942 lines
30 KiB
C++
942 lines
30 KiB
C++
// Allocators -*- C++ -*-
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// Copyright (C) 2001, 2002 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, 59 Temple Place - Suite 330, Boston, MA 02111-1307,
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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 stl_alloc.h
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* This is an internal header file, included by other library headers.
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* You should not attempt to use it directly.
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*/
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#ifndef __GLIBCPP_INTERNAL_ALLOC_H
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#define __GLIBCPP_INTERNAL_ALLOC_H
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/**
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* @defgroup Allocators Memory Allocators
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* @if maint
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* stl_alloc.h implements some node allocators. These are NOT the same as
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* allocators in the C++ standard, nor in the original H-P STL. They do not
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* encapsulate different pointer types; we assume that there is only one
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* pointer type. The C++ standard allocators are intended to allocate
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* individual objects, not pools or arenas.
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*
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* In this file allocators are of two different styles: "standard" and
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* "SGI" (quotes included). "Standard" allocators conform to 20.4. "SGI"
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* allocators differ in AT LEAST the following ways (add to this list as you
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* discover them):
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*
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* - "Standard" allocate() takes two parameters (n_count,hint=0) but "SGI"
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* allocate() takes one paramter (n_size).
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* - Likewise, "standard" deallocate()'s argument is a count, but in "SGI"
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* is a byte size.
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* - max_size(), construct(), and destroy() are missing in "SGI" allocators.
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* - reallocate(p,oldsz,newsz) is added in "SGI", and behaves as
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* if p=realloc(p,newsz).
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*
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* "SGI" allocators may be wrapped in __allocator to convert the interface
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* into a "standard" one.
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* @endif
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*
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* The canonical description of these classes is in docs/html/ext/howto.html
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* or online at http://gcc.gnu.org/onlinedocs/libstdc++/ext/howto.html#3
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*/
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#include <cstddef>
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#include <cstdlib>
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#include <cstring>
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#include <cassert>
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#include <bits/functexcept.h> // For __throw_bad_alloc
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#include <bits/stl_threads.h>
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namespace std
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{
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/**
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* @if maint
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* A new-based allocator, as required by the standard. Allocation and
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* deallocation forward to global new and delete. "SGI" style, minus
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* reallocate().
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* @endif
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* (See @link Allocators allocators info @endlink for more.)
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*/
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class __new_alloc
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{
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public:
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static void*
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allocate(size_t __n)
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{ return ::operator new(__n); }
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static void
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deallocate(void* __p, size_t)
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{ ::operator delete(__p); }
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};
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/**
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* @if maint
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* A malloc-based allocator. Typically slower than the
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* __default_alloc_template (below). Typically thread-safe and more
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* storage efficient. The template argument is unused and is only present
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* to permit multiple instantiations (but see __default_alloc_template
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* for caveats). "SGI" style, plus __set_malloc_handler for OOM conditions.
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* @endif
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* (See @link Allocators allocators info @endlink for more.)
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*/
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template <int __inst>
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class __malloc_alloc_template
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{
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private:
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static void* _S_oom_malloc(size_t);
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static void* _S_oom_realloc(void*, size_t);
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static void (* __malloc_alloc_oom_handler)();
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public:
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static void*
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allocate(size_t __n)
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{
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void* __result = malloc(__n);
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if (0 == __result) __result = _S_oom_malloc(__n);
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return __result;
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}
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static void
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deallocate(void* __p, size_t /* __n */)
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{ free(__p); }
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static void*
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reallocate(void* __p, size_t /* old_sz */, size_t __new_sz)
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{
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void* __result = realloc(__p, __new_sz);
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if (0 == __result) __result = _S_oom_realloc(__p, __new_sz);
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return __result;
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}
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static void (* __set_malloc_handler(void (*__f)()))()
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{
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void (* __old)() = __malloc_alloc_oom_handler;
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__malloc_alloc_oom_handler = __f;
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return(__old);
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}
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};
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// malloc_alloc out-of-memory handling
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template <int __inst>
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void (* __malloc_alloc_template<__inst>::__malloc_alloc_oom_handler)() = 0;
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template <int __inst>
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void*
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__malloc_alloc_template<__inst>::_S_oom_malloc(size_t __n)
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{
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void (* __my_malloc_handler)();
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void* __result;
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for (;;)
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{
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__my_malloc_handler = __malloc_alloc_oom_handler;
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if (0 == __my_malloc_handler)
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std::__throw_bad_alloc();
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(*__my_malloc_handler)();
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__result = malloc(__n);
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if (__result)
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return(__result);
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}
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}
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template <int __inst>
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void*
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__malloc_alloc_template<__inst>::_S_oom_realloc(void* __p, size_t __n)
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{
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void (* __my_malloc_handler)();
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void* __result;
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for (;;)
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{
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__my_malloc_handler = __malloc_alloc_oom_handler;
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if (0 == __my_malloc_handler)
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std::__throw_bad_alloc();
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(*__my_malloc_handler)();
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__result = realloc(__p, __n);
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if (__result)
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return(__result);
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}
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}
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// Determines the underlying allocator choice for the node allocator.
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#ifdef __USE_MALLOC
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typedef __malloc_alloc_template<0> __mem_interface;
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#else
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typedef __new_alloc __mem_interface;
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#endif
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/**
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* @if maint
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* This is used primarily (only?) in _Alloc_traits and other places to
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* help provide the _Alloc_type typedef.
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*
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* This is neither "standard"-conforming nor "SGI". The _Alloc parameter
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* must be "SGI" style.
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* @endif
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* (See @link Allocators allocators info @endlink for more.)
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*/
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template<class _Tp, class _Alloc>
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class __simple_alloc
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{
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public:
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static _Tp* allocate(size_t __n)
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{ return 0 == __n ? 0 : (_Tp*) _Alloc::allocate(__n * sizeof (_Tp)); }
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static _Tp* allocate()
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{ return (_Tp*) _Alloc::allocate(sizeof (_Tp)); }
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static void deallocate(_Tp* __p, size_t __n)
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{ if (0 != __n) _Alloc::deallocate(__p, __n * sizeof (_Tp)); }
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static void deallocate(_Tp* __p)
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{ _Alloc::deallocate(__p, sizeof (_Tp)); }
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};
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/**
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* @if maint
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* An adaptor for an underlying allocator (_Alloc) to check the size
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* arguments for debugging. Errors are reported using assert; these
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* checks can be disabled via NDEBUG, but the space penalty is still
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* paid, therefore it is far better to just use the underlying allocator
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* by itelf when no checking is desired.
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*
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* "There is some evidence that this can confuse Purify." - SGI comment
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*
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* This adaptor is "SGI" style. The _Alloc parameter must also be "SGI".
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* @endif
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* (See @link Allocators allocators info @endlink for more.)
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*/
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template <class _Alloc>
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class __debug_alloc
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{
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private:
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enum {_S_extra = 8}; // Size of space used to store size. Note that this
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// must be large enough to preserve alignment.
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public:
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static void* allocate(size_t __n)
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{
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char* __result = (char*)_Alloc::allocate(__n + (int) _S_extra);
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*(size_t*)__result = __n;
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return __result + (int) _S_extra;
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}
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static void deallocate(void* __p, size_t __n)
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{
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char* __real_p = (char*)__p - (int) _S_extra;
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assert(*(size_t*)__real_p == __n);
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_Alloc::deallocate(__real_p, __n + (int) _S_extra);
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}
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static void* reallocate(void* __p, size_t __old_sz, size_t __new_sz)
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{
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char* __real_p = (char*)__p - (int) _S_extra;
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assert(*(size_t*)__real_p == __old_sz);
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char* __result = (char*)
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_Alloc::reallocate(__real_p, __old_sz + (int) _S_extra,
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__new_sz + (int) _S_extra);
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*(size_t*)__result = __new_sz;
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return __result + (int) _S_extra;
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}
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};
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#ifdef __USE_MALLOC
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typedef __mem_interface __alloc;
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typedef __mem_interface __single_client_alloc;
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#else
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/**
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* @if maint
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* Default node allocator. "SGI" style. Uses __mem_interface for its
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* underlying requests (and makes as few requests as possible).
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* **** Currently __mem_interface is always __new_alloc, never __malloc*.
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*
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* Important implementation properties:
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* 1. If the clients request an object of size > _MAX_BYTES, the resulting
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* object will be obtained directly from the underlying __mem_interface.
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* 2. In all other cases, we allocate an object of size exactly
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* _S_round_up(requested_size). Thus the client has enough size
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* information that we can return the object to the proper free list
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* without permanently losing part of the object.
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*
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* The first template parameter specifies whether more than one thread may
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* use this allocator. It is safe to allocate an object from one instance
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* of a default_alloc and deallocate it with another one. This effectively
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* transfers its ownership to the second one. This may have undesirable
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* effects on reference locality.
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*
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* The second parameter is unused and serves only to allow the creation of
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* multiple default_alloc instances. Note that containers built on different
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* allocator instances have different types, limiting the utility of this
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* approach. If you do not wish to share the free lists with the main
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* default_alloc instance, instantiate this with a non-zero __inst.
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*
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* @endif
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* (See @link Allocators allocators info @endlink for more.)
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*/
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template<bool __threads, int __inst>
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class __default_alloc_template
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{
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private:
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enum {_ALIGN = 8};
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enum {_MAX_BYTES = 128};
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enum {_NFREELISTS = _MAX_BYTES / _ALIGN};
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union _Obj
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{
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union _Obj* _M_free_list_link;
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char _M_client_data[1]; // The client sees this.
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};
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static _Obj* volatile _S_free_list[_NFREELISTS];
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// Chunk allocation state.
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static char* _S_start_free;
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static char* _S_end_free;
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static size_t _S_heap_size;
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static _STL_mutex_lock _S_node_allocator_lock;
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static size_t
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_S_round_up(size_t __bytes)
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{ return (((__bytes) + (size_t) _ALIGN-1) & ~((size_t) _ALIGN - 1)); }
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static size_t
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_S_freelist_index(size_t __bytes)
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{ return (((__bytes) + (size_t)_ALIGN-1)/(size_t)_ALIGN - 1); }
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// Returns an object of size __n, and optionally adds to size __n
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// free list.
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static void*
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_S_refill(size_t __n);
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// Allocates a chunk for nobjs of size size. nobjs may be reduced
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// if it is inconvenient to allocate the requested number.
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static char*
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_S_chunk_alloc(size_t __size, int& __nobjs);
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// It would be nice to use _STL_auto_lock here. But we need a
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// test whether threads are in use.
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class _Lock
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{
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public:
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_Lock() { if (__threads) _S_node_allocator_lock._M_acquire_lock(); }
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~_Lock() { if (__threads) _S_node_allocator_lock._M_release_lock(); }
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} __attribute__ ((__unused__));
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friend class _Lock;
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public:
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// __n must be > 0
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static void*
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allocate(size_t __n)
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{
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void* __ret = 0;
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if (__n > (size_t) _MAX_BYTES)
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__ret = __mem_interface::allocate(__n);
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else
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{
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_Obj* volatile* __my_free_list = _S_free_list
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+ _S_freelist_index(__n);
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// Acquire the lock here with a constructor call. This
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// ensures that it is released in exit or during stack
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// unwinding.
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_Lock __lock_instance;
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_Obj* __restrict__ __result = *__my_free_list;
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if (__result == 0)
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__ret = _S_refill(_S_round_up(__n));
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else
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{
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*__my_free_list = __result -> _M_free_list_link;
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__ret = __result;
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}
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}
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return __ret;
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};
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// __p may not be 0
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static void
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deallocate(void* __p, size_t __n)
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{
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if (__n > (size_t) _MAX_BYTES)
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__mem_interface::deallocate(__p, __n);
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else
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{
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_Obj* volatile* __my_free_list
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= _S_free_list + _S_freelist_index(__n);
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_Obj* __q = (_Obj*)__p;
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// Acquire the lock here with a constructor call. This ensures that
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// it is released in exit or during stack unwinding.
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_Lock __lock_instance;
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__q -> _M_free_list_link = *__my_free_list;
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*__my_free_list = __q;
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}
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}
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static void*
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reallocate(void* __p, size_t __old_sz, size_t __new_sz);
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};
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template<bool __threads, int __inst>
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inline bool
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operator==(const __default_alloc_template<__threads, __inst>&,
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const __default_alloc_template<__threads, __inst>&)
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{ return true; }
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template<bool __threads, int __inst>
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inline bool
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operator!=(const __default_alloc_template<__threads, __inst>&,
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const __default_alloc_template<__threads, __inst>&)
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{ return false; }
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// We allocate memory in large chunks in order to avoid fragmenting the
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// malloc heap (or whatever __mem_interface is using) too much. We assume
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// that __size is properly aligned. We hold the allocation lock.
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template<bool __threads, int __inst>
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char*
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__default_alloc_template<__threads, __inst>::_S_chunk_alloc(size_t __size,
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int& __nobjs)
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{
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char* __result;
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size_t __total_bytes = __size * __nobjs;
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size_t __bytes_left = _S_end_free - _S_start_free;
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if (__bytes_left >= __total_bytes)
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{
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__result = _S_start_free;
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_S_start_free += __total_bytes;
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return(__result);
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}
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else if (__bytes_left >= __size)
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{
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__nobjs = (int)(__bytes_left/__size);
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__total_bytes = __size * __nobjs;
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__result = _S_start_free;
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_S_start_free += __total_bytes;
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return(__result);
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}
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else
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{
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size_t __bytes_to_get =
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2 * __total_bytes + _S_round_up(_S_heap_size >> 4);
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// Try to make use of the left-over piece.
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if (__bytes_left > 0)
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{
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_Obj* volatile* __my_free_list =
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_S_free_list + _S_freelist_index(__bytes_left);
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((_Obj*)_S_start_free) -> _M_free_list_link = *__my_free_list;
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*__my_free_list = (_Obj*)_S_start_free;
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}
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_S_start_free = (char*) __mem_interface::allocate(__bytes_to_get);
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if (0 == _S_start_free)
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{
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size_t __i;
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_Obj* volatile* __my_free_list;
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_Obj* __p;
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// Try to make do with what we have. That can't hurt. We
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// do not try smaller requests, since that tends to result
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// in disaster on multi-process machines.
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__i = __size;
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for (; __i <= (size_t) _MAX_BYTES; __i += (size_t) _ALIGN)
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{
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__my_free_list = _S_free_list + _S_freelist_index(__i);
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__p = *__my_free_list;
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if (0 != __p)
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{
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*__my_free_list = __p -> _M_free_list_link;
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_S_start_free = (char*)__p;
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_S_end_free = _S_start_free + __i;
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return(_S_chunk_alloc(__size, __nobjs));
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// Any leftover piece will eventually make it to the
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// right free list.
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}
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}
|
|
_S_end_free = 0; // In case of exception.
|
|
_S_start_free = (char*)__mem_interface::allocate(__bytes_to_get);
|
|
// This should either throw an exception or remedy the situation.
|
|
// Thus we assume it succeeded.
|
|
}
|
|
_S_heap_size += __bytes_to_get;
|
|
_S_end_free = _S_start_free + __bytes_to_get;
|
|
return(_S_chunk_alloc(__size, __nobjs));
|
|
}
|
|
}
|
|
|
|
|
|
// Returns an object of size __n, and optionally adds to "size
|
|
// __n"'s free list. We assume that __n is properly aligned. We
|
|
// hold the allocation lock.
|
|
template<bool __threads, int __inst>
|
|
void*
|
|
__default_alloc_template<__threads, __inst>::_S_refill(size_t __n)
|
|
{
|
|
int __nobjs = 20;
|
|
char* __chunk = _S_chunk_alloc(__n, __nobjs);
|
|
_Obj* volatile* __my_free_list;
|
|
_Obj* __result;
|
|
_Obj* __current_obj;
|
|
_Obj* __next_obj;
|
|
int __i;
|
|
|
|
if (1 == __nobjs) return(__chunk);
|
|
__my_free_list = _S_free_list + _S_freelist_index(__n);
|
|
|
|
/* Build free list in chunk */
|
|
__result = (_Obj*)__chunk;
|
|
*__my_free_list = __next_obj = (_Obj*)(__chunk + __n);
|
|
for (__i = 1; ; __i++) {
|
|
__current_obj = __next_obj;
|
|
__next_obj = (_Obj*)((char*)__next_obj + __n);
|
|
if (__nobjs - 1 == __i) {
|
|
__current_obj -> _M_free_list_link = 0;
|
|
break;
|
|
} else {
|
|
__current_obj -> _M_free_list_link = __next_obj;
|
|
}
|
|
}
|
|
return(__result);
|
|
}
|
|
|
|
|
|
template<bool threads, int inst>
|
|
void*
|
|
__default_alloc_template<threads, inst>::reallocate(void* __p,
|
|
size_t __old_sz,
|
|
size_t __new_sz)
|
|
{
|
|
void* __result;
|
|
size_t __copy_sz;
|
|
|
|
if (__old_sz > (size_t) _MAX_BYTES && __new_sz > (size_t) _MAX_BYTES) {
|
|
return(realloc(__p, __new_sz));
|
|
}
|
|
if (_S_round_up(__old_sz) == _S_round_up(__new_sz)) return(__p);
|
|
__result = allocate(__new_sz);
|
|
__copy_sz = __new_sz > __old_sz? __old_sz : __new_sz;
|
|
memcpy(__result, __p, __copy_sz);
|
|
deallocate(__p, __old_sz);
|
|
return(__result);
|
|
}
|
|
|
|
template<bool __threads, int __inst>
|
|
_STL_mutex_lock
|
|
__default_alloc_template<__threads, __inst>::_S_node_allocator_lock
|
|
__STL_MUTEX_INITIALIZER;
|
|
|
|
template<bool __threads, int __inst>
|
|
char* __default_alloc_template<__threads, __inst>::_S_start_free = 0;
|
|
|
|
template<bool __threads, int __inst>
|
|
char* __default_alloc_template<__threads, __inst>::_S_end_free = 0;
|
|
|
|
template<bool __threads, int __inst>
|
|
size_t __default_alloc_template<__threads, __inst>::_S_heap_size = 0;
|
|
|
|
template<bool __threads, int __inst>
|
|
typename __default_alloc_template<__threads, __inst>::_Obj* volatile
|
|
__default_alloc_template<__threads, __inst>::_S_free_list[_NFREELISTS];
|
|
|
|
typedef __default_alloc_template<true, 0> __alloc;
|
|
typedef __default_alloc_template<false, 0> __single_client_alloc;
|
|
|
|
|
|
#endif /* ! __USE_MALLOC */
|
|
|
|
|
|
/**
|
|
* This is a "standard" allocator, as per [20.4]. The private _Alloc is
|
|
* "SGI" style. (See comments at the top of stl_alloc.h.)
|
|
*
|
|
* The underlying allocator behaves as follows.
|
|
* - if __USE_MALLOC then
|
|
* - thread safety depends on malloc and is entirely out of our hands
|
|
* - __malloc_alloc_template is used for memory requests
|
|
* - else (the default)
|
|
* - __default_alloc_template is used via two typedefs
|
|
* - "__single_client_alloc" typedef does no locking for threads
|
|
* - "__alloc" typedef is threadsafe via the locks
|
|
* - __new_alloc is used for memory requests
|
|
*
|
|
* (See @link Allocators allocators info @endlink for more.)
|
|
*/
|
|
template <class _Tp>
|
|
class allocator
|
|
{
|
|
typedef __alloc _Alloc; // The underlying allocator.
|
|
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;
|
|
|
|
template <class _Tp1> struct rebind {
|
|
typedef allocator<_Tp1> other;
|
|
};
|
|
|
|
allocator() throw() {}
|
|
allocator(const allocator&) throw() {}
|
|
template <class _Tp1> allocator(const allocator<_Tp1>&) throw() {}
|
|
~allocator() throw() {}
|
|
|
|
pointer address(reference __x) const { return &__x; }
|
|
const_pointer address(const_reference __x) const { return &__x; }
|
|
|
|
// __n is permitted to be 0. The C++ standard says nothing about what
|
|
// the return value is when __n == 0.
|
|
_Tp* allocate(size_type __n, const void* = 0) {
|
|
return __n != 0 ? static_cast<_Tp*>(_Alloc::allocate(__n * sizeof(_Tp)))
|
|
: 0;
|
|
}
|
|
|
|
// __p is not permitted to be a null pointer.
|
|
void deallocate(pointer __p, size_type __n)
|
|
{ _Alloc::deallocate(__p, __n * sizeof(_Tp)); }
|
|
|
|
size_type max_size() const throw()
|
|
{ return size_t(-1) / sizeof(_Tp); }
|
|
|
|
void construct(pointer __p, const _Tp& __val) { new(__p) _Tp(__val); }
|
|
void destroy(pointer __p) { __p->~_Tp(); }
|
|
};
|
|
|
|
template<>
|
|
class allocator<void> {
|
|
public:
|
|
typedef size_t size_type;
|
|
typedef ptrdiff_t difference_type;
|
|
typedef void* pointer;
|
|
typedef const void* const_pointer;
|
|
typedef void value_type;
|
|
|
|
template <class _Tp1> struct rebind {
|
|
typedef allocator<_Tp1> other;
|
|
};
|
|
};
|
|
|
|
|
|
template <class _T1, class _T2>
|
|
inline bool operator==(const allocator<_T1>&, const allocator<_T2>&)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
template <class _T1, class _T2>
|
|
inline bool operator!=(const allocator<_T1>&, const allocator<_T2>&)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
|
|
/**
|
|
* @if maint
|
|
* Allocator adaptor to turn an "SGI" style allocator (e.g., __alloc,
|
|
* __malloc_alloc_template) into a "standard" conforming allocator. Note
|
|
* that this adaptor does *not* assume that all objects of the underlying
|
|
* alloc class are identical, nor does it assume that all of the underlying
|
|
* alloc's member functions are static member functions. Note, also, that
|
|
* __allocator<_Tp, __alloc> is essentially the same thing as allocator<_Tp>.
|
|
* @endif
|
|
* (See @link Allocators allocators info @endlink for more.)
|
|
*/
|
|
template <class _Tp, class _Alloc>
|
|
struct __allocator
|
|
{
|
|
_Alloc __underlying_alloc;
|
|
|
|
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;
|
|
|
|
template <class _Tp1> struct rebind {
|
|
typedef __allocator<_Tp1, _Alloc> other;
|
|
};
|
|
|
|
__allocator() throw() {}
|
|
__allocator(const __allocator& __a) throw()
|
|
: __underlying_alloc(__a.__underlying_alloc) {}
|
|
template <class _Tp1>
|
|
__allocator(const __allocator<_Tp1, _Alloc>& __a) throw()
|
|
: __underlying_alloc(__a.__underlying_alloc) {}
|
|
~__allocator() throw() {}
|
|
|
|
pointer address(reference __x) const { return &__x; }
|
|
const_pointer address(const_reference __x) const { return &__x; }
|
|
|
|
// __n is permitted to be 0.
|
|
_Tp* allocate(size_type __n, const void* = 0) {
|
|
return __n != 0
|
|
? static_cast<_Tp*>(__underlying_alloc.allocate(__n * sizeof(_Tp)))
|
|
: 0;
|
|
}
|
|
|
|
// __p is not permitted to be a null pointer.
|
|
void deallocate(pointer __p, size_type __n)
|
|
{ __underlying_alloc.deallocate(__p, __n * sizeof(_Tp)); }
|
|
|
|
size_type max_size() const throw()
|
|
{ return size_t(-1) / sizeof(_Tp); }
|
|
|
|
void construct(pointer __p, const _Tp& __val) { new(__p) _Tp(__val); }
|
|
void destroy(pointer __p) { __p->~_Tp(); }
|
|
};
|
|
|
|
template <class _Alloc>
|
|
class __allocator<void, _Alloc> {
|
|
typedef size_t size_type;
|
|
typedef ptrdiff_t difference_type;
|
|
typedef void* pointer;
|
|
typedef const void* const_pointer;
|
|
typedef void value_type;
|
|
|
|
template <class _Tp1> struct rebind {
|
|
typedef __allocator<_Tp1, _Alloc> other;
|
|
};
|
|
};
|
|
|
|
template <class _Tp, class _Alloc>
|
|
inline bool operator==(const __allocator<_Tp, _Alloc>& __a1,
|
|
const __allocator<_Tp, _Alloc>& __a2)
|
|
{
|
|
return __a1.__underlying_alloc == __a2.__underlying_alloc;
|
|
}
|
|
|
|
template <class _Tp, class _Alloc>
|
|
inline bool operator!=(const __allocator<_Tp, _Alloc>& __a1,
|
|
const __allocator<_Tp, _Alloc>& __a2)
|
|
{
|
|
return __a1.__underlying_alloc != __a2.__underlying_alloc;
|
|
}
|
|
|
|
|
|
//@{
|
|
/** Comparison operators for all of the predifined SGI-style allocators.
|
|
* This ensures that __allocator<malloc_alloc> (for example) will work
|
|
* correctly. As required, all allocators compare equal.
|
|
*/
|
|
template <int inst>
|
|
inline bool operator==(const __malloc_alloc_template<inst>&,
|
|
const __malloc_alloc_template<inst>&)
|
|
{
|
|
return true;
|
|
}
|
|
|
|
template <int __inst>
|
|
inline bool operator!=(const __malloc_alloc_template<__inst>&,
|
|
const __malloc_alloc_template<__inst>&)
|
|
{
|
|
return false;
|
|
}
|
|
|
|
template <class _Alloc>
|
|
inline bool operator==(const __debug_alloc<_Alloc>&,
|
|
const __debug_alloc<_Alloc>&) {
|
|
return true;
|
|
}
|
|
|
|
template <class _Alloc>
|
|
inline bool operator!=(const __debug_alloc<_Alloc>&,
|
|
const __debug_alloc<_Alloc>&) {
|
|
return false;
|
|
}
|
|
//@}
|
|
|
|
|
|
/**
|
|
* @if maint
|
|
* Another allocator adaptor: _Alloc_traits. This serves two purposes.
|
|
* First, make it possible to write containers that can use either "SGI"
|
|
* style allocators or "standard" allocators. Second, provide a mechanism
|
|
* so that containers can query whether or not the allocator has distinct
|
|
* instances. If not, the container can avoid wasting a word of memory to
|
|
* store an empty object. For examples of use, see stl_vector.h, etc, or
|
|
* any of the other classes derived from this one.
|
|
*
|
|
* This adaptor uses partial specialization. The general case of
|
|
* _Alloc_traits<_Tp, _Alloc> assumes that _Alloc is a
|
|
* standard-conforming allocator, possibly with non-equal instances and
|
|
* non-static members. (It still behaves correctly even if _Alloc has
|
|
* static member and if all instances are equal. Refinements affect
|
|
* performance, not correctness.)
|
|
*
|
|
* There are always two members: allocator_type, which is a standard-
|
|
* conforming allocator type for allocating objects of type _Tp, and
|
|
* _S_instanceless, a static const member of type bool. If
|
|
* _S_instanceless is true, this means that there is no difference
|
|
* between any two instances of type allocator_type. Furthermore, if
|
|
* _S_instanceless is true, then _Alloc_traits has one additional
|
|
* member: _Alloc_type. This type encapsulates allocation and
|
|
* deallocation of objects of type _Tp through a static interface; it
|
|
* has two member functions, whose signatures are
|
|
*
|
|
* - static _Tp* allocate(size_t)
|
|
* - static void deallocate(_Tp*, size_t)
|
|
*
|
|
* The size_t parameters are "standard" style (see top of stl_alloc.h) in
|
|
* that they take counts, not sizes.
|
|
*
|
|
* @endif
|
|
* (See @link Allocators allocators info @endlink for more.)
|
|
*/
|
|
//@{
|
|
// The fully general version.
|
|
template <class _Tp, class _Allocator>
|
|
struct _Alloc_traits
|
|
{
|
|
static const bool _S_instanceless = false;
|
|
typedef typename _Allocator::template rebind<_Tp>::other allocator_type;
|
|
};
|
|
|
|
template <class _Tp, class _Allocator>
|
|
const bool _Alloc_traits<_Tp, _Allocator>::_S_instanceless;
|
|
|
|
/// The version for the default allocator.
|
|
template <class _Tp, class _Tp1>
|
|
struct _Alloc_traits<_Tp, allocator<_Tp1> >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __alloc> _Alloc_type;
|
|
typedef allocator<_Tp> allocator_type;
|
|
};
|
|
//@}
|
|
|
|
//@{
|
|
/// Versions for the predefined "SGI" style allocators.
|
|
template <class _Tp, int __inst>
|
|
struct _Alloc_traits<_Tp, __malloc_alloc_template<__inst> >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __malloc_alloc_template<__inst> > _Alloc_type;
|
|
typedef __allocator<_Tp, __malloc_alloc_template<__inst> > allocator_type;
|
|
};
|
|
|
|
#ifndef __USE_MALLOC
|
|
template <class _Tp, bool __threads, int __inst>
|
|
struct _Alloc_traits<_Tp, __default_alloc_template<__threads, __inst> >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __default_alloc_template<__threads, __inst> >
|
|
_Alloc_type;
|
|
typedef __allocator<_Tp, __default_alloc_template<__threads, __inst> >
|
|
allocator_type;
|
|
};
|
|
#endif
|
|
|
|
template <class _Tp, class _Alloc>
|
|
struct _Alloc_traits<_Tp, __debug_alloc<_Alloc> >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __debug_alloc<_Alloc> > _Alloc_type;
|
|
typedef __allocator<_Tp, __debug_alloc<_Alloc> > allocator_type;
|
|
};
|
|
//@}
|
|
|
|
//@{
|
|
/// Versions for the __allocator adaptor used with the predefined "SGI" style allocators.
|
|
template <class _Tp, class _Tp1, int __inst>
|
|
struct _Alloc_traits<_Tp,
|
|
__allocator<_Tp1, __malloc_alloc_template<__inst> > >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __malloc_alloc_template<__inst> > _Alloc_type;
|
|
typedef __allocator<_Tp, __malloc_alloc_template<__inst> > allocator_type;
|
|
};
|
|
|
|
#ifndef __USE_MALLOC
|
|
template <class _Tp, class _Tp1, bool __thr, int __inst>
|
|
struct _Alloc_traits<_Tp,
|
|
__allocator<_Tp1,
|
|
__default_alloc_template<__thr, __inst> > >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __default_alloc_template<__thr,__inst> >
|
|
_Alloc_type;
|
|
typedef __allocator<_Tp, __default_alloc_template<__thr,__inst> >
|
|
allocator_type;
|
|
};
|
|
#endif
|
|
|
|
template <class _Tp, class _Tp1, class _Alloc>
|
|
struct _Alloc_traits<_Tp, __allocator<_Tp1, __debug_alloc<_Alloc> > >
|
|
{
|
|
static const bool _S_instanceless = true;
|
|
typedef __simple_alloc<_Tp, __debug_alloc<_Alloc> > _Alloc_type;
|
|
typedef __allocator<_Tp, __debug_alloc<_Alloc> > allocator_type;
|
|
};
|
|
//@}
|
|
|
|
// Inhibit implicit instantiations for required instantiations,
|
|
// which are defined via explicit instantiations elsewhere.
|
|
// NB: This syntax is a GNU extension.
|
|
extern template class allocator<char>;
|
|
extern template class allocator<wchar_t>;
|
|
#ifdef __USE_MALLOC
|
|
extern template class __malloc_alloc_template<0>;
|
|
#else
|
|
extern template class __default_alloc_template<true, 0>;
|
|
#endif
|
|
} // namespace std
|
|
|
|
#endif /* __GLIBCPP_INTERNAL_ALLOC_H */
|
|
|
|
// Local Variables:
|
|
// mode:C++
|
|
// End:
|