| // Allocators -*- C++ -*- |
| |
| // Copyright (C) 2001-2020 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/>. |
| |
| /* |
| * Copyright (c) 1996-1997 |
| * Silicon Graphics Computer Systems, Inc. |
| * |
| * Permission to use, copy, modify, distribute and sell this software |
| * and its documentation for any purpose is hereby granted without fee, |
| * provided that the above copyright notice appear in all copies and |
| * that both that copyright notice and this permission notice appear |
| * in supporting documentation. Silicon Graphics makes no |
| * representations about the suitability of this software for any |
| * purpose. It is provided "as is" without express or implied warranty. |
| */ |
| |
| /** @file ext/debug_allocator.h |
| * This file is a GNU extension to the Standard C++ Library. |
| */ |
| |
| #ifndef _DEBUG_ALLOCATOR_H |
| #define _DEBUG_ALLOCATOR_H 1 |
| |
| #include <stdexcept> |
| #include <bits/functexcept.h> |
| #include <ext/alloc_traits.h> |
| |
| namespace __gnu_cxx _GLIBCXX_VISIBILITY(default) |
| { |
| _GLIBCXX_BEGIN_NAMESPACE_VERSION |
| |
| /** |
| * @brief A meta-allocator with debugging bits. |
| * @ingroup allocators |
| * |
| * This is precisely the allocator defined in the C++03 Standard. |
| */ |
| template<typename _Alloc> |
| class debug_allocator |
| { |
| template<typename> friend class debug_allocator; |
| |
| typedef __alloc_traits<_Alloc> _Traits; |
| |
| public: |
| typedef typename _Traits::size_type size_type; |
| typedef typename _Traits::difference_type difference_type; |
| typedef typename _Traits::pointer pointer; |
| typedef typename _Traits::const_pointer const_pointer; |
| typedef typename _Traits::reference reference; |
| typedef typename _Traits::const_reference const_reference; |
| typedef typename _Traits::value_type value_type; |
| |
| template<typename _Up> |
| class rebind |
| { |
| typedef typename _Traits::template rebind<_Up>::other __other; |
| |
| public: |
| typedef debug_allocator<__other> other; |
| }; |
| |
| private: |
| // _M_extra is the number of objects that correspond to the |
| // extra space where debug information is stored. |
| size_type _M_extra; |
| |
| _Alloc _M_allocator; |
| |
| template<typename _Alloc2, |
| typename = typename __alloc_traits<_Alloc2>::template |
| rebind<value_type>::other> |
| struct __convertible |
| { }; |
| |
| template<typename _Alloc2> |
| struct __convertible<_Alloc2, _Alloc> |
| { |
| typedef void* __type; |
| }; |
| |
| size_type _S_extra() |
| { |
| const std::size_t __obj_size = sizeof(value_type); |
| return (sizeof(size_type) + __obj_size - 1) / __obj_size; |
| } |
| |
| public: |
| debug_allocator() : _M_extra(_S_extra()) { } |
| |
| template<typename _Alloc2> |
| debug_allocator(const debug_allocator<_Alloc2>& __a2, |
| typename __convertible<_Alloc2>::__type = 0) |
| : _M_allocator(__a2._M_allocator), _M_extra(_S_extra()) { } |
| |
| debug_allocator(const _Alloc& __a) |
| : _M_allocator(__a), _M_extra(_S_extra()) { } |
| |
| _GLIBCXX_NODISCARD pointer |
| allocate(size_type __n) |
| { |
| pointer __res = _M_allocator.allocate(__n + _M_extra); |
| size_type* __ps = reinterpret_cast<size_type*>(__res); |
| *__ps = __n; |
| return __res + _M_extra; |
| } |
| |
| _GLIBCXX_NODISCARD pointer |
| allocate(size_type __n, const void* __hint) |
| { |
| pointer __res = _M_allocator.allocate(__n + _M_extra, __hint); |
| size_type* __ps = reinterpret_cast<size_type*>(__res); |
| *__ps = __n; |
| return __res + _M_extra; |
| } |
| |
| void |
| deallocate(pointer __p, size_type __n) |
| { |
| using std::__throw_runtime_error; |
| if (__p) |
| { |
| pointer __real_p = __p - _M_extra; |
| if (*reinterpret_cast<size_type*>(__real_p) != __n) |
| __throw_runtime_error("debug_allocator::deallocate wrong size"); |
| _M_allocator.deallocate(__real_p, __n + _M_extra); |
| } |
| else |
| __throw_runtime_error("debug_allocator::deallocate null pointer"); |
| } |
| |
| void |
| construct(pointer __p, const value_type& __val) |
| { _Traits::construct(_M_allocator, __p, __val); } |
| |
| #if __cplusplus >= 201103L |
| template<typename _Tp, typename... _Args> |
| void |
| construct(_Tp* __p, _Args&&... __args) |
| { |
| _Traits::construct(_M_allocator, __p, |
| std::forward<_Args>(__args)...); |
| } |
| #endif |
| |
| template<typename _Tp> |
| void |
| destroy(_Tp* __p) |
| { _Traits::destroy(_M_allocator, __p); } |
| |
| size_type |
| max_size() const throw() |
| { return _Traits::max_size(_M_allocator) - _M_extra; } |
| |
| template<typename _Alloc2> |
| friend bool |
| operator==(const debug_allocator& __lhs, |
| const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW |
| { return __lhs._M_allocator == debug_allocator(__rhs)._M_allocator; } |
| |
| #if __cpp_impl_three_way_comparison < 201907L |
| template<typename _Alloc2> |
| friend bool |
| operator!=(const debug_allocator& __lhs, |
| const debug_allocator<_Alloc2>& __rhs) _GLIBCXX_NOTHROW |
| { return !(__lhs == __rhs); } |
| #endif |
| }; |
| |
| _GLIBCXX_END_NAMESPACE_VERSION |
| } // namespace |
| |
| #endif |