x86_64-unknown-linux-gnu/include/c++/4.5.3/ext/pool_allocator.h - toolchains/kvm - Git at Google

 // Allocators -*- C++ -*-

 // Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
 // 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/pool_allocator.h
  *  This file is a GNU extension to the Standard C++ Library.
  */

 #ifndef _POOL_ALLOCATOR_H
 #define _POOL_ALLOCATOR_H 1

 #include <bits/c++config.h>
 #include <cstdlib>
 #include <new>
 #include <bits/functexcept.h>
 #include <ext/atomicity.h>
 #include <ext/concurrence.h>
 #include <bits/move.h>

 _GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

   using std::size_t;
   using std::ptrdiff_t;

   /**
    *  @brief  Base class for __pool_alloc.
    *
    *  Uses various allocators to fulfill underlying requests (and makes as
    *  few requests as possible when in default high-speed pool mode).
    *
    *  Important implementation properties:
    *  0. If globally mandated, then allocate objects from new
    *  1. If the clients request an object of size > _S_max_bytes, the resulting
    *     object will be obtained directly from new
    *  2. In all other cases, we allocate an object of size exactly
    *     _S_round_up(requested_size).  Thus the client has enough size
    *     information that we can return the object to the proper free list
    *     without permanently losing part of the object.
    */
     class __pool_alloc_base
     {
     protected:

       enum { _S_align = 8 };
       enum { _S_max_bytes = 128 };
       enum { _S_free_list_size = (size_t)_S_max_bytes / (size_t)_S_align };

       union _Obj
       {
 	union _Obj* _M_free_list_link;
 	char        _M_client_data[1];    // The client sees this.
       };

       static _Obj* volatile         _S_free_list[_S_free_list_size];

       // Chunk allocation state.
       static char*                  _S_start_free;
       static char*                  _S_end_free;
       static size_t                 _S_heap_size;

       size_t
       _M_round_up(size_t __bytes)
       { return ((__bytes + (size_t)_S_align - 1) & ~((size_t)_S_align - 1)); }

       _GLIBCXX_CONST _Obj* volatile*
       _M_get_free_list(size_t __bytes) throw ();

       __mutex&
       _M_get_mutex() throw ();

       // Returns an object of size __n, and optionally adds to size __n
       // free list.
       void*
       _M_refill(size_t __n);

       // Allocates a chunk for nobjs of size size.  nobjs may be reduced
       // if it is inconvenient to allocate the requested number.
       char*
       _M_allocate_chunk(size_t __n, int& __nobjs);
     };


   /**
    * @brief  Allocator using a memory pool with a single lock.
    * @ingroup allocators
    */
   template<typename _Tp>
     class __pool_alloc : private __pool_alloc_base
     {
     private:
       static _Atomic_word	    _S_force_new;

     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<typename _Tp1>
         struct rebind
         { typedef __pool_alloc<_Tp1> other; };

       __pool_alloc() throw() { }

       __pool_alloc(const __pool_alloc&) throw() { }

       template<typename _Tp1>
         __pool_alloc(const __pool_alloc<_Tp1>&) throw() { }

       ~__pool_alloc() throw() { }

       pointer
       address(reference __x) const { return &__x; }

       const_pointer
       address(const_reference __x) const { return &__x; }

       size_type
       max_size() const throw()
       { return size_t(-1) / sizeof(_Tp); }

       // _GLIBCXX_RESOLVE_LIB_DEFECTS
       // 402. wrong new expression in [some_] allocator::construct
       void
       construct(pointer __p, const _Tp& __val)
       { ::new((void *)__p) _Tp(__val); }

 #ifdef __GXX_EXPERIMENTAL_CXX0X__
       template<typename... _Args>
         void
         construct(pointer __p, _Args&&... __args)
 	{ ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
 #endif

       void
       destroy(pointer __p) { __p->~_Tp(); }

       pointer
       allocate(size_type __n, const void* = 0);

       void
       deallocate(pointer __p, size_type __n);
     };

   template<typename _Tp>
     inline bool
     operator==(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
     { return true; }

   template<typename _Tp>
     inline bool
     operator!=(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
     { return false; }

   template<typename _Tp>
     _Atomic_word
     __pool_alloc<_Tp>::_S_force_new;

   template<typename _Tp>
     _Tp*
     __pool_alloc<_Tp>::allocate(size_type __n, const void*)
     {
       pointer __ret = 0;
       if (__builtin_expect(__n != 0, true))
 	{
 	  if (__n > this->max_size())
 	    std::__throw_bad_alloc();

 	  // If there is a race through here, assume answer from getenv
 	  // will resolve in same direction.  Inspired by techniques
 	  // to efficiently support threading found in basic_string.h.
 	  if (_S_force_new == 0)
 	    {
 	      if (std::getenv("GLIBCXX_FORCE_NEW"))
 		__atomic_add_dispatch(&_S_force_new, 1);
 	      else
 		__atomic_add_dispatch(&_S_force_new, -1);
 	    }

 	  const size_t __bytes = __n * sizeof(_Tp);
 	  if (__bytes > size_t(_S_max_bytes) || _S_force_new > 0)
 	    __ret = static_cast<_Tp*>(::operator new(__bytes));
 	  else
 	    {
 	      _Obj* volatile* __free_list = _M_get_free_list(__bytes);

 	      __scoped_lock sentry(_M_get_mutex());
 	      _Obj* __restrict__ __result = *__free_list;
 	      if (__builtin_expect(__result == 0, 0))
 		__ret = static_cast<_Tp*>(_M_refill(_M_round_up(__bytes)));
 	      else
 		{
 		  *__free_list = __result->_M_free_list_link;
 		  __ret = reinterpret_cast<_Tp*>(__result);
 		}
 	      if (__ret == 0)
 		std::__throw_bad_alloc();
 	    }
 	}
       return __ret;
     }

   template<typename _Tp>
     void
     __pool_alloc<_Tp>::deallocate(pointer __p, size_type __n)
     {
       if (__builtin_expect(__n != 0 && __p != 0, true))
 	{
 	  const size_t __bytes = __n * sizeof(_Tp);
 	  if (__bytes > static_cast<size_t>(_S_max_bytes) || _S_force_new > 0)
 	    ::operator delete(__p);
 	  else
 	    {
 	      _Obj* volatile* __free_list = _M_get_free_list(__bytes);
 	      _Obj* __q = reinterpret_cast<_Obj*>(__p);

 	      __scoped_lock sentry(_M_get_mutex());
 	      __q ->_M_free_list_link = *__free_list;
 	      *__free_list = __q;
 	    }
 	}
     }

 _GLIBCXX_END_NAMESPACE

 #endif
	// Allocators -- C++ --

	// Copyright (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009
	// 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/pool_allocator.h
	* This file is a GNU extension to the Standard C++ Library.
	*/

	#ifndef _POOL_ALLOCATOR_H
	#define _POOL_ALLOCATOR_H 1

	#include <bits/c++config.h>
	#include <cstdlib>
	#include <new>
	#include <bits/functexcept.h>
	#include <ext/atomicity.h>
	#include <ext/concurrence.h>
	#include <bits/move.h>

	_GLIBCXX_BEGIN_NAMESPACE(__gnu_cxx)

	using std::size_t;
	using std::ptrdiff_t;

	/**
	* @brief Base class for __pool_alloc.
	*
	* Uses various allocators to fulfill underlying requests (and makes as
	* few requests as possible when in default high-speed pool mode).
	*
	* Important implementation properties:
	* 0. If globally mandated, then allocate objects from new
	* 1. If the clients request an object of size > _S_max_bytes, the resulting
	* object will be obtained directly from new
	* 2. In all other cases, we allocate an object of size exactly
	* _S_round_up(requested_size). Thus the client has enough size
	* information that we can return the object to the proper free list
	* without permanently losing part of the object.
	*/
	class __pool_alloc_base
	{
	protected:

	enum { _S_align = 8 };
	enum { _S_max_bytes = 128 };
	enum { _S_free_list_size = (size_t)_S_max_bytes / (size_t)_S_align };

	union _Obj
	{
	union _Obj* _M_free_list_link;
	char _M_client_data[1]; // The client sees this.
	};

	static _Obj* volatile _S_free_list[_S_free_list_size];

	// Chunk allocation state.
	static char* _S_start_free;
	static char* _S_end_free;
	static size_t _S_heap_size;

	size_t
	_M_round_up(size_t __bytes)
	{ return ((__bytes + (size_t)_S_align - 1) & ~((size_t)_S_align - 1)); }

	_GLIBCXX_CONST _Obj* volatile*
	_M_get_free_list(size_t __bytes) throw ();

	__mutex&
	_M_get_mutex() throw ();

	// Returns an object of size __n, and optionally adds to size __n
	// free list.
	void*
	_M_refill(size_t __n);

	// Allocates a chunk for nobjs of size size. nobjs may be reduced
	// if it is inconvenient to allocate the requested number.
	char*
	_M_allocate_chunk(size_t __n, int& __nobjs);
	};


	/**
	* @brief Allocator using a memory pool with a single lock.
	* @ingroup allocators
	*/
	template<typename _Tp>
	class __pool_alloc : private __pool_alloc_base
	{
	private:
	static _Atomic_word _S_force_new;

	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<typename _Tp1>
	struct rebind
	{ typedef __pool_alloc<_Tp1> other; };

	__pool_alloc() throw() { }

	__pool_alloc(const __pool_alloc&) throw() { }

	template<typename _Tp1>
	__pool_alloc(const __pool_alloc<_Tp1>&) throw() { }

	~__pool_alloc() throw() { }

	pointer
	address(reference __x) const { return &__x; }

	const_pointer
	address(const_reference __x) const { return &__x; }

	size_type
	max_size() const throw()
	{ return size_t(-1) / sizeof(_Tp); }

	// _GLIBCXX_RESOLVE_LIB_DEFECTS
	// 402. wrong new expression in [some_] allocator::construct
	void
	construct(pointer __p, const _Tp& __val)
	{ ::new((void *)__p) _Tp(__val); }

	#ifdef __GXX_EXPERIMENTAL_CXX0X__
	template<typename... _Args>
	void
	construct(pointer __p, _Args&&... __args)
	{ ::new((void *)__p) _Tp(std::forward<_Args>(__args)...); }
	#endif

	void
	destroy(pointer __p) { __p->~_Tp(); }

	pointer
	allocate(size_type __n, const void* = 0);

	void
	deallocate(pointer __p, size_type __n);
	};

	template<typename _Tp>
	inline bool
	operator==(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
	{ return true; }

	template<typename _Tp>
	inline bool
	operator!=(const __pool_alloc<_Tp>&, const __pool_alloc<_Tp>&)
	{ return false; }

	template<typename _Tp>
	_Atomic_word
	__pool_alloc<_Tp>::_S_force_new;

	template<typename _Tp>
	_Tp*
	__pool_alloc<_Tp>::allocate(size_type __n, const void*)
	{
	pointer __ret = 0;
	if (__builtin_expect(__n != 0, true))
	{
	if (__n > this->max_size())
	std::__throw_bad_alloc();

	// If there is a race through here, assume answer from getenv
	// will resolve in same direction. Inspired by techniques
	// to efficiently support threading found in basic_string.h.
	if (_S_force_new == 0)
	{
	if (std::getenv("GLIBCXX_FORCE_NEW"))
	__atomic_add_dispatch(&_S_force_new, 1);
	else
	__atomic_add_dispatch(&_S_force_new, -1);
	}

	const size_t __bytes = __n * sizeof(_Tp);
	if (__bytes > size_t(_S_max_bytes) \|\| _S_force_new > 0)
	__ret = static_cast<_Tp*>(::operator new(__bytes));
	else
	{
	_Obj* volatile* __free_list = _M_get_free_list(__bytes);

	__scoped_lock sentry(_M_get_mutex());
	_Obj* __restrict__ __result = *__free_list;
	if (__builtin_expect(__result == 0, 0))
	__ret = static_cast<_Tp*>(_M_refill(_M_round_up(__bytes)));
	else
	{
	*__free_list = __result->_M_free_list_link;
	__ret = reinterpret_cast<_Tp*>(__result);
	}
	if (__ret == 0)
	std::__throw_bad_alloc();
	}
	}
	return __ret;
	}

	template<typename _Tp>
	void
	__pool_alloc<_Tp>::deallocate(pointer __p, size_type __n)
	{
	if (__builtin_expect(__n != 0 && __p != 0, true))
	{
	const size_t __bytes = __n * sizeof(_Tp);
	if (__bytes > static_cast<size_t>(_S_max_bytes) \|\| _S_force_new > 0)
	::operator delete(__p);
	else
	{
	_Obj* volatile* __free_list = _M_get_free_list(__bytes);
	_Obj* __q = reinterpret_cast<_Obj*>(__p);

	__scoped_lock sentry(_M_get_mutex());
	__q ->_M_free_list_link = *__free_list;
	*__free_list = __q;
	}
	}
	}

	_GLIBCXX_END_NAMESPACE

	#endif