boost/interprocess/allocators/allocator.hpp
///////////////////////////////////////////////////////////////////////////////
//
// (C) Copyright Ion Gaztanaga 2005-2012. 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_ALLOCATOR_HPP
#define BOOST_INTERPROCESS_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/intrusive/pointer_traits.hpp>
#include <boost/interprocess/interprocess_fwd.hpp>
#include <boost/interprocess/containers/allocation_type.hpp>
#include <boost/container/detail/multiallocation_chain.hpp>
#include <boost/interprocess/allocators/detail/allocator_common.hpp>
#include <boost/interprocess/detail/utilities.hpp>
#include <boost/interprocess/containers/version_type.hpp>
#include <boost/interprocess/exceptions.hpp>
#include <boost/assert.hpp>
#include <boost/utility/addressof.hpp>
#include <boost/interprocess/detail/type_traits.hpp>
#include <memory>
#include <new>
#include <algorithm>
#include <cstddef>
#include <stdexcept>
//!\file
//!Describes an allocator that allocates portions of fixed size
//!memory buffer (shared memory, mapped file...)
namespace boost {
namespace interprocess {
//!An STL compatible 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...
template<class T, class SegmentManager>
class allocator
{
public:
//Segment manager
typedef SegmentManager segment_manager;
typedef typename SegmentManager::void_pointer void_pointer;
/// @cond
private:
//Self type
typedef allocator<T, SegmentManager> self_t;
//Pointer to void
typedef typename segment_manager::void_pointer aux_pointer_t;
//Typedef to const void pointer
typedef typename boost::intrusive::
pointer_traits<aux_pointer_t>::template
rebind_pointer<const void>::type cvoid_ptr;
//Pointer to the allocator
typedef typename boost::intrusive::
pointer_traits<cvoid_ptr>::template
rebind_pointer<segment_manager>::type alloc_ptr_t;
//Not assignable from related allocator
template<class T2, class SegmentManager2>
allocator& operator=(const allocator<T2, SegmentManager2>&);
//Not assignable from other allocator
allocator& operator=(const allocator&);
//Pointer to the allocator
alloc_ptr_t mp_mngr;
/// @endcond
public:
typedef T value_type;
typedef typename boost::intrusive::
pointer_traits<cvoid_ptr>::template
rebind_pointer<T>::type pointer;
typedef typename boost::intrusive::
pointer_traits<pointer>::template
rebind_pointer<const T>::type const_pointer;
typedef typename ipcdetail::add_reference
<value_type>::type reference;
typedef typename ipcdetail::add_reference
<const value_type>::type const_reference;
typedef typename segment_manager::size_type size_type;
typedef typename segment_manager::difference_type difference_type;
typedef boost::interprocess::version_type<allocator, 2> version;
/// @cond
//Experimental. Don't use.
typedef boost::container::container_detail::transform_multiallocation_chain
<typename SegmentManager::multiallocation_chain, T>multiallocation_chain;
/// @endcond
//!Obtains an allocator that allocates
//!objects of type T2
template<class T2>
struct rebind
{
typedef allocator<T2, SegmentManager> other;
};
//!Returns the segment manager.
//!Never throws
segment_manager* get_segment_manager()const
{ return ipcdetail::to_raw_pointer(mp_mngr); }
//!Constructor from the segment manager.
//!Never throws
allocator(segment_manager *segment_mngr)
: mp_mngr(segment_mngr) { }
//!Constructor from other allocator.
//!Never throws
allocator(const allocator &other)
: mp_mngr(other.get_segment_manager()){ }
//!Constructor from related allocator.
//!Never throws
template<class T2>
allocator(const allocator<T2, SegmentManager> &other)
: mp_mngr(other.get_segment_manager()){}
//!Allocates memory for an array of count elements.
//!Throws boost::interprocess::bad_alloc if there is no enough memory
pointer allocate(size_type count, cvoid_ptr hint = 0)
{
(void)hint;
if(size_overflows<sizeof(T)>(count)){
throw bad_alloc();
}
return pointer(static_cast<value_type*>(mp_mngr->allocate(count*sizeof(T))));
}
//!Deallocates memory previously allocated.
//!Never throws
void deallocate(const pointer &ptr, size_type)
{ mp_mngr->deallocate((void*)ipcdetail::to_raw_pointer(ptr)); }
//!Returns the number of elements that could be allocated.
//!Never throws
size_type max_size() const
{ return mp_mngr->get_size()/sizeof(T); }
//!Swap segment manager. Does not throw. If each allocator is placed in
//!different memory segments, the result is undefined.
friend void swap(self_t &alloc1, self_t &alloc2)
{ ipcdetail::do_swap(alloc1.mp_mngr, alloc2.mp_mngr); }
//!Returns maximum the number of objects the previously allocated memory
//!pointed by p can hold. This size only works for memory allocated with
//!allocate, allocation_command and allocate_many.
size_type size(const pointer &p) const
{
return (size_type)mp_mngr->size(ipcdetail::to_raw_pointer(p))/sizeof(T);
}
std::pair<pointer, bool>
allocation_command(boost::interprocess::allocation_type command,
size_type limit_size,
size_type preferred_size,
size_type &received_size, const pointer &reuse = 0)
{
return mp_mngr->allocation_command
(command, limit_size, preferred_size, received_size, ipcdetail::to_raw_pointer(reuse));
}
//!Allocates many elements of size elem_size in a contiguous block
//!of memory. The minimum number to be allocated is min_elements,
//!the preferred and maximum number is
//!preferred_elements. The number of actually allocated elements is
//!will be assigned to received_size. The elements must be deallocated
//!with deallocate(...)
multiallocation_chain allocate_many
(size_type elem_size, size_type num_elements)
{
if(size_overflows<sizeof(T)>(elem_size)){
throw bad_alloc();
}
return multiallocation_chain(mp_mngr->allocate_many(elem_size*sizeof(T), num_elements));
}
//!Allocates n_elements elements, each one of size elem_sizes[i]in a
//!contiguous block
//!of memory. The elements must be deallocated
multiallocation_chain allocate_many
(const size_type *elem_sizes, size_type n_elements)
{
multiallocation_chain(mp_mngr->allocate_many(elem_sizes, n_elements, sizeof(T)));
}
//!Allocates many elements of size elem_size in a contiguous block
//!of memory. The minimum number to be allocated is min_elements,
//!the preferred and maximum number is
//!preferred_elements. The number of actually allocated elements is
//!will be assigned to received_size. The elements must be deallocated
//!with deallocate(...)
void deallocate_many(multiallocation_chain chain)
{
return mp_mngr->deallocate_many(chain.extract_multiallocation_chain());
}
//!Allocates just one object. Memory allocated with this function
//!must be deallocated only with deallocate_one().
//!Throws boost::interprocess::bad_alloc if there is no enough memory
pointer allocate_one()
{ return this->allocate(1); }
//!Allocates many elements of size == 1 in a contiguous block
//!of memory. The minimum number to be allocated is min_elements,
//!the preferred and maximum number is
//!preferred_elements. The number of actually allocated elements is
//!will be assigned to received_size. Memory allocated with this function
//!must be deallocated only with deallocate_one().
multiallocation_chain allocate_individual
(size_type num_elements)
{ return this->allocate_many(1, num_elements); }
//!Deallocates memory previously allocated with allocate_one().
//!You should never use deallocate_one to deallocate memory allocated
//!with other functions different from allocate_one(). Never throws
void deallocate_one(const pointer &p)
{ return this->deallocate(p, 1); }
//!Allocates many elements of size == 1 in a contiguous block
//!of memory. The minimum number to be allocated is min_elements,
//!the preferred and maximum number is
//!preferred_elements. The number of actually allocated elements is
//!will be assigned to received_size. Memory allocated with this function
//!must be deallocated only with deallocate_one().
void deallocate_individual(multiallocation_chain chain)
{ return this->deallocate_many(boost::move(chain)); }
//!Returns address of mutable object.
//!Never throws
pointer address(reference value) const
{ return pointer(boost::addressof(value)); }
//!Returns address of non mutable object.
//!Never throws
const_pointer address(const_reference value) const
{ return const_pointer(boost::addressof(value)); }
//!Constructs an object
//!Throws if T's constructor throws
//!For backwards compatibility with libraries using C++03 allocators
template<class P>
void construct(const pointer &ptr, BOOST_FWD_REF(P) p)
{ ::new((void*)ipcdetail::to_raw_pointer(ptr)) value_type(::boost::forward<P>(p)); }
//!Destroys object. Throws if object's
//!destructor throws
void destroy(const pointer &ptr)
{ BOOST_ASSERT(ptr != 0); (*ptr).~value_type(); }
};
//!Equality test for same type
//!of allocator
template<class T, class SegmentManager> inline
bool operator==(const allocator<T , SegmentManager> &alloc1,
const allocator<T, SegmentManager> &alloc2)
{ return alloc1.get_segment_manager() == alloc2.get_segment_manager(); }
//!Inequality test for same type
//!of allocator
template<class T, class SegmentManager> inline
bool operator!=(const allocator<T, SegmentManager> &alloc1,
const allocator<T, SegmentManager> &alloc2)
{ return alloc1.get_segment_manager() != alloc2.get_segment_manager(); }
} //namespace interprocess {
/// @cond
template<class T>
struct has_trivial_destructor;
template<class T, class SegmentManager>
struct has_trivial_destructor
<boost::interprocess::allocator <T, SegmentManager> >
{
static const bool value = true;
};
/// @endcond
} //namespace boost {
#include <boost/interprocess/detail/config_end.hpp>
#endif //BOOST_INTERPROCESS_ALLOCATOR_HPP