boost/interprocess/allocators/allocator.hpp
/////////////////////////////////////////////////////////////////////////////// // // (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_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/interprocess/interprocess_fwd.hpp> #include <boost/interprocess/allocators/allocation_type.hpp> #include <boost/interprocess/detail/utilities.hpp> #include <boost/interprocess/detail/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 <boost/interprocess/detail/iterators.hpp> #include <memory> #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 detail::pointer_to_other <aux_pointer_t, const void>::type cvoid_ptr; //Pointer to the allocator typedef typename detail::pointer_to_other <cvoid_ptr, 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 detail::pointer_to_other <cvoid_ptr, T>::type pointer; typedef typename detail:: pointer_to_other<pointer, const T>::type const_pointer; 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<allocator, 2> version; /// @cond //Experimental. Don't use. typedef transform_iterator < typename SegmentManager:: multiallocation_iterator , detail::cast_functor <T> > multiallocation_iterator; typedef detail::multiallocation_chain_adaptor <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 detail::get_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(count > this->max_size()) 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*)detail::get_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) { detail::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(detail::get_pointer(p))/sizeof(T); } std::pair<pointer, bool> allocation_command(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, detail::get_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_iterator allocate_many(size_type elem_size, std::size_t num_elements) { return multiallocation_iterator (mp_mngr->allocate_many(sizeof(T)*elem_size, 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_iterator allocate_many(const size_type *elem_sizes, size_type n_elements) { return multiallocation_iterator (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_iterator it) { return mp_mngr->deallocate_many(it.base()); } //!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_iterator allocate_individual(std::size_t 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_iterator it) { return this->deallocate_many(it); } //!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)); } //!Copy construct an object //!Throws if T's copy constructor throws void construct(const pointer &ptr, const_reference v) { new((void*)detail::get_pointer(ptr)) value_type(v); } //!Default construct an object. //!Throws if T's default constructor throws void construct(const pointer &ptr) { new((void*)detail::get_pointer(ptr)) value_type; } //!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> > { enum { value = true }; }; /// @endcond } //namespace boost { #include <boost/interprocess/detail/config_end.hpp> #endif //BOOST_INTERPROCESS_ALLOCATOR_HPP