diff options
Diffstat (limited to 'gcc-4.4.3/libstdc++-v3/include/ext/bitmap_allocator.h')
| -rw-r--r-- | gcc-4.4.3/libstdc++-v3/include/ext/bitmap_allocator.h | 1145 |
1 files changed, 0 insertions, 1145 deletions
diff --git a/gcc-4.4.3/libstdc++-v3/include/ext/bitmap_allocator.h b/gcc-4.4.3/libstdc++-v3/include/ext/bitmap_allocator.h deleted file mode 100644 index 3ad08fbef..000000000 --- a/gcc-4.4.3/libstdc++-v3/include/ext/bitmap_allocator.h +++ /dev/null @@ -1,1145 +0,0 @@ -// Bitmap Allocator. -*- C++ -*- - -// Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 -// Free Software Foundation, Inc. -// -// This file is part of the GNU ISO C++ Library. This library is free -// software; you can redistribute it and/or modify it under the -// terms of the GNU General Public License as published by the -// Free Software Foundation; either version 3, or (at your option) -// any later version. - -// This library is distributed in the hope that it will be useful, -// but WITHOUT ANY WARRANTY; without even the implied warranty of -// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the -// GNU General Public License for more details. - -// Under Section 7 of GPL version 3, you are granted additional -// permissions described in the GCC Runtime Library Exception, version -// 3.1, as published by the Free Software Foundation. - -// You should have received a copy of the GNU General Public License and -// a copy of the GCC Runtime Library Exception along with this program; -// see the files COPYING3 and COPYING.RUNTIME respectively. If not, see -// <http://www.gnu.org/licenses/>. - -/** @file ext/bitmap_allocator.h - * This file is a GNU extension to the Standard C++ Library. - */ - -#ifndef _BITMAP_ALLOCATOR_H -#define _BITMAP_ALLOCATOR_H 1 - -#include <cstddef> // For std::size_t, and ptrdiff_t. -#include <bits/functexcept.h> // For __throw_bad_alloc(). -#include <utility> // For std::pair. -#include <functional> // For greater_equal, and less_equal. -#include <new> // For operator new. -#include <debug/debug.h> // _GLIBCXX_DEBUG_ASSERT -#include <ext/concurrence.h> -#include <bits/move.h> - -/** @brief The constant in the expression below is the alignment - * required in bytes. - */ -#define _BALLOC_ALIGN_BYTES 8 - -_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) - - using std::size_t; - using std::ptrdiff_t; - - namespace __detail - { - /** @class __mini_vector bitmap_allocator.h bitmap_allocator.h - * - * @brief __mini_vector<> is a stripped down version of the - * full-fledged std::vector<>. - * - * It is to be used only for built-in types or PODs. Notable - * differences are: - * - * @detail - * 1. Not all accessor functions are present. - * 2. Used ONLY for PODs. - * 3. No Allocator template argument. Uses ::operator new() to get - * memory, and ::operator delete() to free it. - * Caveat: The dtor does NOT free the memory allocated, so this a - * memory-leaking vector! - */ - template<typename _Tp> - class __mini_vector - { - __mini_vector(const __mini_vector&); - __mini_vector& operator=(const __mini_vector&); - - public: - typedef _Tp value_type; - typedef _Tp* pointer; - typedef _Tp& reference; - typedef const _Tp& const_reference; - typedef size_t size_type; - typedef ptrdiff_t difference_type; - typedef pointer iterator; - - private: - pointer _M_start; - pointer _M_finish; - pointer _M_end_of_storage; - - size_type - _M_space_left() const throw() - { return _M_end_of_storage - _M_finish; } - - pointer - allocate(size_type __n) - { return static_cast<pointer>(::operator new(__n * sizeof(_Tp))); } - - void - deallocate(pointer __p, size_type) - { ::operator delete(__p); } - - public: - // Members used: size(), push_back(), pop_back(), - // insert(iterator, const_reference), erase(iterator), - // begin(), end(), back(), operator[]. - - __mini_vector() : _M_start(0), _M_finish(0), - _M_end_of_storage(0) - { } - -#if 0 - ~__mini_vector() - { - if (this->_M_start) - { - this->deallocate(this->_M_start, this->_M_end_of_storage - - this->_M_start); - } - } -#endif - - size_type - size() const throw() - { return _M_finish - _M_start; } - - iterator - begin() const throw() - { return this->_M_start; } - - iterator - end() const throw() - { return this->_M_finish; } - - reference - back() const throw() - { return *(this->end() - 1); } - - reference - operator[](const size_type __pos) const throw() - { return this->_M_start[__pos]; } - - void - insert(iterator __pos, const_reference __x); - - void - push_back(const_reference __x) - { - if (this->_M_space_left()) - { - *this->end() = __x; - ++this->_M_finish; - } - else - this->insert(this->end(), __x); - } - - void - pop_back() throw() - { --this->_M_finish; } - - void - erase(iterator __pos) throw(); - - void - clear() throw() - { this->_M_finish = this->_M_start; } - }; - - // Out of line function definitions. - template<typename _Tp> - void __mini_vector<_Tp>:: - insert(iterator __pos, const_reference __x) - { - if (this->_M_space_left()) - { - size_type __to_move = this->_M_finish - __pos; - iterator __dest = this->end(); - iterator __src = this->end() - 1; - - ++this->_M_finish; - while (__to_move) - { - *__dest = *__src; - --__dest; --__src; --__to_move; - } - *__pos = __x; - } - else - { - size_type __new_size = this->size() ? this->size() * 2 : 1; - iterator __new_start = this->allocate(__new_size); - iterator __first = this->begin(); - iterator __start = __new_start; - while (__first != __pos) - { - *__start = *__first; - ++__start; ++__first; - } - *__start = __x; - ++__start; - while (__first != this->end()) - { - *__start = *__first; - ++__start; ++__first; - } - if (this->_M_start) - this->deallocate(this->_M_start, this->size()); - - this->_M_start = __new_start; - this->_M_finish = __start; - this->_M_end_of_storage = this->_M_start + __new_size; - } - } - - template<typename _Tp> - void __mini_vector<_Tp>:: - erase(iterator __pos) throw() - { - while (__pos + 1 != this->end()) - { - *__pos = __pos[1]; - ++__pos; - } - --this->_M_finish; - } - - - template<typename _Tp> - struct __mv_iter_traits - { - typedef typename _Tp::value_type value_type; - typedef typename _Tp::difference_type difference_type; - }; - - template<typename _Tp> - struct __mv_iter_traits<_Tp*> - { - typedef _Tp value_type; - typedef ptrdiff_t difference_type; - }; - - enum - { - bits_per_byte = 8, - bits_per_block = sizeof(size_t) * size_t(bits_per_byte) - }; - - template<typename _ForwardIterator, typename _Tp, typename _Compare> - _ForwardIterator - __lower_bound(_ForwardIterator __first, _ForwardIterator __last, - const _Tp& __val, _Compare __comp) - { - typedef typename __mv_iter_traits<_ForwardIterator>::value_type - _ValueType; - typedef typename __mv_iter_traits<_ForwardIterator>::difference_type - _DistanceType; - - _DistanceType __len = __last - __first; - _DistanceType __half; - _ForwardIterator __middle; - - while (__len > 0) - { - __half = __len >> 1; - __middle = __first; - __middle += __half; - if (__comp(*__middle, __val)) - { - __first = __middle; - ++__first; - __len = __len - __half - 1; - } - else - __len = __half; - } - return __first; - } - - template<typename _InputIterator, typename _Predicate> - inline _InputIterator - __find_if(_InputIterator __first, _InputIterator __last, _Predicate __p) - { - while (__first != __last && !__p(*__first)) - ++__first; - return __first; - } - - /** @brief The number of Blocks pointed to by the address pair - * passed to the function. - */ - template<typename _AddrPair> - inline size_t - __num_blocks(_AddrPair __ap) - { return (__ap.second - __ap.first) + 1; } - - /** @brief The number of Bit-maps pointed to by the address pair - * passed to the function. - */ - template<typename _AddrPair> - inline size_t - __num_bitmaps(_AddrPair __ap) - { return __num_blocks(__ap) / size_t(bits_per_block); } - - // _Tp should be a pointer type. - template<typename _Tp> - class _Inclusive_between - : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> - { - typedef _Tp pointer; - pointer _M_ptr_value; - typedef typename std::pair<_Tp, _Tp> _Block_pair; - - public: - _Inclusive_between(pointer __ptr) : _M_ptr_value(__ptr) - { } - - bool - operator()(_Block_pair __bp) const throw() - { - if (std::less_equal<pointer>()(_M_ptr_value, __bp.second) - && std::greater_equal<pointer>()(_M_ptr_value, __bp.first)) - return true; - else - return false; - } - }; - - // Used to pass a Functor to functions by reference. - template<typename _Functor> - class _Functor_Ref - : public std::unary_function<typename _Functor::argument_type, - typename _Functor::result_type> - { - _Functor& _M_fref; - - public: - typedef typename _Functor::argument_type argument_type; - typedef typename _Functor::result_type result_type; - - _Functor_Ref(_Functor& __fref) : _M_fref(__fref) - { } - - result_type - operator()(argument_type __arg) - { return _M_fref(__arg); } - }; - - /** @class _Ffit_finder bitmap_allocator.h bitmap_allocator.h - * - * @brief The class which acts as a predicate for applying the - * first-fit memory allocation policy for the bitmap allocator. - */ - // _Tp should be a pointer type, and _Alloc is the Allocator for - // the vector. - template<typename _Tp> - class _Ffit_finder - : public std::unary_function<typename std::pair<_Tp, _Tp>, bool> - { - typedef typename std::pair<_Tp, _Tp> _Block_pair; - typedef typename __detail::__mini_vector<_Block_pair> _BPVector; - typedef typename _BPVector::difference_type _Counter_type; - - size_t* _M_pbitmap; - _Counter_type _M_data_offset; - - public: - _Ffit_finder() : _M_pbitmap(0), _M_data_offset(0) - { } - - bool - operator()(_Block_pair __bp) throw() - { - // Set the _rover to the last physical location bitmap, - // which is the bitmap which belongs to the first free - // block. Thus, the bitmaps are in exact reverse order of - // the actual memory layout. So, we count down the bitmaps, - // which is the same as moving up the memory. - - // If the used count stored at the start of the Bit Map headers - // is equal to the number of Objects that the current Block can - // store, then there is definitely no space for another single - // object, so just return false. - _Counter_type __diff = - __gnu_cxx::__detail::__num_bitmaps(__bp); - - if (*(reinterpret_cast<size_t*> - (__bp.first) - (__diff + 1)) - == __gnu_cxx::__detail::__num_blocks(__bp)) - return false; - - size_t* __rover = reinterpret_cast<size_t*>(__bp.first) - 1; - - for (_Counter_type __i = 0; __i < __diff; ++__i) - { - _M_data_offset = __i; - if (*__rover) - { - _M_pbitmap = __rover; - return true; - } - --__rover; - } - return false; - } - - - size_t* - _M_get() const throw() - { return _M_pbitmap; } - - _Counter_type - _M_offset() const throw() - { return _M_data_offset * size_t(bits_per_block); } - }; - - - /** @class _Bitmap_counter bitmap_allocator.h bitmap_allocator.h - * - * @brief The bitmap counter which acts as the bitmap - * manipulator, and manages the bit-manipulation functions and - * the searching and identification functions on the bit-map. - */ - // _Tp should be a pointer type. - template<typename _Tp> - class _Bitmap_counter - { - typedef typename __detail::__mini_vector<typename std::pair<_Tp, _Tp> > - _BPVector; - typedef typename _BPVector::size_type _Index_type; - typedef _Tp pointer; - - _BPVector& _M_vbp; - size_t* _M_curr_bmap; - size_t* _M_last_bmap_in_block; - _Index_type _M_curr_index; - - public: - // Use the 2nd parameter with care. Make sure that such an - // entry exists in the vector before passing that particular - // index to this ctor. - _Bitmap_counter(_BPVector& Rvbp, long __index = -1) : _M_vbp(Rvbp) - { this->_M_reset(__index); } - - void - _M_reset(long __index = -1) throw() - { - if (__index == -1) - { - _M_curr_bmap = 0; - _M_curr_index = static_cast<_Index_type>(-1); - return; - } - - _M_curr_index = __index; - _M_curr_bmap = reinterpret_cast<size_t*> - (_M_vbp[_M_curr_index].first) - 1; - - _GLIBCXX_DEBUG_ASSERT(__index <= (long)_M_vbp.size() - 1); - - _M_last_bmap_in_block = _M_curr_bmap - - ((_M_vbp[_M_curr_index].second - - _M_vbp[_M_curr_index].first + 1) - / size_t(bits_per_block) - 1); - } - - // Dangerous Function! Use with extreme care. Pass to this - // function ONLY those values that are known to be correct, - // otherwise this will mess up big time. - void - _M_set_internal_bitmap(size_t* __new_internal_marker) throw() - { _M_curr_bmap = __new_internal_marker; } - - bool - _M_finished() const throw() - { return(_M_curr_bmap == 0); } - - _Bitmap_counter& - operator++() throw() - { - if (_M_curr_bmap == _M_last_bmap_in_block) - { - if (++_M_curr_index == _M_vbp.size()) - _M_curr_bmap = 0; - else - this->_M_reset(_M_curr_index); - } - else - --_M_curr_bmap; - return *this; - } - - size_t* - _M_get() const throw() - { return _M_curr_bmap; } - - pointer - _M_base() const throw() - { return _M_vbp[_M_curr_index].first; } - - _Index_type - _M_offset() const throw() - { - return size_t(bits_per_block) - * ((reinterpret_cast<size_t*>(this->_M_base()) - - _M_curr_bmap) - 1); - } - - _Index_type - _M_where() const throw() - { return _M_curr_index; } - }; - - /** @brief Mark a memory address as allocated by re-setting the - * corresponding bit in the bit-map. - */ - inline void - __bit_allocate(size_t* __pbmap, size_t __pos) throw() - { - size_t __mask = 1 << __pos; - __mask = ~__mask; - *__pbmap &= __mask; - } - - /** @brief Mark a memory address as free by setting the - * corresponding bit in the bit-map. - */ - inline void - __bit_free(size_t* __pbmap, size_t __pos) throw() - { - size_t __mask = 1 << __pos; - *__pbmap |= __mask; - } - } // namespace __detail - - /** @brief Generic Version of the bsf instruction. - */ - inline size_t - _Bit_scan_forward(size_t __num) - { return static_cast<size_t>(__builtin_ctzl(__num)); } - - /** @class free_list bitmap_allocator.h bitmap_allocator.h - * - * @brief The free list class for managing chunks of memory to be - * given to and returned by the bitmap_allocator. - */ - class free_list - { - typedef size_t* value_type; - typedef __detail::__mini_vector<value_type> vector_type; - typedef vector_type::iterator iterator; - typedef __mutex __mutex_type; - - struct _LT_pointer_compare - { - bool - operator()(const size_t* __pui, - const size_t __cui) const throw() - { return *__pui < __cui; } - }; - -#if defined __GTHREADS - __mutex_type& - _M_get_mutex() - { - static __mutex_type _S_mutex; - return _S_mutex; - } -#endif - - vector_type& - _M_get_free_list() - { - static vector_type _S_free_list; - return _S_free_list; - } - - /** @brief Performs validation of memory based on their size. - * - * @param __addr The pointer to the memory block to be - * validated. - * - * @detail Validates the memory block passed to this function and - * appropriately performs the action of managing the free list of - * blocks by adding this block to the free list or deleting this - * or larger blocks from the free list. - */ - void - _M_validate(size_t* __addr) throw() - { - vector_type& __free_list = _M_get_free_list(); - const vector_type::size_type __max_size = 64; - if (__free_list.size() >= __max_size) - { - // Ok, the threshold value has been reached. We determine - // which block to remove from the list of free blocks. - if (*__addr >= *__free_list.back()) - { - // Ok, the new block is greater than or equal to the - // last block in the list of free blocks. We just free - // the new block. - ::operator delete(static_cast<void*>(__addr)); - return; - } - else - { - // Deallocate the last block in the list of free lists, - // and insert the new one in its correct position. - ::operator delete(static_cast<void*>(__free_list.back())); - __free_list.pop_back(); - } - } - - // Just add the block to the list of free lists unconditionally. - iterator __temp = __gnu_cxx::__detail::__lower_bound - (__free_list.begin(), __free_list.end(), - *__addr, _LT_pointer_compare()); - - // We may insert the new free list before _temp; - __free_list.insert(__temp, __addr); - } - - /** @brief Decides whether the wastage of memory is acceptable for - * the current memory request and returns accordingly. - * - * @param __block_size The size of the block available in the free - * list. - * - * @param __required_size The required size of the memory block. - * - * @return true if the wastage incurred is acceptable, else returns - * false. - */ - bool - _M_should_i_give(size_t __block_size, - size_t __required_size) throw() - { - const size_t __max_wastage_percentage = 36; - if (__block_size >= __required_size && - (((__block_size - __required_size) * 100 / __block_size) - < __max_wastage_percentage)) - return true; - else - return false; - } - - public: - /** @brief This function returns the block of memory to the - * internal free list. - * - * @param __addr The pointer to the memory block that was given - * by a call to the _M_get function. - */ - inline void - _M_insert(size_t* __addr) throw() - { -#if defined __GTHREADS - __gnu_cxx::__scoped_lock __bfl_lock(_M_get_mutex()); -#endif - // Call _M_validate to decide what should be done with - // this particular free list. - this->_M_validate(reinterpret_cast<size_t*>(__addr) - 1); - // See discussion as to why this is 1! - } - - /** @brief This function gets a block of memory of the specified - * size from the free list. - * - * @param __sz The size in bytes of the memory required. - * - * @return A pointer to the new memory block of size at least - * equal to that requested. - */ - size_t* - _M_get(size_t __sz) throw(std::bad_alloc); - - /** @brief This function just clears the internal Free List, and - * gives back all the memory to the OS. - */ - void - _M_clear(); - }; - - - // Forward declare the class. - template<typename _Tp> - class bitmap_allocator; - - // Specialize for void: - template<> - class bitmap_allocator<void> - { - public: - typedef void* pointer; - typedef const void* const_pointer; - - // Reference-to-void members are impossible. - typedef void value_type; - template<typename _Tp1> - struct rebind - { - typedef bitmap_allocator<_Tp1> other; - }; - }; - - /** - * @brief Bitmap Allocator, primary template. - * @ingroup allocators - */ - template<typename _Tp> - class bitmap_allocator : private free_list - { - public: - typedef size_t size_type; - typedef ptrdiff_t difference_type; - typedef _Tp* pointer; - typedef const _Tp* const_pointer; - typedef _Tp& reference; - typedef const _Tp& const_reference; - typedef _Tp value_type; - typedef free_list::__mutex_type __mutex_type; - - template<typename _Tp1> - struct rebind - { - typedef bitmap_allocator<_Tp1> other; - }; - - private: - template<size_t _BSize, size_t _AlignSize> - struct aligned_size - { - enum - { - modulus = _BSize % _AlignSize, - value = _BSize + (modulus ? _AlignSize - (modulus) : 0) - }; - }; - - struct _Alloc_block - { - char __M_unused[aligned_size<sizeof(value_type), - _BALLOC_ALIGN_BYTES>::value]; - }; - - - typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair; - - typedef typename - __detail::__mini_vector<_Block_pair> _BPVector; - -#if defined _GLIBCXX_DEBUG - // Complexity: O(lg(N)). Where, N is the number of block of size - // sizeof(value_type). - void - _S_check_for_free_blocks() throw() - { - typedef typename - __gnu_cxx::__detail::_Ffit_finder<_Alloc_block*> _FFF; - _FFF __fff; - typedef typename _BPVector::iterator _BPiter; - _BPiter __bpi = - __gnu_cxx::__detail::__find_if - (_S_mem_blocks.begin(), _S_mem_blocks.end(), - __gnu_cxx::__detail::_Functor_Ref<_FFF>(__fff)); - - _GLIBCXX_DEBUG_ASSERT(__bpi == _S_mem_blocks.end()); - } -#endif - - /** @brief Responsible for exponentially growing the internal - * memory pool. - * - * @throw std::bad_alloc. If memory can not be allocated. - * - * @detail Complexity: O(1), but internally depends upon the - * complexity of the function free_list::_M_get. The part where - * the bitmap headers are written has complexity: O(X),where X - * is the number of blocks of size sizeof(value_type) within - * the newly acquired block. Having a tight bound. - */ - void - _S_refill_pool() throw(std::bad_alloc) - { -#if defined _GLIBCXX_DEBUG - _S_check_for_free_blocks(); -#endif - - const size_t __num_bitmaps = (_S_block_size - / size_t(__detail::bits_per_block)); - const size_t __size_to_allocate = sizeof(size_t) - + _S_block_size * sizeof(_Alloc_block) - + __num_bitmaps * sizeof(size_t); - - size_t* __temp = - reinterpret_cast<size_t*> - (this->_M_get(__size_to_allocate)); - *__temp = 0; - ++__temp; - - // The Header information goes at the Beginning of the Block. - _Block_pair __bp = - std::make_pair(reinterpret_cast<_Alloc_block*> - (__temp + __num_bitmaps), - reinterpret_cast<_Alloc_block*> - (__temp + __num_bitmaps) - + _S_block_size - 1); - - // Fill the Vector with this information. - _S_mem_blocks.push_back(__bp); - - size_t __bit_mask = 0; // 0 Indicates all Allocated. - __bit_mask = ~__bit_mask; // 1 Indicates all Free. - - for (size_t __i = 0; __i < __num_bitmaps; ++__i) - __temp[__i] = __bit_mask; - - _S_block_size *= 2; - } - - - static _BPVector _S_mem_blocks; - static size_t _S_block_size; - static __gnu_cxx::__detail:: - _Bitmap_counter<_Alloc_block*> _S_last_request; - static typename _BPVector::size_type _S_last_dealloc_index; -#if defined __GTHREADS - static __mutex_type _S_mut; -#endif - - public: - - /** @brief Allocates memory for a single object of size - * sizeof(_Tp). - * - * @throw std::bad_alloc. If memory can not be allocated. - * - * @detail Complexity: Worst case complexity is O(N), but that - * is hardly ever hit. If and when this particular case is - * encountered, the next few cases are guaranteed to have a - * worst case complexity of O(1)! That's why this function - * performs very well on average. You can consider this - * function to have a complexity referred to commonly as: - * Amortized Constant time. - */ - pointer - _M_allocate_single_object() throw(std::bad_alloc) - { -#if defined __GTHREADS - __gnu_cxx::__scoped_lock __bit_lock(_S_mut); -#endif - - // The algorithm is something like this: The last_request - // variable points to the last accessed Bit Map. When such a - // condition occurs, we try to find a free block in the - // current bitmap, or succeeding bitmaps until the last bitmap - // is reached. If no free block turns up, we resort to First - // Fit method. - - // WARNING: Do not re-order the condition in the while - // statement below, because it relies on C++'s short-circuit - // evaluation. The return from _S_last_request->_M_get() will - // NOT be dereference able if _S_last_request->_M_finished() - // returns true. This would inevitably lead to a NULL pointer - // dereference if tinkered with. - while (_S_last_request._M_finished() == false - && (*(_S_last_request._M_get()) == 0)) - { - _S_last_request.operator++(); - } - - if (__builtin_expect(_S_last_request._M_finished() == true, false)) - { - // Fall Back to First Fit algorithm. - typedef typename - __gnu_cxx::__detail::_Ffit_finder<_Alloc_block*> _FFF; - _FFF __fff; - typedef typename _BPVector::iterator _BPiter; - _BPiter __bpi = - __gnu_cxx::__detail::__find_if - (_S_mem_blocks.begin(), _S_mem_blocks.end(), - __gnu_cxx::__detail::_Functor_Ref<_FFF>(__fff)); - - if (__bpi != _S_mem_blocks.end()) - { - // Search was successful. Ok, now mark the first bit from - // the right as 0, meaning Allocated. This bit is obtained - // by calling _M_get() on __fff. - size_t __nz_bit = _Bit_scan_forward(*__fff._M_get()); - __detail::__bit_allocate(__fff._M_get(), __nz_bit); - - _S_last_request._M_reset(__bpi - _S_mem_blocks.begin()); - - // Now, get the address of the bit we marked as allocated. - pointer __ret = reinterpret_cast<pointer> - (__bpi->first + __fff._M_offset() + __nz_bit); - size_t* __puse_count = - reinterpret_cast<size_t*> - (__bpi->first) - - (__gnu_cxx::__detail::__num_bitmaps(*__bpi) + 1); - - ++(*__puse_count); - return __ret; - } - else - { - // Search was unsuccessful. We Add more memory to the - // pool by calling _S_refill_pool(). - _S_refill_pool(); - - // _M_Reset the _S_last_request structure to the first - // free block's bit map. - _S_last_request._M_reset(_S_mem_blocks.size() - 1); - - // Now, mark that bit as allocated. - } - } - - // _S_last_request holds a pointer to a valid bit map, that - // points to a free block in memory. - size_t __nz_bit = _Bit_scan_forward(*_S_last_request._M_get()); - __detail::__bit_allocate(_S_last_request._M_get(), __nz_bit); - - pointer __ret = reinterpret_cast<pointer> - (_S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit); - - size_t* __puse_count = reinterpret_cast<size_t*> - (_S_mem_blocks[_S_last_request._M_where()].first) - - (__gnu_cxx::__detail:: - __num_bitmaps(_S_mem_blocks[_S_last_request._M_where()]) + 1); - - ++(*__puse_count); - return __ret; - } - - /** @brief Deallocates memory that belongs to a single object of - * size sizeof(_Tp). - * - * @detail Complexity: O(lg(N)), but the worst case is not hit - * often! This is because containers usually deallocate memory - * close to each other and this case is handled in O(1) time by - * the deallocate function. - */ - void - _M_deallocate_single_object(pointer __p) throw() - { -#if defined __GTHREADS - __gnu_cxx::__scoped_lock __bit_lock(_S_mut); -#endif - _Alloc_block* __real_p = reinterpret_cast<_Alloc_block*>(__p); - - typedef typename _BPVector::iterator _Iterator; - typedef typename _BPVector::difference_type _Difference_type; - - _Difference_type __diff; - long __displacement; - - _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index >= 0); - - - if (__gnu_cxx::__detail::_Inclusive_between<_Alloc_block*> - (__real_p) (_S_mem_blocks[_S_last_dealloc_index])) - { - _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index - <= _S_mem_blocks.size() - 1); - - // Initial Assumption was correct! - __diff = _S_last_dealloc_index; - __displacement = __real_p - _S_mem_blocks[__diff].first; - } - else - { - _Iterator _iter = __gnu_cxx::__detail:: - __find_if(_S_mem_blocks.begin(), - _S_mem_blocks.end(), - __gnu_cxx::__detail:: - _Inclusive_between<_Alloc_block*>(__real_p)); - - _GLIBCXX_DEBUG_ASSERT(_iter != _S_mem_blocks.end()); - - __diff = _iter - _S_mem_blocks.begin(); - __displacement = __real_p - _S_mem_blocks[__diff].first; - _S_last_dealloc_index = __diff; - } - - // Get the position of the iterator that has been found. - const size_t __rotate = (__displacement - % size_t(__detail::bits_per_block)); - size_t* __bitmapC = - reinterpret_cast<size_t*> - (_S_mem_blocks[__diff].first) - 1; - __bitmapC -= (__displacement / size_t(__detail::bits_per_block)); - - __detail::__bit_free(__bitmapC, __rotate); - size_t* __puse_count = reinterpret_cast<size_t*> - (_S_mem_blocks[__diff].first) - - (__gnu_cxx::__detail::__num_bitmaps(_S_mem_blocks[__diff]) + 1); - - _GLIBCXX_DEBUG_ASSERT(*__puse_count != 0); - - --(*__puse_count); - - if (__builtin_expect(*__puse_count == 0, false)) - { - _S_block_size /= 2; - - // We can safely remove this block. - // _Block_pair __bp = _S_mem_blocks[__diff]; - this->_M_insert(__puse_count); - _S_mem_blocks.erase(_S_mem_blocks.begin() + __diff); - - // Reset the _S_last_request variable to reflect the - // erased block. We do this to protect future requests - // after the last block has been removed from a particular - // memory Chunk, which in turn has been returned to the - // free list, and hence had been erased from the vector, - // so the size of the vector gets reduced by 1. - if ((_Difference_type)_S_last_request._M_where() >= __diff--) - _S_last_request._M_reset(__diff); - - // If the Index into the vector of the region of memory - // that might hold the next address that will be passed to - // deallocated may have been invalidated due to the above - // erase procedure being called on the vector, hence we - // try to restore this invariant too. - if (_S_last_dealloc_index >= _S_mem_blocks.size()) - { - _S_last_dealloc_index =(__diff != -1 ? __diff : 0); - _GLIBCXX_DEBUG_ASSERT(_S_last_dealloc_index >= 0); - } - } - } - - public: - bitmap_allocator() throw() - { } - - bitmap_allocator(const bitmap_allocator&) - { } - - template<typename _Tp1> - bitmap_allocator(const bitmap_allocator<_Tp1>&) throw() - { } - - ~bitmap_allocator() throw() - { } - - pointer - allocate(size_type __n) - { - if (__builtin_expect(__n > this->max_size(), false)) - std::__throw_bad_alloc(); - - if (__builtin_expect(__n == 1, true)) - return this->_M_allocate_single_object(); - else - { - const size_type __b = __n * sizeof(value_type); - return reinterpret_cast<pointer>(::operator new(__b)); - } - } - - pointer - allocate(size_type __n, typename bitmap_allocator<void>::const_pointer) - { return allocate(__n); } - - void - deallocate(pointer __p, size_type __n) throw() - { - if (__builtin_expect(__p != 0, true)) - { - if (__builtin_expect(__n == 1, true)) - this->_M_deallocate_single_object(__p); - else - ::operator delete(__p); - } - } - - pointer - address(reference __r) const - { return &__r; } - - const_pointer - address(const_reference __r) const - { return &__r; } - - size_type - max_size() const throw() - { return size_type(-1) / sizeof(value_type); } - - void - construct(pointer __p, const_reference __data) - { ::new((void *)__p) value_type(__data); } - -#ifdef __GXX_EXPERIMENTAL_CXX0X__ - template<typename... _Args> - void - construct(pointer __p, _Args&&... __args) - { ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); } -#endif - - void - destroy(pointer __p) - { __p->~value_type(); } - }; - - template<typename _Tp1, typename _Tp2> - bool - operator==(const bitmap_allocator<_Tp1>&, - const bitmap_allocator<_Tp2>&) throw() - { return true; } - - template<typename _Tp1, typename _Tp2> - bool - operator!=(const bitmap_allocator<_Tp1>&, - const bitmap_allocator<_Tp2>&) throw() - { return false; } - - // Static member definitions. - template<typename _Tp> - typename bitmap_allocator<_Tp>::_BPVector - bitmap_allocator<_Tp>::_S_mem_blocks; - - template<typename _Tp> - size_t bitmap_allocator<_Tp>::_S_block_size = - 2 * size_t(__detail::bits_per_block); - - template<typename _Tp> - typename __gnu_cxx::bitmap_allocator<_Tp>::_BPVector::size_type - bitmap_allocator<_Tp>::_S_last_dealloc_index = 0; - - template<typename _Tp> - __gnu_cxx::__detail::_Bitmap_counter - <typename bitmap_allocator<_Tp>::_Alloc_block*> - bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks); - -#if defined __GTHREADS - template<typename _Tp> - typename bitmap_allocator<_Tp>::__mutex_type - bitmap_allocator<_Tp>::_S_mut; -#endif - -_GLIBCXX_END_NAMESPACE - -#endif - |