From 1bc5aee63eb72b341f506ad058502cd0361f0d10 Mon Sep 17 00:00:00 2001 From: Ben Cheng Date: Tue, 25 Mar 2014 22:37:19 -0700 Subject: Initial checkin of GCC 4.9.0 from trunk (r208799). Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba --- .../libstdc++-v3/include/ext/bitmap_allocator.h | 1119 ++++++++++++++++++++ 1 file changed, 1119 insertions(+) create mode 100644 gcc-4.9/libstdc++-v3/include/ext/bitmap_allocator.h (limited to 'gcc-4.9/libstdc++-v3/include/ext/bitmap_allocator.h') diff --git a/gcc-4.9/libstdc++-v3/include/ext/bitmap_allocator.h b/gcc-4.9/libstdc++-v3/include/ext/bitmap_allocator.h new file mode 100644 index 0000000..2bfbbf5 --- /dev/null +++ b/gcc-4.9/libstdc++-v3/include/ext/bitmap_allocator.h @@ -0,0 +1,1119 @@ +// Bitmap Allocator. -*- C++ -*- + +// Copyright (C) 2004-2014 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 +// . + +/** @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 // For std::pair. +#include // For __throw_bad_alloc(). +#include // For greater_equal, and less_equal. +#include // For operator new. +#include // _GLIBCXX_DEBUG_ASSERT +#include +#include + +/** @brief The constant in the expression below is the alignment + * required in bytes. + */ +#define _BALLOC_ALIGN_BYTES 8 + +namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) +{ + using std::size_t; + using std::ptrdiff_t; + + namespace __detail + { + _GLIBCXX_BEGIN_NAMESPACE_VERSION + /** @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: + * + * 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 + 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(::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) { } + + 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 + 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 + void __mini_vector<_Tp>:: + erase(iterator __pos) throw() + { + while (__pos + 1 != this->end()) + { + *__pos = __pos[1]; + ++__pos; + } + --this->_M_finish; + } + + + template + struct __mv_iter_traits + { + typedef typename _Tp::value_type value_type; + typedef typename _Tp::difference_type difference_type; + }; + + template + 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 + _ForwardIterator + __lower_bound(_ForwardIterator __first, _ForwardIterator __last, + const _Tp& __val, _Compare __comp) + { + 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; + } + + /** @brief The number of Blocks pointed to by the address pair + * passed to the function. + */ + template + 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 + inline size_t + __num_bitmaps(_AddrPair __ap) + { return __num_blocks(__ap) / size_t(bits_per_block); } + + // _Tp should be a pointer type. + template + class _Inclusive_between + : public std::unary_function, 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()(_M_ptr_value, __bp.second) + && std::greater_equal()(_M_ptr_value, __bp.first)) + return true; + else + return false; + } + }; + + // Used to pass a Functor to functions by reference. + template + class _Functor_Ref + : public std::unary_function + { + _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 + class _Ffit_finder + : public std::unary_function, 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 = __detail::__num_bitmaps(__bp); + + if (*(reinterpret_cast + (__bp.first) - (__diff + 1)) == __detail::__num_blocks(__bp)) + return false; + + size_t* __rover = reinterpret_cast(__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 + class _Bitmap_counter + { + typedef typename + __detail::__mini_vector > _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 + (_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(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; + } + + _GLIBCXX_END_NAMESPACE_VERSION + } // namespace __detail + +_GLIBCXX_BEGIN_NAMESPACE_VERSION + + /** @brief Generic Version of the bsf instruction. + */ + inline size_t + _Bit_scan_forward(size_t __num) + { return static_cast(__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 + { + public: + typedef size_t* value_type; + typedef __detail::__mini_vector vector_type; + typedef vector_type::iterator iterator; + typedef __mutex __mutex_type; + + private: + 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. + * + * 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(__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(__free_list.back())); + __free_list.pop_back(); + } + } + + // Just add the block to the list of free lists unconditionally. + iterator __temp = __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 + __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(__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 + class bitmap_allocator; + + // Specialize for void: + template<> + class bitmap_allocator + { + public: + typedef void* pointer; + typedef const void* const_pointer; + + // Reference-to-void members are impossible. + typedef void value_type; + template + struct rebind + { + typedef bitmap_allocator<_Tp1> other; + }; + }; + + /** + * @brief Bitmap Allocator, primary template. + * @ingroup allocators + */ + template + 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 + struct rebind + { + typedef bitmap_allocator<_Tp1> other; + }; + +#if __cplusplus >= 201103L + // _GLIBCXX_RESOLVE_LIB_DEFECTS + // 2103. propagate_on_container_move_assignment + typedef std::true_type propagate_on_container_move_assignment; +#endif + + private: + template + struct aligned_size + { + enum + { + modulus = _BSize % _AlignSize, + value = _BSize + (modulus ? _AlignSize - (modulus) : 0) + }; + }; + + struct _Alloc_block + { + char __M_unused[aligned_size::value]; + }; + + + typedef typename std::pair<_Alloc_block*, _Alloc_block*> _Block_pair; + + typedef typename __detail::__mini_vector<_Block_pair> _BPVector; + typedef typename _BPVector::iterator _BPiter; + + template + static _BPiter + _S_find(_Predicate __p) + { + _BPiter __first = _S_mem_blocks.begin(); + while (__first != _S_mem_blocks.end() && !__p(*__first)) + ++__first; + return __first; + } + +#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 __detail::_Ffit_finder<_Alloc_block*> _FFF; + _BPiter __bpi = _S_find(_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. + * + * 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(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); + + for (size_t __i = 0; __i < __num_bitmaps; ++__i) + __temp[__i] = ~static_cast(0); // 1 Indicates all Free. + + _S_block_size *= 2; + } + + static _BPVector _S_mem_blocks; + static size_t _S_block_size; + static __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. + * + * 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 + __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 __detail::_Ffit_finder<_Alloc_block*> _FFF; + _FFF __fff; + _BPiter __bpi = _S_find(__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 + (__bpi->first + __fff._M_offset() + __nz_bit); + size_t* __puse_count = + reinterpret_cast + (__bpi->first) - (__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 + (_S_last_request._M_base() + _S_last_request._M_offset() + __nz_bit); + + size_t* __puse_count = reinterpret_cast + (_S_mem_blocks[_S_last_request._M_where()].first) + - (__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). + * + * 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 + __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); + + __detail::_Inclusive_between<_Alloc_block*> __ibt(__real_p); + if (__ibt(_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 = _S_find(__ibt); + + _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 + (_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 + (_S_mem_blocks[__diff].first) + - (__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() _GLIBCXX_USE_NOEXCEPT + { } + + bitmap_allocator(const bitmap_allocator&) _GLIBCXX_USE_NOEXCEPT + { } + + template + bitmap_allocator(const bitmap_allocator<_Tp1>&) _GLIBCXX_USE_NOEXCEPT + { } + + ~bitmap_allocator() _GLIBCXX_USE_NOEXCEPT + { } + + pointer + allocate(size_type __n) + { + if (__n > this->max_size()) + 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(::operator new(__b)); + } + } + + pointer + allocate(size_type __n, typename bitmap_allocator::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 _GLIBCXX_NOEXCEPT + { return std::__addressof(__r); } + + const_pointer + address(const_reference __r) const _GLIBCXX_NOEXCEPT + { return std::__addressof(__r); } + + size_type + max_size() const _GLIBCXX_USE_NOEXCEPT + { return size_type(-1) / sizeof(value_type); } + +#if __cplusplus >= 201103L + template + void + construct(_Up* __p, _Args&&... __args) + { ::new((void *)__p) _Up(std::forward<_Args>(__args)...); } + + template + void + destroy(_Up* __p) + { __p->~_Up(); } +#else + void + construct(pointer __p, const_reference __data) + { ::new((void *)__p) value_type(__data); } + + void + destroy(pointer __p) + { __p->~value_type(); } +#endif + }; + + template + bool + operator==(const bitmap_allocator<_Tp1>&, + const bitmap_allocator<_Tp2>&) throw() + { return true; } + + template + bool + operator!=(const bitmap_allocator<_Tp1>&, + const bitmap_allocator<_Tp2>&) throw() + { return false; } + + // Static member definitions. + template + typename bitmap_allocator<_Tp>::_BPVector + bitmap_allocator<_Tp>::_S_mem_blocks; + + template + size_t bitmap_allocator<_Tp>::_S_block_size = + 2 * size_t(__detail::bits_per_block); + + template + typename bitmap_allocator<_Tp>::_BPVector::size_type + bitmap_allocator<_Tp>::_S_last_dealloc_index = 0; + + template + __detail::_Bitmap_counter + ::_Alloc_block*> + bitmap_allocator<_Tp>::_S_last_request(_S_mem_blocks); + +#if defined __GTHREADS + template + typename bitmap_allocator<_Tp>::__mutex_type + bitmap_allocator<_Tp>::_S_mut; +#endif + +_GLIBCXX_END_NAMESPACE_VERSION +} // namespace __gnu_cxx + +#endif + -- cgit v1.1