alloc_ptr_t;
  80
  81    //Not assignable from related allocator
  82    template<class T2, class SegmentManager2>
  83    allocator& operator=(const allocator<T2, SegmentManager2>&);
  84
  85    //Not assignable from other allocator
  86    allocator& operator=(const allocator&);
  87
  88    //Pointer to the allocator
  89    alloc_ptr_t mp_mngr;
  90    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
  91
  92    public:
  93    typedef T                                    value_type;
  94    typedef typename boost::intrusive::
  95       pointer_traits<cvoid_ptr>::template
  96          rebind_pointer<T>::type                pointer;
  97    typedef typename boost::intrusive::
  98       pointer_traits<pointer>::template
  99          rebind_pointer<const T>::type          const_pointer;
 100    typedef typename ipcdetail::add_reference
 101                      <value_type>::type         reference;
 102    typedef typename ipcdetail::add_reference
 103                      <const value_type>::type   const_reference;
 104    typedef typename segment_manager::size_type               size_type;
 105    typedef typename segment_manager::difference_type         difference_type;
 106
 107    typedef boost::interprocess::version_type<allocator, 2>   version;
 108
 109    #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 110
 111    //Experimental. Don't use.
 112    typedef boost::container::container_detail::transform_multiallocation_chain
 113       <typename SegmentManager::multiallocation_chain, T>multiallocation_chain;
 114    #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 115
 116    //!Obtains an allocator that allocates
 117    //!objects of type T2
 118    template<class T2>
 119    struct rebind
 120    {
 121       typedef allocator<T2, SegmentManager>     other;
 122    };
 123
 124    //!Returns the segment manager.
 125    //!Never throws
 126    segment_manager* get_segment_manager()const
 127    {  return ipcdetail::to_raw_pointer(mp_mngr);   }
 128
 129    //!Constructor from the segment manager.
 130    //!Never throws
 131    allocator(segment_manager *segment_mngr)
 132       : mp_mngr(segment_mngr) { }
 133
 134    //!Constructor from other allocator.
 135    //!Never throws
 136    allocator(const allocator &other)
 137       : mp_mngr(other.get_segment_manager()){ }
 138
 139    //!Constructor from related allocator.
 140    //!Never throws
 141    template<class T2>
 142    allocator(const allocator<T2, SegmentManager> &other)
 143       : mp_mngr(other.get_segment_manager()){}
 144
 145    //!Allocates memory for an array of count elements.
 146    //!Throws boost::interprocess::bad_alloc if there is no enough memory
 147    pointer allocate(size_type count, cvoid_ptr hint = 0)
 148    {
 149       (void)hint;
 150       if(size_overflows<sizeof(T)>(count)){
 151          throw bad_alloc();
 152       }
 153       return pointer(static_cast<value_type*>(mp_mngr->allocate(count*sizeof(T))));
 154    }
 155
 156    //!Deallocates memory previously allocated.
 157    //!Never throws
 158    void deallocate(const pointer &ptr, size_type)
 159    {  mp_mngr->deallocate((void*)ipcdetail::to_raw_pointer(ptr));  }
 160
 161    //!Returns the number of elements that could be allocated.
 162    //!Never throws
 163    size_type max_size() const
 164    {  return mp_mngr->get_size()/sizeof(T);   }
 165
 166    //!Swap segment manager. Does not throw. If each allocator is placed in
 167    //!different memory segments, the result is undefined.
 168    friend void swap(self_t &alloc1, self_t &alloc2)
 169    {  boost::adl_move_swap(alloc1.mp_mngr, alloc2.mp_mngr);   }
 170
 171    //!Returns maximum the number of objects the previously allocated memory
 172    //!pointed by p can hold. This size only works for memory allocated with
 173    //!allocate, allocation_command and allocate_many.
 174    size_type size(const pointer &p) const
 175    {
 176       return (size_type)mp_mngr->size(ipcdetail::to_raw_pointer(p))/sizeof(T);
 177    }
 178
 179    pointer allocation_command(boost::interprocess::allocation_type command,
 180                            size_type limit_size, size_type &prefer_in_recvd_out_size, pointer &reuse)
 181    {
 182       value_type *reuse_raw = ipcdetail::to_raw_pointer(reuse);
 183       pointer const p = mp_mngr->allocation_command(command, limit_size, prefer_in_recvd_out_size, reuse_raw);
 184       reuse = reuse_raw;
 185       return p;
 186    }
 187
 188    //!Allocates many elements of size elem_size in a contiguous block
 189    //!of memory. The minimum number to be allocated is min_elements,
 190    //!the preferred and maximum number is
 191    //!preferred_elements. The number of actually allocated elements is
 192    //!will be assigned to received_size. The elements must be deallocated
 193    //!with deallocate(...)
 194    void allocate_many(size_type elem_size, size_type num_elements, multiallocation_chain &chain)
 195    {
 196       if(size_overflows<sizeof(T)>(elem_size)){
 197          throw bad_alloc();
 198       }
 199       mp_mngr->allocate_many(elem_size*sizeof(T), num_elements, chain);
 200    }
 201
 202    //!Allocates n_elements elements, each one of size elem_sizes[i]in a
 203    //!contiguous block
 204    //!of memory. The elements must be deallocated
 205    void allocate_many(const size_type *elem_sizes, size_type n_elements, multiallocation_chain &chain)
 206    {
 207       mp_mngr->allocate_many(elem_sizes, n_elements, sizeof(T), chain);
 208    }
 209
 210    //!Allocates many elements of size elem_size in a contiguous block
 211    //!of memory. The minimum number to be allocated is min_elements,
 212    //!the preferred and maximum number is
 213    //!preferred_elements. The number of actually allocated elements is
 214    //!will be assigned to received_size. The elements must be deallocated
 215    //!with deallocate(...)
 216    void deallocate_many(multiallocation_chain &chain)
 217    {  mp_mngr->deallocate_many(chain); }
 218
 219    //!Allocates just one object. Memory allocated with this function
 220    //!must be deallocated only with deallocate_one().
 221    //!Throws boost::interprocess::bad_alloc if there is no enough memory
 222    pointer allocate_one()
 223    {  return this->allocate(1);  }
 224
 225    //!Allocates many elements of size == 1 in a contiguous block
 226    //!of memory. The minimum number to be allocated is min_elements,
 227    //!the preferred and maximum number is
 228    //!preferred_elements. The number of actually allocated elements is
 229    //!will be assigned to received_size. Memory allocated with this function
 230    //!must be deallocated only with deallocate_one().
 231    void allocate_individual(size_type num_elements, multiallocation_chain &chain)
 232    {  this->allocate_many(1, num_elements, chain); }
 233
 234    //!Deallocates memory previously allocated with allocate_one().
 235    //!You should never use deallocate_one to deallocate memory allocated
 236    //!with other functions different from allocate_one(). Never throws
 237    void deallocate_one(const pointer &p)
 238    {  return this->deallocate(p, 1);  }
 239
 240    //!Allocates many elements of size == 1 in a contiguous block
 241    //!of memory. The minimum number to be allocated is min_elements,
 242    //!the preferred and maximum number is
 243    //!preferred_elements. The number of actually allocated elements is
 244    //!will be assigned to received_size. Memory allocated with this function
 245    //!must be deallocated only with deallocate_one().
 246    void deallocate_individual(multiallocation_chain &chain)
 247    {  this->deallocate_many(chain); }
 248
 249    //!Returns address of mutable object.
 250    //!Never throws
 251    pointer address(reference value) const
 252    {  return pointer(boost::addressof(value));  }
 253
 254    //!Returns address of non mutable object.
 255    //!Never throws
 256    const_pointer address(const_reference value) const
 257    {  return const_pointer(boost::addressof(value));  }
 258
 259    //!Constructs an object
 260    //!Throws if T's constructor throws
 261    //!For backwards compatibility with libraries using C++03 allocators
 262    template<class P>
 263    void construct(const pointer &ptr, BOOST_FWD_REF(P) p)
 264    {  ::new((void*)ipcdetail::to_raw_pointer(ptr), boost_container_new_t()) value_type(::boost::forward<P>(p));  }
 265
 266    //!Destroys object. Throws if object's
 267    //!destructor throws
 268    void destroy(const pointer &ptr)
 269    {  BOOST_ASSERT(ptr != 0); (*ptr).~value_type();  }
 270
 271 };
 272
 273 //!Equality test for same type
 274 //!of allocator
 275 template<class T, class SegmentManager> inline
 276 bool operator==(const allocator<T , SegmentManager>  &alloc1,
 277                 const allocator<T, SegmentManager>  &alloc2)
 278    {  return alloc1.get_segment_manager() == alloc2.get_segment_manager(); }
 279
 280 //!Inequality test for same type
 281 //!of allocator
 282 template<class T, class SegmentManager> inline
 283 bool operator!=(const allocator<T, SegmentManager>  &alloc1,
 284                 const allocator<T, SegmentManager>  &alloc2)
 285    {  return alloc1.get_segment_manager() != alloc2.get_segment_manager(); }
 286
 287 }  //namespace interprocess {
 288
 289 #if !defined(BOOST_INTERPROCESS_DOXYGEN_INVOKED)
 290
 291 template<class T>
 292 struct has_trivial_destructor;
 293
 294 template<class T, class SegmentManager>
 295 struct has_trivial_destructor
 296    <boost::interprocess::allocator <T, SegmentManager> >
 297 {
 298    static const bool value = true;
 299 };
 300 #endif   //#ifndef BOOST_INTERPROCESS_DOXYGEN_INVOKED
 301
 302 }  //namespace boost {
 303
 304 #include <boost/interprocess/detail/config_end.hpp>
 305
 306 #endif   //BOOST_INTERPROCESS_ALLOCATOR_HPP
 307