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// Allocators -*- C++ -*-
// Copyright (C) 2001, 2002, 2003, 2004 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 2, 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.
// You should have received a copy of the GNU General Public License along
// with this library; see the file COPYING. If not, write to the Free
// Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
// USA.
// As a special exception, you may use this file as part of a free software
// library without restriction. Specifically, if other files instantiate
// templates or use macros or inline functions from this file, or you compile
// this file and link it with other files to produce an executable, this
// file does not by itself cause the resulting executable to be covered by
// the GNU General Public License. This exception does not however
// invalidate any other reasons why the executable file might be covered by
// the GNU General Public License.
/*
* 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.
* You should only include this header if you are using GCC 3 or later.
*/
#ifndef _DEBUG_ALLOCATOR_H
#define _DEBUG_ALLOCATOR_H 1
#include <stdexcept>
namespace __gnu_cxx
{
/**
* @brief A meta-allocator with debugging bits, as per [20.4].
*
* This is precisely the allocator defined in the C++ Standard.
* - all allocation calls operator new
* - all deallocation calls operator delete
*/
template<typename _Alloc>
class debug_allocator
{
public:
typedef typename _Alloc::size_type size_type;
typedef typename _Alloc::difference_type difference_type;
typedef typename _Alloc::pointer pointer;
typedef typename _Alloc::const_pointer const_pointer;
typedef typename _Alloc::reference reference;
typedef typename _Alloc::const_reference const_reference;
typedef typename _Alloc::value_type value_type;
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;
public:
debug_allocator()
{
const size_t __obj_size = sizeof(value_type);
_M_extra = (sizeof(size_type) + __obj_size - 1) / __obj_size;
}
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;
}
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)
{
if (__p)
{
pointer __real_p = __p - _M_extra;
if (*reinterpret_cast<size_type*>(__real_p) != __n)
{
throw std::runtime_error("debug_allocator::deallocate"
" wrong size");
}
_M_allocator.deallocate(__real_p, __n + _M_extra);
}
else
throw std::runtime_error("debug_allocator::deallocate null pointer");
}
};
} // namespace __gnu_cxx
#endif
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