129 lines
4.3 KiB
C++
129 lines
4.3 KiB
C++
// Allocators -*- C++ -*-
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// Copyright (C) 2001, 2002, 2003, 2004, 2005 Free Software Foundation, Inc.
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//
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// This file is part of the GNU ISO C++ Library. This library is free
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// software; you can redistribute it and/or modify it under the
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// terms of the GNU General Public License as published by the
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// Free Software Foundation; either version 2, or (at your option)
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// any later version.
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// This library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU General Public License for more details.
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// You should have received a copy of the GNU General Public License along
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// with this library; see the file COPYING. If not, write to the Free
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// Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301,
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// USA.
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// As a special exception, you may use this file as part of a free software
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// library without restriction. Specifically, if other files instantiate
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// templates or use macros or inline functions from this file, or you compile
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// this file and link it with other files to produce an executable, this
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// file does not by itself cause the resulting executable to be covered by
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// the GNU General Public License. This exception does not however
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// invalidate any other reasons why the executable file might be covered by
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// the GNU General Public License.
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/*
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* Copyright (c) 1996-1997
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* Silicon Graphics Computer Systems, Inc.
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*
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* Permission to use, copy, modify, distribute and sell this software
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* and its documentation for any purpose is hereby granted without fee,
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* provided that the above copyright notice appear in all copies and
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* that both that copyright notice and this permission notice appear
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* in supporting documentation. Silicon Graphics makes no
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* representations about the suitability of this software for any
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* purpose. It is provided "as is" without express or implied warranty.
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*/
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/** @file ext/debug_allocator.h
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* This file is a GNU extension to the Standard C++ Library.
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* You should only include this header if you are using GCC 3 or later.
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*/
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#ifndef _DEBUG_ALLOCATOR_H
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#define _DEBUG_ALLOCATOR_H 1
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#include <stdexcept>
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_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)
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using std::size_t;
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/**
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* @brief A meta-allocator with debugging bits, as per [20.4].
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*
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* This is precisely the allocator defined in the C++ Standard.
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* - all allocation calls operator new
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* - all deallocation calls operator delete
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*/
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template<typename _Alloc>
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class debug_allocator
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{
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public:
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typedef typename _Alloc::size_type size_type;
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typedef typename _Alloc::difference_type difference_type;
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typedef typename _Alloc::pointer pointer;
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typedef typename _Alloc::const_pointer const_pointer;
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typedef typename _Alloc::reference reference;
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typedef typename _Alloc::const_reference const_reference;
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typedef typename _Alloc::value_type value_type;
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private:
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// _M_extra is the number of objects that correspond to the
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// extra space where debug information is stored.
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size_type _M_extra;
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_Alloc _M_allocator;
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public:
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debug_allocator()
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{
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const size_t __obj_size = sizeof(value_type);
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_M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size;
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}
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pointer
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allocate(size_type __n)
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{
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pointer __res = _M_allocator.allocate(__n + _M_extra);
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size_type* __ps = reinterpret_cast<size_type*>(__res);
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*__ps = __n;
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return __res + _M_extra;
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}
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pointer
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allocate(size_type __n, const void* __hint)
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{
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pointer __res = _M_allocator.allocate(__n + _M_extra, __hint);
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size_type* __ps = reinterpret_cast<size_type*>(__res);
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*__ps = __n;
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return __res + _M_extra;
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}
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void
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deallocate(pointer __p, size_type __n)
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{
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if (__p)
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{
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pointer __real_p = __p - _M_extra;
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if (*reinterpret_cast<size_type*>(__real_p) != __n)
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{
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throw std::runtime_error("debug_allocator::deallocate"
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" wrong size");
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}
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_M_allocator.deallocate(__real_p, __n + _M_extra);
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}
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else
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throw std::runtime_error("debug_allocator::deallocate null pointer");
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}
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};
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_GLIBCXX_END_NAMESPACE
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#endif
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