1132720Skan// Allocators -*- C++ -*- 2132720Skan 3169691Skan// Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc. 4132720Skan// 5132720Skan// This file is part of the GNU ISO C++ Library. This library is free 6132720Skan// software; you can redistribute it and/or modify it under the 7132720Skan// terms of the GNU General Public License as published by the 8132720Skan// Free Software Foundation; either version 2, or (at your option) 9132720Skan// any later version. 10132720Skan 11132720Skan// This library is distributed in the hope that it will be useful, 12132720Skan// but WITHOUT ANY WARRANTY; without even the implied warranty of 13132720Skan// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14132720Skan// GNU General Public License for more details. 15132720Skan 16132720Skan// You should have received a copy of the GNU General Public License along 17132720Skan// with this library; see the file COPYING. If not, write to the Free 18169691Skan// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, 19132720Skan// USA. 20132720Skan 21132720Skan// As a special exception, you may use this file as part of a free software 22132720Skan// library without restriction. Specifically, if other files instantiate 23132720Skan// templates or use macros or inline functions from this file, or you compile 24132720Skan// this file and link it with other files to produce an executable, this 25132720Skan// file does not by itself cause the resulting executable to be covered by 26132720Skan// the GNU General Public License. This exception does not however 27132720Skan// invalidate any other reasons why the executable file might be covered by 28132720Skan// the GNU General Public License. 29132720Skan 30132720Skan/* 31132720Skan * Copyright (c) 1996-1997 32132720Skan * Silicon Graphics Computer Systems, Inc. 33132720Skan * 34132720Skan * Permission to use, copy, modify, distribute and sell this software 35132720Skan * and its documentation for any purpose is hereby granted without fee, 36132720Skan * provided that the above copyright notice appear in all copies and 37132720Skan * that both that copyright notice and this permission notice appear 38132720Skan * in supporting documentation. Silicon Graphics makes no 39132720Skan * representations about the suitability of this software for any 40132720Skan * purpose. It is provided "as is" without express or implied warranty. 41132720Skan */ 42132720Skan 43132720Skan/** @file ext/debug_allocator.h 44132720Skan * This file is a GNU extension to the Standard C++ Library. 45132720Skan * You should only include this header if you are using GCC 3 or later. 46132720Skan */ 47132720Skan 48132720Skan#ifndef _DEBUG_ALLOCATOR_H 49132720Skan#define _DEBUG_ALLOCATOR_H 1 50132720Skan 51169691Skan#include <stdexcept> 52132720Skan 53169691Skan_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx) 54169691Skan 55169691Skan using std::size_t; 56169691Skan 57132720Skan /** 58132720Skan * @brief A meta-allocator with debugging bits, as per [20.4]. 59132720Skan * 60132720Skan * This is precisely the allocator defined in the C++ Standard. 61132720Skan * - all allocation calls operator new 62132720Skan * - all deallocation calls operator delete 63132720Skan */ 64132720Skan template<typename _Alloc> 65132720Skan class debug_allocator 66132720Skan { 67132720Skan public: 68132720Skan typedef typename _Alloc::size_type size_type; 69132720Skan typedef typename _Alloc::difference_type difference_type; 70132720Skan typedef typename _Alloc::pointer pointer; 71132720Skan typedef typename _Alloc::const_pointer const_pointer; 72132720Skan typedef typename _Alloc::reference reference; 73132720Skan typedef typename _Alloc::const_reference const_reference; 74132720Skan typedef typename _Alloc::value_type value_type; 75132720Skan 76132720Skan private: 77132720Skan // _M_extra is the number of objects that correspond to the 78132720Skan // extra space where debug information is stored. 79132720Skan size_type _M_extra; 80132720Skan 81132720Skan _Alloc _M_allocator; 82132720Skan 83132720Skan public: 84132720Skan debug_allocator() 85132720Skan { 86132720Skan const size_t __obj_size = sizeof(value_type); 87132720Skan _M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size; 88132720Skan } 89132720Skan 90132720Skan pointer 91132720Skan allocate(size_type __n) 92132720Skan { 93132720Skan pointer __res = _M_allocator.allocate(__n + _M_extra); 94132720Skan size_type* __ps = reinterpret_cast<size_type*>(__res); 95132720Skan *__ps = __n; 96132720Skan return __res + _M_extra; 97132720Skan } 98132720Skan 99132720Skan pointer 100132720Skan allocate(size_type __n, const void* __hint) 101132720Skan { 102132720Skan pointer __res = _M_allocator.allocate(__n + _M_extra, __hint); 103132720Skan size_type* __ps = reinterpret_cast<size_type*>(__res); 104132720Skan *__ps = __n; 105132720Skan return __res + _M_extra; 106132720Skan } 107132720Skan 108132720Skan void 109132720Skan deallocate(pointer __p, size_type __n) 110132720Skan { 111169691Skan if (__p) 112169691Skan { 113169691Skan pointer __real_p = __p - _M_extra; 114169691Skan if (*reinterpret_cast<size_type*>(__real_p) != __n) 115169691Skan { 116169691Skan throw std::runtime_error("debug_allocator::deallocate" 117169691Skan " wrong size"); 118169691Skan } 119169691Skan _M_allocator.deallocate(__real_p, __n + _M_extra); 120169691Skan } 121169691Skan else 122169691Skan throw std::runtime_error("debug_allocator::deallocate null pointer"); 123132720Skan } 124132720Skan }; 125132720Skan 126169691Skan_GLIBCXX_END_NAMESPACE 127169691Skan 128132720Skan#endif 129